├── .gitignore ├── LICENSE ├── README.md ├── main.go └── pdf ├── action.go ├── array.go ├── dictionary.go ├── encryption.go ├── errors.go ├── file.go ├── filters.go ├── font.go ├── keyword.go ├── logger.go ├── name.go ├── number.go ├── object.go ├── output.go ├── page.go ├── parser.go ├── pdf.go ├── reference.go ├── string.go ├── test ├── carriage_return.pdf ├── comments.pdf ├── empty_array.pdf ├── empty_dictionary.pdf ├── encrypted.pdf ├── filter_ascii_85_decode.pdf ├── filter_ascii_hex_decode.pdf ├── filter_flate_decode.pdf ├── filter_lzw_decode.pdf ├── filter_lzw_tiff_decode.pdf ├── filter_multiple.pdf ├── filter_run_length_decode.pdf ├── malformed_dictionary_key.pdf ├── max_cmap_size.pdf ├── names.pdf ├── reference.pdf ├── reference_loop.pdf ├── reference_null.pdf ├── strings.pdf ├── unclosed_array.pdf ├── unclosed_comment.pdf ├── unclosed_dictionary.pdf ├── unclosed_dictionary_key.pdf ├── unclosed_hex_string.pdf ├── unclosed_name.pdf ├── unclosed_name_escape_1.pdf ├── unclosed_name_escape_2.pdf ├── unclosed_string.pdf ├── unclosed_string_escape.pdf ├── unclosed_string_octal_1.pdf ├── unclosed_string_octal_2.pdf ├── xref_loop.pdf ├── xref_repair.pdf ├── xref_stream_chain.pdf ├── xref_stream_index_default.pdf └── xref_table_chain.pdf ├── unit_test.go ├── utility.go └── xref.go /.gitignore: -------------------------------------------------------------------------------- 1 | *.swp 2 | pdfparser 3 | *.extracted/ 4 | output/ 5 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | PDF Parser 2 | Decrypts PDF files and extracts contents 3 | Copyright (C) 2019 Cole Robinette 4 | 5 | This program is free software: you can redistribute it and/or modify 6 | it under the terms of the GNU General Public License version 3 as published 7 | by the Free Software Foundation. 8 | 9 | This program is distributed in the hope that it will be useful, 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 | GNU General Public License for more details. 13 | 14 | GNU GENERAL PUBLIC LICENSE 15 | Version 3, 29 June 2007 16 | 17 | Copyright (C) 2007 Free Software Foundation, Inc. 18 | Everyone is permitted to copy and distribute verbatim copies 19 | of this license document, but changing it is not allowed. 20 | 21 | Preamble 22 | 23 | The GNU General Public License is a free, copyleft license for 24 | software and other kinds of works. 25 | 26 | The licenses for most software and other practical works are designed 27 | to take away your freedom to share and change the works. By contrast, 28 | the GNU General Public License is intended to guarantee your freedom to 29 | share and change all versions of a program--to make sure it remains free 30 | software for all its users. We, the Free Software Foundation, use the 31 | GNU General Public License for most of our software; it applies also to 32 | any other work released this way by its authors. You can apply it to 33 | your programs, too. 34 | 35 | When we speak of free software, we are referring to freedom, not 36 | price. Our General Public Licenses are designed to make sure that you 37 | have the freedom to distribute copies of free software (and charge for 38 | them if you wish), that you receive source code or can get it if you 39 | want it, that you can change the software or use pieces of it in new 40 | free programs, and that you know you can do these things. 41 | 42 | To protect your rights, we need to prevent others from denying you 43 | these rights or asking you to surrender the rights. Therefore, you have 44 | certain responsibilities if you distribute copies of the software, or if 45 | you modify it: responsibilities to respect the freedom of others. 46 | 47 | For example, if you distribute copies of such a program, whether 48 | gratis or for a fee, you must pass on to the recipients the same 49 | freedoms that you received. You must make sure that they, too, receive 50 | or can get the source code. And you must show them these terms so they 51 | know their rights. 52 | 53 | Developers that use the GNU GPL protect your rights with two steps: 54 | (1) assert copyright on the software, and (2) offer you this License 55 | giving you legal permission to copy, distribute and/or modify it. 56 | 57 | For the developers' and authors' protection, the GPL clearly explains 58 | that there is no warranty for this free software. For both users' and 59 | authors' sake, the GPL requires that modified versions be marked as 60 | changed, so that their problems will not be attributed erroneously to 61 | authors of previous versions. 62 | 63 | Some devices are designed to deny users access to install or run 64 | modified versions of the software inside them, although the manufacturer 65 | can do so. This is fundamentally incompatible with the aim of 66 | protecting users' freedom to change the software. The systematic 67 | pattern of such abuse occurs in the area of products for individuals to 68 | use, which is precisely where it is most unacceptable. Therefore, we 69 | have designed this version of the GPL to prohibit the practice for those 70 | products. If such problems arise substantially in other domains, we 71 | stand ready to extend this provision to those domains in future versions 72 | of the GPL, as needed to protect the freedom of users. 73 | 74 | Finally, every program is threatened constantly by software patents. 75 | States should not allow patents to restrict development and use of 76 | software on general-purpose computers, but in those that do, we wish to 77 | avoid the special danger that patents applied to a free program could 78 | make it effectively proprietary. To prevent this, the GPL assures that 79 | patents cannot be used to render the program non-free. 80 | 81 | The precise terms and conditions for copying, distribution and 82 | modification follow. 83 | 84 | TERMS AND CONDITIONS 85 | 86 | 0. Definitions. 87 | 88 | "This License" refers to version 3 of the GNU General Public License. 89 | 90 | "Copyright" also means copyright-like laws that apply to other kinds of 91 | works, such as semiconductor masks. 92 | 93 | "The Program" refers to any copyrightable work licensed under this 94 | License. Each licensee is addressed as "you". "Licensees" and 95 | "recipients" may be individuals or organizations. 96 | 97 | To "modify" a work means to copy from or adapt all or part of the work 98 | in a fashion requiring copyright permission, other than the making of an 99 | exact copy. The resulting work is called a "modified version" of the 100 | earlier work or a work "based on" the earlier work. 101 | 102 | A "covered work" means either the unmodified Program or a work based 103 | on the Program. 104 | 105 | To "propagate" a work means to do anything with it that, without 106 | permission, would make you directly or secondarily liable for 107 | infringement under applicable copyright law, except executing it on a 108 | computer or modifying a private copy. Propagation includes copying, 109 | distribution (with or without modification), making available to the 110 | public, and in some countries other activities as well. 111 | 112 | To "convey" a work means any kind of propagation that enables other 113 | parties to make or receive copies. Mere interaction with a user through 114 | a computer network, with no transfer of a copy, is not conveying. 115 | 116 | An interactive user interface displays "Appropriate Legal Notices" 117 | to the extent that it includes a convenient and prominently visible 118 | feature that (1) displays an appropriate copyright notice, and (2) 119 | tells the user that there is no warranty for the work (except to the 120 | extent that warranties are provided), that licensees may convey the 121 | work under this License, and how to view a copy of this License. If 122 | the interface presents a list of user commands or options, such as a 123 | menu, a prominent item in the list meets this criterion. 124 | 125 | 1. Source Code. 126 | 127 | The "source code" for a work means the preferred form of the work 128 | for making modifications to it. "Object code" means any non-source 129 | form of a work. 130 | 131 | A "Standard Interface" means an interface that either is an official 132 | standard defined by a recognized standards body, or, in the case of 133 | interfaces specified for a particular programming language, one that 134 | is widely used among developers working in that language. 135 | 136 | The "System Libraries" of an executable work include anything, other 137 | than the work as a whole, that (a) is included in the normal form of 138 | packaging a Major Component, but which is not part of that Major 139 | Component, and (b) serves only to enable use of the work with that 140 | Major Component, or to implement a Standard Interface for which an 141 | implementation is available to the public in source code form. A 142 | "Major Component", in this context, means a major essential component 143 | (kernel, window system, and so on) of the specific operating system 144 | (if any) on which the executable work runs, or a compiler used to 145 | produce the work, or an object code interpreter used to run it. 146 | 147 | The "Corresponding Source" for a work in object code form means all 148 | the source code needed to generate, install, and (for an executable 149 | work) run the object code and to modify the work, including scripts to 150 | control those activities. However, it does not include the work's 151 | System Libraries, or general-purpose tools or generally available free 152 | programs which are used unmodified in performing those activities but 153 | which are not part of the work. For example, Corresponding Source 154 | includes interface definition files associated with source files for 155 | the work, and the source code for shared libraries and dynamically 156 | linked subprograms that the work is specifically designed to require, 157 | such as by intimate data communication or control flow between those 158 | subprograms and other parts of the work. 159 | 160 | The Corresponding Source need not include anything that users 161 | can regenerate automatically from other parts of the Corresponding 162 | Source. 163 | 164 | The Corresponding Source for a work in source code form is that 165 | same work. 166 | 167 | 2. Basic Permissions. 168 | 169 | All rights granted under this License are granted for the term of 170 | copyright on the Program, and are irrevocable provided the stated 171 | conditions are met. This License explicitly affirms your unlimited 172 | permission to run the unmodified Program. The output from running a 173 | covered work is covered by this License only if the output, given its 174 | content, constitutes a covered work. This License acknowledges your 175 | rights of fair use or other equivalent, as provided by copyright law. 176 | 177 | You may make, run and propagate covered works that you do not 178 | convey, without conditions so long as your license otherwise remains 179 | in force. You may convey covered works to others for the sole purpose 180 | of having them make modifications exclusively for you, or provide you 181 | with facilities for running those works, provided that you comply with 182 | the terms of this License in conveying all material for which you do 183 | not control copyright. Those thus making or running the covered works 184 | for you must do so exclusively on your behalf, under your direction 185 | and control, on terms that prohibit them from making any copies of 186 | your copyrighted material outside their relationship with you. 187 | 188 | Conveying under any other circumstances is permitted solely under 189 | the conditions stated below. Sublicensing is not allowed; section 10 190 | makes it unnecessary. 191 | 192 | 3. Protecting Users' Legal Rights From Anti-Circumvention Law. 193 | 194 | No covered work shall be deemed part of an effective technological 195 | measure under any applicable law fulfilling obligations under article 196 | 11 of the WIPO copyright treaty adopted on 20 December 1996, or 197 | similar laws prohibiting or restricting circumvention of such 198 | measures. 199 | 200 | When you convey a covered work, you waive any legal power to forbid 201 | circumvention of technological measures to the extent such circumvention 202 | is effected by exercising rights under this License with respect to 203 | the covered work, and you disclaim any intention to limit operation or 204 | modification of the work as a means of enforcing, against the work's 205 | users, your or third parties' legal rights to forbid circumvention of 206 | technological measures. 207 | 208 | 4. Conveying Verbatim Copies. 209 | 210 | You may convey verbatim copies of the Program's source code as you 211 | receive it, in any medium, provided that you conspicuously and 212 | appropriately publish on each copy an appropriate copyright notice; 213 | keep intact all notices stating that this License and any 214 | non-permissive terms added in accord with section 7 apply to the code; 215 | keep intact all notices of the absence of any warranty; and give all 216 | recipients a copy of this License along with the Program. 217 | 218 | You may charge any price or no price for each copy that you convey, 219 | and you may offer support or warranty protection for a fee. 220 | 221 | 5. Conveying Modified Source Versions. 222 | 223 | You may convey a work based on the Program, or the modifications to 224 | produce it from the Program, in the form of source code under the 225 | terms of section 4, provided that you also meet all of these conditions: 226 | 227 | a) The work must carry prominent notices stating that you modified 228 | it, and giving a relevant date. 229 | 230 | b) The work must carry prominent notices stating that it is 231 | released under this License and any conditions added under section 232 | 7. This requirement modifies the requirement in section 4 to 233 | "keep intact all notices". 234 | 235 | c) You must license the entire work, as a whole, under this 236 | License to anyone who comes into possession of a copy. This 237 | License will therefore apply, along with any applicable section 7 238 | additional terms, to the whole of the work, and all its parts, 239 | regardless of how they are packaged. This License gives no 240 | permission to license the work in any other way, but it does not 241 | invalidate such permission if you have separately received it. 242 | 243 | d) If the work has interactive user interfaces, each must display 244 | Appropriate Legal Notices; however, if the Program has interactive 245 | interfaces that do not display Appropriate Legal Notices, your 246 | work need not make them do so. 247 | 248 | A compilation of a covered work with other separate and independent 249 | works, which are not by their nature extensions of the covered work, 250 | and which are not combined with it such as to form a larger program, 251 | in or on a volume of a storage or distribution medium, is called an 252 | "aggregate" if the compilation and its resulting copyright are not 253 | used to limit the access or legal rights of the compilation's users 254 | beyond what the individual works permit. Inclusion of a covered work 255 | in an aggregate does not cause this License to apply to the other 256 | parts of the aggregate. 257 | 258 | 6. Conveying Non-Source Forms. 259 | 260 | You may convey a covered work in object code form under the terms 261 | of sections 4 and 5, provided that you also convey the 262 | machine-readable Corresponding Source under the terms of this License, 263 | in one of these ways: 264 | 265 | a) Convey the object code in, or embodied in, a physical product 266 | (including a physical distribution medium), accompanied by the 267 | Corresponding Source fixed on a durable physical medium 268 | customarily used for software interchange. 269 | 270 | b) Convey the object code in, or embodied in, a physical product 271 | (including a physical distribution medium), accompanied by a 272 | written offer, valid for at least three years and valid for as 273 | long as you offer spare parts or customer support for that product 274 | model, to give anyone who possesses the object code either (1) a 275 | copy of the Corresponding Source for all the software in the 276 | product that is covered by this License, on a durable physical 277 | medium customarily used for software interchange, for a price no 278 | more than your reasonable cost of physically performing this 279 | conveying of source, or (2) access to copy the 280 | Corresponding Source from a network server at no charge. 281 | 282 | c) Convey individual copies of the object code with a copy of the 283 | written offer to provide the Corresponding Source. This 284 | alternative is allowed only occasionally and noncommercially, and 285 | only if you received the object code with such an offer, in accord 286 | with subsection 6b. 287 | 288 | d) Convey the object code by offering access from a designated 289 | place (gratis or for a charge), and offer equivalent access to the 290 | Corresponding Source in the same way through the same place at no 291 | further charge. You need not require recipients to copy the 292 | Corresponding Source along with the object code. If the place to 293 | copy the object code is a network server, the Corresponding Source 294 | may be on a different server (operated by you or a third party) 295 | that supports equivalent copying facilities, provided you maintain 296 | clear directions next to the object code saying where to find the 297 | Corresponding Source. Regardless of what server hosts the 298 | Corresponding Source, you remain obligated to ensure that it is 299 | available for as long as needed to satisfy these requirements. 300 | 301 | e) Convey the object code using peer-to-peer transmission, provided 302 | you inform other peers where the object code and Corresponding 303 | Source of the work are being offered to the general public at no 304 | charge under subsection 6d. 305 | 306 | A separable portion of the object code, whose source code is excluded 307 | from the Corresponding Source as a System Library, need not be 308 | included in conveying the object code work. 309 | 310 | A "User Product" is either (1) a "consumer product", which means any 311 | tangible personal property which is normally used for personal, family, 312 | or household purposes, or (2) anything designed or sold for incorporation 313 | into a dwelling. In determining whether a product is a consumer product, 314 | doubtful cases shall be resolved in favor of coverage. For a particular 315 | product received by a particular user, "normally used" refers to a 316 | typical or common use of that class of product, regardless of the status 317 | of the particular user or of the way in which the particular user 318 | actually uses, or expects or is expected to use, the product. A product 319 | is a consumer product regardless of whether the product has substantial 320 | commercial, industrial or non-consumer uses, unless such uses represent 321 | the only significant mode of use of the product. 322 | 323 | "Installation Information" for a User Product means any methods, 324 | procedures, authorization keys, or other information required to install 325 | and execute modified versions of a covered work in that User Product from 326 | a modified version of its Corresponding Source. The information must 327 | suffice to ensure that the continued functioning of the modified object 328 | code is in no case prevented or interfered with solely because 329 | modification has been made. 330 | 331 | If you convey an object code work under this section in, or with, or 332 | specifically for use in, a User Product, and the conveying occurs as 333 | part of a transaction in which the right of possession and use of the 334 | User Product is transferred to the recipient in perpetuity or for a 335 | fixed term (regardless of how the transaction is characterized), the 336 | Corresponding Source conveyed under this section must be accompanied 337 | by the Installation Information. But this requirement does not apply 338 | if neither you nor any third party retains the ability to install 339 | modified object code on the User Product (for example, the work has 340 | been installed in ROM). 341 | 342 | The requirement to provide Installation Information does not include a 343 | requirement to continue to provide support service, warranty, or updates 344 | for a work that has been modified or installed by the recipient, or for 345 | the User Product in which it has been modified or installed. Access to a 346 | network may be denied when the modification itself materially and 347 | adversely affects the operation of the network or violates the rules and 348 | protocols for communication across the network. 349 | 350 | Corresponding Source conveyed, and Installation Information provided, 351 | in accord with this section must be in a format that is publicly 352 | documented (and with an implementation available to the public in 353 | source code form), and must require no special password or key for 354 | unpacking, reading or copying. 355 | 356 | 7. Additional Terms. 357 | 358 | "Additional permissions" are terms that supplement the terms of this 359 | License by making exceptions from one or more of its conditions. 360 | Additional permissions that are applicable to the entire Program shall 361 | be treated as though they were included in this License, to the extent 362 | that they are valid under applicable law. If additional permissions 363 | apply only to part of the Program, that part may be used separately 364 | under those permissions, but the entire Program remains governed by 365 | this License without regard to the additional permissions. 366 | 367 | When you convey a copy of a covered work, you may at your option 368 | remove any additional permissions from that copy, or from any part of 369 | it. (Additional permissions may be written to require their own 370 | removal in certain cases when you modify the work.) You may place 371 | additional permissions on material, added by you to a covered work, 372 | for which you have or can give appropriate copyright permission. 373 | 374 | Notwithstanding any other provision of this License, for material you 375 | add to a covered work, you may (if authorized by the copyright holders of 376 | that material) supplement the terms of this License with terms: 377 | 378 | a) Disclaiming warranty or limiting liability differently from the 379 | terms of sections 15 and 16 of this License; or 380 | 381 | b) Requiring preservation of specified reasonable legal notices or 382 | author attributions in that material or in the Appropriate Legal 383 | Notices displayed by works containing it; or 384 | 385 | c) Prohibiting misrepresentation of the origin of that material, or 386 | requiring that modified versions of such material be marked in 387 | reasonable ways as different from the original version; or 388 | 389 | d) Limiting the use for publicity purposes of names of licensors or 390 | authors of the material; or 391 | 392 | e) Declining to grant rights under trademark law for use of some 393 | trade names, trademarks, or service marks; or 394 | 395 | f) Requiring indemnification of licensors and authors of that 396 | material by anyone who conveys the material (or modified versions of 397 | it) with contractual assumptions of liability to the recipient, for 398 | any liability that these contractual assumptions directly impose on 399 | those licensors and authors. 400 | 401 | All other non-permissive additional terms are considered "further 402 | restrictions" within the meaning of section 10. If the Program as you 403 | received it, or any part of it, contains a notice stating that it is 404 | governed by this License along with a term that is a further 405 | restriction, you may remove that term. If a license document contains 406 | a further restriction but permits relicensing or conveying under this 407 | License, you may add to a covered work material governed by the terms 408 | of that license document, provided that the further restriction does 409 | not survive such relicensing or conveying. 410 | 411 | If you add terms to a covered work in accord with this section, you 412 | must place, in the relevant source files, a statement of the 413 | additional terms that apply to those files, or a notice indicating 414 | where to find the applicable terms. 415 | 416 | Additional terms, permissive or non-permissive, may be stated in the 417 | form of a separately written license, or stated as exceptions; 418 | the above requirements apply either way. 419 | 420 | 8. Termination. 421 | 422 | You may not propagate or modify a covered work except as expressly 423 | provided under this License. Any attempt otherwise to propagate or 424 | modify it is void, and will automatically terminate your rights under 425 | this License (including any patent licenses granted under the third 426 | paragraph of section 11). 427 | 428 | However, if you cease all violation of this License, then your 429 | license from a particular copyright holder is reinstated (a) 430 | provisionally, unless and until the copyright holder explicitly and 431 | finally terminates your license, and (b) permanently, if the copyright 432 | holder fails to notify you of the violation by some reasonable means 433 | prior to 60 days after the cessation. 434 | 435 | Moreover, your license from a particular copyright holder is 436 | reinstated permanently if the copyright holder notifies you of the 437 | violation by some reasonable means, this is the first time you have 438 | received notice of violation of this License (for any work) from that 439 | copyright holder, and you cure the violation prior to 30 days after 440 | your receipt of the notice. 441 | 442 | Termination of your rights under this section does not terminate the 443 | licenses of parties who have received copies or rights from you under 444 | this License. If your rights have been terminated and not permanently 445 | reinstated, you do not qualify to receive new licenses for the same 446 | material under section 10. 447 | 448 | 9. Acceptance Not Required for Having Copies. 449 | 450 | You are not required to accept this License in order to receive or 451 | run a copy of the Program. Ancillary propagation of a covered work 452 | occurring solely as a consequence of using peer-to-peer transmission 453 | to receive a copy likewise does not require acceptance. However, 454 | nothing other than this License grants you permission to propagate or 455 | modify any covered work. These actions infringe copyright if you do 456 | not accept this License. Therefore, by modifying or propagating a 457 | covered work, you indicate your acceptance of this License to do so. 458 | 459 | 10. Automatic Licensing of Downstream Recipients. 460 | 461 | Each time you convey a covered work, the recipient automatically 462 | receives a license from the original licensors, to run, modify and 463 | propagate that work, subject to this License. You are not responsible 464 | for enforcing compliance by third parties with this License. 465 | 466 | An "entity transaction" is a transaction transferring control of an 467 | organization, or substantially all assets of one, or subdividing an 468 | organization, or merging organizations. If propagation of a covered 469 | work results from an entity transaction, each party to that 470 | transaction who receives a copy of the work also receives whatever 471 | licenses to the work the party's predecessor in interest had or could 472 | give under the previous paragraph, plus a right to possession of the 473 | Corresponding Source of the work from the predecessor in interest, if 474 | the predecessor has it or can get it with reasonable efforts. 475 | 476 | You may not impose any further restrictions on the exercise of the 477 | rights granted or affirmed under this License. For example, you may 478 | not impose a license fee, royalty, or other charge for exercise of 479 | rights granted under this License, and you may not initiate litigation 480 | (including a cross-claim or counterclaim in a lawsuit) alleging that 481 | any patent claim is infringed by making, using, selling, offering for 482 | sale, or importing the Program or any portion of it. 483 | 484 | 11. Patents. 485 | 486 | A "contributor" is a copyright holder who authorizes use under this 487 | License of the Program or a work on which the Program is based. The 488 | work thus licensed is called the contributor's "contributor version". 489 | 490 | A contributor's "essential patent claims" are all patent claims 491 | owned or controlled by the contributor, whether already acquired or 492 | hereafter acquired, that would be infringed by some manner, permitted 493 | by this License, of making, using, or selling its contributor version, 494 | but do not include claims that would be infringed only as a 495 | consequence of further modification of the contributor version. For 496 | purposes of this definition, "control" includes the right to grant 497 | patent sublicenses in a manner consistent with the requirements of 498 | this License. 499 | 500 | Each contributor grants you a non-exclusive, worldwide, royalty-free 501 | patent license under the contributor's essential patent claims, to 502 | make, use, sell, offer for sale, import and otherwise run, modify and 503 | propagate the contents of its contributor version. 504 | 505 | In the following three paragraphs, a "patent license" is any express 506 | agreement or commitment, however denominated, not to enforce a patent 507 | (such as an express permission to practice a patent or covenant not to 508 | sue for patent infringement). To "grant" such a patent license to a 509 | party means to make such an agreement or commitment not to enforce a 510 | patent against the party. 511 | 512 | If you convey a covered work, knowingly relying on a patent license, 513 | and the Corresponding Source of the work is not available for anyone 514 | to copy, free of charge and under the terms of this License, through a 515 | publicly available network server or other readily accessible means, 516 | then you must either (1) cause the Corresponding Source to be so 517 | available, or (2) arrange to deprive yourself of the benefit of the 518 | patent license for this particular work, or (3) arrange, in a manner 519 | consistent with the requirements of this License, to extend the patent 520 | license to downstream recipients. "Knowingly relying" means you have 521 | actual knowledge that, but for the patent license, your conveying the 522 | covered work in a country, or your recipient's use of the covered work 523 | in a country, would infringe one or more identifiable patents in that 524 | country that you have reason to believe are valid. 525 | 526 | If, pursuant to or in connection with a single transaction or 527 | arrangement, you convey, or propagate by procuring conveyance of, a 528 | covered work, and grant a patent license to some of the parties 529 | receiving the covered work authorizing them to use, propagate, modify 530 | or convey a specific copy of the covered work, then the patent license 531 | you grant is automatically extended to all recipients of the covered 532 | work and works based on it. 533 | 534 | A patent license is "discriminatory" if it does not include within 535 | the scope of its coverage, prohibits the exercise of, or is 536 | conditioned on the non-exercise of one or more of the rights that are 537 | specifically granted under this License. You may not convey a covered 538 | work if you are a party to an arrangement with a third party that is 539 | in the business of distributing software, under which you make payment 540 | to the third party based on the extent of your activity of conveying 541 | the work, and under which the third party grants, to any of the 542 | parties who would receive the covered work from you, a discriminatory 543 | patent license (a) in connection with copies of the covered work 544 | conveyed by you (or copies made from those copies), or (b) primarily 545 | for and in connection with specific products or compilations that 546 | contain the covered work, unless you entered into that arrangement, 547 | or that patent license was granted, prior to 28 March 2007. 548 | 549 | Nothing in this License shall be construed as excluding or limiting 550 | any implied license or other defenses to infringement that may 551 | otherwise be available to you under applicable patent law. 552 | 553 | 12. No Surrender of Others' Freedom. 554 | 555 | If conditions are imposed on you (whether by court order, agreement or 556 | otherwise) that contradict the conditions of this License, they do not 557 | excuse you from the conditions of this License. If you cannot convey a 558 | covered work so as to satisfy simultaneously your obligations under this 559 | License and any other pertinent obligations, then as a consequence you may 560 | not convey it at all. For example, if you agree to terms that obligate you 561 | to collect a royalty for further conveying from those to whom you convey 562 | the Program, the only way you could satisfy both those terms and this 563 | License would be to refrain entirely from conveying the Program. 564 | 565 | 13. Use with the GNU Affero General Public License. 566 | 567 | Notwithstanding any other provision of this License, you have 568 | permission to link or combine any covered work with a work licensed 569 | under version 3 of the GNU Affero General Public License into a single 570 | combined work, and to convey the resulting work. The terms of this 571 | License will continue to apply to the part which is the covered work, 572 | but the special requirements of the GNU Affero General Public License, 573 | section 13, concerning interaction through a network will apply to the 574 | combination as such. 575 | 576 | 14. Revised Versions of this License. 577 | 578 | The Free Software Foundation may publish revised and/or new versions of 579 | the GNU General Public License from time to time. Such new versions will 580 | be similar in spirit to the present version, but may differ in detail to 581 | address new problems or concerns. 582 | 583 | Each version is given a distinguishing version number. If the 584 | Program specifies that a certain numbered version of the GNU General 585 | Public License "or any later version" applies to it, you have the 586 | option of following the terms and conditions either of that numbered 587 | version or of any later version published by the Free Software 588 | Foundation. If the Program does not specify a version number of the 589 | GNU General Public License, you may choose any version ever published 590 | by the Free Software Foundation. 591 | 592 | If the Program specifies that a proxy can decide which future 593 | versions of the GNU General Public License can be used, that proxy's 594 | public statement of acceptance of a version permanently authorizes you 595 | to choose that version for the Program. 596 | 597 | Later license versions may give you additional or different 598 | permissions. However, no additional obligations are imposed on any 599 | author or copyright holder as a result of your choosing to follow a 600 | later version. 601 | 602 | 15. Disclaimer of Warranty. 603 | 604 | THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY 605 | APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT 606 | HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY 607 | OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, 608 | THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 609 | PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM 610 | IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF 611 | ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 612 | 613 | 16. Limitation of Liability. 614 | 615 | IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 616 | WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS 617 | THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY 618 | GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE 619 | USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF 620 | DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD 621 | PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), 622 | EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF 623 | SUCH DAMAGES. 624 | 625 | 17. Interpretation of Sections 15 and 16. 626 | 627 | If the disclaimer of warranty and limitation of liability provided 628 | above cannot be given local legal effect according to their terms, 629 | reviewing courts shall apply local law that most closely approximates 630 | an absolute waiver of all civil liability in connection with the 631 | Program, unless a warranty or assumption of liability accompanies a 632 | copy of the Program in return for a fee. 633 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # PDF Parser 2 | PDF Parser is a command line tool and go library that decrypts PDF files and extracts commands, files, javascript, text and urls. PDF Parser also logs formatting errors and abnormalities that are used to obfuscate malicious PDF files. 3 | 4 | ## Installation 5 | First, [Install Go](https://golang.org/doc/install#install) 6 | 7 | Then install/update the PDF Parser 8 | ```bash 9 | go get -u github.com/KarmaPenny/pdfparser 10 | ``` 11 | 12 | #### To uninstall the PDF parser run: 13 | ```bash 14 | go clean -i github.com/KarmaPenny/pdfparser && rm -rf $(go env GOPATH)/src/github.com/KarmaPenny/pdfparser 15 | ``` 16 | 17 | #### Run unit tests with: 18 | ```bash 19 | go test github.com/KarmaPenny/pdfparser/pdf 20 | ``` 21 | 22 | ## Usage 23 | #### Command Line 24 | The following command extracts the contents of input.pdf to the output directory using "password" for decryption: 25 | ```bash 26 | $(go env GOPATH)/bin/pdfparser -p password input.pdf output/ 27 | ``` 28 | 29 | #### Library 30 | The following program extracts the contents of input.pdf to the output directory using "password" for decryption: 31 | ```go 32 | package main 33 | 34 | import "github.com/KarmaPenny/pdfparser/pdf" 35 | 36 | func main() { 37 | pdf.Parse("input.pdf", "password", "output") 38 | } 39 | ``` 40 | 41 | ## Output 42 | PDF parser creates the following files in the output directory: 43 | 44 | #### commands.txt 45 | Commands run by launch actions are logged to the commands.txt file. Example: 46 | ``` 47 | cmd.exe /c hello.exe 48 | calc.exe 49 | ``` 50 | 51 | #### contents.txt 52 | The text content of the PDF is written to the contents.txt file. 53 | 54 | #### errors.txt 55 | Format errors and other abnormailites that are sometimes used to obfuscate malicious PDF files are logged to the errors.txt file. Bellow is an example errors.txt file containing the complete list of possible log messages: 56 | ``` 57 | invalid dictionary key type 58 | invalid hex string character 59 | invalid name escape character 60 | invalid octal in string 61 | missing dictionary value 62 | unclosed array 63 | unclosed dictionary 64 | unclosed hex string 65 | unclosed stream 66 | unclosed string 67 | unclosed escape in string 68 | unclosed octal in string 69 | unnecessary espace sequence in name 70 | unnecessary espace sequence in string 71 | ``` 72 | #### files.txt 73 | The MD5 hash and file path of referenced embedded and external files are logged to the files.txt file. Embedded files are extracted to the output directory using the MD5 hash as the file name. The MD5 hash for external files is all zeros. Example: 74 | ``` 75 | 6adb6f85e541f14d7ecec12a6af8ef65:hello.exe 76 | 00000000000000000000000000000000:C:\Windows\System32\calc.exe 77 | ``` 78 | 79 | #### javascript.js 80 | The javascript of all actions is extracted to the javascript.js file. 81 | 82 | #### raw.pdf 83 | A decrypted and decoded version of the PDF is written to the raw.pdf file. 84 | 85 | #### urls.txt 86 | All URLs referenced by actions are extracted to the urls.txt file. Example: 87 | ``` 88 | http://www.google.com 89 | https://github.com/KarmaPenny 90 | ``` 91 | -------------------------------------------------------------------------------- /main.go: -------------------------------------------------------------------------------- 1 | package main 2 | 3 | import ( 4 | "flag" 5 | "fmt" 6 | "github.com/KarmaPenny/pdfparser/pdf" 7 | "os" 8 | ) 9 | 10 | var overwrite *bool 11 | var password *string 12 | 13 | func usage() { 14 | fmt.Fprintln(os.Stderr, "PDF Parser - Decrypts a PDF file and extracts contents") 15 | fmt.Fprintln(os.Stderr, "") 16 | fmt.Fprintln(os.Stderr, "") 17 | fmt.Fprintln(os.Stderr, "Usage: pdfparser [OPTION]... [FILE] [DIRECTORY]") 18 | fmt.Fprintln(os.Stderr, "Example: pdfparser -v -f -p password input.pdf output/") 19 | fmt.Fprintln(os.Stderr, "") 20 | fmt.Fprintln(os.Stderr, "Options:") 21 | fmt.Fprintln(os.Stderr, " -f overwrite output directory") 22 | fmt.Fprintln(os.Stderr, " -p decryption password") 23 | fmt.Fprintln(os.Stderr, " -v display verbose messages") 24 | fmt.Fprintln(os.Stderr, "") 25 | fmt.Fprintln(os.Stderr, "Copyright (C) 2019 Cole Robinette") 26 | fmt.Fprintln(os.Stderr, "This program is free to use, redistribute, and modify under") 27 | fmt.Fprintln(os.Stderr, "the terms of the GNU General Public License version 3. This") 28 | fmt.Fprintln(os.Stderr, "program is distributed without any warranty.") 29 | fmt.Fprintln(os.Stderr, "") 30 | } 31 | 32 | func init() { 33 | overwrite = flag.Bool("f", false, "overwrite of output directory if it already exists") 34 | password = flag.String("p", "", "encryption password (default: empty)") 35 | pdf.Verbose = flag.Bool("v", false, "display verbose messages") 36 | flag.Usage = usage 37 | flag.Parse() 38 | if flag.NArg() != 2 { 39 | usage() 40 | os.Exit(1) 41 | } 42 | } 43 | 44 | func main() { 45 | // check if output directory already exists 46 | if _, err := os.Stat(flag.Arg(1)); !os.IsNotExist(err) && !*overwrite { 47 | fmt.Printf("output directory \"%s\" already exists, use -f to overwrite\n", flag.Arg(1)) 48 | return 49 | } 50 | 51 | // parse the pdf 52 | if err := pdf.Parse(flag.Arg(0), *password, flag.Arg(1)); err != nil { 53 | fmt.Fprintln(os.Stderr, err.Error()) 54 | } 55 | } 56 | -------------------------------------------------------------------------------- /pdf/action.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | import ( 4 | "fmt" 5 | ) 6 | 7 | type Action Dictionary 8 | 9 | func (a Action) Extract(output *Output) { 10 | d := Dictionary(a) 11 | 12 | isCommand := false 13 | if s, ok := d.GetName("S"); ok && s == "Launch" { 14 | isCommand = true 15 | } 16 | 17 | // filespecification can be in either F or Win[F] 18 | if f, ok := d.GetString("F"); ok { 19 | fmt.Fprintf(output.Files, "%s:%s\n", unknownHash, f) 20 | } else if f, ok := d.GetDictionary("F"); ok { 21 | File(f).Extract(output, isCommand) 22 | } 23 | if win, ok := d.GetDictionary("Win"); ok { 24 | File(win).Extract(output, isCommand) 25 | } 26 | } 27 | -------------------------------------------------------------------------------- /pdf/array.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | import ( 4 | "strings" 5 | ) 6 | 7 | type Array []Object 8 | 9 | func (a Array) String() string { 10 | var s strings.Builder 11 | s.WriteString("[") 12 | for i, value := range a { 13 | s.WriteString(value.String()) 14 | if i != len(a) - 1 { 15 | s.WriteString(" ") 16 | } 17 | } 18 | s.WriteString("]") 19 | return s.String() 20 | } 21 | 22 | func (a Array) GetArray(index int) (Array, bool) { 23 | if object, ok := a.GetObject(index); ok { 24 | if array, ok := object.(Array); ok { 25 | return array, true 26 | } 27 | } 28 | return Array{}, false 29 | } 30 | 31 | func (a Array) GetBool(index int) (bool, bool) { 32 | if object, ok := a.GetObject(index); ok { 33 | if keyword, ok := object.(Keyword); ok { 34 | if keyword == KEYWORD_TRUE { 35 | return true, true 36 | } else if keyword == KEYWORD_FALSE { 37 | return false, true 38 | } 39 | } 40 | } 41 | return false, false 42 | } 43 | 44 | func (a Array) GetBytes(index int) ([]byte, bool) { 45 | s, ok := a.GetString(index) 46 | return []byte(s), ok 47 | } 48 | 49 | func (a Array) GetDictionary(index int) (Dictionary, bool) { 50 | if object, ok := a.GetObject(index); ok { 51 | if dictionary, ok := object.(Dictionary); ok { 52 | return dictionary, true 53 | } 54 | } 55 | return Dictionary{}, false 56 | } 57 | 58 | func (a Array) GetInt(index int) (int, bool) { 59 | number, ok := a.GetNumber(index) 60 | return int(number), ok 61 | } 62 | 63 | func (a Array) GetInt64(index int) (int64, bool) { 64 | number, ok := a.GetNumber(index) 65 | return int64(number), ok 66 | } 67 | 68 | func (a Array) GetName(index int) (string, bool) { 69 | if object, ok := a.GetObject(index); ok { 70 | if name, ok := object.(Name); ok { 71 | return string(name), true 72 | } 73 | } 74 | return "", false 75 | } 76 | 77 | func (a Array) GetNumber(index int) (Number, bool) { 78 | if object, ok := a.GetObject(index); ok { 79 | if number, ok := object.(Number); ok { 80 | return number, true 81 | } 82 | } 83 | return Number(0), false 84 | } 85 | 86 | func (a Array) GetObject(index int) (Object, bool) { 87 | if index >= 0 && index < len(a) { 88 | object := a[index] 89 | if reference, ok := object.(*Reference); ok { 90 | return reference.Resolve(), true 91 | } 92 | return object, true 93 | } 94 | return KEYWORD_NULL, false 95 | } 96 | 97 | func (a Array) GetStream(index int) ([]byte, bool) { 98 | if index >= 0 && index < len(a) { 99 | if reference, ok := a[index].(*Reference); ok { 100 | return reference.ResolveStream(), true 101 | } 102 | } 103 | return []byte{}, false 104 | } 105 | 106 | func (a Array) GetString(index int) (string, bool) { 107 | if object, ok := a.GetObject(index); ok { 108 | if s, ok := object.(String); ok { 109 | return string(s), true 110 | } 111 | } 112 | return "", false 113 | } 114 | -------------------------------------------------------------------------------- /pdf/dictionary.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | import ( 4 | "strings" 5 | ) 6 | 7 | type Dictionary map[string]Object 8 | 9 | func (d Dictionary) String() string { 10 | var s strings.Builder 11 | s.WriteString("<<") 12 | for key, value := range d { 13 | s.WriteString("/") 14 | s.WriteString(key) 15 | s.WriteString(" ") 16 | s.WriteString(value.String()) 17 | } 18 | s.WriteString(">>") 19 | return s.String() 20 | } 21 | 22 | func (d Dictionary) GetArray(key string) (Array, bool) { 23 | if object, ok := d.GetObject(key); ok { 24 | if array, ok := object.(Array); ok { 25 | return array, true 26 | } 27 | } 28 | return Array{}, false 29 | } 30 | 31 | func (d Dictionary) GetBool(key string) (bool, bool) { 32 | if object, ok := d.GetObject(key); ok { 33 | if keyword, ok := object.(Keyword); ok { 34 | if keyword == KEYWORD_TRUE { 35 | return true, true 36 | } else if keyword == KEYWORD_FALSE { 37 | return false, true 38 | } 39 | } 40 | } 41 | return false, false 42 | } 43 | 44 | func (d Dictionary) GetBytes(key string) ([]byte, bool) { 45 | s, ok := d.GetString(key) 46 | return []byte(s), ok 47 | } 48 | 49 | func (d Dictionary) GetDictionary(key string) (Dictionary, bool) { 50 | if object, ok := d.GetObject(key); ok { 51 | if dictionary, ok := object.(Dictionary); ok { 52 | return dictionary, true 53 | } 54 | } 55 | return Dictionary{}, false 56 | } 57 | 58 | func (d Dictionary) GetInt(key string) (int, bool) { 59 | number, ok := d.GetNumber(key) 60 | return int(number), ok 61 | } 62 | 63 | func (d Dictionary) GetInt64(key string) (int64, bool) { 64 | number, ok := d.GetNumber(key) 65 | return int64(number), ok 66 | } 67 | 68 | func (d Dictionary) GetName(key string) (string, bool) { 69 | if object, ok := d.GetObject(key); ok { 70 | if name, ok := object.(Name); ok { 71 | return string(name), true 72 | } 73 | } 74 | return "", false 75 | } 76 | 77 | func (d Dictionary) GetNameTreeMap(key string) Array { 78 | if root, ok := d.GetDictionary(key); ok { 79 | return root.getNameTreeMap(map[int]interface{}{}) 80 | } 81 | return Array{} 82 | } 83 | 84 | func (d Dictionary) getNameTreeMap(resolved_kids map[int]interface{}) Array { 85 | nameTreeMap := Array{} 86 | if names, ok := d.GetArray("Names"); ok { 87 | // append names to name tree map 88 | nameTreeMap = append(nameTreeMap, names...) 89 | } 90 | if kids, ok := d.GetArray("Kids"); ok { 91 | for i := range kids { 92 | // prevent infinite resolve reference loop 93 | if r, ok := kids[i].(*Reference); ok { 94 | if _, resolved := resolved_kids[r.Number]; resolved { 95 | continue 96 | } 97 | resolved_kids[r.Number] = nil 98 | } 99 | 100 | // get child dictionary 101 | kid, _ := kids.GetDictionary(i) 102 | nameTreeMap = append(nameTreeMap, kid.getNameTreeMap(resolved_kids)...) 103 | } 104 | } 105 | return nameTreeMap 106 | } 107 | 108 | func (d Dictionary) GetNumber(key string) (Number, bool) { 109 | if object, ok := d.GetObject(key); ok { 110 | if number, ok := object.(Number); ok { 111 | return number, true 112 | } 113 | } 114 | return Number(0), false 115 | } 116 | 117 | func (d Dictionary) GetObject(key string) (Object, bool) { 118 | if object, ok := d[key]; ok { 119 | if reference, ok := object.(*Reference); ok { 120 | return reference.Resolve(), true 121 | } 122 | return object, true 123 | } 124 | return KEYWORD_NULL, false 125 | } 126 | 127 | func (d Dictionary) GetPageTree(key string) ([]Dictionary, bool) { 128 | if pageTree, ok := d.GetDictionary(key); ok { 129 | return pageTree.ResolveKids(map[int]interface{}{}), true 130 | } 131 | return []Dictionary{}, false 132 | } 133 | 134 | func (d Dictionary) ResolveKids(resolved_kids map[int]interface{}) []Dictionary { 135 | kids_list := []Dictionary{d} 136 | if kids, ok := d.GetArray("Kids"); ok { 137 | for i := range kids { 138 | if r, ok := kids[i].(*Reference); ok { 139 | // ignore circular references 140 | if _, resolved := resolved_kids[r.Number]; resolved { 141 | continue 142 | } 143 | resolved_kids[r.Number] = nil 144 | 145 | // resolve 146 | object := r.Resolve() 147 | if kid_d, ok := object.(Dictionary); ok { 148 | // recursively resolve kids 149 | kids_list = append(kids_list, kid_d.ResolveKids(resolved_kids)...) 150 | } 151 | } 152 | } 153 | } 154 | return kids_list 155 | } 156 | 157 | func (d Dictionary) GetReference(key string) (*Reference, bool) { 158 | if object, ok := d[key]; ok { 159 | if reference, ok := object.(*Reference); ok { 160 | return reference, true 161 | } 162 | } 163 | return nil, false 164 | } 165 | 166 | func (d Dictionary) GetStream(key string) ([]byte, bool) { 167 | if object, ok := d[key]; ok { 168 | if reference, ok := object.(*Reference); ok { 169 | return reference.ResolveStream(), true 170 | } 171 | } 172 | return []byte{}, false 173 | } 174 | 175 | func (d Dictionary) GetString(key string) (string, bool) { 176 | if object, ok := d.GetObject(key); ok { 177 | if s, ok := object.(String); ok { 178 | return string(s), true 179 | } 180 | } 181 | return "", false 182 | } 183 | -------------------------------------------------------------------------------- /pdf/encryption.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | import ( 4 | "crypto/aes" 5 | "crypto/cipher" 6 | "crypto/md5" 7 | "crypto/rc4" 8 | "encoding/binary" 9 | ) 10 | 11 | var padding_string []byte = []byte("\x28\xBF\x4E\x5E\x4E\x75\x8A\x41\x64\x00\x4E\x56\xFF\xFA\x01\x08\x2E\x2E\x00\xB6\xD0\x68\x3E\x80\x2F\x0C\xA9\xFE\x64\x53\x69\x7A") 12 | var noFilter = &CryptFilterNone{} 13 | var noDecryptor = &DecryptorNone{} 14 | type CryptFilter interface { 15 | NewDecryptor(int, int) Decryptor 16 | } 17 | 18 | type Decryptor interface { 19 | Decrypt([]byte) 20 | } 21 | 22 | // No encryption 23 | type CryptFilterNone struct {} 24 | 25 | func (c *CryptFilterNone) NewDecryptor(n int, g int) Decryptor { 26 | return &DecryptorNone{} 27 | } 28 | 29 | type DecryptorNone struct {} 30 | 31 | func (d *DecryptorNone) Decrypt(data []byte) {} 32 | 33 | // AES 34 | type CryptFilterAES struct { 35 | encryption_key []byte 36 | } 37 | 38 | func (c *CryptFilterAES) NewDecryptor(n int, g int) Decryptor { 39 | // allocate space for salt and copy encryption key into it 40 | salt := make([]byte, len(c.encryption_key), len(c.encryption_key) + 9) 41 | copy(salt, c.encryption_key) 42 | 43 | // get n as byte little endian byte array, add first 3 bytes to salt 44 | nb := make([]byte, 4) 45 | binary.LittleEndian.PutUint32(nb, uint32(n)) 46 | salt = append(salt, nb[:3]...) 47 | 48 | // get g as byte little endian byte array, add first 2 bytes to salt 49 | gb := make([]byte, 4) 50 | binary.LittleEndian.PutUint32(gb, uint32(g)) 51 | salt = append(salt, gb[:2]...) 52 | 53 | // add sAlT to key 54 | salt = append(salt, []byte("sAlT")...) 55 | 56 | // hash the salt to produce the key 57 | hash := md5.New() 58 | hash.Write(salt) 59 | key := hash.Sum(nil) 60 | 61 | // trucate key to length + 5 max 16 62 | l := len(c.encryption_key) + 5 63 | if l > 16 { 64 | l = 16 65 | } 66 | key = key[:l] 67 | 68 | // return new crypt filter with salted key 69 | return &DecryptorAES{key} 70 | } 71 | 72 | type DecryptorAES struct { 73 | encryption_key []byte 74 | } 75 | 76 | func (d *DecryptorAES) Decrypt(data []byte) { 77 | // catch crypt block panic 78 | defer func() { 79 | if err := recover(); err != nil { 80 | Debug("recovered from panic: %s", err) 81 | } 82 | }() 83 | 84 | // create new cipher 85 | block, _ := aes.NewCipher(d.encryption_key) 86 | 87 | // no data to decrypt, first block is initialization vector 88 | if len(data) <= aes.BlockSize { 89 | return 90 | } 91 | 92 | // set iv to first block and decrypt remaining blocks with cbc decryptor 93 | iv := data[:aes.BlockSize] 94 | data = data[aes.BlockSize:] 95 | cbc := cipher.NewCBCDecrypter(block, iv) 96 | cbc.CryptBlocks(data, data) 97 | } 98 | 99 | // RC4 100 | type CryptFilterRC4 struct { 101 | encryption_key []byte 102 | } 103 | 104 | func (c *CryptFilterRC4) NewDecryptor(n int, g int) Decryptor { 105 | // allocate space for salt and copy encryption key into it 106 | salt := make([]byte, len(c.encryption_key), len(c.encryption_key) + 5) 107 | copy(salt, c.encryption_key) 108 | 109 | // get n as byte little endian byte array, add first 3 bytes to salt 110 | nb := make([]byte, 4) 111 | binary.LittleEndian.PutUint32(nb, uint32(n)) 112 | salt = append(salt, nb[:3]...) 113 | 114 | // get g as byte little endian byte array, add first 2 bytes to salt 115 | gb := make([]byte, 4) 116 | binary.LittleEndian.PutUint32(gb, uint32(g)) 117 | salt = append(salt, gb[:2]...) 118 | 119 | // hash the salt to produce the key 120 | hash := md5.New() 121 | hash.Write(salt) 122 | key := hash.Sum(nil) 123 | 124 | // trucate key to length + 5 max 16 125 | l := len(c.encryption_key) + 5 126 | if l > 16 { 127 | l = 16 128 | } 129 | key = key[:l] 130 | 131 | // return new crypt filter with salted key 132 | return &DecryptorRC4{key} 133 | } 134 | 135 | type DecryptorRC4 struct { 136 | encryption_key []byte 137 | } 138 | 139 | func (d *DecryptorRC4) Decrypt(data []byte) { 140 | cipher, _ := rc4.NewCipher(d.encryption_key) 141 | cipher.XORKeyStream(data, data) 142 | } 143 | 144 | type SecurityHandler struct { 145 | v int 146 | length int 147 | r int 148 | o []byte 149 | u []byte 150 | p []byte 151 | encrypt_meta_data bool 152 | id []byte 153 | stream_filter CryptFilter 154 | string_filter CryptFilter 155 | file_filter CryptFilter 156 | crypt_filters map[string]CryptFilter 157 | encryption_key []byte 158 | } 159 | 160 | func NewSecurityHandler() *SecurityHandler { 161 | sh := &SecurityHandler{} 162 | sh.stream_filter = noFilter 163 | sh.string_filter = noFilter 164 | sh.file_filter = noFilter 165 | sh.crypt_filters = map[string]CryptFilter{} 166 | return sh 167 | } 168 | 169 | func (sh *SecurityHandler) Init(password []byte, trailer Dictionary) error { 170 | var ok bool = false 171 | 172 | // get encryption dictionary 173 | encrypt, ok := trailer.GetDictionary("Encrypt") 174 | if !ok { 175 | return EncryptionError 176 | } 177 | 178 | // get filter 179 | filter, _ := encrypt.GetName("Filter") 180 | if filter != "Standard" { 181 | return EncryptionUnsupported 182 | } 183 | 184 | // get V 185 | sh.v, _ = encrypt.GetInt("V") 186 | if sh.v != 1 && sh.v != 2 && sh.v != 4 { 187 | return EncryptionUnsupported 188 | } 189 | 190 | // get R 191 | sh.r, _ = encrypt.GetInt("R") 192 | if sh.r < 2 || sh.r > 4 { 193 | return EncryptionUnsupported 194 | } 195 | 196 | // get Length 197 | if sh.v == 1 { 198 | sh.length = 40 199 | } else { 200 | sh.length, ok = encrypt.GetInt("Length") 201 | if !ok { 202 | sh.length = 40 203 | } 204 | } 205 | sh.length = sh.length/8 206 | if sh.length < 5 { 207 | sh.length = 5 208 | } else if sh.length > 16 { 209 | sh.length = 16 210 | } 211 | 212 | // get O 213 | sh.o, ok = encrypt.GetBytes("O") 214 | if !ok { 215 | return EncryptionError 216 | } 217 | 218 | // get U 219 | sh.u, ok = encrypt.GetBytes("U") 220 | if !ok { 221 | return EncryptionError 222 | } 223 | 224 | // get P 225 | p, ok := encrypt.GetInt("P") 226 | if !ok { 227 | return EncryptionError 228 | } 229 | sh.p = make([]byte, 4) 230 | binary.LittleEndian.PutUint32(sh.p, uint32(p)) 231 | 232 | // get EncryptMetadata 233 | sh.encrypt_meta_data, ok = encrypt.GetBool("EncryptMetadata") 234 | if !ok { 235 | sh.encrypt_meta_data = true 236 | } 237 | 238 | // get ID[0] from trailer 239 | ids, ok := trailer.GetArray("ID") 240 | if !ok { 241 | return EncryptionError 242 | } 243 | sh.id, ok = ids.GetBytes(0) 244 | if !ok { 245 | return EncryptionError 246 | } 247 | 248 | // compute encryption key from password 249 | sh.encryption_key = sh.computeEncryptionKey(password, sh.length) 250 | 251 | // verify key 252 | if sh.r == 2 { // if revision 2 use algorithm 4 253 | u := make([]byte, 32) 254 | cipher, _ := rc4.NewCipher(sh.encryption_key) 255 | cipher.XORKeyStream(u, padding_string) 256 | if string(u) != string(sh.u) { 257 | return EncryptionPasswordError 258 | } 259 | } else if sh.r >= 3 { // for revision 3+ use algorithm 5 260 | // step b, c 261 | hash := md5.New() 262 | hash.Write(padding_string) 263 | hash.Write(sh.id) 264 | u := hash.Sum(nil) 265 | 266 | // step d, e 267 | temp_key := make([]byte, len(sh.encryption_key)) 268 | for i := 0; i < 20; i++ { 269 | for j := range sh.encryption_key { 270 | temp_key[j] = sh.encryption_key[j] ^ byte(i) 271 | } 272 | cipher, _ := rc4.NewCipher(temp_key) 273 | cipher.XORKeyStream(u, u) 274 | } 275 | 276 | // compare to first 16 bytes of U entry 277 | if string(u) != string(sh.u[:16]) { 278 | return EncryptionPasswordError 279 | } 280 | } 281 | 282 | // set default crypt filters 283 | sh.stream_filter = &CryptFilterRC4{sh.encryption_key} 284 | sh.string_filter = sh.stream_filter 285 | sh.file_filter = sh.stream_filter 286 | sh.crypt_filters = map[string]CryptFilter{} 287 | sh.crypt_filters["Identity"] = noFilter 288 | 289 | // load additional crypt filters 290 | if sh.r == 4 { 291 | cf, _ := encrypt.GetDictionary("CF") 292 | for k, entry := range cf { 293 | if cfd, isDictionary := entry.(Dictionary); isDictionary { 294 | if method, ok := cfd.GetName("CFM"); ok { 295 | // get optional length 296 | length, ok := cfd.GetInt("Length") 297 | if !ok { 298 | length = sh.length 299 | } 300 | 301 | // create filter entry 302 | if method == "None" { 303 | sh.crypt_filters[k] = noFilter 304 | } else if method == "V2" { 305 | sh.crypt_filters[k] = &CryptFilterRC4{sh.computeEncryptionKey(password, length)} 306 | } else if method == "AESV2" { 307 | sh.crypt_filters[k] = &CryptFilterAES{sh.computeEncryptionKey(password, length)} 308 | } 309 | } 310 | } 311 | } 312 | 313 | // assign default filter overrides 314 | if name, ok := encrypt.GetName("StmF"); ok { 315 | if filter, exists := sh.crypt_filters[name]; exists { 316 | sh.stream_filter = filter 317 | } 318 | } 319 | if name, ok := encrypt.GetName("StrF"); ok { 320 | if filter, exists := sh.crypt_filters[name]; exists { 321 | sh.string_filter = filter 322 | } 323 | } 324 | if name, ok := encrypt.GetName("EEF"); ok { 325 | if filter, exists := sh.crypt_filters[name]; exists { 326 | sh.file_filter = filter 327 | } 328 | } 329 | } 330 | 331 | return nil 332 | } 333 | 334 | // Algorithm 2: Computing an encryption key 335 | func (sh *SecurityHandler) computeEncryptionKey(password []byte, key_length int) []byte { 336 | // step a) pad or truncate password to exactly 32 bytes 337 | if len(password) < 32 { 338 | password = append(password, padding_string[:32 - len(password)]...) 339 | } else { 340 | password = password[:32] 341 | } 342 | 343 | // step b, c, d, e, f, g 344 | hash := md5.New() 345 | hash.Write(password) 346 | hash.Write(sh.o) 347 | hash.Write(sh.p) 348 | hash.Write(sh.id) 349 | if sh.r >= 4 && !sh.encrypt_meta_data { 350 | hash.Write([]byte("\xff\xff\xff\xff")) 351 | } 352 | encryption_key := hash.Sum(nil)[:key_length] 353 | 354 | // step h) for revision 3+, re-hash key 50 times 355 | if sh.r >= 3 { 356 | for i := 0; i < 50; i++ { 357 | hash = md5.New() 358 | hash.Write(encryption_key) 359 | encryption_key = hash.Sum(nil)[:key_length] 360 | } 361 | } 362 | 363 | return encryption_key 364 | } 365 | -------------------------------------------------------------------------------- /pdf/errors.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | import ( 4 | "errors" 5 | ) 6 | 7 | 8 | // errors 9 | var EncryptionError = errors.New("missing required encryption info") 10 | var EncryptionPasswordError = errors.New("incorrect password") 11 | var EncryptionUnsupported = errors.New("unsupported encryption") 12 | var EndOfArray = errors.New("end of array") 13 | var EndOfDictionary = errors.New("end of dictionary") 14 | var EndOfHexString = errors.New("end of hex string") 15 | var EndOfString = errors.New("end of string") 16 | var ReadError = errors.New("read failed") 17 | 18 | // format errors and abnormalities 19 | var InvalidDictionaryKeyType = "invalid dictionary key type" 20 | var InvalidHexStringChar = "invalid hex string character" 21 | var InvalidNameEscapeChar = "invalid name escape character" 22 | var InvalidOctal = "invalid octal in string" 23 | var MissingDictionaryValue = "missing dictionary value" 24 | var UnclosedArray = "unclosed array" 25 | var UnclosedDictionary = "unclosed dictionary" 26 | var UnclosedHexString = "unclosed hex string" 27 | var UnclosedStream = "unclosed stream" 28 | var UnclosedString = "unclosed string" 29 | var UnclosedStringEscape = "unclosed escape in string" 30 | var UnclosedStringOctal = "unclosed octal in string" 31 | var UnnecessaryEscapeName = "unnecessary espace sequence in name" 32 | var UnnecessaryEscapeString = "unnecessary espace sequence in string" 33 | -------------------------------------------------------------------------------- /pdf/file.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | import ( 4 | "fmt" 5 | ) 6 | 7 | var unknownHash string = "00000000000000000000000000000000" 8 | 9 | type File Dictionary 10 | 11 | func (file File) Extract(output *Output, isCommand bool) { 12 | d := Dictionary(file) 13 | 14 | // file specification can be a url or file 15 | fs, _ := d.GetString("FS") 16 | if fs == "URL" { 17 | if f, ok := d.GetString("F"); ok { 18 | fmt.Fprintln(output.URLs, f) 19 | } 20 | } else if ef, ok := d.GetDictionary("EF"); ok { 21 | // get the file data 22 | file_data, _ := ef.GetStream("F") 23 | 24 | // get the file path 25 | f, ok := d.GetString("F") 26 | if !ok { 27 | f = unknownHash 28 | } 29 | 30 | // dump file 31 | output.DumpFile(f, file_data) 32 | } else if p, ok := d.GetString("P"); ok { 33 | if f, ok := d.GetString("F"); ok { 34 | fmt.Fprintf(output.Files, "%s:%s\n", unknownHash, f) 35 | fmt.Fprintf(output.Commands, "%s %s\n", f, p) 36 | } 37 | } else if f, ok := d.GetString("F"); ok { 38 | if isCommand { 39 | fmt.Fprintf(output.Commands, "%s %s\n", f, p) 40 | } 41 | fmt.Fprintf(output.Files, "%s:%s\n", unknownHash, f) 42 | } 43 | } 44 | -------------------------------------------------------------------------------- /pdf/filters.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | import ( 4 | "bytes" 5 | "compress/lzw" 6 | "compress/zlib" 7 | "encoding/binary" 8 | "io" 9 | "math" 10 | "strconv" 11 | tiff_lzw "golang.org/x/image/tiff/lzw" 12 | ) 13 | 14 | func DecodeStream(filter string, data []byte, decode_parms Dictionary) []byte { 15 | // do nothing if data is empty 16 | if len(data) == 0 { 17 | return data 18 | } 19 | 20 | // apply hex filter 21 | if filter == "ASCIIHexDecode" { 22 | return ASCIIHexDecode(data) 23 | } 24 | 25 | // apply ascii 85 filter 26 | if filter == "ASCII85Decode" { 27 | return ASCII85Decode(data) 28 | } 29 | 30 | // apply run length filter 31 | if filter == "RunLengthDecode" { 32 | return RunLengthDecode(data) 33 | } 34 | 35 | // apply zlib filter 36 | if filter == "FlateDecode" { 37 | return FlateDecode(data, decode_parms) 38 | } 39 | 40 | // apply lzw filter 41 | if filter == "LZWDecode" { 42 | return LZWDecode(data, decode_parms) 43 | } 44 | 45 | // filter is not supported 46 | return data 47 | } 48 | 49 | func ASCIIHexDecode(data []byte) []byte { 50 | // allocate buffer for decoded bytes 51 | decoded_data := make([]byte, 0, len(data)) 52 | 53 | // decode data 54 | for i := 0; i < len(data); i++ { 55 | // get the first byte 56 | b1 := data[i] 57 | 58 | // skip whitespace 59 | if bytes.IndexByte(whitespace, b1) >= 0 { 60 | continue 61 | } 62 | 63 | // EOD marker 64 | if b1 == byte('>') { 65 | break 66 | } 67 | 68 | // get the second byte defaulting to zero 69 | b2 := byte('0') 70 | for ; i + 1 < len(data); i++ { 71 | // skip whitespace 72 | if bytes.IndexByte(whitespace, data[i+1]) >= 0 { 73 | continue 74 | } 75 | 76 | // EOD marker 77 | if data[i+1] == byte('>') { 78 | break 79 | } 80 | 81 | // set second byte 82 | i++ 83 | b2 = data[i] 84 | break 85 | } 86 | 87 | // add decoded byte to decoded data 88 | val, err := strconv.ParseUint(string([]byte{b1, b2}), 16, 8) 89 | if err != nil { 90 | // TODO: report illegal character 91 | continue 92 | } 93 | decoded_data = append(decoded_data, byte(val)) 94 | } 95 | 96 | return decoded_data 97 | } 98 | 99 | func ASCII85Decode(data []byte) []byte { 100 | reader := bytes.NewReader(data) 101 | decoded_data := bytes.NewBuffer([]byte{}) 102 | 103 | v := uint32(0) 104 | n := 0 105 | 106 | for { 107 | b, err := reader.ReadByte() 108 | if err != nil || b == '~' { 109 | // finish partial group by adding zeros 110 | if n > 1 { 111 | for m := n; m < 5; m++ { 112 | v *= 85 113 | } 114 | 115 | // write result in big endian order 116 | buff := make([]byte, 4) 117 | binary.BigEndian.PutUint32(buff, v) 118 | decoded_data.Write(buff[:n-1]) 119 | } 120 | 121 | return decoded_data.Bytes() 122 | } 123 | 124 | // skip whitespace 125 | if bytes.IndexByte(whitespace, b) >= 0 { 126 | continue 127 | } 128 | 129 | // handle special case 130 | if b == 'z' { 131 | if n != 0 { 132 | // TODO: report invalid use of z character 133 | continue 134 | } 135 | 136 | // write all zeros then continue 137 | decoded_data.Write([]byte{0,0,0,0}) 138 | continue 139 | } 140 | 141 | // validate byte 142 | if b < '!' || b > 'u' { 143 | // TODO: report invalid ascii85 character 144 | continue 145 | } 146 | 147 | // increment counter, multiply value by 85 then add value of new byte 148 | n++ 149 | v *= 85 150 | v += uint32(b) - 33 151 | 152 | if n >= 5 { 153 | // write result in big endian order 154 | buff := make([]byte, 4) 155 | binary.BigEndian.PutUint32(buff, v) 156 | decoded_data.Write(buff) 157 | 158 | // reset value and count 159 | v = 0 160 | n =0 161 | } 162 | } 163 | } 164 | 165 | func RunLengthDecode(data []byte) []byte { 166 | var decoded_data bytes.Buffer 167 | for i := 0; i < len(data); { 168 | // get length byte 169 | length := int(data[i]) 170 | 171 | // EOD 172 | if length == 128 { 173 | break 174 | } else if length < 128 { 175 | // length is value of byte plus one 176 | length++ 177 | 178 | // increment index 179 | i++ 180 | if i >= len(data) { 181 | break 182 | } 183 | 184 | // copy as much data as we can up to length 185 | if i + length > len(data) { 186 | decoded_data.Write(data[i:]) 187 | break 188 | } else { 189 | decoded_data.Write(data[i:i + length]) 190 | i += length 191 | } 192 | } else if length > 128 { 193 | // increment index 194 | i++ 195 | if i >= len(data) { 196 | break 197 | } 198 | 199 | // copy byte 257 - length times 200 | times := 257 - length 201 | for n := 0; n < times; n++ { 202 | decoded_data.WriteByte(data[i]) 203 | } 204 | i++ 205 | } 206 | } 207 | return decoded_data.Bytes() 208 | } 209 | 210 | func FlateDecode(data []byte, decode_parms Dictionary) []byte { 211 | // create zlib reader from data 212 | byte_reader := bytes.NewReader(data) 213 | zlib_reader, err := zlib.NewReader(byte_reader) 214 | if err != nil { 215 | return data 216 | } 217 | defer zlib_reader.Close() 218 | 219 | // decode data with zlib reader and return 220 | var decoded_data bytes.Buffer 221 | bytes_read, err := decoded_data.ReadFrom(zlib_reader) 222 | if bytes_read == 0 && err != nil { 223 | return data 224 | } 225 | 226 | // reverse predictor 227 | return ReversePredictor(decoded_data.Bytes(), decode_parms) 228 | } 229 | 230 | func LZWDecode(data []byte, decode_parms Dictionary) []byte { 231 | // create lzw reader from data using different implementation based on early change parm 232 | var lzw_reader io.ReadCloser 233 | early_change, ok := decode_parms.GetInt("EarlyChange") 234 | if !ok { 235 | early_change = 1 236 | } 237 | if early_change == 0 { 238 | lzw_reader = lzw.NewReader(bytes.NewReader(data), lzw.MSB, 8) 239 | } else { 240 | lzw_reader = tiff_lzw.NewReader(bytes.NewReader(data), tiff_lzw.MSB, 8) 241 | } 242 | defer lzw_reader.Close() 243 | 244 | // decode data with lzw reader and return 245 | var decoded_data bytes.Buffer 246 | bytes_read, err := decoded_data.ReadFrom(lzw_reader) 247 | if bytes_read == 0 && err != nil { 248 | return data 249 | } 250 | 251 | // reverse predictor 252 | return ReversePredictor(decoded_data.Bytes(), decode_parms) 253 | } 254 | 255 | func ReversePredictor(data []byte, decode_parms Dictionary) []byte { 256 | // get predictor parms using default when not found 257 | predictor, ok := decode_parms.GetInt("Predictor") 258 | if !ok { 259 | predictor = 1 260 | } 261 | bits_per_component, ok := decode_parms.GetInt("BitsPerComponent") 262 | if !ok { 263 | bits_per_component = 8 264 | } 265 | colors, ok := decode_parms.GetInt("Colors") 266 | if !ok { 267 | colors = 1 268 | } 269 | columns, ok := decode_parms.GetInt("Columns") 270 | if !ok { 271 | columns = 1 272 | } 273 | 274 | // make sure bits_per_component value is acceptable 275 | if bits_per_component <= 0 || bits_per_component > 16 { 276 | return data 277 | } 278 | 279 | // determine row widths in bytes 280 | row_width := (bits_per_component * colors * columns) / 8 281 | if (bits_per_component * colors * columns) % 8 > 0 { 282 | row_width++ 283 | } 284 | if row_width <= 0 { 285 | return data 286 | } 287 | 288 | // no predictor applied 289 | if predictor == 1 { 290 | return data 291 | } 292 | 293 | // TIFF predictor 294 | if predictor == 2 { 295 | for r := 0; r * row_width < len(data); r ++ { 296 | row_start := r * row_width * 8 297 | for c := 1; c < columns; c++ { 298 | for i := 0; i < colors; i++ { 299 | pos := row_start + ((c * colors + i) * bits_per_component) 300 | if pos >= len(data) * 8 { 301 | return data 302 | } 303 | prev_value := GetBits(data, pos - (colors * bits_per_component), bits_per_component) 304 | value := GetBits(data, pos, bits_per_component) 305 | SetBits(data, pos, bits_per_component, value + prev_value) 306 | } 307 | } 308 | } 309 | return data 310 | } 311 | 312 | // PNG predictors 313 | if predictor >= 10 && predictor <= 15 { 314 | // allocate buffer for decoded data 315 | decoded_data := make([]byte, 0, len(data)) 316 | 317 | // png row includes an algorithm tag as first byte of each row 318 | d_row_width := row_width 319 | row_width++ 320 | 321 | // determine the method 322 | method := predictor - 10 323 | 324 | // for each row 325 | for r := 0; r < len(data); r += row_width { 326 | // optimum predictor allows the method to change each row based on algorithm tag 327 | if predictor == 15 { 328 | method = int(data[r]) 329 | } 330 | 331 | // calculate start of row in decoded buffer 332 | dr := (r / row_width) * (row_width - 1) 333 | 334 | // apply predictors based on method 335 | for c := 1; c < row_width && r + c < len(data); c++ { 336 | // calculate column in decoded buffer 337 | dc := c - 1 338 | 339 | if method == 0 { 340 | // no predictor 341 | decoded_data = append(decoded_data, data[r + c]) 342 | } else if method == 1 { 343 | // sub predictor 344 | left := 0 345 | if dc > 0 { 346 | left = int(decoded_data[dr + dc - 1]) 347 | } 348 | decoded_data = append(decoded_data, byte((int(data[r + c]) + left) % 256)) 349 | } else if method == 2 { 350 | // up predictor 351 | up := 0 352 | if dr + dc - d_row_width >= 0 { 353 | up = int(decoded_data[dr + dc - d_row_width]) 354 | } 355 | decoded_data = append(decoded_data, byte((int(data[r + c]) + up) % 256)) 356 | } else if method == 3 { 357 | // avg predictor 358 | left := 0 359 | if dc > 0 { 360 | left = int(decoded_data[dr + dc - 1]) 361 | } 362 | up := 0 363 | if dr + dc - d_row_width >= 0 { 364 | up = int(decoded_data[dr + dc - d_row_width]) 365 | } 366 | avg := (left + up) / 2 367 | decoded_data = append(decoded_data, byte((int(data[r + c]) + avg) % 256)) 368 | } else if method == 4 { 369 | //paeth predictor 370 | left := 0 371 | if dc > 0 { 372 | left = int(decoded_data[dr + dc - 1]) 373 | } 374 | up := 0 375 | if dr + dc - d_row_width >= 0 { 376 | up = int(decoded_data[dr + dc - d_row_width]) 377 | } 378 | up_left := 0 379 | if dr + dc - d_row_width - 1 >= 0 && dc > 0 { 380 | up_left = int(decoded_data[dr + dc - d_row_width - 1]) 381 | } 382 | p := left + up - up_left 383 | p_left := int(math.Abs(float64(p - left))) 384 | p_up := int(math.Abs(float64(p - up))) 385 | p_up_left := int(math.Abs(float64(p - up_left))) 386 | if p_left <= p_up && p_left <= p_up_left { 387 | decoded_data = append(decoded_data, byte((int(data[r + c]) + left) % 256)) 388 | } else if p_up <= p_up_left { 389 | decoded_data = append(decoded_data, byte((int(data[r + c]) + up) % 256)) 390 | } else { 391 | decoded_data = append(decoded_data, byte((int(data[r + c]) + up_left) % 256)) 392 | } 393 | } else { 394 | // unknown predictor, do nothing 395 | decoded_data = append(decoded_data, data[r + c]) 396 | } 397 | } 398 | } 399 | return decoded_data 400 | } 401 | 402 | // unknown predictor 403 | return data 404 | } 405 | -------------------------------------------------------------------------------- /pdf/font.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | import ( 4 | "bytes" 5 | "strings" 6 | ) 7 | 8 | var FontDefault *Font = &Font{map[int]string{}, 1} 9 | 10 | type Font struct { 11 | Cmap map[int]string 12 | Width int 13 | } 14 | 15 | func NewFont(d Dictionary) *Font { 16 | cmap_string, _ := d.GetStream("ToUnicode") 17 | cmap := []byte(cmap_string) 18 | 19 | // create new font object 20 | font := &Font{map[int]string{}, 1} 21 | 22 | // create parser for parsing cmap 23 | parser := NewParser(bytes.NewReader(cmap), nil) 24 | 25 | for { 26 | // read next command 27 | command, operands, err := parser.ReadCommand() 28 | if err == ReadError { 29 | break 30 | } 31 | 32 | if command == KEYWORD_BEGIN_BF_RANGE { 33 | count, _ := operands.GetInt(len(operands) - 1) 34 | for i := 0; i < count; i++ { 35 | start_b := parser.ReadHexString(noDecryptor) 36 | if start_b == "" { 37 | break 38 | } 39 | font.Width = len([]byte(start_b)) 40 | start := BytesToInt([]byte(start_b)) 41 | 42 | end_b := parser.ReadHexString(noDecryptor) 43 | if end_b == "" { 44 | break 45 | } 46 | end := BytesToInt([]byte(end_b)) 47 | 48 | value := parser.ReadHexString(noDecryptor) 49 | if value == "" { 50 | break 51 | } 52 | 53 | for j := start; j <= end; j++ { 54 | font.Cmap[j] = string(value) 55 | } 56 | } 57 | } else if command == KEYWORD_BEGIN_BF_CHAR { 58 | count, _ := operands.GetInt(len(operands) - 1) 59 | for i := 0; i < count; i++ { 60 | key_b := parser.ReadHexString(noDecryptor) 61 | if key_b == "" { 62 | break 63 | } 64 | font.Width = len([]byte(key_b)) 65 | key := BytesToInt([]byte(key_b)) 66 | 67 | value := parser.ReadHexString(noDecryptor) 68 | if value == "" { 69 | break 70 | } 71 | 72 | font.Cmap[key] = string(value) 73 | } 74 | } 75 | } 76 | 77 | return font 78 | } 79 | 80 | func (font *Font) Decode(b []byte) string { 81 | var s strings.Builder 82 | for i := 0; i + font.Width <= len(b); i += font.Width { 83 | bs := b[i:i + font.Width] 84 | k := BytesToInt(bs) 85 | if v, ok := font.Cmap[k]; ok { 86 | s.WriteString(v) 87 | } else { 88 | s.WriteString(string(bs)) 89 | } 90 | } 91 | return s.String() 92 | } 93 | -------------------------------------------------------------------------------- /pdf/keyword.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | const ( 4 | KEYWORD_XREF = Keyword("xref") 5 | KEYWORD_TRAILER = Keyword("trailer") 6 | KEYWORD_OBJ = Keyword("obj") 7 | KEYWORD_STREAM = Keyword("stream") 8 | KEYWORD_R = Keyword("R") 9 | KEYWORD_N = Keyword("n") 10 | KEYWORD_NULL = Keyword("null") 11 | KEYWORD_TRUE = Keyword("true") 12 | KEYWORD_FALSE = Keyword("false") 13 | KEYWORD_TEXT = Keyword("BT") 14 | KEYWORD_TEXT_END = Keyword("ET") 15 | KEYWORD_TEXT_FONT = Keyword("Tf") 16 | KEYWORD_TEXT_MOVE_1 = Keyword("T*") 17 | KEYWORD_TEXT_MOVE_2 = Keyword("Td") 18 | KEYWORD_TEXT_MOVE_3 = Keyword("TD") 19 | KEYWORD_TEXT_POSITION = Keyword("TJ") 20 | KEYWORD_TEXT_SHOW_1 = Keyword("Tj") 21 | KEYWORD_TEXT_SHOW_2 = Keyword("'") 22 | KEYWORD_TEXT_SHOW_3 = Keyword("\"") 23 | KEYWORD_BEGIN_BF_RANGE = Keyword("beginbfrange") 24 | KEYWORD_BEGIN_BF_CHAR = Keyword("beginbfchar") 25 | ) 26 | 27 | type Keyword string 28 | 29 | func NewKeyword(keyword string) Keyword { 30 | return Keyword(keyword) 31 | } 32 | 33 | func (keyword Keyword) String() string { 34 | return string(keyword) 35 | } 36 | -------------------------------------------------------------------------------- /pdf/logger.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | import ( 4 | "fmt" 5 | "os" 6 | ) 7 | 8 | var Verbose *bool 9 | 10 | func Debug(format string, a ...interface{}) { 11 | if *Verbose { 12 | if len(a) > 0 { 13 | fmt.Fprintf(os.Stderr, format, a...) 14 | fmt.Fprintln(os.Stderr, "") 15 | } else { 16 | fmt.Fprintln(os.Stderr, format) 17 | } 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /pdf/name.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | type Name string 4 | 5 | func (name Name) String() string { 6 | return "/" + string(name) 7 | } 8 | -------------------------------------------------------------------------------- /pdf/number.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | import ( 4 | "fmt" 5 | ) 6 | 7 | type Number float64 8 | 9 | func (number Number) String() string { 10 | return fmt.Sprint(float64(number)) 11 | } 12 | -------------------------------------------------------------------------------- /pdf/object.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | import ( 4 | "fmt" 5 | "strings" 6 | ) 7 | 8 | type Object interface { 9 | String() string 10 | } 11 | 12 | type IndirectObject struct { 13 | Number int 14 | Generation int 15 | Value Object 16 | Stream []byte 17 | } 18 | 19 | func NewIndirectObject(number int) *IndirectObject { 20 | return &IndirectObject{number, 0, KEYWORD_NULL, nil} 21 | } 22 | 23 | func (object *IndirectObject) String() string { 24 | var sb strings.Builder 25 | sb.WriteString(fmt.Sprintf("%d %d obj\n%s\n", object.Number, object.Generation, object.Value)) 26 | if object.Stream != nil { 27 | sb.WriteString(fmt.Sprintf("stream\n%s\nendstream\n", string(object.Stream))) 28 | } 29 | sb.WriteString("endobj\n") 30 | return sb.String() 31 | } 32 | 33 | func (object *IndirectObject) Extract(output *Output) { 34 | // get object dictionary 35 | if d, ok := object.Value.(Dictionary); ok { 36 | extract(d, output) 37 | } 38 | } 39 | 40 | func extract(o Object, output *Output) { 41 | if d, ok := o.(Dictionary); ok { 42 | // dump actions 43 | if a, ok := d.GetDictionary("A"); ok { 44 | Action(a).Extract(output) 45 | } 46 | 47 | // dump open action 48 | if open_action, ok := d.GetDictionary("OpenAction"); ok { 49 | Action(open_action).Extract(output) 50 | } 51 | 52 | // dump additional actions 53 | if aa, ok := d.GetDictionary("AA"); ok { 54 | for key := range aa { 55 | if a, ok := aa.GetDictionary(key); ok { 56 | Action(a).Extract(output) 57 | } 58 | } 59 | } 60 | 61 | // dump forms 62 | if xfa, ok := d.GetStream("XFA"); ok { 63 | output.DumpFile("form.xml", xfa) 64 | } else if xfa, ok := d.GetArray("XFA"); ok { 65 | var form_data strings.Builder 66 | for i := range xfa { 67 | if s, ok := xfa.GetStream(i); ok { 68 | form_data.WriteString(string(s)) 69 | } 70 | } 71 | output.DumpFile("form.xml", []byte(form_data.String())) 72 | } 73 | 74 | // dump Embedded Files 75 | embedded_files := d.GetNameTreeMap("EmbeddedFiles") 76 | for i := 1; i < len(embedded_files); i += 2 { 77 | if f, ok := embedded_files.GetString(i); ok { 78 | fmt.Fprintf(output.Files, "%s:%s\n", unknownHash, f) 79 | } else if f, ok := embedded_files.GetDictionary(i); ok { 80 | File(f).Extract(output, false) 81 | } 82 | } 83 | 84 | // dump javascript 85 | if js, ok := d.GetString("JS"); ok { 86 | fmt.Fprintln(output.Javascript, js) 87 | } else if js, ok := d.GetStream("JS"); ok { 88 | fmt.Fprintln(output.Javascript, string(js)) 89 | } 90 | 91 | // dump page text 92 | if pages, ok := d.GetPageTree("Pages"); ok { 93 | for i := range pages { 94 | Page(pages[i]).Extract(output) 95 | } 96 | } 97 | 98 | // dump URIs 99 | if url, ok := d.GetString("URI"); ok { 100 | fmt.Fprintln(output.URLs, string(url)) 101 | } else if url, ok := d.GetDictionary("URI"); ok { 102 | if base, ok := url.GetString("Base"); ok { 103 | fmt.Fprintln(output.URLs, string(base)) 104 | } 105 | } 106 | 107 | // dump URLs 108 | urls := d.GetNameTreeMap("URLS") 109 | for i := 0; i < len(urls); i += 2 { 110 | if url, ok := urls.GetString(i); ok { 111 | fmt.Fprintln(output.URLs, string(url)) 112 | } 113 | } 114 | 115 | for key := range d { 116 | extract(d[key], output) 117 | } 118 | } else if a, ok := o.(Array); ok { 119 | for i := range a { 120 | extract(a[i], output) 121 | } 122 | } 123 | } 124 | -------------------------------------------------------------------------------- /pdf/output.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | import ( 4 | "crypto/md5" 5 | "encoding/hex" 6 | "fmt" 7 | "io/ioutil" 8 | "os" 9 | "path" 10 | ) 11 | 12 | type Output struct { 13 | Commands *os.File 14 | Directory string 15 | Errors *os.File 16 | Files *os.File 17 | Javascript *os.File 18 | Raw *os.File 19 | Text *os.File 20 | URLs *os.File 21 | } 22 | 23 | func NewOutput(directory string) (output *Output, err error) { 24 | // create new output object 25 | output = &Output{} 26 | output.Directory = directory 27 | 28 | // create output dir 29 | os.RemoveAll(directory) 30 | os.MkdirAll(directory, 0755) 31 | 32 | // create commands file 33 | if output.Commands, err = os.Create(path.Join(directory, "commands.txt")); err != nil { 34 | return 35 | } 36 | 37 | // create errors file 38 | if output.Errors, err = os.Create(path.Join(directory, "errors.txt")); err != nil { 39 | return 40 | } 41 | 42 | // create manifest file 43 | if output.Files, err = os.Create(path.Join(directory, "files.txt")); err != nil { 44 | return 45 | } 46 | 47 | // create javascript file 48 | if output.Javascript, err = os.Create(path.Join(directory, "javascript.js")); err != nil { 49 | return 50 | } 51 | 52 | // create raw.pdf file 53 | if output.Raw, err = os.Create(path.Join(directory, "raw.pdf")); err != nil { 54 | return 55 | } 56 | 57 | // create text content file in output dir 58 | if output.Text, err = os.Create(path.Join(directory, "contents.txt")); err != nil { 59 | return 60 | } 61 | 62 | // create urls file 63 | if output.URLs, err = os.Create(path.Join(directory, "urls.txt")); err != nil { 64 | return 65 | } 66 | return 67 | } 68 | 69 | func (output *Output) Close() { 70 | if output.Commands != nil { 71 | output.Commands.Close() 72 | } 73 | if output.Errors != nil { 74 | output.Files.Close() 75 | } 76 | if output.Files != nil { 77 | output.Files.Close() 78 | } 79 | if output.Javascript != nil { 80 | output.Javascript.Close() 81 | } 82 | if output.Raw != nil { 83 | output.Raw.Close() 84 | } 85 | if output.Text != nil { 86 | output.Text.Close() 87 | } 88 | if output.URLs != nil { 89 | output.URLs.Close() 90 | } 91 | } 92 | 93 | func (output *Output) DumpFile(name string, data []byte) { 94 | // get md5 hash of the file 95 | hash := md5.New() 96 | hash.Write(data) 97 | md5sum := hex.EncodeToString(hash.Sum(nil)) 98 | 99 | // add to manifest 100 | fmt.Fprintf(output.Files, "%s:%s\n", md5sum, name) 101 | 102 | // write file data to file in extract dir 103 | ioutil.WriteFile(path.Join(output.Directory, md5sum), data, 0644) 104 | } 105 | 106 | func (output *Output) Error(message string) { 107 | if output.Errors != nil { 108 | fmt.Fprintln(output.Errors, message) 109 | } 110 | } 111 | -------------------------------------------------------------------------------- /pdf/page.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | import ( 4 | "bytes" 5 | "io" 6 | "strings" 7 | ) 8 | 9 | type Page Dictionary 10 | 11 | func (page Page) Extract(output *Output) { 12 | d := Dictionary(page) 13 | 14 | // load fonts 15 | font_map := map[string]*Font{} 16 | resources, _ := d.GetDictionary("Resources") 17 | fonts, _ := resources.GetDictionary("Font") 18 | for font := range fonts { 19 | font_info, _ := fonts.GetDictionary(font) 20 | font_map[font] = NewFont(font_info) 21 | } 22 | 23 | // get contents 24 | if contents, ok := d.GetStream("Contents"); ok { 25 | page.extract(output, font_map, contents) 26 | } else if contents_array, ok := d.GetArray("Contents"); ok { 27 | for i := range contents_array { 28 | if contents, ok := contents_array.GetStream(i); ok { 29 | page.extract(output, font_map, contents) 30 | } 31 | } 32 | } 33 | } 34 | 35 | func (page Page) extract(output *Output, font_map map[string]*Font, contents []byte) { 36 | // create parser for parsing contents 37 | page_parser := NewParser(bytes.NewReader(contents), nil) 38 | 39 | for { 40 | // read next command 41 | command, _, err := page_parser.ReadCommand() 42 | if err == ReadError { 43 | break 44 | } 45 | 46 | // start of text block 47 | if command == KEYWORD_TEXT { 48 | // initial font is none 49 | current_font := FontDefault 50 | 51 | for { 52 | command, operands, err := page_parser.ReadCommand() 53 | // stop if end of stream or end of text block 54 | if err == ReadError || command == KEYWORD_TEXT_END { 55 | break 56 | } 57 | 58 | // handle font changes 59 | if command == KEYWORD_TEXT_FONT { 60 | font_name, _ := operands.GetName(len(operands) - 2) 61 | if font, ok := font_map[font_name]; ok { 62 | current_font = font 63 | } else { 64 | current_font = FontDefault 65 | } 66 | } else if command == KEYWORD_TEXT_SHOW_1 || command == KEYWORD_TEXT_SHOW_2 || command == KEYWORD_TEXT_SHOW_3 { 67 | // decode text with current font font 68 | s, _ := operands.GetString(len(operands) - 1) 69 | io.WriteString(output.Text, current_font.Decode([]byte(s))) 70 | io.WriteString(output.Text, "\n") 71 | } else if command == KEYWORD_TEXT_POSITION { 72 | // decode positioned text with current font 73 | var sb strings.Builder 74 | a, _ := operands.GetArray(len(operands) - 1) 75 | for i := 0; i < len(a); i += 2 { 76 | s, _ := a.GetString(i) 77 | sb.WriteString(string(s)) 78 | } 79 | io.WriteString(output.Text, current_font.Decode([]byte(sb.String()))) 80 | io.WriteString(output.Text, "\n") 81 | } 82 | } 83 | } 84 | } 85 | } 86 | -------------------------------------------------------------------------------- /pdf/parser.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | import ( 4 | "bufio" 5 | "bytes" 6 | "io" 7 | "regexp" 8 | "sort" 9 | "strconv" 10 | "strings" 11 | ) 12 | 13 | var start_xref_scan_buffer_size int64 = 256 14 | var start_xref_regexp = regexp.MustCompile(`startxref\s*(\d+)\s*%%EOF`) 15 | var start_obj_regexp = regexp.MustCompile(`\d+([\s\x00]|(%[^\r\n]*))+\d+([\s\x00]|(%[^\r\n]*))+obj`) 16 | var xref_regexp = regexp.MustCompile(`xref`) 17 | var whitespace = []byte("\x00\t\n\f\r ") 18 | var delimiters = []byte("()<>[]/%") 19 | 20 | type Parser struct { 21 | *bufio.Reader 22 | seeker io.ReadSeeker 23 | Xref map[int]*XrefEntry 24 | trailer Dictionary 25 | security_handler *SecurityHandler 26 | output *Output 27 | } 28 | 29 | func NewParser(readSeeker io.ReadSeeker, output *Output) *Parser { 30 | return &Parser{bufio.NewReader(readSeeker), readSeeker, map[int]*XrefEntry{}, Dictionary{}, NewSecurityHandler(), output} 31 | } 32 | 33 | func (parser *Parser) Load(password string) error { 34 | // find location of all xref tables 35 | xref_offsets := parser.findXrefOffsets() 36 | 37 | // find location of all objects 38 | objects := parser.findObjects() 39 | 40 | // add xref stream offsets to xref offsets then sort first to last 41 | for _, object := range objects { 42 | if object.IsXrefStream { 43 | xref_offsets = append(xref_offsets, object.Offset) 44 | } 45 | } 46 | sort.Slice(xref_offsets, func(i, j int) bool { return xref_offsets[i] < xref_offsets[j] }) 47 | 48 | // add start xref offset as last entry in xref_offsets so it overrides xref entries 49 | if start_xref_offset, ok := parser.getStartXrefOffset(); ok { 50 | xref_offsets = append(xref_offsets, start_xref_offset) 51 | } 52 | 53 | // load all xrefs 54 | for i := range xref_offsets { 55 | parser.loadXref(xref_offsets[i], map[int64]interface{}{}) 56 | } 57 | 58 | // repair broken and missing xref entries 59 | for object_number, object := range objects { 60 | if xref_entry, ok := parser.Xref[object_number]; ok { 61 | // replace xref entry if it does not point to an object or points to the wrong object 62 | parser.Seek(xref_entry.Offset, io.SeekStart) 63 | if n, _, ok := parser.ReadObjectHeader(); ok || n != object_number { 64 | xref_entry.Offset = object.Offset 65 | } 66 | } else { 67 | // add missing object to xref 68 | parser.Xref[object_number] = object 69 | } 70 | } 71 | 72 | // setup security handler if pdf is encrypted 73 | if encrypt, ok := parser.trailer["Encrypt"]; ok { 74 | // make sure we don't decrypt the encryption dictionary 75 | if ref, ok := encrypt.(*Reference); ok { 76 | if xref_entry, ok := parser.Xref[ref.Number]; ok { 77 | xref_entry.IsEncrypted = false 78 | } 79 | } 80 | 81 | // set encryption password 82 | if err := parser.SetPassword(password); err != nil { 83 | return err 84 | } 85 | } 86 | 87 | return nil 88 | } 89 | 90 | func (parser *Parser) SetPassword(password string) error { 91 | return parser.security_handler.Init([]byte(password), parser.trailer) 92 | } 93 | 94 | // FindXrefOffsets locates all xref tables 95 | func (parser *Parser) findXrefOffsets() []int64 { 96 | offsets := []int64{} 97 | 98 | // jump to start of file 99 | offset, _ := parser.Seek(0, io.SeekStart) 100 | 101 | for { 102 | // scan for xref table marker 103 | index := xref_regexp.FindReaderIndex(parser) 104 | if index == nil { 105 | break 106 | } 107 | 108 | // add location to offsets 109 | offsets = append(offsets, offset + int64(index[0])) 110 | 111 | // seek to end of xref marker 112 | offset, _ = parser.Seek(offset + int64(index[1]), io.SeekStart) 113 | } 114 | 115 | return offsets 116 | } 117 | 118 | // FindObjects locates all object markers 119 | func (parser *Parser) findObjects() map[int]*XrefEntry { 120 | // create xref map 121 | objects := map[int]*XrefEntry{} 122 | 123 | // jump to start of file 124 | offset, _ := parser.Seek(0, io.SeekStart) 125 | 126 | for { 127 | // scan for object start marker 128 | index := start_obj_regexp.FindReaderIndex(parser) 129 | if index == nil { 130 | break 131 | } 132 | 133 | // seek to start of object 134 | parser.Seek(offset + int64(index[0]), io.SeekStart) 135 | 136 | // get object number, generation 137 | n, g, _ := parser.ReadObjectHeader() 138 | 139 | // add xref entry 140 | objects[n] = NewXrefEntry(offset + int64(index[0]), g, XrefTypeIndirectObject) 141 | 142 | // determine if object is xref stream 143 | d := parser.ReadDictionary(noDecryptor) 144 | if t, ok := d.GetName("Type"); ok && t == "XRef" { 145 | objects[n].IsXrefStream = true 146 | objects[n].IsEncrypted = false 147 | } 148 | 149 | // seek to end of object start marker 150 | offset, _ = parser.Seek(offset + int64(index[1]), io.SeekStart) 151 | } 152 | 153 | return objects 154 | } 155 | 156 | func (parser *Parser) getStartXrefOffset() (int64, bool) { 157 | // start reading from the end of the file 158 | offset, _ := parser.Seek(0, io.SeekEnd) 159 | 160 | // dont start past begining of file 161 | offset -= start_xref_scan_buffer_size 162 | if offset < 0 { 163 | offset = 0 164 | } 165 | 166 | // read in buffer at offset 167 | buffer := make([]byte, start_xref_scan_buffer_size) 168 | parser.Seek(offset, io.SeekStart) 169 | parser.Read(buffer) 170 | 171 | // check for start xref 172 | matches := start_xref_regexp.FindAllSubmatch(buffer, -1) 173 | if matches == nil { 174 | return 0, false 175 | } 176 | 177 | // convert match to int64 178 | start_xref_offset, err := strconv.ParseInt(string(matches[len(matches)-1][1]), 10, 64) 179 | if err != nil { 180 | return 0, false 181 | } 182 | 183 | // return the start xref offset 184 | return start_xref_offset, true 185 | } 186 | 187 | func (parser *Parser) loadXref(offset int64, offsets map[int64]interface{}) { 188 | // dont load same xref twice 189 | if _, ok := offsets[offset]; !ok { 190 | offsets[offset] = nil 191 | 192 | // if xref is a table 193 | parser.Seek(offset, io.SeekStart) 194 | if keyword := parser.ReadKeyword(); keyword == KEYWORD_XREF { 195 | parser.loadXrefTable(offsets) 196 | } else { 197 | // if xref is a stream 198 | parser.Seek(offset, io.SeekStart) 199 | if n, g, ok := parser.ReadObjectHeader(); ok { 200 | // prevent decrypting xref streams 201 | parser.Xref[n] = NewXrefEntry(offset, g, XrefTypeIndirectObject) 202 | parser.Xref[n].IsEncrypted = false 203 | 204 | // read the xref object 205 | parser.loadXrefStream(n, offsets) 206 | } 207 | } 208 | } 209 | } 210 | 211 | func (parser *Parser) loadXrefTable(offsets map[int64]interface{}) { 212 | // read all xref entries 213 | xrefs := map[int]*XrefEntry{} 214 | for { 215 | // get subsection start 216 | subsection_start, ok := parser.ReadInt() 217 | if !ok { 218 | break 219 | } 220 | 221 | // get subsection length 222 | subsection_length, ok := parser.ReadInt() 223 | if !ok { 224 | break 225 | } 226 | 227 | // load each object in xref subsection 228 | for i := 0; i < subsection_length; i++ { 229 | // find xref entry offset 230 | offset, ok := parser.ReadInt64() 231 | if !ok { 232 | break 233 | } 234 | 235 | // find xref entry generation 236 | generation, ok := parser.ReadInt() 237 | if !ok { 238 | break 239 | } 240 | 241 | // find xref entry in use flag 242 | flag := parser.ReadKeyword() 243 | xref_type := XrefTypeFreeObject 244 | if flag == KEYWORD_N { 245 | xref_type = XrefTypeIndirectObject 246 | } 247 | 248 | // determine object number from subsection start 249 | object_number := subsection_start + i 250 | 251 | // add the object to xrefs 252 | xrefs[object_number] = NewXrefEntry(offset, generation, xref_type) 253 | } 254 | } 255 | 256 | // read trailer keyword 257 | parser.ReadKeyword(); 258 | 259 | // read in trailer dictionary 260 | trailer := parser.ReadDictionary(noDecryptor); 261 | 262 | // load previous xref section if it exists 263 | if prev, ok := trailer.GetInt64("Prev"); ok { 264 | parser.loadXref(prev, offsets) 265 | } 266 | 267 | // merge trailer 268 | for key, value := range trailer { 269 | parser.trailer[key] = value 270 | } 271 | 272 | // merge xrefs 273 | for key, value := range xrefs { 274 | parser.Xref[key] = value 275 | } 276 | } 277 | 278 | func (parser *Parser) loadXrefStream(n int, offsets map[int64]interface{}) { 279 | xref_stream_offset := parser.CurrentOffset() 280 | 281 | // Get the xref stream object 282 | object := parser.GetObject(n) 283 | 284 | // get the stream dictionary which is also the trailer dictionary 285 | trailer, ok := object.Value.(Dictionary) 286 | if !ok { 287 | return 288 | } 289 | 290 | // load previous xref section if it exists 291 | if prev, ok := trailer.GetInt64("Prev"); ok { 292 | parser.loadXref(prev, offsets) 293 | } 294 | 295 | // merge trailer 296 | for key, value := range trailer { 297 | parser.trailer[key] = value 298 | } 299 | 300 | // get the index and width arrays 301 | index, ok := trailer.GetArray("Index") 302 | if !ok { 303 | // if there is no Index field then use default of [0 Size] 304 | size, ok := trailer.GetNumber("Size") 305 | if !ok { 306 | return 307 | } 308 | index = Array{Number(0), size} 309 | } 310 | width, ok := trailer.GetArray("W") 311 | if !ok { 312 | return 313 | } 314 | 315 | // get widths of each field 316 | type_width, ok := width.GetInt(0) 317 | if !ok { 318 | return 319 | } 320 | offset_width, ok := width.GetInt(1) 321 | if !ok { 322 | return 323 | } 324 | generation_width, ok := width.GetInt(2) 325 | if !ok { 326 | return 327 | } 328 | 329 | // parse xref subsections 330 | data_reader := bytes.NewReader(object.Stream) 331 | for i := 0; i < len(index) - 1; i += 2 { 332 | // get subsection start and length 333 | subsection_start, ok := index.GetInt(i) 334 | if !ok { 335 | return 336 | } 337 | subsection_length, ok := index.GetInt(i + 1) 338 | if !ok { 339 | return 340 | } 341 | 342 | // read in each entry in subsection 343 | for j := 0; j < subsection_length; j++ { 344 | xref_type, ok := ReadInt(data_reader, type_width) 345 | if !ok { 346 | return 347 | } 348 | offset, ok := ReadInt64(data_reader, offset_width) 349 | if !ok { 350 | return 351 | } 352 | generation, ok := ReadInt(data_reader, generation_width) 353 | if !ok { 354 | return 355 | } 356 | 357 | // determine object number from subsection_start 358 | object_number := subsection_start + j 359 | 360 | // add the object to the xrefs 361 | parser.Xref[object_number] = NewXrefEntry(offset, generation, xref_type) 362 | } 363 | } 364 | 365 | // dont decrypt xref streams 366 | parser.Xref[object.Number] = NewXrefEntry(xref_stream_offset, object.Generation, XrefTypeIndirectObject) 367 | parser.Xref[object.Number].IsEncrypted = false 368 | } 369 | 370 | func (parser *Parser) GetObject(number int) *IndirectObject { 371 | object := NewIndirectObject(number) 372 | 373 | if xref_entry, ok := parser.Xref[number]; ok { 374 | if xref_entry.Type == XrefTypeIndirectObject { 375 | // set generation number 376 | object.Generation = xref_entry.Generation 377 | 378 | // seek to start of object 379 | parser.Seek(xref_entry.Offset, io.SeekStart) 380 | 381 | // skip object header 382 | parser.ReadObjectHeader() 383 | 384 | // initialize string decryption filter 385 | var string_filter CryptFilter = noFilter 386 | if parser.security_handler != nil && xref_entry.IsEncrypted { 387 | string_filter = parser.security_handler.string_filter 388 | } 389 | string_decryptor := string_filter.NewDecryptor(number, object.Generation) 390 | 391 | // get the value of the object 392 | object.Value, _ = parser.ReadObject(string_decryptor) 393 | 394 | // get next keyword 395 | if keyword := parser.ReadKeyword(); keyword == KEYWORD_STREAM { 396 | // get stream dictionary 397 | d, ok := object.Value.(Dictionary) 398 | if !ok { 399 | d = Dictionary{} 400 | } 401 | 402 | // create list of decode filters 403 | filter_list, ok := d.GetArray("Filter") 404 | if !ok { 405 | if filter, ok := d.GetName("Filter"); ok { 406 | filter_list = Array{Name(filter)} 407 | } else { 408 | filter_list = Array{} 409 | } 410 | } 411 | 412 | // create list of decode parms 413 | decode_parms_list, ok := d.GetArray("DecodeParms") 414 | if !ok { 415 | if decode_parms, ok := d.GetDictionary("DecodeParms"); ok { 416 | decode_parms_list = Array{decode_parms} 417 | } else { 418 | decode_parms_list = Array{} 419 | } 420 | } 421 | 422 | // create a stream decryptor 423 | var crypt_filter CryptFilter = noFilter 424 | if parser.security_handler != nil && xref_entry.IsEncrypted { 425 | // use stream filter by default 426 | crypt_filter = parser.security_handler.stream_filter 427 | 428 | // use embedded file filter if object is an embedded file 429 | if t, ok := d.GetName("Type"); ok && t == "EmbeddedFile" { 430 | crypt_filter = parser.security_handler.file_filter 431 | } 432 | 433 | // handle crypt filter override 434 | if len(filter_list) > 0 { 435 | if filter, _ := filter_list.GetName(0); filter == "Crypt" { 436 | decode_parms, _ := decode_parms_list.GetDictionary(0) 437 | filter_name, ok := decode_parms.GetName("Name") 438 | if !ok { 439 | filter_name = "Identity" 440 | } 441 | if cf, exists := parser.security_handler.crypt_filters[filter_name]; exists { 442 | crypt_filter = cf 443 | } 444 | filter_list = filter_list[1:] 445 | if len(decode_parms_list) > 0 { 446 | decode_parms_list = decode_parms_list[1:] 447 | } 448 | } 449 | } 450 | } 451 | stream_decryptor := crypt_filter.NewDecryptor(number, xref_entry.Generation) 452 | 453 | // read the stream 454 | object.Stream = parser.ReadStream(stream_decryptor, filter_list, decode_parms_list) 455 | } 456 | } 457 | } 458 | 459 | return object 460 | } 461 | 462 | func (parser *Parser) Seek(offset int64, whence int) (int64, error) { 463 | parser.Reset(parser.seeker) 464 | return parser.seeker.Seek(offset, whence) 465 | } 466 | 467 | func (parser *Parser) CurrentOffset() int64 { 468 | offset, err := parser.seeker.Seek(0, io.SeekCurrent) 469 | if err != nil { 470 | return 0 471 | } 472 | return offset - int64(parser.Buffered()) 473 | } 474 | 475 | // ReadObjectHeader reads an object header (10 0 obj) from the current position and returns the object number and generation 476 | func (parser *Parser) ReadObjectHeader() (int, int, bool) { 477 | // read object number 478 | number, ok := parser.ReadInt() 479 | if !ok { 480 | return number, 0, false 481 | } 482 | 483 | // read object generation 484 | generation, ok := parser.ReadInt() 485 | if !ok { 486 | return number, generation, false 487 | } 488 | 489 | // read object start marker 490 | if keyword := parser.ReadKeyword(); keyword != KEYWORD_OBJ { 491 | return number, generation, false 492 | } 493 | return number, generation, true 494 | } 495 | 496 | func (parser *Parser) ReadObject(decryptor Decryptor) (Object, error) { 497 | // consume any leading whitespace/comments 498 | parser.consumeWhitespace() 499 | 500 | // peek at next 2 bytes to determine object type 501 | b, _ := parser.Peek(2) 502 | if len(b) == 0 { 503 | return KEYWORD_NULL, ReadError 504 | } 505 | 506 | // handle names 507 | if b[0] == '/' { 508 | return parser.ReadName(), nil 509 | } 510 | 511 | // handle arrays 512 | if b[0] == '[' { 513 | return parser.ReadArray(decryptor), nil 514 | } 515 | if b[0] == ']' { 516 | parser.Discard(1) 517 | return KEYWORD_NULL, EndOfArray 518 | } 519 | 520 | // handle strings 521 | if b[0] == '(' { 522 | return parser.ReadString(decryptor), nil 523 | } 524 | if b[0] == ')' { 525 | parser.Discard(1) 526 | return KEYWORD_NULL, EndOfString 527 | } 528 | 529 | // handle dictionaries 530 | if string(b) == "<<" { 531 | return parser.ReadDictionary(decryptor), nil 532 | } 533 | if string(b) == ">>" { 534 | parser.Discard(2) 535 | return KEYWORD_NULL, EndOfDictionary 536 | } 537 | 538 | // handle hex strings 539 | if b[0] == '<' { 540 | return parser.ReadHexString(decryptor), nil 541 | } 542 | if b[0] == '>' { 543 | parser.Discard(1) 544 | return KEYWORD_NULL, EndOfHexString 545 | } 546 | 547 | // handle numbers and references 548 | if (b[0] >= '0' && b[0] <= '9') || b[0] == '+' || b[0] == '-' || b[0] == '.' { 549 | number := parser.ReadNumber() 550 | 551 | // save offset so we can revert if this is not a reference 552 | offset := parser.CurrentOffset() 553 | 554 | // if generation number does not follow then revert to saved offset and return number 555 | generation, ok := parser.ReadInt() 556 | if !ok { 557 | parser.Seek(offset, io.SeekStart) 558 | return number, nil 559 | } 560 | 561 | // if not a reference then revert to saved offset and return the number 562 | if keyword := parser.ReadKeyword(); keyword != KEYWORD_R { 563 | parser.Seek(offset, io.SeekStart) 564 | return number, nil 565 | } 566 | 567 | // return the reference 568 | return NewReference(parser, int(number), generation), nil 569 | } 570 | 571 | // handle keywords 572 | return parser.ReadKeyword(), nil 573 | } 574 | 575 | func (parser *Parser) ReadArray(decryptor Decryptor) Array { 576 | // consume any leading whitespace/comments 577 | parser.consumeWhitespace() 578 | 579 | // create a new array 580 | array := Array{} 581 | 582 | // read start of array marker 583 | b, err := parser.ReadByte() 584 | if err != nil || b != '[' { 585 | return array 586 | } 587 | 588 | // read in elements and append to array 589 | for { 590 | element, err := parser.ReadObject(decryptor) 591 | if err == ReadError { 592 | parser.log_error(UnclosedArray) 593 | break 594 | } 595 | if err == EndOfArray { 596 | break 597 | } 598 | array = append(array, element) 599 | } 600 | 601 | // return array 602 | return array 603 | } 604 | 605 | func (parser *Parser) ReadCommand() (Keyword, Array, error) { 606 | // read in operands until command keyword 607 | operands := Array{} 608 | for { 609 | operand, err := parser.ReadObject(noDecryptor) 610 | if err != nil { 611 | return KEYWORD_NULL, operands, err 612 | } 613 | if keyword, ok := operand.(Keyword); ok { 614 | return keyword, operands, nil 615 | } 616 | operands = append(operands, operand) 617 | } 618 | } 619 | 620 | func (parser *Parser) ReadDictionary(decryptor Decryptor) Dictionary { 621 | // consume any leading whitespace/comments 622 | parser.consumeWhitespace() 623 | 624 | // create new dictionary 625 | dictionary := Dictionary{} 626 | 627 | // read start of dictionary markers 628 | b := make([]byte, 2) 629 | _, err := parser.Read(b) 630 | if err != nil || string(b) != "<<" { 631 | return dictionary 632 | } 633 | 634 | // parse all key value pairs 635 | for { 636 | // read next object 637 | name, err := parser.ReadObject(decryptor) 638 | if err == ReadError { 639 | parser.log_error(UnclosedDictionary) 640 | break 641 | } 642 | if err == EndOfDictionary { 643 | break 644 | } 645 | 646 | // skip if not a name 647 | key, ok := name.(Name) 648 | if !ok { 649 | parser.log_error(InvalidDictionaryKeyType) 650 | continue 651 | } 652 | 653 | // get value 654 | value, err := parser.ReadObject(decryptor) 655 | if err == ReadError || err == EndOfDictionary { 656 | parser.log_error(MissingDictionaryValue) 657 | break 658 | } 659 | 660 | // add key value pair to dictionary 661 | dictionary[string(key)] = value 662 | } 663 | return dictionary 664 | } 665 | 666 | func (parser *Parser) ReadHexString(decryptor Decryptor) String { 667 | // consume any leading whitespace/comments 668 | parser.consumeWhitespace() 669 | 670 | // create new string builder 671 | var s strings.Builder 672 | 673 | // read start of hex string marker 674 | b, err := parser.ReadByte() 675 | if err != nil || b != '<' { 676 | return String(s.String()) 677 | } 678 | 679 | // read hex code pairs until end of hex string or file 680 | for { 681 | code := []byte{'0', '0'} 682 | for i := 0; i < 2; { 683 | parser.consumeWhitespace() 684 | b, err := parser.ReadByte() 685 | if err != nil || b == '>' { 686 | if err != nil { 687 | parser.log_error(UnclosedHexString) 688 | } 689 | if i > 0 { 690 | val, _ := strconv.ParseUint(string(code), 16, 8) 691 | s.WriteByte(byte(val)) 692 | } 693 | s_data := []byte(s.String()) 694 | decryptor.Decrypt(s_data) 695 | return String(s_data) 696 | } 697 | if !IsHex(b) { 698 | parser.log_error(InvalidHexStringChar) 699 | continue 700 | } 701 | code[i] = b 702 | i++ 703 | } 704 | val, _ := strconv.ParseUint(string(code), 16, 8) 705 | s.WriteByte(byte(val)) 706 | } 707 | } 708 | 709 | func (parser *Parser) ReadInt() (int, bool) { 710 | value, ok := parser.ReadInt64() 711 | return int(value), ok 712 | } 713 | 714 | func (parser *Parser) ReadInt64() (int64, bool) { 715 | // consume any leading whitespace/comments 716 | parser.consumeWhitespace() 717 | 718 | // create a new number object 719 | value := int64(0) 720 | 721 | // ensure first byte is a digit 722 | b, err := parser.ReadByte() 723 | if err != nil || b < '0' || b > '9' { 724 | parser.UnreadByte() 725 | return value, false 726 | } 727 | 728 | // add digit to value 729 | value = value * 10 + int64(b - '0') 730 | 731 | // parse int part 732 | for { 733 | b, err = parser.ReadByte() 734 | if err != nil { 735 | break 736 | } 737 | 738 | // stop if no numeric char 739 | if b < '0' || b > '9' { 740 | parser.UnreadByte() 741 | break 742 | } 743 | 744 | // add digit to value 745 | value = value * 10 + int64(b - '0') 746 | } 747 | 748 | return value, true 749 | } 750 | 751 | func (parser *Parser) ReadKeyword() Keyword { 752 | // consume any leading whitespace/comments 753 | parser.consumeWhitespace() 754 | 755 | // build keyword 756 | var keyword strings.Builder 757 | 758 | for { 759 | // read in the next byte 760 | b, err := parser.ReadByte() 761 | if err != nil { 762 | break 763 | } 764 | 765 | // stop if not keyword character 766 | if bytes.IndexByte(whitespace, b) >= 0 || bytes.IndexByte(delimiters, b) >= 0 { 767 | parser.UnreadByte() 768 | break 769 | } 770 | 771 | // add character to keyword 772 | keyword.WriteByte(b) 773 | } 774 | 775 | // interpret keyword value 776 | return NewKeyword(keyword.String()) 777 | } 778 | 779 | func (parser *Parser) ReadName() Name { 780 | // consume any leading whitespace/comments 781 | parser.consumeWhitespace() 782 | 783 | // build name 784 | var name strings.Builder 785 | 786 | // read start of name marker 787 | b, err := parser.ReadByte() 788 | if err != nil || b != '/' { 789 | return Name(name.String()) 790 | } 791 | 792 | for { 793 | // read in the next byte 794 | b, err = parser.ReadByte() 795 | if err != nil { 796 | return Name(name.String()) 797 | } 798 | 799 | // if the next byte is whitespace or delimiter then unread it and return the name 800 | if bytes.IndexByte(delimiters, b) >= 0 || bytes.IndexByte(whitespace, b) >= 0 { 801 | parser.UnreadByte() 802 | break 803 | } 804 | 805 | // if next byte is the start of a hex character code 806 | if b == '#' { 807 | // read in the hex code 808 | code := []byte{'0', '0'} 809 | for i := 0; i < 2; i++ { 810 | b, err = parser.ReadByte() 811 | if err != nil { 812 | break 813 | } 814 | if !IsHex(b) { 815 | parser.log_error(InvalidNameEscapeChar) 816 | parser.UnreadByte() 817 | break 818 | } 819 | code[i] = b 820 | } 821 | 822 | // convert the hex code to a byte 823 | val, _ := strconv.ParseUint(string(code), 16, 8) 824 | b = byte(val) 825 | 826 | // if b did not need to be escaped 827 | if b >= '!' && b <= '~' && b != '#' && bytes.IndexByte(delimiters, b) < 0 { 828 | parser.log_error(UnnecessaryEscapeName) 829 | } 830 | } 831 | 832 | // add byte to name 833 | name.WriteByte(b) 834 | } 835 | 836 | return Name(name.String()) 837 | } 838 | 839 | func (parser *Parser) ReadNumber() Number { 840 | // consume any leading whitespace/comments 841 | parser.consumeWhitespace() 842 | 843 | // create a new number object 844 | var number Number 845 | isReal := false 846 | isNegative := false 847 | 848 | // process first byte 849 | b, err := parser.ReadByte() 850 | if err != nil { 851 | return number 852 | } 853 | if b == '-' { 854 | isNegative = true 855 | } else if b >= '0' && b <= '9' { 856 | number = Number(float64(number) * 10 + float64(b - '0')) 857 | } else if b == '.' { 858 | isReal = true 859 | } else if b != '+' { 860 | parser.UnreadByte() 861 | return number 862 | } 863 | 864 | // parse int part 865 | for !isReal { 866 | b, err = parser.ReadByte() 867 | if err != nil { 868 | break 869 | } 870 | 871 | if b >= '0' && b <= '9' { 872 | number = Number(float64(number) * 10 + float64(b - '0')) 873 | } else if b == '.' { 874 | isReal = true 875 | } else { 876 | parser.UnreadByte() 877 | break 878 | } 879 | } 880 | 881 | // parse real part 882 | if isReal { 883 | for i := 1; true; i++ { 884 | b, err = parser.ReadByte() 885 | if err != nil { 886 | break 887 | } 888 | 889 | if b >= '0' && b <= '9' { 890 | number = Number(float64(number) + float64(b - '0') / (10 * float64(i))) 891 | } else { 892 | parser.UnreadByte() 893 | break 894 | } 895 | } 896 | } 897 | 898 | // make negative if first byte was a minus sign 899 | if isNegative { 900 | number = -number 901 | } 902 | 903 | // return the number 904 | return number 905 | } 906 | 907 | func (parser *Parser) ReadStream(decryptor Decryptor, filter_list Array, decode_parms_list Array) []byte { 908 | // create buffers for stream data 909 | stream_data := bytes.NewBuffer([]byte{}) 910 | 911 | // read until new line 912 | for { 913 | b, err := parser.ReadByte() 914 | if err != nil { 915 | return stream_data.Bytes() 916 | } 917 | 918 | // if new line then we are at the start of the stream data 919 | if b == '\n' { 920 | break 921 | } 922 | 923 | // if carriage return check if next byte is line feed 924 | if b == '\r' { 925 | b, err := parser.ReadByte() 926 | if err != nil { 927 | return stream_data.Bytes() 928 | } 929 | // if not new line then put it back cause it is part of the stream data 930 | if b != '\n' { 931 | parser.UnreadByte() 932 | } 933 | break 934 | } 935 | } 936 | 937 | // read first 9 bytes to get started 938 | end_buff := bytes.NewBuffer([]byte{}) 939 | buff := make([]byte, 9) 940 | bytes_read, _ := parser.Read(buff) 941 | if bytes_read > 0 { 942 | end_buff.Write(buff[:bytes_read]) 943 | } 944 | 945 | // read in stream data until endstream marker 946 | for { 947 | if end_buff.String() == "endstream" { 948 | // truncate last new line from stream_data and stop reading stream data 949 | l := stream_data.Len() 950 | if l-1 >= 0 && stream_data.Bytes()[l-1] == '\n' { 951 | if l-2 >= 0 && stream_data.Bytes()[l-2] == '\r' { 952 | stream_data.Truncate(l-2) 953 | } else { 954 | stream_data.Truncate(l-1) 955 | } 956 | } else if l-1 >= 0 && stream_data.Bytes()[l-1] == '\r' { 957 | stream_data.Truncate(l-1) 958 | } 959 | break 960 | } 961 | 962 | // add first byte of end_buff to stream_data 963 | b, err := end_buff.ReadByte() 964 | if err != nil { 965 | break 966 | } 967 | stream_data.WriteByte(b) 968 | 969 | // add next byte of stream to end_buff 970 | b, err = parser.ReadByte() 971 | if err != nil { 972 | parser.log_error(UnclosedStream) 973 | stream_data.Write(end_buff.Bytes()) 974 | break 975 | } 976 | end_buff.WriteByte(b) 977 | } 978 | 979 | // decrypt stream 980 | stream_data_bytes := stream_data.Bytes() 981 | decryptor.Decrypt(stream_data_bytes) 982 | 983 | // decode stream 984 | for i := 0; i < len(filter_list); i++ { 985 | filter, _ := filter_list.GetName(i) 986 | decode_parms, _ := decode_parms_list.GetDictionary(i) 987 | stream_data_bytes = DecodeStream(filter, stream_data_bytes, decode_parms) 988 | } 989 | 990 | // return the decrypted and decoded stream 991 | return stream_data_bytes 992 | } 993 | 994 | func (parser *Parser) ReadString(decryptor Decryptor) String { 995 | // consume any leading whitespace/comments 996 | parser.consumeWhitespace() 997 | 998 | // create new string builder 999 | var s strings.Builder 1000 | 1001 | // read start of string marker 1002 | b, err := parser.ReadByte() 1003 | if err != nil { 1004 | return String(s.String()) 1005 | } 1006 | if b != '(' { 1007 | return String(s.String()) 1008 | } 1009 | 1010 | // find balanced closing bracket 1011 | for open_parens := 1; true; { 1012 | // read next byte 1013 | b, err = parser.ReadByte() 1014 | if err != nil { 1015 | parser.log_error(UnclosedString) 1016 | s_data := []byte(s.String()) 1017 | decryptor.Decrypt(s_data) 1018 | return String(s_data) 1019 | } 1020 | 1021 | // if this is the start of an escape sequence 1022 | if b == '\\' { 1023 | // read next byte 1024 | b, err = parser.ReadByte() 1025 | if err != nil { 1026 | parser.log_error(UnclosedStringEscape) 1027 | s.WriteByte('\\') 1028 | s_data := []byte(s.String()) 1029 | decryptor.Decrypt(s_data) 1030 | return String(s_data) 1031 | } 1032 | 1033 | // ignore escaped line breaks \n or \r or \r\n 1034 | if b == '\n' { 1035 | continue 1036 | } 1037 | if b == '\r' { 1038 | // read next byte 1039 | b, err = parser.ReadByte() 1040 | if err != nil { 1041 | parser.log_error(UnclosedStringEscape) 1042 | s_data := []byte(s.String()) 1043 | decryptor.Decrypt(s_data) 1044 | return String(s_data) 1045 | } 1046 | // if byte is not a new line then unread it 1047 | if b != '\n' { 1048 | parser.UnreadByte() 1049 | } 1050 | continue 1051 | } 1052 | 1053 | // special escape values 1054 | if b == 'n' { 1055 | b = '\n' 1056 | } else if b == 'r' { 1057 | b = '\r' 1058 | } else if b == 't' { 1059 | b = '\t' 1060 | } else if b == 'b' { 1061 | b = '\b' 1062 | } else if b == 'f' { 1063 | b = '\f' 1064 | } 1065 | 1066 | // if this is the start of an octal character code 1067 | if b >= '0' && b <= '7' { 1068 | // add byte to character code 1069 | code := bytes.NewBuffer([]byte{b}) 1070 | 1071 | // add at most 2 more bytes to code 1072 | for i := 0; i < 2; i++ { 1073 | // read next byte 1074 | b, err = parser.ReadByte() 1075 | if err != nil { 1076 | parser.log_error(UnclosedStringOctal) 1077 | break 1078 | } 1079 | 1080 | // if next byte is not part of the octal code 1081 | if b < '0' || b > '7' { 1082 | // unread the byte and stop collecting code 1083 | parser.UnreadByte() 1084 | break 1085 | } 1086 | 1087 | // add byte to code 1088 | code.WriteByte(b) 1089 | } 1090 | 1091 | // convert code into byte 1092 | val, err := strconv.ParseUint(string(code.Bytes()), 8, 8) 1093 | if err != nil { 1094 | // octal code is too large so ignore last byte 1095 | parser.log_error(InvalidOctal) 1096 | parser.UnreadByte() 1097 | val, _ = strconv.ParseUint(string(code.Bytes()[:code.Len()-1]), 8, 8) 1098 | } 1099 | b = byte(val) 1100 | 1101 | // if b did not need to be escaped 1102 | if b >= '!' && b <= '~' && b != '\\' && b != '(' && b != ')' { 1103 | parser.log_error(UnnecessaryEscapeString) 1104 | } 1105 | } 1106 | 1107 | // add byte to string and continue 1108 | s.WriteByte(b) 1109 | continue 1110 | } 1111 | 1112 | // keep track of number of open parens 1113 | if b == '(' { 1114 | open_parens++ 1115 | } else if b == ')' { 1116 | open_parens-- 1117 | } 1118 | 1119 | // stop if last paren was read 1120 | if open_parens == 0 { 1121 | break 1122 | } 1123 | 1124 | // add byte to string 1125 | s.WriteByte(b) 1126 | } 1127 | 1128 | // return string 1129 | s_data := []byte(s.String()) 1130 | decryptor.Decrypt(s_data) 1131 | return String(s_data) 1132 | } 1133 | 1134 | // consumeWhitespace reads until end of whitespace/comments 1135 | func (parser *Parser) consumeWhitespace() { 1136 | for { 1137 | // get next byte 1138 | b, err := parser.ReadByte() 1139 | if err != nil { 1140 | return 1141 | } 1142 | 1143 | // consume comments and whitespace 1144 | if b == '%' { 1145 | parser.consumeComment() 1146 | } else if bytes.IndexByte(whitespace, b) < 0 { 1147 | parser.UnreadByte() 1148 | return 1149 | } 1150 | } 1151 | } 1152 | 1153 | func (parser *Parser) consumeComment() { 1154 | for { 1155 | // get next byte 1156 | b, err := parser.ReadByte() 1157 | if err != nil { 1158 | return 1159 | } 1160 | 1161 | // stop on line feed 1162 | if b == '\n' { 1163 | return 1164 | } 1165 | 1166 | // stop on carriage return 1167 | if b == '\r' { 1168 | // consume optional line feed 1169 | b, err := parser.ReadByte() 1170 | if err != nil { 1171 | return 1172 | } 1173 | if b != '\n' { 1174 | parser.UnreadByte() 1175 | } 1176 | return 1177 | } 1178 | } 1179 | } 1180 | 1181 | func (parser *Parser) log_error(message string) { 1182 | if parser.output != nil { 1183 | parser.output.Error(message) 1184 | } 1185 | } 1186 | -------------------------------------------------------------------------------- /pdf/pdf.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | import ( 4 | "fmt" 5 | "os" 6 | ) 7 | 8 | func Parse(file_path string, password string, output_dir string) error { 9 | // open the pdf 10 | file, err := os.Open(file_path) 11 | if err != nil { 12 | return err 13 | } 14 | defer file.Close() 15 | 16 | // create output directory and files 17 | output, err := NewOutput(output_dir) 18 | defer output.Close() 19 | if err != nil { 20 | return err 21 | } 22 | 23 | // create a new parser 24 | parser := NewParser(file, output) 25 | 26 | // load the pdf 27 | Debug("Loading xref") 28 | if err := parser.Load(password); err != nil { 29 | return err 30 | } 31 | 32 | // extract and dump all objects 33 | for object_number, xref_entry := range parser.Xref { 34 | if xref_entry.Type == XrefTypeIndirectObject { 35 | Debug("Extracting object %d", object_number) 36 | object := parser.GetObject(object_number) 37 | object.Extract(output) 38 | fmt.Fprintln(output.Raw, object.String()) 39 | } 40 | } 41 | 42 | return nil 43 | } 44 | -------------------------------------------------------------------------------- /pdf/reference.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | import ( 4 | "fmt" 5 | "io" 6 | ) 7 | 8 | type Reference struct { 9 | parser *Parser 10 | Number int 11 | Generation int 12 | } 13 | 14 | func NewReference(parser *Parser, number int, generation int) *Reference { 15 | return &Reference{parser, number, generation} 16 | } 17 | 18 | func (reference *Reference) String() string { 19 | return fmt.Sprintf("%d %d R", reference.Number, reference.Generation) 20 | } 21 | 22 | func (reference *Reference) Resolve() Object { 23 | // save current offset so we can come back 24 | current_offset := reference.parser.CurrentOffset() 25 | 26 | // resolve the referenced object value 27 | object := reference.resolve(map[int]interface{}{}) 28 | 29 | // revert offset 30 | reference.parser.Seek(current_offset, io.SeekStart) 31 | 32 | // return the resolved object value 33 | return object.Value 34 | } 35 | 36 | func (reference *Reference) ResolveStream() []byte { 37 | // save current offset so we can come back 38 | current_offset := reference.parser.CurrentOffset() 39 | 40 | // resolve the referenced object value 41 | object := reference.resolve(map[int]interface{}{}) 42 | 43 | // revert offset 44 | reference.parser.Seek(current_offset, io.SeekStart) 45 | 46 | // return the resolved object value 47 | return object.Stream 48 | } 49 | 50 | func (reference *Reference) resolve(resolved_references map[int]interface{}) *IndirectObject { 51 | // prevent infinite loop 52 | if _, ok := resolved_references[reference.Number]; ok { 53 | return NewIndirectObject(reference.Number) 54 | } 55 | resolved_references[reference.Number] = nil 56 | 57 | // use parser to get object 58 | object := reference.parser.GetObject(reference.Number) 59 | 60 | // recursively resolve references 61 | if ref, ok := object.Value.(*Reference); ok { 62 | return ref.resolve(resolved_references) 63 | } 64 | 65 | // return the object 66 | return object 67 | } 68 | -------------------------------------------------------------------------------- /pdf/string.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | type String string 4 | 5 | func (s String) String() string { 6 | return "(" + string(s) + ")" 7 | } 8 | -------------------------------------------------------------------------------- /pdf/test/carriage_return.pdf: -------------------------------------------------------------------------------- 1 | 1 0%comment obj 2 | <> 3 | stream Hello 4 | endstream 5 | endobj 6 | -------------------------------------------------------------------------------- /pdf/test/comments.pdf: -------------------------------------------------------------------------------- 1 | % lets see if some comments mess this up 2 | 1 %comment 3 | %comment 4 | 0%%comment 5 | %comment 6 | obj %comment 7 | (%this is not a comment) %comment 8 | %comment 9 | endobj 10 | -------------------------------------------------------------------------------- /pdf/test/empty_array.pdf: -------------------------------------------------------------------------------- 1 | 1 0 obj 2 | [] 3 | endobj 4 | -------------------------------------------------------------------------------- /pdf/test/empty_dictionary.pdf: -------------------------------------------------------------------------------- 1 | 1 0 obj 2 | <<>> 3 | endobj 4 | -------------------------------------------------------------------------------- /pdf/test/encrypted.pdf: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/KarmaPenny/pdfparser/1aaf59651af9068195333554506630bf2fb6f652/pdf/test/encrypted.pdf -------------------------------------------------------------------------------- /pdf/test/filter_ascii_85_decode.pdf: -------------------------------------------------------------------------------- 1 | 1 0 obj 2 | <>stream 3 | z,p >`r 4 | DK Jj'E+L~> 5 | endstream 6 | endobj 7 | -------------------------------------------------------------------------------- /pdf/test/filter_ascii_hex_decode.pdf: -------------------------------------------------------------------------------- 1 | 1 0 obj 2 | <> 3 | stream 4 | 4 8656c6C6f7>71qwe 5 | endstream 6 | endobj 7 | -------------------------------------------------------------------------------- /pdf/test/filter_flate_decode.pdf: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/KarmaPenny/pdfparser/1aaf59651af9068195333554506630bf2fb6f652/pdf/test/filter_flate_decode.pdf -------------------------------------------------------------------------------- /pdf/test/filter_lzw_decode.pdf: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/KarmaPenny/pdfparser/1aaf59651af9068195333554506630bf2fb6f652/pdf/test/filter_lzw_decode.pdf -------------------------------------------------------------------------------- /pdf/test/filter_lzw_tiff_decode.pdf: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/KarmaPenny/pdfparser/1aaf59651af9068195333554506630bf2fb6f652/pdf/test/filter_lzw_tiff_decode.pdf -------------------------------------------------------------------------------- /pdf/test/filter_multiple.pdf: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/KarmaPenny/pdfparser/1aaf59651af9068195333554506630bf2fb6f652/pdf/test/filter_multiple.pdf -------------------------------------------------------------------------------- /pdf/test/filter_run_length_decode.pdf: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/KarmaPenny/pdfparser/1aaf59651af9068195333554506630bf2fb6f652/pdf/test/filter_run_length_decode.pdf -------------------------------------------------------------------------------- /pdf/test/malformed_dictionary_key.pdf: -------------------------------------------------------------------------------- 1 | 1 0 obj 2 | <> 3 | endobj 4 | -------------------------------------------------------------------------------- /pdf/test/max_cmap_size.pdf: -------------------------------------------------------------------------------- 1 | 1 0 obj 2 | <> 3 | endobj 4 | 5 | 2 0 obj 6 | <> 7 | stream 8 | /CIDInit /ProcSet findresource begin 9 | 12 dict begin 10 | begincmap 11 | /CIDSystemInfo << /Registry (Adobe) /Ordering (UCS) /Supplement 0 >> def 12 | /CMapName /Adobe-Identity-UCS def 13 | /CMapType 2 def 14 | /WMode 0 def 15 | 1 begincodespacerange 16 | <0000> 17 | endcodespacerange 18 | 100 beginbfrange 19 | <0000> <00ff> <0000> 20 | <0100> <01ff> <0100> 21 | <0200> <02ff> <0200> 22 | <0300> <03ff> <0300> 23 | <0400> <04ff> <0400> 24 | <0500> <05ff> <0500> 25 | <0600> <06ff> <0600> 26 | <0700> <07ff> <0700> 27 | <0800> <08ff> <0800> 28 | <0900> <09ff> <0900> 29 | <0a00> <0aff> <0a00> 30 | <0b00> <0bff> <0b00> 31 | <0c00> <0cff> <0c00> 32 | <0d00> <0dff> <0d00> 33 | <0e00> <0eff> <0e00> 34 | <0f00> <0fff> <0f00> 35 | <1000> <10ff> <1000> 36 | <1100> <11ff> <1100> 37 | <1200> <12ff> <1200> 38 | <1300> <13ff> <1300> 39 | <1400> <14ff> <1400> 40 | <1500> <15ff> <1500> 41 | <1600> <16ff> <1600> 42 | <1700> <17ff> <1700> 43 | <1800> <18ff> <1800> 44 | <1900> <19ff> <1900> 45 | <1a00> <1aff> <1a00> 46 | <1b00> <1bff> <1b00> 47 | <1c00> <1cff> <1c00> 48 | <1d00> <1dff> <1d00> 49 | <1e00> <1eff> <1e00> 50 | <1f00> <1fff> <1f00> 51 | <2000> <20ff> <2000> 52 | <2100> <21ff> <2100> 53 | <2200> <22ff> <2200> 54 | <2300> <23ff> <2300> 55 | <2400> <24ff> <2400> 56 | <2500> <25ff> <2500> 57 | <2600> <26ff> <2600> 58 | <2700> <27ff> <2700> 59 | <2800> <28ff> <2800> 60 | <2900> <29ff> <2900> 61 | <2a00> <2aff> <2a00> 62 | <2b00> <2bff> <2b00> 63 | <2c00> <2cff> <2c00> 64 | <2d00> <2dff> <2d00> 65 | <2e00> <2eff> <2e00> 66 | <2f00> <2fff> <2f00> 67 | <3000> <30ff> <3000> 68 | <3100> <31ff> <3100> 69 | <3200> <32ff> <3200> 70 | <3300> <33ff> <3300> 71 | <3400> <34ff> <3400> 72 | <3500> <35ff> <3500> 73 | <3600> <36ff> <3600> 74 | <3700> <37ff> <3700> 75 | <3800> <38ff> <3800> 76 | <3900> <39ff> <3900> 77 | <3a00> <3aff> <3a00> 78 | <3b00> <3bff> <3b00> 79 | <3c00> <3cff> <3c00> 80 | <3d00> <3dff> <3d00> 81 | <3e00> <3eff> <3e00> 82 | <3f00> <3fff> <3f00> 83 | <4000> <40ff> <4000> 84 | <4100> <41ff> <4100> 85 | <4200> <42ff> <4200> 86 | <4300> <43ff> <4300> 87 | <4400> <44ff> <4400> 88 | <4500> <45ff> <4500> 89 | <4600> <46ff> <4600> 90 | <4700> <47ff> <4700> 91 | <4800> <48ff> <4800> 92 | <4900> <49ff> <4900> 93 | <4a00> <4aff> <4a00> 94 | <4b00> <4bff> <4b00> 95 | <4c00> <4cff> <4c00> 96 | <4d00> <4dff> <4d00> 97 | <4e00> <4eff> <4e00> 98 | <4f00> <4fff> <4f00> 99 | <5000> <50ff> <5000> 100 | <5100> <51ff> <5100> 101 | <5200> <52ff> <5200> 102 | <5300> <53ff> <5300> 103 | <5400> <54ff> <5400> 104 | <5500> <55ff> <5500> 105 | <5600> <56ff> <5600> 106 | <5700> <57ff> <5700> 107 | <5800> <58ff> <5800> 108 | <5900> <59ff> <5900> 109 | <5a00> <5aff> <5a00> 110 | <5b00> <5bff> <5b00> 111 | <5c00> <5cff> <5c00> 112 | <5d00> <5dff> <5d00> 113 | <5e00> <5eff> <5e00> 114 | <5f00> <5fff> <5f00> 115 | <6000> <60ff> <6000> 116 | <6100> <61ff> <6100> 117 | <6200> <62ff> <6200> 118 | <6300> <63ff> <6300> 119 | endbfrange 120 | 100 beginbfrange 121 | <6400> <64ff> <6400> 122 | <6500> <65ff> <6500> 123 | <6600> <66ff> <6600> 124 | <6700> <67ff> <6700> 125 | <6800> <68ff> <6800> 126 | <6900> <69ff> <6900> 127 | <6a00> <6aff> <6a00> 128 | <6b00> <6bff> <6b00> 129 | <6c00> <6cff> <6c00> 130 | <6d00> <6dff> <6d00> 131 | <6e00> <6eff> <6e00> 132 | <6f00> <6fff> <6f00> 133 | <7000> <70ff> <7000> 134 | <7100> <71ff> <7100> 135 | <7200> <72ff> <7200> 136 | <7300> <73ff> <7300> 137 | <7400> <74ff> <7400> 138 | <7500> <75ff> <7500> 139 | <7600> <76ff> <7600> 140 | <7700> <77ff> <7700> 141 | <7800> <78ff> <7800> 142 | <7900> <79ff> <7900> 143 | <7a00> <7aff> <7a00> 144 | <7b00> <7bff> <7b00> 145 | <7c00> <7cff> <7c00> 146 | <7d00> <7dff> <7d00> 147 | <7e00> <7eff> <7e00> 148 | <7f00> <7fff> <7f00> 149 | <8000> <80ff> <8000> 150 | <8100> <81ff> <8100> 151 | <8200> <82ff> <8200> 152 | <8300> <83ff> <8300> 153 | <8400> <84ff> <8400> 154 | <8500> <85ff> <8500> 155 | <8600> <86ff> <8600> 156 | <8700> <87ff> <8700> 157 | <8800> <88ff> <8800> 158 | <8900> <89ff> <8900> 159 | <8a00> <8aff> <8a00> 160 | <8b00> <8bff> <8b00> 161 | <8c00> <8cff> <8c00> 162 | <8d00> <8dff> <8d00> 163 | <8e00> <8eff> <8e00> 164 | <8f00> <8fff> <8f00> 165 | <9000> <90ff> <9000> 166 | <9100> <91ff> <9100> 167 | <9200> <92ff> <9200> 168 | <9300> <93ff> <9300> 169 | <9400> <94ff> <9400> 170 | <9500> <95ff> <9500> 171 | <9600> <96ff> <9600> 172 | <9700> <97ff> <9700> 173 | <9800> <98ff> <9800> 174 | <9900> <99ff> <9900> 175 | <9a00> <9aff> <9a00> 176 | <9b00> <9bff> <9b00> 177 | <9c00> <9cff> <9c00> 178 | <9d00> <9dff> <9d00> 179 | <9e00> <9eff> <9e00> 180 | <9f00> <9fff> <9f00> 181 | 182 | 183 | 184 | 185 | 186 | 187 | 188 | 189 | 190 | 191 | 192 | 193 | 194 | 195 | 196 | 197 | 198 | 199 | 200 | 201 | 202 | 203 | 204 | 205 | 206 | 207 | 208 | 209 | 210 | 211 | 212 | 213 | 214 | 215 | 216 | 217 | 218 | 219 | 220 | 221 | endbfrange 222 | 56 beginbfrange 223 | 224 | 225 | 226 | 227 | 228 | 229 | 230 | 231 | 232 | 233 | 234 | 235 | 236 | 237 | 238 | 239 | 240 | 241 | 242 | 243 | 244 | 245 | 246 | 247 | 248 | 249 | 250 | 251 | 252 | 253 | 254 | 255 | 256 | 257 | 258 | 259 | 260 | 261 | 262 | 263 | 264 | 265 | 266 | 267 | 268 | 269 | 270 | 271 | 272 | 273 | 274 | 275 | 276 | 277 | 278 | 279 | endbfrange 280 | endcmap 281 | CMapName currentdict /CMap defineresource pop 282 | end 283 | end 284 | endstream 285 | endobj 286 | -------------------------------------------------------------------------------- /pdf/test/names.pdf: -------------------------------------------------------------------------------- 1 | 1 0 obj 2 | /H#65llo#20#2fW#6Frld!#qz 3 | endobj 4 | -------------------------------------------------------------------------------- /pdf/test/reference.pdf: -------------------------------------------------------------------------------- 1 | 1 0 obj 2 | 2 0 R 3 | endobj 4 | 5 | 2 0 obj 6 | (Hello World!) 7 | endobj 8 | -------------------------------------------------------------------------------- /pdf/test/reference_loop.pdf: -------------------------------------------------------------------------------- 1 | 1 0 obj 2 | 1 0 R 3 | endobj 4 | -------------------------------------------------------------------------------- /pdf/test/reference_null.pdf: -------------------------------------------------------------------------------- 1 | 1 0 obj 2 | 2 0 R 3 | endobj 4 | -------------------------------------------------------------------------------- /pdf/test/strings.pdf: -------------------------------------------------------------------------------- 1 | 1 0 obj 2 | [ 3 | (newline 4 | newline char\nno newline\ 5 | (balance parens allowed) escaped paren \) \\n \110ello\77\777) 6 | < 4 8 656c6C6fg7ignor> 7 | <> 8 | () 9 | ] 10 | endobj 11 | -------------------------------------------------------------------------------- /pdf/test/unclosed_array.pdf: -------------------------------------------------------------------------------- 1 | 1 0 obj 2 | [ 3 | -------------------------------------------------------------------------------- /pdf/test/unclosed_comment.pdf: -------------------------------------------------------------------------------- 1 | 1 0 obj 2 | % 3 | -------------------------------------------------------------------------------- /pdf/test/unclosed_dictionary.pdf: -------------------------------------------------------------------------------- 1 | 1 0 obj 2 | << 3 | -------------------------------------------------------------------------------- /pdf/test/unclosed_dictionary_key.pdf: -------------------------------------------------------------------------------- 1 | 1 0 obj 2 | <> 16 | 17 | xref 18 | 9 1 19 | 0000000000 00000 f 20 | trailer 21 | <> 22 | 23 | startxref 24 | 10 25 | %%EOF 26 | -------------------------------------------------------------------------------- /pdf/test/xref_repair.pdf: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/KarmaPenny/pdfparser/1aaf59651af9068195333554506630bf2fb6f652/pdf/test/xref_repair.pdf -------------------------------------------------------------------------------- /pdf/test/xref_stream_chain.pdf: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/KarmaPenny/pdfparser/1aaf59651af9068195333554506630bf2fb6f652/pdf/test/xref_stream_chain.pdf -------------------------------------------------------------------------------- /pdf/test/xref_stream_index_default.pdf: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/KarmaPenny/pdfparser/1aaf59651af9068195333554506630bf2fb6f652/pdf/test/xref_stream_index_default.pdf -------------------------------------------------------------------------------- /pdf/test/xref_table_chain.pdf: -------------------------------------------------------------------------------- 1 | %PDF-1.7 2 | 3 | xref 4 | 0 9 5 | 0000000000 00000 f 6 | 0000000000 00000 f 7 | 0000000000 00000 f 8 | 0000000000 00000 f 9 | 0000000000 00000 f 10 | 0000000000 00000 f 11 | 0000000000 00000 f 12 | 0000000000 00000 f 13 | 0000000000 00000 f 14 | trailer 15 | <> 16 | 17 | xref 18 | 9 1 19 | 0000000000 00000 f 20 | trailer 21 | <> 22 | 23 | startxref 24 | 10 25 | %%EOF 26 | -------------------------------------------------------------------------------- /pdf/unit_test.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | import ( 4 | "os" 5 | "path/filepath" 6 | "runtime" 7 | "testing" 8 | "time" 9 | ) 10 | 11 | func openTestPdf(pdf_name string) (*os.File, error) { 12 | _, test_path, _, _ := runtime.Caller(0) 13 | test_dir := filepath.Dir(test_path) 14 | return os.Open(filepath.Join(test_dir, "test", pdf_name)) 15 | } 16 | 17 | func TestComments(test *testing.T) { 18 | // open the pdf 19 | f, err := openTestPdf("comments.pdf") 20 | if err != nil { 21 | test.Fatal(err) 22 | } 23 | defer f.Close() 24 | 25 | // load the pdf 26 | parser := NewParser(f, nil) 27 | err = parser.Load("") 28 | if err != nil { 29 | test.Fatal(err) 30 | } 31 | 32 | // read the object 33 | object := parser.GetObject(1) 34 | 35 | // assert value is correct 36 | if object.Value.String() != "(%this is not a comment)" { 37 | test.Fatalf("incorrect value %s", object.Value.String()) 38 | } 39 | } 40 | 41 | func TestEmptyArray(test *testing.T) { 42 | // open the pdf 43 | f, err := openTestPdf("empty_array.pdf") 44 | if err != nil { 45 | test.Fatal(err) 46 | } 47 | defer f.Close() 48 | 49 | // load the pdf 50 | parser := NewParser(f, nil) 51 | err = parser.Load("") 52 | if err != nil { 53 | test.Fatal(err) 54 | } 55 | 56 | // read the object 57 | object := parser.GetObject(1) 58 | 59 | // assert value is correct 60 | if object.Value.String() != "[]" { 61 | test.Fatalf("incorrect value %s", object.Value.String()) 62 | } 63 | } 64 | 65 | func TestEmptyDictionary(test *testing.T) { 66 | // open the pdf 67 | f, err := openTestPdf("empty_dictionary.pdf") 68 | if err != nil { 69 | test.Fatal(err) 70 | } 71 | defer f.Close() 72 | 73 | // load the pdf 74 | parser := NewParser(f, nil) 75 | err = parser.Load("") 76 | if err != nil { 77 | test.Fatal(err) 78 | } 79 | 80 | // read the object 81 | object := parser.GetObject(1) 82 | 83 | // assert value is correct 84 | if object.Value.String() != "<<>>" { 85 | test.Fatalf("incorrect value %s", object.Value.String()) 86 | } 87 | } 88 | 89 | func TestEncrypted(test *testing.T) { 90 | // open the pdf 91 | f, err := openTestPdf("encrypted.pdf") 92 | if err != nil { 93 | test.Fatal(err) 94 | } 95 | defer f.Close() 96 | 97 | // load the pdf 98 | parser := NewParser(f, nil) 99 | err = parser.Load("") 100 | if err != nil { 101 | test.Fatal(err) 102 | } 103 | 104 | // test string decryption 105 | object := parser.GetObject(12) 106 | d12, ok := object.Value.(Dictionary) 107 | if !ok { 108 | test.Fatalf("expected dictionary") 109 | } 110 | if lang, _ := d12.GetString("Lang"); lang != "en-US" { 111 | test.Fatalf("incorrect value %s", lang) 112 | } 113 | 114 | // test stream decryption 115 | object = parser.GetObject(8) 116 | if string(object.Stream[:8]) != "/CIDInit" { 117 | test.Fatalf("incorrect value %s", string(object.Stream[:8])) 118 | } 119 | } 120 | 121 | func TestFilterASCII85Decode(test *testing.T) { 122 | // open the pdf 123 | f, err := openTestPdf("filter_ascii_85_decode.pdf") 124 | if err != nil { 125 | test.Fatal(err) 126 | } 127 | defer f.Close() 128 | 129 | // load the pdf 130 | parser := NewParser(f, nil) 131 | err = parser.Load("") 132 | if err != nil { 133 | test.Fatal(err) 134 | } 135 | 136 | // read the object 137 | object := parser.GetObject(1) 138 | 139 | // assert value is correct 140 | if string(object.Stream) != "\x00\x00\x00\x00%!FontType" { 141 | test.Fatalf("incorrect value %s", string(object.Stream)) 142 | } 143 | } 144 | 145 | func TestFilterASCIIHexDecode(test *testing.T) { 146 | // open the pdf 147 | f, err := openTestPdf("filter_ascii_hex_decode.pdf") 148 | if err != nil { 149 | test.Fatal(err) 150 | } 151 | defer f.Close() 152 | 153 | // load the pdf 154 | parser := NewParser(f, nil) 155 | err = parser.Load("") 156 | if err != nil { 157 | test.Fatal(err) 158 | } 159 | 160 | // read the object 161 | object := parser.GetObject(1) 162 | 163 | // assert value is correct 164 | if string(object.Stream) != "Hellop" { 165 | test.Fatalf("incorrect value %s", string(object.Stream)) 166 | } 167 | } 168 | 169 | func TestFilterFlateDecode(test *testing.T) { 170 | // open the pdf 171 | f, err := openTestPdf("filter_flate_decode.pdf") 172 | if err != nil { 173 | test.Fatal(err) 174 | } 175 | defer f.Close() 176 | 177 | // load the pdf 178 | parser := NewParser(f, nil) 179 | err = parser.Load("") 180 | if err != nil { 181 | test.Fatal(err) 182 | } 183 | 184 | // read the object 185 | object := parser.GetObject(1) 186 | 187 | // assert value is correct 188 | if string(object.Stream) != "hello world\nhello world\nhello world\nhello world\nhello world\n" { 189 | test.Fatalf("incorrect value %s", string(object.Stream)) 190 | } 191 | } 192 | 193 | func TestFilterLZWDecode(test *testing.T) { 194 | // open the pdf 195 | f, err := openTestPdf("filter_lzw_decode.pdf") 196 | if err != nil { 197 | test.Fatal(err) 198 | } 199 | defer f.Close() 200 | 201 | // load the pdf 202 | parser := NewParser(f, nil) 203 | err = parser.Load("") 204 | if err != nil { 205 | test.Fatal(err) 206 | } 207 | 208 | // read the object 209 | object := parser.GetObject(1) 210 | 211 | // assert value is correct 212 | if string(object.Stream) != "hello world!" { 213 | test.Fatalf("incorrect value %s", string(object.Stream)) 214 | } 215 | } 216 | 217 | func TestFilterLZWTiffDecode(test *testing.T) { 218 | // open the pdf 219 | f, err := openTestPdf("filter_lzw_tiff_decode.pdf") 220 | if err != nil { 221 | test.Fatal(err) 222 | } 223 | defer f.Close() 224 | 225 | // load the pdf 226 | parser := NewParser(f, nil) 227 | err = parser.Load("") 228 | if err != nil { 229 | test.Fatal(err) 230 | } 231 | 232 | // read the object 233 | object := parser.GetObject(1) 234 | 235 | // assert value is correct 236 | if string(object.Stream) != "hello world!" { 237 | test.Fatalf("incorrect value %s", string(object.Stream)) 238 | } 239 | } 240 | 241 | func TestFilterMultiple(test *testing.T) { 242 | // open the pdf 243 | f, err := openTestPdf("filter_multiple.pdf") 244 | if err != nil { 245 | test.Fatal(err) 246 | } 247 | defer f.Close() 248 | 249 | // load the pdf 250 | parser := NewParser(f, nil) 251 | err = parser.Load("") 252 | if err != nil { 253 | test.Fatal(err) 254 | } 255 | 256 | // read the object 257 | object := parser.GetObject(1) 258 | 259 | // assert value is correct 260 | if string(object.Stream) != "hello world\nhello world\nhello world\nhello world\nhello world\n" { 261 | test.Fatalf("incorrect value %s", string(object.Stream)) 262 | } 263 | } 264 | 265 | func TestFilterRunLengthDecode(test *testing.T) { 266 | // open the pdf 267 | f, err := openTestPdf("filter_run_length_decode.pdf") 268 | if err != nil { 269 | test.Fatal(err) 270 | } 271 | defer f.Close() 272 | 273 | // load the pdf 274 | parser := NewParser(f, nil) 275 | err = parser.Load("") 276 | if err != nil { 277 | test.Fatal(err) 278 | } 279 | 280 | // read the object 281 | object := parser.GetObject(1) 282 | 283 | // assert value is correct 284 | if string(object.Stream) != "Hello" { 285 | test.Fatalf("incorrect value %s", string(object.Stream)) 286 | } 287 | } 288 | 289 | func TestMalformedDictionaryKey(test *testing.T) { 290 | // open the pdf 291 | f, err := openTestPdf("malformed_dictionary_key.pdf") 292 | if err != nil { 293 | test.Fatal(err) 294 | } 295 | defer f.Close() 296 | 297 | // load the pdf 298 | parser := NewParser(f, nil) 299 | err = parser.Load("") 300 | if err != nil { 301 | test.Fatal(err) 302 | } 303 | 304 | // read object 305 | object := parser.GetObject(1) 306 | 307 | // assert value is correct 308 | if d, ok := object.Value.(Dictionary); ok { 309 | if hidden, _ := d.GetString("HiddenObject"); hidden != "Hello World" { 310 | test.Fatalf("incorrect value %s", hidden) 311 | } 312 | } 313 | } 314 | 315 | func TestMaxCmapSize(test *testing.T) { 316 | // create a done signal channel 317 | done := make(chan bool, 1) 318 | 319 | // run test in background 320 | go func() { 321 | // send done signal when returning 322 | defer func() {done <- true}() 323 | 324 | // open the pdf 325 | f, err := openTestPdf("max_cmap_size.pdf") 326 | if err != nil { 327 | test.Fatal(err) 328 | } 329 | defer f.Close() 330 | 331 | // load the pdf 332 | parser := NewParser(f, nil) 333 | err = parser.Load("") 334 | if err != nil { 335 | test.Fatal(err) 336 | } 337 | 338 | // read the object 339 | object := parser.GetObject(1) 340 | if d, ok := object.Value.(Dictionary); ok { 341 | NewFont(d) 342 | } 343 | }() 344 | 345 | // wait until done or timed out 346 | select { 347 | case <-done: 348 | case <-time.After(time.Second): 349 | test.Fatal("timed out") 350 | } 351 | } 352 | 353 | func TestNames(test *testing.T) { 354 | // open the pdf 355 | f, err := openTestPdf("names.pdf") 356 | if err != nil { 357 | test.Fatal(err) 358 | } 359 | defer f.Close() 360 | 361 | // load the pdf 362 | parser := NewParser(f, nil) 363 | err = parser.Load("") 364 | if err != nil { 365 | test.Fatal(err) 366 | } 367 | 368 | // read object 369 | object := parser.GetObject(1) 370 | 371 | // assert value is correct 372 | if object.Value.String() != "/Hello /World!\x00qz" { 373 | test.Fatalf("incorrect value %s", object.Value.String()) 374 | } 375 | } 376 | 377 | func TestReference(test *testing.T) { 378 | // open the pdf 379 | f, err := openTestPdf("reference.pdf") 380 | if err != nil { 381 | test.Fatal(err) 382 | } 383 | defer f.Close() 384 | 385 | // load the pdf 386 | parser := NewParser(f, nil) 387 | err = parser.Load("") 388 | if err != nil { 389 | test.Fatal(err) 390 | } 391 | 392 | // read object 393 | object := parser.GetObject(1) 394 | 395 | // make sure object is a reference 396 | reference, ok := object.Value.(*Reference) 397 | if !ok { 398 | test.Fatal("object is not a reference") 399 | } 400 | 401 | // resolve the reference 402 | resolved_object := reference.Resolve() 403 | 404 | // assert value is correct 405 | if resolved_object.String() != "(Hello World!)" { 406 | test.Fatalf("incorrect value %s", resolved_object.String()) 407 | } 408 | } 409 | 410 | func TestReferenceLoop(test *testing.T) { 411 | // create a done signal channel 412 | done := make(chan bool, 1) 413 | 414 | // run test in background 415 | go func() { 416 | // send done signal when returning 417 | defer func() {done <- true}() 418 | 419 | // open the pdf 420 | f, err := openTestPdf("reference_loop.pdf") 421 | if err != nil { 422 | test.Fatal(err) 423 | } 424 | defer f.Close() 425 | 426 | // load the pdf 427 | parser := NewParser(f, nil) 428 | err = parser.Load("") 429 | if err != nil { 430 | test.Fatal(err) 431 | } 432 | 433 | // read object 434 | object := parser.GetObject(1) 435 | 436 | // make sure object is a reference 437 | reference, ok := object.Value.(*Reference) 438 | if !ok { 439 | test.Fatal("object is not a reference") 440 | } 441 | 442 | // resolve the reference 443 | resolved_object := reference.Resolve() 444 | 445 | // assert value is correct 446 | if resolved_object.String() != "null" { 447 | test.Fatalf("incorrect value %s", resolved_object.String()) 448 | } 449 | }() 450 | 451 | // wait until done or timed out 452 | select { 453 | case <-done: 454 | case <-time.After(time.Second): 455 | test.Fatal("timed out") 456 | } 457 | } 458 | 459 | func TestReferenceNull(test *testing.T) { 460 | // open the pdf 461 | f, err := openTestPdf("reference_null.pdf") 462 | if err != nil { 463 | test.Fatal(err) 464 | } 465 | defer f.Close() 466 | 467 | // load the pdf 468 | parser := NewParser(f, nil) 469 | err = parser.Load("") 470 | if err != nil { 471 | test.Fatal(err) 472 | } 473 | 474 | // read object 475 | object := parser.GetObject(1) 476 | 477 | // make sure object is a reference 478 | reference, ok := object.Value.(*Reference) 479 | if !ok { 480 | test.Fatal("object is not a reference") 481 | } 482 | 483 | // resolve the reference 484 | resolved_object := reference.Resolve() 485 | 486 | // assert value is correct 487 | if resolved_object.String() != "null" { 488 | test.Fatalf("incorrect value %s", resolved_object.String()) 489 | } 490 | } 491 | 492 | func TestCarriageReturn(test *testing.T) { 493 | // open the pdf 494 | f, err := openTestPdf("carriage_return.pdf") 495 | if err != nil { 496 | test.Fatal(err) 497 | } 498 | defer f.Close() 499 | 500 | // load the pdf 501 | parser := NewParser(f, nil) 502 | err = parser.Load("") 503 | if err != nil { 504 | test.Fatal(err) 505 | } 506 | 507 | // read the object 508 | object := parser.GetObject(1) 509 | 510 | // assert value is correct 511 | if string(object.Stream) != "Hello" { 512 | test.Fatalf("incorrect value %s", string(object.Stream)) 513 | } 514 | } 515 | 516 | func TestStrings(test *testing.T) { 517 | // open the pdf 518 | f, err := openTestPdf("strings.pdf") 519 | if err != nil { 520 | test.Fatal(err) 521 | } 522 | defer f.Close() 523 | 524 | // load the pdf 525 | parser := NewParser(f, nil) 526 | err = parser.Load("") 527 | if err != nil { 528 | test.Fatal(err) 529 | } 530 | 531 | // read the object 532 | object := parser.GetObject(1) 533 | 534 | // make sure object is an array 535 | array, ok := object.Value.(Array) 536 | if !ok { 537 | test.Fatal("object is not an Array") 538 | } 539 | 540 | // assert values are correct 541 | if array[0].String() != "(newline\nnewline char\nno newline(balance parens allowed) escaped paren ) \\n Hello??7)" { 542 | test.Fatalf("incorrect value %s", array[0].String()) 543 | } 544 | if array[1].String() != "(Hellop)" { 545 | test.Fatalf("incorrect value %s", array[1].String()) 546 | } 547 | if array[2].String() != "()" { 548 | test.Fatalf("incorrect value %s", array[2].String()) 549 | } 550 | if array[3].String() != "()" { 551 | test.Fatalf("incorrect value %s", array[2].String()) 552 | } 553 | } 554 | 555 | func TestUnclosedArray(test *testing.T) { 556 | // create a done signal channel 557 | done := make(chan bool, 1) 558 | 559 | // run test in background 560 | go func() { 561 | // send done signal when returning 562 | defer func() {done <- true}() 563 | 564 | // open the pdf 565 | f, err := openTestPdf("unclosed_array.pdf") 566 | if err != nil { 567 | test.Fatal(err) 568 | } 569 | defer f.Close() 570 | 571 | // load the pdf 572 | parser := NewParser(f, nil) 573 | err = parser.Load("") 574 | if err != nil { 575 | test.Fatal(err) 576 | } 577 | 578 | // read the object 579 | object := parser.GetObject(1) 580 | 581 | // make sure object value is correct 582 | if object.Value.String() != "[]" { 583 | test.Fatalf("incorrect value %s", object.Value.String()) 584 | } 585 | }() 586 | 587 | // wait until done or timed out 588 | select { 589 | case <-done: 590 | case <-time.After(time.Second): 591 | test.Fatal("timed out") 592 | } 593 | } 594 | 595 | func TestUnclosedComment(test *testing.T) { 596 | // create a done signal channel 597 | done := make(chan bool, 1) 598 | 599 | // run test in background 600 | go func() { 601 | // send done signal when returning 602 | defer func() {done <- true}() 603 | 604 | // open the pdf 605 | f, err := openTestPdf("unclosed_comment.pdf") 606 | if err != nil { 607 | test.Fatal(err) 608 | } 609 | defer f.Close() 610 | 611 | // load the pdf 612 | parser := NewParser(f, nil) 613 | err = parser.Load("") 614 | if err != nil { 615 | test.Fatal(err) 616 | } 617 | 618 | // read the object 619 | object := parser.GetObject(1) 620 | 621 | // make sure object value is correct 622 | if object.Value.String() != "null" { 623 | test.Fatalf("incorrect value %s", object.Value.String()) 624 | } 625 | }() 626 | 627 | // wait until done or timed out 628 | select { 629 | case <-done: 630 | case <-time.After(time.Second): 631 | test.Fatal("timed out") 632 | } 633 | } 634 | 635 | func TestUnclosedDictionary(test *testing.T) { 636 | // create a done signal channel 637 | done := make(chan bool, 1) 638 | 639 | // run test in background 640 | go func() { 641 | // send done signal when returning 642 | defer func() {done <- true}() 643 | 644 | // open the pdf 645 | f, err := openTestPdf("unclosed_dictionary.pdf") 646 | if err != nil { 647 | test.Fatal(err) 648 | } 649 | defer f.Close() 650 | 651 | // load the pdf 652 | parser := NewParser(f, nil) 653 | err = parser.Load("") 654 | if err != nil { 655 | test.Fatal(err) 656 | } 657 | 658 | // read the object 659 | parser.GetObject(1) 660 | }() 661 | 662 | // wait until done or timed out 663 | select { 664 | case <-done: 665 | case <-time.After(time.Second): 666 | test.Fatal("timed out") 667 | } 668 | } 669 | func TestUnclosedDictionaryKey(test *testing.T) { 670 | // create a done signal channel 671 | done := make(chan bool, 1) 672 | 673 | // run test in background 674 | go func() { 675 | // send done signal when returning 676 | defer func() {done <- true}() 677 | 678 | // open the pdf 679 | f, err := openTestPdf("unclosed_dictionary_key.pdf") 680 | if err != nil { 681 | test.Fatal(err) 682 | } 683 | defer f.Close() 684 | 685 | // load the pdf 686 | parser := NewParser(f, nil) 687 | err = parser.Load("") 688 | if err != nil { 689 | test.Fatal(err) 690 | } 691 | 692 | // read the object 693 | parser.GetObject(1) 694 | }() 695 | 696 | // wait until done or timed out 697 | select { 698 | case <-done: 699 | case <-time.After(time.Second): 700 | test.Fatal("timed out") 701 | } 702 | } 703 | 704 | func TestUnclosedHexString(test *testing.T) { 705 | // create a done signal channel 706 | done := make(chan bool, 1) 707 | 708 | // run test in background 709 | go func() { 710 | // send done signal when returning 711 | defer func() {done <- true}() 712 | 713 | // open the pdf 714 | f, err := openTestPdf("unclosed_hex_string.pdf") 715 | if err != nil { 716 | test.Fatal(err) 717 | } 718 | defer f.Close() 719 | 720 | // load the pdf 721 | parser := NewParser(f, nil) 722 | err = parser.Load("") 723 | if err != nil { 724 | test.Fatal(err) 725 | } 726 | 727 | // read the object 728 | object := parser.GetObject(1) 729 | 730 | // make sure object value is correct 731 | if object.Value.String() != "()" { 732 | test.Fatalf("incorrect value %s", object.Value.String()) 733 | } 734 | }() 735 | 736 | // wait until done or timed out 737 | select { 738 | case <-done: 739 | case <-time.After(time.Second): 740 | test.Fatal("timed out") 741 | } 742 | } 743 | 744 | func TestUnclosedName(test *testing.T) { 745 | // create a done signal channel 746 | done := make(chan bool, 1) 747 | 748 | // run test in background 749 | go func() { 750 | // send done signal when returning 751 | defer func() {done <- true}() 752 | 753 | // open the pdf 754 | f, err := openTestPdf("unclosed_name.pdf") 755 | if err != nil { 756 | test.Fatal(err) 757 | } 758 | defer f.Close() 759 | 760 | // load the pdf 761 | parser := NewParser(f, nil) 762 | err = parser.Load("") 763 | if err != nil { 764 | test.Fatal(err) 765 | } 766 | 767 | // read the object 768 | object := parser.GetObject(1) 769 | 770 | // make sure object value is correct 771 | if object.Value.String() != "/" { 772 | test.Fatalf("incorrect value %s", object.Value.String()) 773 | } 774 | }() 775 | 776 | // wait until done or timed out 777 | select { 778 | case <-done: 779 | case <-time.After(time.Second): 780 | test.Fatal("timed out") 781 | } 782 | } 783 | 784 | func TestUnclosedNameEscape1(test *testing.T) { 785 | // create a done signal channel 786 | done := make(chan bool, 1) 787 | 788 | // run test in background 789 | go func() { 790 | // send done signal when returning 791 | defer func() {done <- true}() 792 | 793 | // open the pdf 794 | f, err := openTestPdf("unclosed_name_escape_1.pdf") 795 | if err != nil { 796 | test.Fatal(err) 797 | } 798 | defer f.Close() 799 | 800 | // load the pdf 801 | parser := NewParser(f, nil) 802 | err = parser.Load("") 803 | if err != nil { 804 | test.Fatal(err) 805 | } 806 | 807 | // read the object 808 | object := parser.GetObject(1) 809 | 810 | // make sure object value is correct 811 | if object.Value.String() != "/\x00" { 812 | test.Fatalf("incorrect value %s", object.Value.String()) 813 | } 814 | }() 815 | 816 | // wait until done or timed out 817 | select { 818 | case <-done: 819 | case <-time.After(time.Second): 820 | test.Fatal("timed out") 821 | } 822 | } 823 | 824 | func TestUnclosedNameEscape2(test *testing.T) { 825 | // create a done signal channel 826 | done := make(chan bool, 1) 827 | 828 | // run test in background 829 | go func() { 830 | // send done signal when returning 831 | defer func() {done <- true}() 832 | 833 | // open the pdf 834 | f, err := openTestPdf("unclosed_name_escape_2.pdf") 835 | if err != nil { 836 | test.Fatal(err) 837 | } 838 | defer f.Close() 839 | 840 | // load the pdf 841 | parser := NewParser(f, nil) 842 | err = parser.Load("") 843 | if err != nil { 844 | test.Fatal(err) 845 | } 846 | 847 | // read the object 848 | object := parser.GetObject(1) 849 | 850 | // make sure object value is correct 851 | if object.Value.String() != "/0" { 852 | test.Fatalf("incorrect value %s", object.Value.String()) 853 | } 854 | }() 855 | 856 | // wait until done or timed out 857 | select { 858 | case <-done: 859 | case <-time.After(time.Second): 860 | test.Fatal("timed out") 861 | } 862 | } 863 | 864 | func TestUnclosedString(test *testing.T) { 865 | // create a done signal channel 866 | done := make(chan bool, 1) 867 | 868 | // run test in background 869 | go func() { 870 | // send done signal when returning 871 | defer func() {done <- true}() 872 | 873 | // open the pdf 874 | f, err := openTestPdf("unclosed_string.pdf") 875 | if err != nil { 876 | test.Fatal(err) 877 | } 878 | defer f.Close() 879 | 880 | // load the pdf 881 | parser := NewParser(f, nil) 882 | err = parser.Load("") 883 | if err != nil { 884 | test.Fatal(err) 885 | } 886 | 887 | // read the object 888 | object := parser.GetObject(1) 889 | 890 | // make sure object value is correct 891 | if object.Value.String() != "()" { 892 | test.Fatalf("incorrect value %s", object.Value.String()) 893 | } 894 | }() 895 | 896 | // wait until done or timed out 897 | select { 898 | case <-done: 899 | case <-time.After(time.Second): 900 | test.Fatal("timed out") 901 | } 902 | } 903 | 904 | func TestUnclosedStringEscape(test *testing.T) { 905 | // create a done signal channel 906 | done := make(chan bool, 1) 907 | 908 | // run test in background 909 | go func() { 910 | // send done signal when returning 911 | defer func() {done <- true}() 912 | 913 | // open the pdf 914 | f, err := openTestPdf("unclosed_string_escape.pdf") 915 | if err != nil { 916 | test.Fatal(err) 917 | } 918 | defer f.Close() 919 | 920 | // load the pdf 921 | parser := NewParser(f, nil) 922 | err = parser.Load("") 923 | if err != nil { 924 | test.Fatal(err) 925 | } 926 | 927 | // read the object 928 | object := parser.GetObject(1) 929 | 930 | // make sure object value is correct 931 | if object.Value.String() != "(\\)" { 932 | test.Fatalf("incorrect value %s", object.Value.String()) 933 | } 934 | }() 935 | 936 | // wait until done or timed out 937 | select { 938 | case <-done: 939 | case <-time.After(time.Second): 940 | test.Fatal("timed out") 941 | } 942 | } 943 | 944 | func TestUnclosedStringOctal1(test *testing.T) { 945 | // create a done signal channel 946 | done := make(chan bool, 1) 947 | 948 | // run test in background 949 | go func() { 950 | // send done signal when returning 951 | defer func() {done <- true}() 952 | 953 | // open the pdf 954 | f, err := openTestPdf("unclosed_string_octal_1.pdf") 955 | if err != nil { 956 | test.Fatal(err) 957 | } 958 | defer f.Close() 959 | 960 | // load the pdf 961 | parser := NewParser(f, nil) 962 | err = parser.Load("") 963 | if err != nil { 964 | test.Fatal(err) 965 | } 966 | 967 | // read the object 968 | object := parser.GetObject(1) 969 | 970 | // make sure object value is correct 971 | if object.Value.String() != "(\x01)" { 972 | test.Fatalf("incorrect value %s", object.Value.String()) 973 | } 974 | }() 975 | 976 | // wait until done or timed out 977 | select { 978 | case <-done: 979 | case <-time.After(time.Second): 980 | test.Fatal("timed out") 981 | } 982 | } 983 | 984 | func TestUnclosedStringOctal2(test *testing.T) { 985 | // create a done signal channel 986 | done := make(chan bool, 1) 987 | 988 | // run test in background 989 | go func() { 990 | // send done signal when returning 991 | defer func() {done <- true}() 992 | 993 | // open the pdf 994 | f, err := openTestPdf("unclosed_string_octal_2.pdf") 995 | if err != nil { 996 | test.Fatal(err) 997 | } 998 | defer f.Close() 999 | 1000 | // load the pdf 1001 | parser := NewParser(f, nil) 1002 | err = parser.Load("") 1003 | if err != nil { 1004 | test.Fatal(err) 1005 | } 1006 | 1007 | // read the object 1008 | object := parser.GetObject(1) 1009 | 1010 | // make sure object value is correct 1011 | if object.Value.String() != "(\n)" { 1012 | test.Fatalf("incorrect value %s", object.Value.String()) 1013 | } 1014 | }() 1015 | 1016 | // wait until done or timed out 1017 | select { 1018 | case <-done: 1019 | case <-time.After(time.Second): 1020 | test.Fatal("timed out") 1021 | } 1022 | } 1023 | 1024 | func TestXrefLoop(test *testing.T) { 1025 | // create a done signal channel 1026 | done := make(chan bool, 1) 1027 | 1028 | // run test in background 1029 | go func() { 1030 | // send done signal when returning 1031 | defer func() {done <- true}() 1032 | 1033 | // open the pdf 1034 | f, err := openTestPdf("xref_loop.pdf") 1035 | if err != nil { 1036 | test.Fatal(err) 1037 | } 1038 | defer f.Close() 1039 | 1040 | // load the pdf 1041 | parser := NewParser(f, nil) 1042 | err = parser.Load("") 1043 | if err != nil { 1044 | test.Fatal(err) 1045 | } 1046 | 1047 | // assert xref length is correct 1048 | if len(parser.Xref) != 10 { 1049 | test.Fatal("xref length != 10") 1050 | } 1051 | }() 1052 | 1053 | // wait until done or timed out 1054 | select { 1055 | case <-done: 1056 | case <-time.After(time.Second): 1057 | test.Fatal("timed out") 1058 | } 1059 | } 1060 | 1061 | func TestXrefRepair(test *testing.T) { 1062 | // open the pdf 1063 | f, err := openTestPdf("xref_repair.pdf") 1064 | if err != nil { 1065 | test.Fatal(err) 1066 | } 1067 | defer f.Close() 1068 | 1069 | // load the pdf 1070 | parser := NewParser(f, nil) 1071 | err = parser.Load("") 1072 | if err != nil { 1073 | test.Fatal(err) 1074 | } 1075 | 1076 | // assert xref length is correct 1077 | if len(parser.Xref) != 9 { 1078 | test.Fatalf("%d != 9", len(parser.Xref)) 1079 | } 1080 | 1081 | // read the object 1082 | object := parser.GetObject(9) 1083 | 1084 | // assert values are correct 1085 | if object.Value.String() != "(Hello world)" { 1086 | test.Fatalf("incorrect value %s", object.Value.String()) 1087 | } 1088 | } 1089 | 1090 | func TestXrefStreamChain(test *testing.T) { 1091 | // open the pdf 1092 | f, err := openTestPdf("xref_stream_chain.pdf") 1093 | if err != nil { 1094 | test.Fatal(err) 1095 | } 1096 | defer f.Close() 1097 | 1098 | // load the pdf 1099 | parser := NewParser(f, nil) 1100 | err = parser.Load("") 1101 | if err != nil { 1102 | test.Fatal(err) 1103 | } 1104 | 1105 | // assert xref length is correct 1106 | if len(parser.Xref) != 11 { 1107 | test.Fatalf("%d != 11", len(parser.Xref)) 1108 | } 1109 | 1110 | // read the object 1111 | object := parser.GetObject(10) 1112 | 1113 | // assert values are correct 1114 | if object.Value.String() != "(Hello World!)" { 1115 | test.Fatalf("incorrect value %s", object.Value.String()) 1116 | } 1117 | } 1118 | 1119 | func TestXrefStreamIndexDefault(test *testing.T) { 1120 | // open the pdf 1121 | f, err := openTestPdf("xref_stream_index_default.pdf") 1122 | if err != nil { 1123 | test.Fatal(err) 1124 | } 1125 | defer f.Close() 1126 | 1127 | // load the pdf 1128 | parser := NewParser(f, nil) 1129 | err = parser.Load("") 1130 | if err != nil { 1131 | test.Fatal(err) 1132 | } 1133 | 1134 | // assert xref length is correct 1135 | if len(parser.Xref) != 10 { 1136 | test.Fatalf("%d != 10", len(parser.Xref)) 1137 | } 1138 | 1139 | // read the object 1140 | object := parser.GetObject(9) 1141 | 1142 | // assert values are correct 1143 | if object.Value.String() != "(Hello World!)" { 1144 | test.Fatalf("incorrect value %s", object.Value.String()) 1145 | } 1146 | } 1147 | 1148 | func TestXrefTableChain(test *testing.T) { 1149 | // open the pdf 1150 | f, err := openTestPdf("xref_table_chain.pdf") 1151 | if err != nil { 1152 | test.Fatal(err) 1153 | } 1154 | defer f.Close() 1155 | 1156 | // load the pdf 1157 | parser := NewParser(f, nil) 1158 | err = parser.Load("") 1159 | if err != nil { 1160 | test.Fatal(err) 1161 | } 1162 | 1163 | // assert xref length is correct 1164 | if len(parser.Xref) != 10 { 1165 | test.Fatal("xref length != 10") 1166 | } 1167 | } 1168 | -------------------------------------------------------------------------------- /pdf/utility.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | import ( 4 | "io" 5 | ) 6 | 7 | // ReadInt reads width bytes from reader and returns the int64 value 8 | func ReadInt(reader io.Reader, width int) (int, bool) { 9 | v, ok := ReadInt64(reader, width) 10 | return int(v), ok 11 | } 12 | 13 | // ReadInt reads width bytes from reader and returns the int64 value 14 | func ReadInt64(reader io.Reader, width int) (int64, bool) { 15 | data := make([]byte, width) 16 | bytes_read, _ := reader.Read(data) 17 | if bytes_read != width { 18 | return 0, false 19 | } 20 | v := int64(0) 21 | for i := 0; i < len(data); i++ { 22 | v *= 256 23 | v += int64(data[i]) 24 | } 25 | return v, true 26 | } 27 | 28 | // IsHex returns true if the byte is a hex character 29 | func IsHex(b byte) bool { 30 | return (b >= '0' && b <= '9') || (b >= 'a' && b <= 'f') || (b >= 'A' && b <= 'F') 31 | } 32 | 33 | // GetBits gets n bits from d starting at p 34 | func GetBits(d []byte, p int, n int) uint32 { 35 | var v uint32 = 0 36 | for i := 0; i < 4; i++ { 37 | v *= 256 38 | if p / 8 + i < len(d) { 39 | v += uint32(d[p / 8 + i]) 40 | } 41 | } 42 | v <<= uint(p % 8) 43 | v >>= uint(32 - n) 44 | return v 45 | } 46 | 47 | // SetBits sets n bits in d starting at p to the last n bits of v 48 | func SetBits(d []byte, p int, n int, v uint32) { 49 | dv := GetBits(d, (p / 8) * 8, 32) 50 | s := uint(32 - n - (p % 8)) 51 | max := uint32(1 << uint(n)) 52 | m := uint32(1 << uint(n)) - 1 53 | dv += ((v % max) << s) - (dv & (m << s)) 54 | for i := 0; i < 4 && p / 8 + i < len(d); i++ { 55 | d[p / 8 + i] = byte(dv >> (32 - ((uint(i) + 1) * 8))) 56 | } 57 | } 58 | 59 | func BytesToInt(b []byte) int { 60 | val := 0 61 | for i := range b { 62 | val *= 256 63 | val += int(b[i]) 64 | } 65 | return val 66 | } 67 | -------------------------------------------------------------------------------- /pdf/xref.go: -------------------------------------------------------------------------------- 1 | package pdf 2 | 3 | const ( 4 | XrefTypeFreeObject = iota 5 | XrefTypeIndirectObject 6 | XrefTypeCompressedObject 7 | ) 8 | 9 | type XrefEntry struct { 10 | Offset int64 11 | Generation int 12 | Type int 13 | IsEncrypted bool 14 | IsXrefStream bool 15 | } 16 | 17 | func NewXrefEntry(offset int64, generation int, type_value int) *XrefEntry { 18 | return &XrefEntry{offset, generation, type_value, true, false} 19 | } 20 | --------------------------------------------------------------------------------