├── .gitignore
├── CasTocFormats.md
├── LICENSE
├── README.md
├── compression.go
├── cpp
    ├── Pack.bat
    ├── UnpackAllplusManifest.bat
    ├── castoc_x64.dll
    ├── castoc_x64.h
    ├── fix_manifest_and_pack.py
    ├── main.cpp
    └── main.exe
├── dllAPI.go
├── fIoStoreStructs.go
├── go.mod
├── go.sum
├── helpers.go
├── manifest.go
├── pack.go
├── req
    └── Packed_P.pak
├── ucas.go
└── utoc.go


/.gitignore:
--------------------------------------------------------------------------------
1 | /files/
2 | */unpacked*/
3 | /test/
4 | test*
5 | *.bin
6 | /.idea/
7 | Runtime/*
8 | packProgram/Runtime/
9 | unpacking*/


--------------------------------------------------------------------------------
/CasTocFormats.md:
--------------------------------------------------------------------------------
  1 | # utoc File Format
  2 | 
  3 | This document shows the file format of utoc files, and they show their relation with the .ucas files for the Unreal Engine.
  4 | This has been reverse engineered based on the game files of Grounded, and the source code of the Unreal Engine.
  5 | That being said, let's dive right into it.
  6 | 
  7 | The UTOC struct is made up of the following properties:
  8 | 
  9 | ```
 10 | FIoStoreTocHeader - Header
 11 | int64 - TocFileSize
 12 | TArray<FIoChunkId> ChunkIds
 13 | TMap<FIoChunkId, int32> ChunkIdToIndex
 14 | TArray<FIoStoreTocCompressedBlockEntry> CompressionBlocks
 15 | TArray<FIoStoreTocEntryMeta> ChunkMetas
 16 | TArray<FName> Compression
 17 | ```
 18 | 
 19 | First the header:
 20 | For any extra data structure used in the header, an indent is made.
 21 | Everything in the file is Little Endian.
 22 | ```
 23 | FILE HEADER (FIoStoreTocHeader), total bytes: 144
 24 |     uint8 {1}[16]           - static expression of 16 bits for MAGIC word (string: "-==--==--==--==-") 
 25 |     uint8 {1}           - Version - Current options are Initial(1), DirectoryIndex(2), PartitionSize(3)
 26 |     uint8 + uint16 {3}  - Reserved/Padding
 27 |     uint32 {4}          - Header Size (144)
 28 |     uint32 {4}          - Entry Count
 29 |     uint32 {4}          - Count of Compressed Blocks 
 30 |     uint32 {4}          - Entry size of Compressed Block (12)
 31 |     uint32 {4}          - Count Compression method names 
 32 |     uint32 {4}          - Compression method name length (32)
 33 |     uint32 {4}          - Compression block size (0x10000)
 34 |     uint32 {4}          - Directory index Size
 35 |     uint32 {4}          - Partition Count (0) // default value is 0
 36 |     uint64 {8}          - Container ID (FIoContainerID)
 37 |     FGUID {16}          - Guid Encryption Key
 38 |         uint32 {4}      - A
 39 |         uint32 {4}      - B
 40 |         uint32 {4}      - C
 41 |         uint32 {4}      - D
 42 |     uint8 {1}           - Container flags - uint8 bitmask enum - see https://docs.unrealengine.com/5.1/en-US/API/Runtime/Core/IO/EIoContainerFlags/
 43 |     uint8 + uint16      - Reserved/Padding caused by bitmask
 44 |     uint8 [60]          - static 60 bytes of padding - "partition size" is among them as well, but seems unused...
 45 | ```
 46 | Following the header the total TOC file size is serialized:
 47 | ```
 48 |     int64 {4}           - TOC File Size
 49 | ```
 50 |     
 51 | Based on the header, there are several number of data structures parsed.
 52 | The way in which these data structures are parsed and how often they occur are listed here, in the form: "(data structure): {name of variable}"
 53 | The individual data structures can be found below.
 54 | ```
 55 | (CHUNK_ID)            : {Entry Count}
 56 | (OFFSET_AND_LENGTHS)  : {Entry Count}
 57 | (COMPRESSION_BLOCK)   : {Count of Compressed Blocks}
 58 | (byte {32})           : {Count Compression method names} // the 32 is derived from the compression method name length
 59 | (DIRECTORY_INDEX)     : {1} // number of bytes in data structure: Directory index Size
 60 | (CHUNK_META)          : {Entry Count}
 61 | ```
 62 | Note: while there are Count Compression method names entries in some kind of array with the compression methods, this array should start at 1, as index 0 means "No compression method".
 63 | 
 64 | After the chunk meta has been read, there should not be any bytes left to parse from the .utoc file.
 65 | 
 66 | ________
 67 | Data structures:
 68 | 
 69 | ```
 70 | CHUNK_ID, total bytes: 12 - Hash made up of 12 uint8 bytes
 71 |     uint64 {8}          - ID
 72 |     uint16 {2}          - Index // seems to be always 0
 73 |     uint8  {1}          - Padding // making it 0x10 aligned
 74 |     uint8  {1}          - Type - See: https://docs.unrealengine.com/4.26/en-US/API/Runtime/Core/IO/EIoChunkType/ 
 75 | ```
 76 | This hash identifies one chunk. 
 77 | As far as I know, the ID is invalid if the value is 0.
 78 | Otherwise it seems to be random.
 79 | I am not sure what the Index means, as this value is always 0.
 80 | Maybe this is relevant if the files are too large to be described by one chunk.
 81 | In that case you can have multiple chunks describing a file, possibly with multiple indices, but this is all speculation.
 82 | The Type field corresponds to the EIoChunkType of the unreal engine.
 83 | The values I've seen are 2, 3 and 10.
 84 | 
 85 | Value 2 means "BulkData" and is used to represent .uasset files.
 86 | Value 3 means "OptionalBulkData" and is used to represent .ubulk files.
 87 | The .uasset files all have unique chunk IDs, whereas the .ubulk files have an ID that was already taken by a .uasset file.
 88 | The very last chunkID always has value 10, which means "PackageStoreEntry", but I have no clue what this represents.
 89 | The Unreal Engine code isn't too clear about it.
 90 | I suspect that this has something to do with the FPackageStoreEntry struct.
 91 | 
 92 | To investigate what it could mean, I set everything of those sections to 0 and checked with the UnrealPak Viewer tool (https://github.com/jashking/UnrealPakViewer).
 93 | In the one with everything set to zero, it has "dependency counts" at 0, and the class entries are set to "uexp" or "ubulk".
 94 | For the other version, the one with data, it has various "dependency counts", and the class entries are set to different things, such as "Texture2D", "StaticMesh", "Skeleton", "SoundWave" etc.
 95 | Furthermore, the "ExportObjects" field in the empty one has counts 0, while the one with data does not.
 96 | 
 97 | 
 98 | Update: I have found a few more things about this. 
 99 | If the UTOC header version is 2, then the first entry in the list of chunk IDs has type 10, which is not "mapped" to a file.
100 | If the UTOC header version is 3, then this is the last entry.
101 | The compression blocks that the corresponding offset and lengths entry corresponds to, are compressed (or not), and when decompressed, they form a file with some special file format.
102 | I have dubbed this file format as "depsFile", and its specification can be found below.
103 | 
104 | 
105 | 
106 | ```
107 | OFFSET_AND_LENGTHS, total bytes: 10
108 |     byte {5}            - Offset
109 |     byte {5}            - Length
110 | ```
111 | Read as a uint64, with only the lower 5 bytes set, the others should be 0.
112 | There are just as many of these entries as Chunk IDs and file entries.
113 | The offset and lengths actually show the data of the individual files that are compressed in the .ucas file.
114 | Note that all data must be decompressed first.
115 | 
116 | **NOTE:** The length of the offlengths show the length of the decompressed file!
117 | The offset follows directly after the next length, but it's aligned to 0x10000. 
118 | Therefore, there may be large gaps between them.
119 | This is done for indexing in the array of chunks.
120 | 
121 | ```
122 | COMPRESSION_BLOCK, total bytes: 12
123 |     byte {5}            - Offset
124 |     byte {3}            - Compressed block size
125 |     byte {3}            - Uncompressed block size
126 |     uint8 {1}           - Compression method
127 | ``` 
128 | Read offset as uint64, with only lower 5 bytes set.
129 | The others should be read as uint32, with only the lower 3 bytes set.
130 | The compression method is interpreted as an index in the list of compression method names.
131 | 
132 | ```Compression Method Names
133 | NAME_Zlib
134 | NAME_Gzip
135 | NAME_LZ4
136 | "Bogus"
137 | "Oodle"
138 | ```
139 | 
140 | The offset is an offset in the .ucas field, and it is always 16-aligned.
141 | The compression block size is the length of the data in the .ucas field.
142 | If the compression block size equals the uncompressed block size, it is obviously not compressed.
143 | If it is, the compression method is an index in the list of compression method entries.
144 | One note: in case of 0, this is always "None".
145 | 
146 | As the offset values are always 16-aligned, there are bogus values in between the parts that are unallocated.
147 | I don't know the significance of these values, but I think they are just random.
148 | 
149 | 
150 | ```
151 | DIRECTORY_INDEX (total bytes is variable)
152 |     uint32 {4}          - Mount point string length (includes nullbyte)
153 |     byte {X}            - Mount point string
154 |     uint32 {4}          - Directory Index array Entry Count (DIEC)
155 |     DIR_INDEX_ENTRY {DIEC * 16} // an array of DIR_INDEX_ENTRY
156 |         uint32 {4}      - Directory Name index
157 |         uint32 {4}      - First child entry index
158 |         uint32 {4}      - First sibling entry index
159 |         uint32 {4}      - First file entry index
160 |     uint32 {4}          - File Index array Entry Count (FIEC)
161 |     FILE_INDEX_ENTRY {FIEC * 12} // an array of FILE_INDEX_ENTRY
162 |         uint32 {4}      - File name index
163 |         uint32 {4}      - Next file entry index
164 |         uint32 {4}      - UserData (index, I guess)
165 |     uint32 {4}          - number of strings of the string array 
166 |     FSTRING {number_of_strings * (4 + X)} // an array of strings, referred to as StringTable
167 |         uint32 {4}      - string length, nullbyte included
168 |         byte {X}        - actual string
169 | ```
170 | The directory index entries and the file index entries have a "name" index, which is used to refer to a name in the StringTable.
171 | The child and sibling indices for the Directory entries point to a different Directory entry in the same array.
172 | The file entry indices point to the file entry in the FILE_INDEX_ENTRY array.
173 | 
174 | ```
175 | CHUNK_META, total bytes: 33
176 |     byte {32}        - Hash of chunk (This is standard SHA1 hash of 20 bytes, with 12 bytes of padding)
177 |     uint8 {1}        - Flags
178 | ```
179 | Possible flags are: NoneMetaFlag (0), CompressedMetaFlag (1), MemoryMappedMetaFlag (2)
180 | However, in the Grounded utoc file, the flag value is always 1.
181 | 
182 | 
183 | ____
184 | ### depsFile Format
185 | This still belongs to the .utoc file format, but it's encoded in the .ucas file.
186 | In the .ucas file, either the first large chunk of data (in header version 2), or the last chunk of data (in version 3) is specified as follows:
187 | 
188 | ```
189 | depsFile HEADER, total bytes: 32
190 |     uint64 {8}      -   Chunk ID of this "file"
191 |     uint64 {8}      -   Number of IDs (nID)
192 |     uint32 {4}      -   sizeof(chunkID) (always 8)
193 |     uint32 {4}      -   as of now, an unknown value
194 |     byte   {4}      -   zero bytes PADDING
195 |     uint32 {4}      -   Number of IDs (again, but now uint32?)
196 | ```
197 | The header is followed by an ORDERED list of Chunk IDs, of size _nID_. 
198 | The list is unique, and it contains all of the IDs that are present in the .utoc file.
199 | I suspect that this is done for performance, for quick searching.
200 | There's just one Chunk ID missing, and that's the thing with the chunk type being 10 (so the one that contains this "depsFile Format").
201 | 
202 | The list is immediately followed by a uint32 value describing the size in bytes of the rest of the file.
203 | It excludes the trailling (8) zerobytes.
204 | 
205 | The "rest of the file" consists of the following very interesting information.
206 | First, there are blocks of 32 bytes, with data that links .uasset files to other files.
207 | These are the connections that are made between dependencies, and they show how many exports each entry has.
208 | For every single ID that was provided in the previous part with the chunk IDs, there is a corresponding entry with this structure;
209 | 
210 | ```
211 | depsFile DEPENDENCIES, total bytes: 32
212 |     uint64 {8}      - File size (uncompressed)
213 |     uint32 {4}      - Number of Export Objects
214 |     uint32 {4}      - A number either 1, 2 or 3. Not sure what this means
215 | 
216 |     uint64 {8}      - Index of some sort; unique and starting at 0, but skipping some numbers
217 |     uint32 {4}      - Number of Dependency Packages
218 |     uint32 {4}      - Offset to dependency packages
219 | ```
220 | The list of these dependencies is followed by a long list of chunk IDs, which are in fact the dependencies.
221 | The offset in a dependency entry points to the start of such chunk ID, but these offsets are a bit tricky.
222 | This offset is taken from the specific offset entry, before reading the entry, so all offsets jump over the whole list.
223 | The number of dependency packages tells how far one must read!
224 | I think this could have been done a bit more efficiently, but unfortunately I didn't design this file format.
225 | 
226 | The number of IDs in the dependency area can be calculated.
227 | The length of the "rest of the file" is known, which consists of a number of dependency-entries and the IDs.
228 | We know how many dependency-entries there are, so we can calculate how many IDs there are.
229 | The list of IDs is followed by 8 nullbytes, which dictates the end of the file.
230 | 
231 | ____
232 | # UAsset File Format
233 | After unpacking the .ucas file using the .utoc file, I found out that the .uasset files that were created differ quite from the original .uasset files.
234 | They used to be different after unpacking with the .pak files.
235 | Therefore, I decided to figure out the (new) .uasset file format after unpacking.
236 | 
237 | A notable change is that when unpacking, the unreal signature (C1 83 2A 9E) is omitted.
238 | The version number is omitted as well. 
239 | I think this is done to preserve space, as these are probably constant among all .uasset files in the .ucas file.
240 | 
241 | In addition to this, there is no split between .uasset and .uexp anymore; everything is concatenated within one .uasset file.
242 | This is also the intended way in which .uasset files are stored, I believe.
243 | It's just useful to split the two in some cases.
244 | 
245 | The uasset header is divided into two parts; a constant file header (of size 64), and a variable sized part.
246 | After the complete .uasset header, the contents of the would be .uexp file starts.
247 | 
248 | Note: most of this information is reverse-engineerd by looking at the information in the .ucas viewer linked before.
249 | ```
250 | UASSET HEADER, total bytes: 64
251 |     uint64 {8}      - Name in FMappedName format.  See https://docs.unrealengine.com/5.0/en-US/API/Runtime/Core/Serialization/FMappedName/
252 |     uint64 {8}      - SourceName in FMappedName format
253 |     uint32 {4}      - "Package Flags" Generally constant at (00 00 00 80).  See https://docs.unrealengine.com/5.1/en-US/API/Runtime/CoreUObject/UObject/EPackageFlags/ 
254 |     uint32 {4}      - CookedHeaderSize - This is the total header size, if it were an old .uasset file, so it deviates
255 |     int32 {4}      - Name Map Offset
256 |     int32 {4}      - Name Map Size (in bytes)
257 |     int32 {4}      - Name Map Hashes offset
258 |     int32 {4}      - Name Map Hashes Size (in bytes)
259 |     int32 {4}      - Import Map Offset
260 |     int32 {4}      - Export Map offset
261 |     int32 {4}      - Export Bundles Offset
262 |     int32 {4}      - Graph Data Offset / Dependency Packages offset (also duplicated in dependency file in .ucas)
263 |     int32 {4}      - Graph Data Size / Dependency Package Size (in bytes)
264 |     int32 {4}      - Padding
265 | ```
266 | The header indicates a lot of offsets of all the parts in the .uasset file.
267 | The remainder of this section highlights each of these parts in order.
268 | Sometimes, the header lists the length of a few parts, but I'm not sure why it does this, as all lengths can be inferred from the other offsets, except maybe the list of strings.
269 | 
270 | Directly after the file header, there is one nullbyte, after which the name directory index is shown.
271 | ```
272 | NAMES DIRECTORY
273 | for each name
274 |     uint8 {1}       - Name length (EXCLUDING null terminator)
275 |     byte  {X}       - Name
276 |     byte  {1}       - null terminator
277 | ```
278 | Due to the strings in the Names Directory being of different sizes, it is possible that the byte count is not aligned anymore.
279 | After the Names Directory, there are nullbytes to make it aligned to 8 bytes.
280 | This is probably done for performance reasons.
281 | 
282 | 
283 | ### String Hashes
284 | The names directory is followed by a list 64-bit hashes, representing the hashes of the strings.
285 | The very first value is the "AlgorithmID" of the hash.
286 | This value seems to be always `00 00 64 C1 00 00 00 00`, and this corresponds to this line of code in the [Unreal Engine source code](https://github.com/EpicGames/UnrealEngine/blob/d8c1ecd52eb4728637881c550b39794afed78db3/Engine/Source/Runtime/Core/Private/UObject/UnrealNames.cpp#L748).
287 | The hashing algorithm is the CityHash64 algorithm, and it works on strings that were made to be lowercase.
288 | So to get the value, make the string lowercase and hash it with the CityHash64 algorithm.
289 | 
290 | ### Import Objects
291 | The list of string hashes is followed by a list of Import Object IDs.
292 | This is not the same as the file IDs, and I'm not sure what these values represent.
293 | Each value is 8 bytes, and if the import name is "None", the value is `0xFFFFFFFFFFFFFFFF`, or -1.
294 | Not sure what to do with this, but the number of entries correspond to the number of import objects in the ucas file viewer.
295 | 
296 | In Helios' tool, the Import Objects correspond to the Linked Classes.
297 | 
298 | 
299 | ### Export Objects
300 | The next area of the file, are Export Objects.
301 | These are stored in a specific file structure, shown below.
302 | 
303 | ```
304 | EXPORT OBJECTS
305 |     uint64 {8}                   - Cooked Serial Offset
306 |     uint64 {8}                   - Cooked Serial Size
307 |     FMappedName {4}              - Object Name
308 |     FPackageObjectIndex {8}      - Outer Index
309 |     FPackageObjectIndex {8}      - Class Index
310 |     FPackageObjectIndex {8}      - Super Index
311 |     FPackageObjectIndex {8}      - Template Index
312 |     FPackageObjectIndex {8}      - Global Import Index
313 |     uint64 {8}                   - Public Export Hash
314 |     EObjectFlags {1}             - Object Flags
315 |     EExportFilterFlags {1}       - Client/Server Flags
316 |     byte {2}                     - Padding
317 | ```
318 | The fields that were used are mainly copied from the .ucas file viewer. 
319 | In any case, the offsets that are described is an integer describing the offset in the name directory, or the list of strings.
320 | 
321 | The part after the .uasset file header is built up from different ExportObjects.
322 | When there are multiple ExportObjects, they are consecutive, which the SerialOffset and sizes illustrate.
323 | For the very first ExportObject, the Serial Offset field is the exact same value as the "total header size" in the header of the file.
324 | Now in this new file format, this doesn't really hold anymore, as it differs from the regular file.
325 | However, the serial offset states where the .uexp portion of the file starts.
326 | The Serial Size also has great significance, as this is the length of the .uexp portion of the file.
327 | 
328 | The object name offset and the class name offset probably have some use as well, but these probably refer to the old file format.
329 | Therefore, the offset is off and I'm not sure how to correct it right now.
330 | Changing files is probably mostly impacting the serial size and the serial offset, so I'll keep this as a mystery for now.
331 | 
332 | ### ExportObject metadata?
333 | The export objects are followed by a strange data structure.
334 | It first starts with a 64-bit number, which seems to have no relation to the rest.
335 | Afterwards, there is an enumeration of some kind of metadata to the export objects.
336 | The metadata consists of four 32-bit numbers, and there are exactly as many metadata entries as export objects.
337 | This is still a mystery, but I don't think I'll touch ExportObjects anyway.
338 | 
339 | 
340 | ### Dependency packages
341 | After all export objects information, there is a list of dependency packages.
342 | It starts with a uint32 stating how many dependency entries there are.
343 | After this, the following dependencies are shown;
344 | ```
345 | DEPENDENCY PACKAGE
346 |     uint64 {8}      - ID
347 |     uint32 {4}      - Number of Entries (?) // Not quite sure, it's often just 1, sometimes 2 and 3.
348 |     int32 {4}       - is present*
349 |     uint32 {4}      - mostly one // not sure what it is, but almost always 1.
350 |     
351 |     if (number of entries > 1){
352 |         uint32 {4 * (2 * (numberOfEntries - 1))}**
353 |     }
354 | ```
355 | `*` If the value of "is present" is 0, then the ID listed is included in the current .ucas file.
356 | If this value is -1, it's not included in the current .ucas file.
357 | 
358 | `**` If the number of entries is 2 or 3, there are more numbers defined.
359 | For every number larger than 1, there are two additional uint32 numbers in a dependency entry.
360 | 
361 | It's quite clear that I am still not sure what all of the fields mean and how they relate to each other.
362 | However, after the list of the dependencies, the entire former .uexp file starts!
363 | 
364 | ### End of the header
365 | This concludes the .uasset header part of the file.
366 | There are quite some values that are still unknown to me.
367 | However, most of these values will probably not change based on the created mods.
368 | I can only hope that I know enough to do the most interesting stuff with!
369 | 


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105 | feature that (1) displays an appropriate copyright notice, and (2)
106 | tells the user that there is no warranty for the work (except to the
107 | extent that warranties are provided), that licensees may convey the
108 | work under this License, and how to view a copy of this License.  If
109 | the interface presents a list of user commands or options, such as a
110 | menu, a prominent item in the list meets this criterion.
111 | 
112 |   1. Source Code.
113 | 
114 |   The "source code" for a work means the preferred form of the work
115 | for making modifications to it.  "Object code" means any non-source
116 | form of a work.
117 | 
118 |   A "Standard Interface" means an interface that either is an official
119 | standard defined by a recognized standards body, or, in the case of
120 | interfaces specified for a particular programming language, one that
121 | is widely used among developers working in that language.
122 | 
123 |   The "System Libraries" of an executable work include anything, other
124 | than the work as a whole, that (a) is included in the normal form of
125 | packaging a Major Component, but which is not part of that Major
126 | Component, and (b) serves only to enable use of the work with that
127 | Major Component, or to implement a Standard Interface for which an
128 | implementation is available to the public in source code form.  A
129 | "Major Component", in this context, means a major essential component
130 | (kernel, window system, and so on) of the specific operating system
131 | (if any) on which the executable work runs, or a compiler used to
132 | produce the work, or an object code interpreter used to run it.
133 | 
134 |   The "Corresponding Source" for a work in object code form means all
135 | the source code needed to generate, install, and (for an executable
136 | work) run the object code and to modify the work, including scripts to
137 | control those activities.  However, it does not include the work's
138 | System Libraries, or general-purpose tools or generally available free
139 | programs which are used unmodified in performing those activities but
140 | which are not part of the work.  For example, Corresponding Source
141 | includes interface definition files associated with source files for
142 | the work, and the source code for shared libraries and dynamically
143 | linked subprograms that the work is specifically designed to require,
144 | such as by intimate data communication or control flow between those
145 | subprograms and other parts of the work.
146 | 
147 |   The Corresponding Source need not include anything that users
148 | can regenerate automatically from other parts of the Corresponding
149 | Source.
150 | 
151 |   The Corresponding Source for a work in source code form is that
152 | same work.
153 | 
154 |   2. Basic Permissions.
155 | 
156 |   All rights granted under this License are granted for the term of
157 | copyright on the Program, and are irrevocable provided the stated
158 | conditions are met.  This License explicitly affirms your unlimited
159 | permission to run the unmodified Program.  The output from running a
160 | covered work is covered by this License only if the output, given its
161 | content, constitutes a covered work.  This License acknowledges your
162 | rights of fair use or other equivalent, as provided by copyright law.
163 | 
164 |   You may make, run and propagate covered works that you do not
165 | convey, without conditions so long as your license otherwise remains
166 | in force.  You may convey covered works to others for the sole purpose
167 | of having them make modifications exclusively for you, or provide you
168 | with facilities for running those works, provided that you comply with
169 | the terms of this License in conveying all material for which you do
170 | not control copyright.  Those thus making or running the covered works
171 | for you must do so exclusively on your behalf, under your direction
172 | and control, on terms that prohibit them from making any copies of
173 | your copyrighted material outside their relationship with you.
174 | 
175 |   Conveying under any other circumstances is permitted solely under
176 | the conditions stated below.  Sublicensing is not allowed; section 10
177 | makes it unnecessary.
178 | 
179 |   3. Protecting Users' Legal Rights From Anti-Circumvention Law.
180 | 
181 |   No covered work shall be deemed part of an effective technological
182 | measure under any applicable law fulfilling obligations under article
183 | 11 of the WIPO copyright treaty adopted on 20 December 1996, or
184 | similar laws prohibiting or restricting circumvention of such
185 | measures.
186 | 
187 |   When you convey a covered work, you waive any legal power to forbid
188 | circumvention of technological measures to the extent such circumvention
189 | is effected by exercising rights under this License with respect to
190 | the covered work, and you disclaim any intention to limit operation or
191 | modification of the work as a means of enforcing, against the work's
192 | users, your or third parties' legal rights to forbid circumvention of
193 | technological measures.
194 | 
195 |   4. Conveying Verbatim Copies.
196 | 
197 |   You may convey verbatim copies of the Program's source code as you
198 | receive it, in any medium, provided that you conspicuously and
199 | appropriately publish on each copy an appropriate copyright notice;
200 | keep intact all notices stating that this License and any
201 | non-permissive terms added in accord with section 7 apply to the code;
202 | keep intact all notices of the absence of any warranty; and give all
203 | recipients a copy of this License along with the Program.
204 | 
205 |   You may charge any price or no price for each copy that you convey,
206 | and you may offer support or warranty protection for a fee.
207 | 
208 |   5. Conveying Modified Source Versions.
209 | 
210 |   You may convey a work based on the Program, or the modifications to
211 | produce it from the Program, in the form of source code under the
212 | terms of section 4, provided that you also meet all of these conditions:
213 | 
214 |     a) The work must carry prominent notices stating that you modified
215 |     it, and giving a relevant date.
216 | 
217 |     b) The work must carry prominent notices stating that it is
218 |     released under this License and any conditions added under section
219 |     7.  This requirement modifies the requirement in section 4 to
220 |     "keep intact all notices".
221 | 
222 |     c) You must license the entire work, as a whole, under this
223 |     License to anyone who comes into possession of a copy.  This
224 |     License will therefore apply, along with any applicable section 7
225 |     additional terms, to the whole of the work, and all its parts,
226 |     regardless of how they are packaged.  This License gives no
227 |     permission to license the work in any other way, but it does not
228 |     invalidate such permission if you have separately received it.
229 | 
230 |     d) If the work has interactive user interfaces, each must display
231 |     Appropriate Legal Notices; however, if the Program has interactive
232 |     interfaces that do not display Appropriate Legal Notices, your
233 |     work need not make them do so.
234 | 
235 |   A compilation of a covered work with other separate and independent
236 | works, which are not by their nature extensions of the covered work,
237 | and which are not combined with it such as to form a larger program,
238 | in or on a volume of a storage or distribution medium, is called an
239 | "aggregate" if the compilation and its resulting copyright are not
240 | used to limit the access or legal rights of the compilation's users
241 | beyond what the individual works permit.  Inclusion of a covered work
242 | in an aggregate does not cause this License to apply to the other
243 | parts of the aggregate.
244 | 
245 |   6. Conveying Non-Source Forms.
246 | 
247 |   You may convey a covered work in object code form under the terms
248 | of sections 4 and 5, provided that you also convey the
249 | machine-readable Corresponding Source under the terms of this License,
250 | in one of these ways:
251 | 
252 |     a) Convey the object code in, or embodied in, a physical product
253 |     (including a physical distribution medium), accompanied by the
254 |     Corresponding Source fixed on a durable physical medium
255 |     customarily used for software interchange.
256 | 
257 |     b) Convey the object code in, or embodied in, a physical product
258 |     (including a physical distribution medium), accompanied by a
259 |     written offer, valid for at least three years and valid for as
260 |     long as you offer spare parts or customer support for that product
261 |     model, to give anyone who possesses the object code either (1) a
262 |     copy of the Corresponding Source for all the software in the
263 |     product that is covered by this License, on a durable physical
264 |     medium customarily used for software interchange, for a price no
265 |     more than your reasonable cost of physically performing this
266 |     conveying of source, or (2) access to copy the
267 |     Corresponding Source from a network server at no charge.
268 | 
269 |     c) Convey individual copies of the object code with a copy of the
270 |     written offer to provide the Corresponding Source.  This
271 |     alternative is allowed only occasionally and noncommercially, and
272 |     only if you received the object code with such an offer, in accord
273 |     with subsection 6b.
274 | 
275 |     d) Convey the object code by offering access from a designated
276 |     place (gratis or for a charge), and offer equivalent access to the
277 |     Corresponding Source in the same way through the same place at no
278 |     further charge.  You need not require recipients to copy the
279 |     Corresponding Source along with the object code.  If the place to
280 |     copy the object code is a network server, the Corresponding Source
281 |     may be on a different server (operated by you or a third party)
282 |     that supports equivalent copying facilities, provided you maintain
283 |     clear directions next to the object code saying where to find the
284 |     Corresponding Source.  Regardless of what server hosts the
285 |     Corresponding Source, you remain obligated to ensure that it is
286 |     available for as long as needed to satisfy these requirements.
287 | 
288 |     e) Convey the object code using peer-to-peer transmission, provided
289 |     you inform other peers where the object code and Corresponding
290 |     Source of the work are being offered to the general public at no
291 |     charge under subsection 6d.
292 | 
293 |   A separable portion of the object code, whose source code is excluded
294 | from the Corresponding Source as a System Library, need not be
295 | included in conveying the object code work.
296 | 
297 |   A "User Product" is either (1) a "consumer product", which means any
298 | tangible personal property which is normally used for personal, family,
299 | or household purposes, or (2) anything designed or sold for incorporation
300 | into a dwelling.  In determining whether a product is a consumer product,
301 | doubtful cases shall be resolved in favor of coverage.  For a particular
302 | product received by a particular user, "normally used" refers to a
303 | typical or common use of that class of product, regardless of the status
304 | of the particular user or of the way in which the particular user
305 | actually uses, or expects or is expected to use, the product.  A product
306 | is a consumer product regardless of whether the product has substantial
307 | commercial, industrial or non-consumer uses, unless such uses represent
308 | the only significant mode of use of the product.
309 | 
310 |   "Installation Information" for a User Product means any methods,
311 | procedures, authorization keys, or other information required to install
312 | and execute modified versions of a covered work in that User Product from
313 | a modified version of its Corresponding Source.  The information must
314 | suffice to ensure that the continued functioning of the modified object
315 | code is in no case prevented or interfered with solely because
316 | modification has been made.
317 | 
318 |   If you convey an object code work under this section in, or with, or
319 | specifically for use in, a User Product, and the conveying occurs as
320 | part of a transaction in which the right of possession and use of the
321 | User Product is transferred to the recipient in perpetuity or for a
322 | fixed term (regardless of how the transaction is characterized), the
323 | Corresponding Source conveyed under this section must be accompanied
324 | by the Installation Information.  But this requirement does not apply
325 | if neither you nor any third party retains the ability to install
326 | modified object code on the User Product (for example, the work has
327 | been installed in ROM).
328 | 
329 |   The requirement to provide Installation Information does not include a
330 | requirement to continue to provide support service, warranty, or updates
331 | for a work that has been modified or installed by the recipient, or for
332 | the User Product in which it has been modified or installed.  Access to a
333 | network may be denied when the modification itself materially and
334 | adversely affects the operation of the network or violates the rules and
335 | protocols for communication across the network.
336 | 
337 |   Corresponding Source conveyed, and Installation Information provided,
338 | in accord with this section must be in a format that is publicly
339 | documented (and with an implementation available to the public in
340 | source code form), and must require no special password or key for
341 | unpacking, reading or copying.
342 | 
343 |   7. Additional Terms.
344 | 
345 |   "Additional permissions" are terms that supplement the terms of this
346 | License by making exceptions from one or more of its conditions.
347 | Additional permissions that are applicable to the entire Program shall
348 | be treated as though they were included in this License, to the extent
349 | that they are valid under applicable law.  If additional permissions
350 | apply only to part of the Program, that part may be used separately
351 | under those permissions, but the entire Program remains governed by
352 | this License without regard to the additional permissions.
353 | 
354 |   When you convey a copy of a covered work, you may at your option
355 | remove any additional permissions from that copy, or from any part of
356 | it.  (Additional permissions may be written to require their own
357 | removal in certain cases when you modify the work.)  You may place
358 | additional permissions on material, added by you to a covered work,
359 | for which you have or can give appropriate copyright permission.
360 | 
361 |   Notwithstanding any other provision of this License, for material you
362 | add to a covered work, you may (if authorized by the copyright holders of
363 | that material) supplement the terms of this License with terms:
364 | 
365 |     a) Disclaiming warranty or limiting liability differently from the
366 |     terms of sections 15 and 16 of this License; or
367 | 
368 |     b) Requiring preservation of specified reasonable legal notices or
369 |     author attributions in that material or in the Appropriate Legal
370 |     Notices displayed by works containing it; or
371 | 
372 |     c) Prohibiting misrepresentation of the origin of that material, or
373 |     requiring that modified versions of such material be marked in
374 |     reasonable ways as different from the original version; or
375 | 
376 |     d) Limiting the use for publicity purposes of names of licensors or
377 |     authors of the material; or
378 | 
379 |     e) Declining to grant rights under trademark law for use of some
380 |     trade names, trademarks, or service marks; or
381 | 
382 |     f) Requiring indemnification of licensors and authors of that
383 |     material by anyone who conveys the material (or modified versions of
384 |     it) with contractual assumptions of liability to the recipient, for
385 |     any liability that these contractual assumptions directly impose on
386 |     those licensors and authors.
387 | 
388 |   All other non-permissive additional terms are considered "further
389 | restrictions" within the meaning of section 10.  If the Program as you
390 | received it, or any part of it, contains a notice stating that it is
391 | governed by this License along with a term that is a further
392 | restriction, you may remove that term.  If a license document contains
393 | a further restriction but permits relicensing or conveying under this
394 | License, you may add to a covered work material governed by the terms
395 | of that license document, provided that the further restriction does
396 | not survive such relicensing or conveying.
397 | 
398 |   If you add terms to a covered work in accord with this section, you
399 | must place, in the relevant source files, a statement of the
400 | additional terms that apply to those files, or a notice indicating
401 | where to find the applicable terms.
402 | 
403 |   Additional terms, permissive or non-permissive, may be stated in the
404 | form of a separately written license, or stated as exceptions;
405 | the above requirements apply either way.
406 | 
407 |   8. Termination.
408 | 
409 |   You may not propagate or modify a covered work except as expressly
410 | provided under this License.  Any attempt otherwise to propagate or
411 | modify it is void, and will automatically terminate your rights under
412 | this License (including any patent licenses granted under the third
413 | paragraph of section 11).
414 | 
415 |   However, if you cease all violation of this License, then your
416 | license from a particular copyright holder is reinstated (a)
417 | provisionally, unless and until the copyright holder explicitly and
418 | finally terminates your license, and (b) permanently, if the copyright
419 | holder fails to notify you of the violation by some reasonable means
420 | prior to 60 days after the cessation.
421 | 
422 |   Moreover, your license from a particular copyright holder is
423 | reinstated permanently if the copyright holder notifies you of the
424 | violation by some reasonable means, this is the first time you have
425 | received notice of violation of this License (for any work) from that
426 | copyright holder, and you cure the violation prior to 30 days after
427 | your receipt of the notice.
428 | 
429 |   Termination of your rights under this section does not terminate the
430 | licenses of parties who have received copies or rights from you under
431 | this License.  If your rights have been terminated and not permanently
432 | reinstated, you do not qualify to receive new licenses for the same
433 | material under section 10.
434 | 
435 |   9. Acceptance Not Required for Having Copies.
436 | 
437 |   You are not required to accept this License in order to receive or
438 | run a copy of the Program.  Ancillary propagation of a covered work
439 | occurring solely as a consequence of using peer-to-peer transmission
440 | to receive a copy likewise does not require acceptance.  However,
441 | nothing other than this License grants you permission to propagate or
442 | modify any covered work.  These actions infringe copyright if you do
443 | not accept this License.  Therefore, by modifying or propagating a
444 | covered work, you indicate your acceptance of this License to do so.
445 | 
446 |   10. Automatic Licensing of Downstream Recipients.
447 | 
448 |   Each time you convey a covered work, the recipient automatically
449 | receives a license from the original licensors, to run, modify and
450 | propagate that work, subject to this License.  You are not responsible
451 | for enforcing compliance by third parties with this License.
452 | 
453 |   An "entity transaction" is a transaction transferring control of an
454 | organization, or substantially all assets of one, or subdividing an
455 | organization, or merging organizations.  If propagation of a covered
456 | work results from an entity transaction, each party to that
457 | transaction who receives a copy of the work also receives whatever
458 | licenses to the work the party's predecessor in interest had or could
459 | give under the previous paragraph, plus a right to possession of the
460 | Corresponding Source of the work from the predecessor in interest, if
461 | the predecessor has it or can get it with reasonable efforts.
462 | 
463 |   You may not impose any further restrictions on the exercise of the
464 | rights granted or affirmed under this License.  For example, you may
465 | not impose a license fee, royalty, or other charge for exercise of
466 | rights granted under this License, and you may not initiate litigation
467 | (including a cross-claim or counterclaim in a lawsuit) alleging that
468 | any patent claim is infringed by making, using, selling, offering for
469 | sale, or importing the Program or any portion of it.
470 | 
471 |   11. Patents.
472 | 
473 |   A "contributor" is a copyright holder who authorizes use under this
474 | License of the Program or a work on which the Program is based.  The
475 | work thus licensed is called the contributor's "contributor version".
476 | 
477 |   A contributor's "essential patent claims" are all patent claims
478 | owned or controlled by the contributor, whether already acquired or
479 | hereafter acquired, that would be infringed by some manner, permitted
480 | by this License, of making, using, or selling its contributor version,
481 | but do not include claims that would be infringed only as a
482 | consequence of further modification of the contributor version.  For
483 | purposes of this definition, "control" includes the right to grant
484 | patent sublicenses in a manner consistent with the requirements of
485 | this License.
486 | 
487 |   Each contributor grants you a non-exclusive, worldwide, royalty-free
488 | patent license under the contributor's essential patent claims, to
489 | make, use, sell, offer for sale, import and otherwise run, modify and
490 | propagate the contents of its contributor version.
491 | 
492 |   In the following three paragraphs, a "patent license" is any express
493 | agreement or commitment, however denominated, not to enforce a patent
494 | (such as an express permission to practice a patent or covenant not to
495 | sue for patent infringement).  To "grant" such a patent license to a
496 | party means to make such an agreement or commitment not to enforce a
497 | patent against the party.
498 | 
499 |   If you convey a covered work, knowingly relying on a patent license,
500 | and the Corresponding Source of the work is not available for anyone
501 | to copy, free of charge and under the terms of this License, through a
502 | publicly available network server or other readily accessible means,
503 | then you must either (1) cause the Corresponding Source to be so
504 | available, or (2) arrange to deprive yourself of the benefit of the
505 | patent license for this particular work, or (3) arrange, in a manner
506 | consistent with the requirements of this License, to extend the patent
507 | license to downstream recipients.  "Knowingly relying" means you have
508 | actual knowledge that, but for the patent license, your conveying the
509 | covered work in a country, or your recipient's use of the covered work
510 | in a country, would infringe one or more identifiable patents in that
511 | country that you have reason to believe are valid.
512 | 
513 |   If, pursuant to or in connection with a single transaction or
514 | arrangement, you convey, or propagate by procuring conveyance of, a
515 | covered work, and grant a patent license to some of the parties
516 | receiving the covered work authorizing them to use, propagate, modify
517 | or convey a specific copy of the covered work, then the patent license
518 | you grant is automatically extended to all recipients of the covered
519 | work and works based on it.
520 | 
521 |   A patent license is "discriminatory" if it does not include within
522 | the scope of its coverage, prohibits the exercise of, or is
523 | conditioned on the non-exercise of one or more of the rights that are
524 | specifically granted under this License.  You may not convey a covered
525 | work if you are a party to an arrangement with a third party that is
526 | in the business of distributing software, under which you make payment
527 | to the third party based on the extent of your activity of conveying
528 | the work, and under which the third party grants, to any of the
529 | parties who would receive the covered work from you, a discriminatory
530 | patent license (a) in connection with copies of the covered work
531 | conveyed by you (or copies made from those copies), or (b) primarily
532 | for and in connection with specific products or compilations that
533 | contain the covered work, unless you entered into that arrangement,
534 | or that patent license was granted, prior to 28 March 2007.
535 | 
536 |   Nothing in this License shall be construed as excluding or limiting
537 | any implied license or other defenses to infringement that may
538 | otherwise be available to you under applicable patent law.
539 | 
540 |   12. No Surrender of Others' Freedom.
541 | 
542 |   If conditions are imposed on you (whether by court order, agreement or
543 | otherwise) that contradict the conditions of this License, they do not
544 | excuse you from the conditions of this License.  If you cannot convey a
545 | covered work so as to satisfy simultaneously your obligations under this
546 | License and any other pertinent obligations, then as a consequence you may
547 | not convey it at all.  For example, if you agree to terms that obligate you
548 | to collect a royalty for further conveying from those to whom you convey
549 | the Program, the only way you could satisfy both those terms and this
550 | License would be to refrain entirely from conveying the Program.
551 | 
552 |   13. Use with the GNU Affero General Public License.
553 | 
554 |   Notwithstanding any other provision of this License, you have
555 | permission to link or combine any covered work with a work licensed
556 | under version 3 of the GNU Affero General Public License into a single
557 | combined work, and to convey the resulting work.  The terms of this
558 | License will continue to apply to the part which is the covered work,
559 | but the special requirements of the GNU Affero General Public License,
560 | section 13, concerning interaction through a network will apply to the
561 | combination as such.
562 | 
563 |   14. Revised Versions of this License.
564 | 
565 |   The Free Software Foundation may publish revised and/or new versions of
566 | the GNU General Public License from time to time.  Such new versions will
567 | be similar in spirit to the present version, but may differ in detail to
568 | address new problems or concerns.
569 | 
570 |   Each version is given a distinguishing version number.  If the
571 | Program specifies that a certain numbered version of the GNU General
572 | Public License "or any later version" applies to it, you have the
573 | option of following the terms and conditions either of that numbered
574 | version or of any later version published by the Free Software
575 | Foundation.  If the Program does not specify a version number of the
576 | GNU General Public License, you may choose any version ever published
577 | by the Free Software Foundation.
578 | 
579 |   If the Program specifies that a proxy can decide which future
580 | versions of the GNU General Public License can be used, that proxy's
581 | public statement of acceptance of a version permanently authorizes you
582 | to choose that version for the Program.
583 | 
584 |   Later license versions may give you additional or different
585 | permissions.  However, no additional obligations are imposed on any
586 | author or copyright holder as a result of your choosing to follow a
587 | later version.
588 | 
589 |   15. Disclaimer of Warranty.
590 | 
591 |   THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
592 | APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
593 | HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
594 | OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
595 | THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
596 | PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
597 | IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
598 | ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
599 | 
600 |   16. Limitation of Liability.
601 | 
602 |   IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
603 | WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
604 | THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
605 | GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
606 | USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
607 | DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
608 | PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
609 | EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
610 | SUCH DAMAGES.
611 | 
612 |   17. Interpretation of Sections 15 and 16.
613 | 
614 |   If the disclaimer of warranty and limitation of liability provided
615 | above cannot be given local legal effect according to their terms,
616 | reviewing courts shall apply local law that most closely approximates
617 | an absolute waiver of all civil liability in connection with the
618 | Program, unless a warranty or assumption of liability accompanies a
619 | copy of the Program in return for a fee.
620 | 
621 |                      END OF TERMS AND CONDITIONS
622 | 
623 |             How to Apply These Terms to Your New Programs
624 | 
625 |   If you develop a new program, and you want it to be of the greatest
626 | possible use to the public, the best way to achieve this is to make it
627 | free software which everyone can redistribute and change under these terms.
628 | 
629 |   To do so, attach the following notices to the program.  It is safest
630 | to attach them to the start of each source file to most effectively
631 | state the exclusion of warranty; and each file should have at least
632 | the "copyright" line and a pointer to where the full notice is found.
633 | 
634 |     <one line to give the program's name and a brief idea of what it does.>
635 |     Copyright (C) <year>  <name of author>
636 | 
637 |     This program is free software: you can redistribute it and/or modify
638 |     it under the terms of the GNU General Public License as published by
639 |     the Free Software Foundation, either version 3 of the License, or
640 |     (at your option) any later version.
641 | 
642 |     This program is distributed in the hope that it will be useful,
643 |     but WITHOUT ANY WARRANTY; without even the implied warranty of
644 |     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
645 |     GNU General Public License for more details.
646 | 
647 |     You should have received a copy of the GNU General Public License
648 |     along with this program.  If not, see <https://www.gnu.org/licenses/>.
649 | 
650 | Also add information on how to contact you by electronic and paper mail.
651 | 
652 |   If the program does terminal interaction, make it output a short
653 | notice like this when it starts in an interactive mode:
654 | 
655 |     <program>  Copyright (C) <year>  <name of author>
656 |     This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
657 |     This is free software, and you are welcome to redistribute it
658 |     under certain conditions; type `show c' for details.
659 | 
660 | The hypothetical commands `show w' and `show c' should show the appropriate
661 | parts of the General Public License.  Of course, your program's commands
662 | might be different; for a GUI interface, you would use an "about box".
663 | 
664 |   You should also get your employer (if you work as a programmer) or school,
665 | if any, to sign a "copyright disclaimer" for the program, if necessary.
666 | For more information on this, and how to apply and follow the GNU GPL, see
667 | <https://www.gnu.org/licenses/>.
668 | 
669 |   The GNU General Public License does not permit incorporating your program
670 | into proprietary programs.  If your program is a subroutine library, you
671 | may consider it more useful to permit linking proprietary applications with
672 | the library.  If this is what you want to do, use the GNU Lesser General
673 | Public License instead of this License.  But first, please read
674 | <https://www.gnu.org/licenses/why-not-lgpl.html>.
675 | 


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
  1 | ## UECastoc Design for DLL
  2 | 
  3 | I have started this project over a year ago, without knowing whether it would ever work.
  4 | Just jumping in and reverse engineering the file format has proved to be effective.
  5 | However, the resulting code is currently only really usable within Go only.
  6 | For most modding tools, it would be nice if you can create a user interface to go with it.
  7 | Go isn't meant for creating user interfaces, and not many people in the modding scene do anything with Go.
  8 | Therefore, I've decided to make this a DLL for Windows, so that you can still use the code that I wrote, but independent of Go.
  9 | 
 10 | The focus of this DLL is to create packing/unpacking support for Unreal Engine games with an API that is usable.
 11 | This API is documented below
 12 | 
 13 | ## Would you like to support me?
 14 | You can donate using this [link](https://www.paypal.com/donate/?hosted_button_id=VLFVGJ749MQCC).
 15 | 
 16 | ## Core Features of DLL
 17 | 
 18 | This section lists the core features that this DLL will support.
 19 | I do this by showing what the API functions should look like.
 20 | 
 21 | ### Error Handling
 22 | Error handling is unique in Go.
 23 | There's even a specific type for it!
 24 | In C, error handling is often done by returning -1 or NULL if something went wrong.
 25 | If you need more information, it is possible to display a message using the _strerror_ function.
 26 | 
 27 | The displayed message originates from the _errno_ value.
 28 | From a DLL written in Go, this is not easy to set, though.
 29 | Therefore, I provided a function that simply returns the most recent error as a string.
 30 | 
 31 | ```c
 32 | char *getError();
 33 | ```
 34 | 
 35 | This can always be called from your program.
 36 | Whenever this function is called, do free the pointer that is provided!
 37 | 
 38 | ### Listing Game Files
 39 | The .utoc game file indicates which files are included in the .ucas file.
 40 | This is a long list of game files which is structured in directories.
 41 | The DLL provides the following function for this.
 42 | 
 43 | ```c
 44 | char **listGameFiles(char *utocFileName, int *n, char *AESKey);
 45 | ```
 46 | 
 47 | The function requires the name of the .utoc file, as this file contains the list of game files.
 48 | You must also pass in a pointer to an integer _n_, which will contain the number of strings in the list when it returns.
 49 | Optionally, you can provide an AES key for utoc files that are encrypted with AES.
 50 | While this DLL is quite nice, it can not break AES encryption (yet).
 51 | Do provide the key as a hex string, otherwise simply pass NULL.
 52 | 
 53 | If the value of _n_ is -1 after calling, no strings were returned, and the char ** should be NULL.
 54 | Otherwise, the char ** contains _n_ strings, where each string is the entire path to a file.
 55 | 
 56 | The file is read and closed by the DLL, but the list must be freed by the caller.
 57 | This can also be done with the freeStringList function that comes with the DLL.
 58 | Just provide the pointer to the string list and the length of the list.
 59 | Do provide an accurate length, as otherwise memory leaks or double frees may occur.
 60 | ```c
 61 | void freeStringList(char **stringlist, int n);
 62 | ```
 63 | It goes without saying, but the pointer should not be used afterwards.
 64 | 
 65 | 
 66 | ### Create Manifest File
 67 | A Manifest file is required to build game files into a mod file.
 68 | The Manifest file contains a list of filenames with their Chunk IDs, with some other data that is needed to build a mod for the game later.
 69 | ```c
 70 | int createManifestFile(char *utocFileName, char *ucasFileName, char *outputFileName);
 71 | ```
 72 | This function returns 0 upon success and -1 upon error. 
 73 | The error message can be retrieved using the getError function.
 74 | 
 75 | 
 76 | ### Unpack all Game Files
 77 | Unpacking the game files require the .utoc file and the .ucas file.
 78 | All files get unpacked in the path with the provided directory.
 79 | The directory name should end with a slash, and the directory should exist.
 80 | An AES key is required for encrypted .utoc/.ucas files.
 81 | Pass NULL if it is not encrypted.
 82 | **WARNING: Depending on the .utoc and .ucas files, this can take a long time and it could fill your disk.**
 83 | 
 84 | ```c
 85 | int unpackAllGameFiles(char *utocFileName, char *ucasFileName, char *outputDirectory, char *AESKey);
 86 | ```
 87 | This function returns -1 upon error.
 88 | Any other value indicates the number of files that were extracted.
 89 | The error message can be retrieved using the getError function.
 90 | 
 91 | 
 92 | ### Unpack a Selection of Game Files
 93 | Unpacking can take a LOT of time.
 94 | This function allows one to unpack only the files that matches the provided regular expression.
 95 | The regular expression syntax is the one that is default in the Golang language.
 96 | https://regex101.com/ has a golang option for regexes, so I assume this is special.
 97 | It is otherwise the same as the unpackAllGameFiles function.
 98 | 
 99 | ```c
100 | int unpackGameFiles(char *utocFileName, char *ucasFileName, char *outputDirectory, char *regex, char *AESKey);
101 | ```
102 | 
103 | ### Packing Game Files
104 | Packing the game files require the manifest file that you build using the function meant for it.
105 | This function takes the game directory that you are packing, which should follow the same file structure as how it was unpacked.
106 | The outFile is simply a path to a (new) filename, without any extension. 
107 | The filename is used to create the .utoc, .ucas and .pak files in the path that you specify.
108 | 
109 | Three compression methods are currently known; "None", "Zlib", "Oodle" or "lz4".
110 | None is the default, so when NULL is passed, it will not be compressed.
111 | Any other compression method will return errors; the names are not case-sensitive.
112 | If you wish to encrypt the created files, you could provide an AES key, but I am pretty sure Unreal Engine won't be able to decrypt your files.
113 | I just added this encryption "feature" for experimentation.
114 | 
115 | ```c
116 | int packGameFiles(char *dirPath, char *manifestPath, char *outFile, char *compressionMethod, char *AESKey);
117 | ```
118 | The function returns -1 in case of error. 
119 | Otherwise, it returns the number of files that were packed into the .utoc/.ucas files that were created.
120 | 
121 | # Building the DLL yourself!
122 | 
123 | Building a DLL from Go on Windows is done as follows
124 | ```go
125 | go build -o castoc_x64.dll -buildmode=c-shared -ldflags "-s -w" .
126 | ```
127 | This creates a DLL file and a header file. 
128 | Both must be placed in the directory of the C/C++ program you would like to build.
129 | The resulting program can then be used without the header file, but it does require the DLL file!
130 | 
131 | Compiling a C++ program while making use of the DLL file is easy;
132 | ```cpp
133 | g++ main.cpp castoc_x64.dll -o main.exe
134 | ```


--------------------------------------------------------------------------------
/compression.go:
--------------------------------------------------------------------------------
  1 | package main
  2 | 
  3 | import (
  4 | 	"bytes"
  5 | 	"compress/zlib"
  6 | 	"errors"
  7 | 	"io"
  8 | 	"io/ioutil"
  9 | 	"strings"
 10 | 
 11 | 	"github.com/new-world-tools/go-oodle"
 12 | 	"github.com/pierrec/lz4/v4"
 13 | )
 14 | 
 15 | // implemented (de)compression methods (lowercased)
 16 | 
 17 | var (
 18 | 	DecompressionMethods = map[string](func(*[]byte, uint32) (*[]byte, error)){
 19 | 		"none":  decompressNone,
 20 | 		"zlib":  decompressZLIB,
 21 | 		"oodle": decompressOodle,
 22 | 		"lz4":   decompressLZ4,
 23 | 	}
 24 | 	CompressionMethods = map[string](func(*[]byte) (*[]byte, error)){
 25 | 		"none":  compressNone,
 26 | 		"zlib":  compressZLIB,
 27 | 		"oodle": compressOodle, // settings: level 3 Kraken compression
 28 | 		"lz4":   compressLZ4,
 29 | 	}
 30 | )
 31 | 
 32 | /* Decompression functions */
 33 | func decompressNone(inData *[]byte, expectedOutputSize uint32) (*[]byte, error) {
 34 | 	return inData, nil // can't go wrong :D
 35 | }
 36 | 
 37 | func decompressZLIB(inData *[]byte, expectedOutputSize uint32) (*[]byte, error) {
 38 | 	// decompress with zlib
 39 | 	r, err := zlib.NewReader(bytes.NewBuffer(*inData))
 40 | 	defer r.Close()
 41 | 	if err != nil {
 42 | 		return nil, err
 43 | 	}
 44 | 	uncompressed, err := ioutil.ReadAll(r)
 45 | 	if err != nil {
 46 | 		return nil, err
 47 | 	}
 48 | 	if len(uncompressed) != int(expectedOutputSize) {
 49 | 		return nil, errors.New("zlib did not decompress correctly")
 50 | 	}
 51 | 	return &uncompressed, nil
 52 | }
 53 | 
 54 | func decompressOodle(inData *[]byte, expectedOutputSize uint32) (*[]byte, error) {
 55 | 	if !oodle.IsDllExist() {
 56 | 		err := oodle.Download()
 57 | 		if err != nil {
 58 | 			return nil, errors.New("oo2core_9_win64.dll was not found (oodle decompression)")
 59 | 		}
 60 | 	}
 61 | 	output, err := oodle.Decompress(*inData, int64(expectedOutputSize))
 62 | 	// if err is not nil, it's handled by the caller
 63 | 	return &output, err
 64 | }
 65 | func decompressLZ4(inData *[]byte, expectedOutputSize uint32) (*[]byte, error) {
 66 | 	reader := bytes.NewReader(*inData)
 67 | 	decompressed := &bytes.Buffer{}
 68 | 	zr := lz4.NewReader(reader)
 69 | 	_, err := io.Copy(decompressed, zr)
 70 | 	if err != nil {
 71 | 		return nil, err
 72 | 	}
 73 | 	decomp := decompressed.Bytes()
 74 | 	return &decomp, nil
 75 | }
 76 | 
 77 | /* Compression functions */
 78 | 
 79 | func compressNone(inData *[]byte) (*[]byte, error) {
 80 | 	return inData, nil
 81 | }
 82 | func compressZLIB(inData *[]byte) (*[]byte, error) {
 83 | 	var b bytes.Buffer
 84 | 	w := zlib.NewWriter(&b)
 85 | 	_, err := w.Write(*inData)
 86 | 	if err != nil {
 87 | 		return nil, err
 88 | 	}
 89 | 	err = w.Close()
 90 | 	if err != nil {
 91 | 		return nil, err
 92 | 	}
 93 | 	compressedData := b.Bytes()
 94 | 	return &compressedData, nil
 95 | }
 96 | func compressOodle(inData *[]byte) (*[]byte, error) {
 97 | 	// The settings for Oodle _could_ be modified, but this is what Unreal Engine states as example
 98 | 	// https://docs.unrealengine.com/4.27/en-US/TestingAndOptimization/Oodle/Data/
 99 | 	compressedData, err := oodle.Compress(*inData, oodle.AlgoKraken, oodle.CompressionLevelOptimal3)
100 | 	return &compressedData, err
101 | }
102 | 
103 | func compressLZ4(inData *[]byte) (*[]byte, error) {
104 | 	reader := bytes.NewReader(*inData)
105 | 	compressed := &bytes.Buffer{}
106 | 	lzwriter := lz4.NewWriter(compressed)
107 | 	_, err := io.Copy(lzwriter, reader)
108 | 	if err != nil {
109 | 		return nil, err
110 | 	}
111 | 	// Closing is *very* important
112 | 	if err := lzwriter.Close(); err != nil {
113 | 		return nil, err
114 | 	}
115 | 	comp := compressed.Bytes()
116 | 	return &comp, nil
117 | }
118 | 
119 | /* Wrapper for getting the functions */
120 | // depending on the method, return the associated decompression function
121 | func getDecompressionFunction(method string) func(inData *[]byte, outputSize uint32) (*[]byte, error) {
122 | 	if val, ok := DecompressionMethods[strings.ToLower(method)]; ok {
123 | 		return val
124 | 	}
125 | 	return nil
126 | }
127 | func getCompressionFunction(method string) func(inData *[]byte) (*[]byte, error) {
128 | 	if val, ok := CompressionMethods[strings.ToLower(method)]; ok {
129 | 		return val
130 | 	}
131 | 	return nil
132 | }
133 | 


--------------------------------------------------------------------------------
/cpp/Pack.bat:
--------------------------------------------------------------------------------
 1 | @pushd %~dp0
 2 | @if exist "packed" goto 1
 3 | mkdir "packed"
 4 | timeout -t 1 -nobreak
 5 | :1
 6 | @echo off
 7 | @if exist "manifest\manifest.json" goto 2
 8 | color 40
 9 | cls
10 | echo manifest.json missing!
11 | pause
12 | :2
13 | @echo on
14 | @if "%~1"=="" goto skip
15 | @pushd %~dp0
16 | .\main.exe pack "%~dpn1" "manifest\manifest.json" "packed\%~n1" none
17 | :skip


--------------------------------------------------------------------------------
/cpp/UnpackAllplusManifest.bat:
--------------------------------------------------------------------------------
 1 | @pushd %~dp0
 2 | @if exist "output" goto 1
 3 | mkdir "output"
 4 | :1
 5 | @if exist "manifest" goto 2
 6 | mkdir "manifest"
 7 | :2
 8 | timeout -t 1 -nobreak
 9 | @if "%~1"=="" goto skip
10 | .\main.exe unpackAll "%~dpn1.utoc" "%~dpn1.ucas" output\
11 | .\main.exe manifest "%~dpn1.utoc" "%~dpn1.ucas" "manifest\%~n1.json"
12 | :skip


--------------------------------------------------------------------------------
/cpp/castoc_x64.dll:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/gitMenv/UEcastoc/7e8112e4d7617522d60bda812dca11949d6a77cc/cpp/castoc_x64.dll


--------------------------------------------------------------------------------
/cpp/castoc_x64.h:
--------------------------------------------------------------------------------
 1 | /* Code generated by cmd/cgo; DO NOT EDIT. */
 2 | 
 3 | /* package github.com/gitMenv/UEcastoc */
 4 | 
 5 | 
 6 | #line 1 "cgo-builtin-export-prolog"
 7 | 
 8 | #include <stddef.h> /* for ptrdiff_t below */
 9 | 
10 | #ifndef GO_CGO_EXPORT_PROLOGUE_H
11 | #define GO_CGO_EXPORT_PROLOGUE_H
12 | 
13 | #ifndef GO_CGO_GOSTRING_TYPEDEF
14 | typedef struct { const char *p; ptrdiff_t n; } _GoString_;
15 | #endif
16 | 
17 | #endif
18 | 
19 | /* Start of preamble from import "C" comments.  */
20 | 
21 | 
22 | #line 3 "dllAPI.go"
23 |  #include <stdio.h>
24 |  #include <stdlib.h>
25 | 
26 | #line 1 "cgo-generated-wrapper"
27 | 
28 | 
29 | /* End of preamble from import "C" comments.  */
30 | 
31 | 
32 | /* Start of boilerplate cgo prologue.  */
33 | #line 1 "cgo-gcc-export-header-prolog"
34 | 
35 | #ifndef GO_CGO_PROLOGUE_H
36 | #define GO_CGO_PROLOGUE_H
37 | 
38 | typedef signed char GoInt8;
39 | typedef unsigned char GoUint8;
40 | typedef short GoInt16;
41 | typedef unsigned short GoUint16;
42 | typedef int GoInt32;
43 | typedef unsigned int GoUint32;
44 | typedef long long GoInt64;
45 | typedef unsigned long long GoUint64;
46 | typedef GoInt64 GoInt;
47 | typedef GoUint64 GoUint;
48 | typedef __SIZE_TYPE__ GoUintptr;
49 | typedef float GoFloat32;
50 | typedef double GoFloat64;
51 | typedef float _Complex GoComplex64;
52 | typedef double _Complex GoComplex128;
53 | 
54 | /*
55 |   static assertion to make sure the file is being used on architecture
56 |   at least with matching size of GoInt.
57 | */
58 | typedef char _check_for_64_bit_pointer_matching_GoInt[sizeof(void*)==64/8 ? 1:-1];
59 | 
60 | #ifndef GO_CGO_GOSTRING_TYPEDEF
61 | typedef _GoString_ GoString;
62 | #endif
63 | typedef void *GoMap;
64 | typedef void *GoChan;
65 | typedef struct { void *t; void *v; } GoInterface;
66 | typedef struct { void *data; GoInt len; GoInt cap; } GoSlice;
67 | 
68 | #endif
69 | 
70 | /* End of boilerplate cgo prologue.  */
71 | 
72 | #ifdef __cplusplus
73 | extern "C" {
74 | #endif
75 | 
76 | extern __declspec(dllexport) int packGameFiles(char* dirPath, char* manifestPath, char* outFile, char* compressionMethod, char* AESKey);
77 | extern __declspec(dllexport) void freeStringList(char** stringlist, int n);
78 | extern __declspec(dllexport) char** listGameFiles(char* utocFile, int* n, char* AESKey);
79 | extern __declspec(dllexport) char* getError();
80 | extern __declspec(dllexport) int createManifestFile(char* utocFile, char* ucasFile, char* outputFile, char* AESKey);
81 | extern __declspec(dllexport) int unpackAllGameFiles(char* utocFile, char* ucasFile, char* outputDirectory, char* AESKey);
82 | extern __declspec(dllexport) int unpackGameFiles(char* utocFile, char* ucasFile, char* outputDirectory, char* regex, char* AESKey);
83 | 
84 | #ifdef __cplusplus
85 | }
86 | #endif
87 | 


--------------------------------------------------------------------------------
/cpp/fix_manifest_and_pack.py:
--------------------------------------------------------------------------------
 1 | # Python script to fix the paths in the manifest file generated by UECASTOC so that UECASTOC can pack the files.
 2 | # This script should be installed and run from the "cpp" directory of a UECASTOC ( https://github.com/gitMenv/UEcastoc/tags ) installation
 3 | 
 4 | # Caveats:
 5 | #  - The filenames in each mod must be unique.  In other words, a specific mod should not have files with the same name in different folders.
 6 | #  - Mod names should not have spaces or other strange characters (like /, \, or . )
 7 | 
 8 | # Usage:
 9 | #   - Download UECASTOC from https://github.com/gitMenv/UEcastoc/tags
10 | #   - Copy this script into the cpp directory
11 | #   - Point the manifest_file variable below to the manifest file generated by UECASTOC when you unpacked
12 | #   - Point directory_to_pak to the directory you want to pack
13 | #   - The directory structure should be the usual structure we are used to from before IoStore (e.g., as used by FluffyQuack's UnrealPak scripts).
14 | #       For example, for Hogwarts Legacy, it should be z_your_mod_name_P\phoenix\Content\...  and you would then set directory_to_pak = 'z_your_mod_name_P'
15 | #   - Run the script
16 | #   - The script will attempt to find the files in the directory you want to pack, fix the manifest accordingly, and pack the files into packed/...
17 | 
18 | import os
19 | import json
20 | import pathlib
21 | import shutil
22 | 
23 | ##### SET THESE TO POINT TO YOUR MANIFEST FILE AND TO THE DIRECTORY YOU WANT TO PACK ###########
24 | manifest_file = 'test_manifest.json'
25 | directory_to_pak = 'z_your_mod_name_P'
26 | #########################################################################################
27 | 
28 | with open(manifest_file, 'r') as fp:
29 |     manifest_dict = json.load(fp)
30 | 
31 |     with open("fixed_"+manifest_file,'w') as fout:
32 |         print("Fixing the paths in the manifest file so that the packer can find them...")
33 |         file_idx = 0
34 |         for file_entry in manifest_dict['Files']:
35 |             if(not(file_entry['Path']=='dependencies')):
36 |                 filename_to_find = file_entry['Path'][1:]  # get rid of leading /
37 |                 my_file = []
38 |                 for path in pathlib.Path(directory_to_pak).rglob(filename_to_find):
39 |                     my_file.append(path)
40 |                 if (len(my_file)==0):
41 |                     print("WARNING:  could not find "+filename_to_find)
42 |                 if(len(my_file)>1):
43 |                     print("WARNING:  found multiple instances of "+filename_to_find+":")
44 |                     for path in my_file:
45 |                         print(path)
46 |                 for path in my_file:
47 |                     python_path = str(path)
48 |                     fixed_path ='/' + ('/').join(python_path.split('\\')[1:])
49 |                     print(fixed_path)
50 |                     manifest_dict['Files'][file_idx]['Path'] = fixed_path
51 |             file_idx = file_idx+1
52 | 
53 |         print("Writing new manifest file "+"fixed_"+manifest_file)
54 |         json.dump(manifest_dict, fout, indent=2)
55 | 
56 | 
57 | print("Packing "+directory_to_pak)
58 | json_path = pathlib.Path("fixed_"+manifest_file)
59 | 
60 | 
61 | my_cmd = '.\main.exe pack \"' + str(directory_to_pak)+'\" \"' + str(json_path) + '\" \"packed\\' +directory_to_pak+ '\" None'
62 | print(my_cmd)
63 | os.system(my_cmd)
64 | 
65 | #my_cmd = "main.exe pack " + directory_to_pak + " " + str(json_path.with_suffix('')) + ".json packed\\" +directory_to_pak+ " none"
66 | #print(my_cmd)
67 | #os.system(my_cmd)
68 | 
69 | 


--------------------------------------------------------------------------------
/cpp/main.cpp:
--------------------------------------------------------------------------------
  1 | #include <iostream>
  2 | #include "castoc_x64.h"
  3 | 
  4 | #include <string>
  5 | #include <vector>
  6 | 
  7 | using namespace std;
  8 | 
  9 | 
 10 | // Print help text on usage
 11 | void printHelp() {
 12 |     cout << "Usage: castoc.exe <feature> [args]" << endl;
 13 |     cout << "All args that are prepended with an asterisk are optional" << endl;
 14 |     cout << "Features:" << endl;
 15 |     cout << "  help: Print this message" << endl;
 16 |     cout << "  list [utocPath, *AES key]: lists all files that are packed in the .utoc/.ucas file" << endl;
 17 |     cout << "  unpackAll [utocPath, ucasPath, outputDir, *AES key]: unpack entire .utoc/.ucas files" << endl;
 18 |     cout << "  unpack [utocPath, ucasPath, outputDir, regex, *AES key]: unpack .utoc/.ucas files based on regex" << endl;
 19 |     cout << "  manifest [utocPath, ucasPath, outputManifest, *AES key]: creates Manifest file of this .utoc/.ucas file" << endl; 
 20 |     cout << "  pack [packDir, manifestPath, outputFile, compressionMethod, *AES key]: pack directory into .utoc/.ucas file" << endl;
 21 |     cout << endl;
 22 |     cout << "the pack command requires the manifest file, and it packs the input dir to the outputFile{.utoc, .ucas, .pak}; three files are created!" << endl;
 23 |     cout << "the following compression methods for packing are supported; {None, Zlib, Oodle}" << endl;
 24 | }
 25 | 
 26 | void help(vector<string> args) {
 27 |     printHelp();
 28 | }
 29 | 
 30 | void list(vector<string> args) {
 31 |     if (args.size() == 0){
 32 |         cout << "expecting at least one arg for list" << endl;
 33 |         printHelp();
 34 |         return;
 35 |     }
 36 |     int n;
 37 |     char** list;
 38 |     char* aeskey = NULL;
 39 |     const char *utocPath = args[0].c_str();
 40 | 
 41 |     if (args.size() > 1){
 42 |         const char *aes = args[1].c_str();
 43 |         aeskey = const_cast<char*>(aes);
 44 |     }
 45 |     list = listGameFiles(const_cast<char*>(utocPath), &n, aeskey);
 46 |     if(list == NULL){
 47 |         cout << getError() << endl;
 48 |         return;
 49 |     }
 50 |     for(int i = 0; i < n; i++){
 51 |         cout << list[i] << endl;
 52 |     }
 53 |     freeStringList(list, n);
 54 | }
 55 | 
 56 | void unpackAll(vector<string> args){
 57 |     //[utocPath, ucasPath, outputDir, *AES key]
 58 |     if (args.size() < 3){
 59 |         cout << "expecting at least three args for unpackAll" << endl;
 60 |         printHelp();
 61 |         return;
 62 |     }
 63 |     const char* utocPath = args[0].c_str();
 64 |     const char* ucasPath = args[1].c_str();
 65 |     const char* outputDir = args[2].c_str();
 66 | 
 67 |     char* aeskey = NULL;
 68 |     if (args.size() == 4) {
 69 |         const char* aes = args[3].c_str();
 70 |         aeskey = const_cast<char*>(aes);
 71 |     }
 72 |     int n = unpackAllGameFiles(const_cast<char*>(utocPath), 
 73 |         const_cast<char*>(ucasPath), 
 74 |         const_cast<char*>(outputDir), 
 75 |         aeskey);
 76 |     if(n < 0){
 77 |         cout << getError() << endl;
 78 |     } else {
 79 |         cout << "number of unpacked files:" << n << endl;
 80 |     }
 81 | }
 82 | 
 83 | void unpack(vector<string> args){
 84 |     //[utocPath, ucasPath, outputDir, regex, *AES key]
 85 |     if (args.size() < 4){
 86 |         cout << "expecting at least four args for unpack" << endl;
 87 |         printHelp();
 88 |         return;
 89 |     }
 90 |         const char* utocPath = args[0].c_str();
 91 |     const char* ucasPath = args[1].c_str();
 92 |     const char* outputDir = args[2].c_str();
 93 |     const char* regex = args[3].c_str();
 94 | 
 95 |     char* aeskey = NULL;
 96 |     if (args.size() == 5) {
 97 |         const char* aes = args[4].c_str();
 98 |         aeskey = const_cast<char*>(aes);
 99 |     }
100 |     int n = unpackGameFiles(const_cast<char*>(utocPath), 
101 |         const_cast<char*>(ucasPath), 
102 |         const_cast<char*>(outputDir), 
103 |         const_cast<char*>(regex),
104 |         aeskey);
105 |     if(n < 0){
106 |         cout << getError() << endl;
107 |     } else {
108 |         cout << "number of unpacked files:" << n << endl;
109 |     }
110 | }
111 | 
112 | void manifest(vector<string> args){
113 |     //[utocPath, ucasPath, outputManifest, aeskey]
114 |     if(args.size() < 3) {
115 |         cout << "expecting at least 3 arguments for creating a manifest file" << endl;
116 |         printHelp();
117 |         return;
118 |     }
119 |     const char* utocPath = args[0].c_str();
120 |     const char* ucasPath = args[1].c_str();
121 |     const char* outputManifest = args[2].c_str();
122 |     char* aeskey = NULL;
123 |     if (args.size() == 4) {
124 |         const char* aes = args[3].c_str();
125 |         aeskey = const_cast<char*>(aes);
126 |     }
127 |     int n = createManifestFile(const_cast<char*>(utocPath),
128 |         const_cast<char*>(ucasPath),
129 |         const_cast<char*>(outputManifest),
130 |         aeskey);
131 |     if (n < 0){
132 |         cout << getError() << endl;
133 |     }
134 | 
135 | }
136 | 
137 | void pack(vector<string> args){
138 |     // [packDir, manifestPath, outputFile, compressionMethod, *AES key]
139 |     if(args.size() < 4){
140 |         cout << "expecting at least 4 arguments for packing" << endl;
141 |         printHelp();
142 |         return;
143 |     }
144 |     const char* packdir = args[0].c_str();
145 |     const char* manifestPath = args[1].c_str();
146 |     const char* outputfile = args[2].c_str();
147 |     const char* compression = args[3].c_str();
148 |     char* aeskey;
149 |     if(args.size() == 5){
150 |         const char* aes = args[4].c_str();
151 |         aeskey = const_cast<char*>(aes);
152 |     }
153 |     int n = packGameFiles(const_cast<char*>(packdir),
154 |         const_cast<char*>(manifestPath),
155 |         const_cast<char*>(outputfile),
156 |         const_cast<char*>(compression),
157 |         aeskey);
158 |     if(n < 0){
159 |         cout << getError() << endl;
160 |     }else{
161 |         cout << "number of files packed:" << n << endl;
162 |     }
163 | 
164 | }
165 | 
166 | int main(int argc, char** argv) {
167 |     if (argc < 2) {
168 |         cout << "Error: No feature specified" << endl;
169 |         printHelp();
170 |         return 1;
171 |     }
172 | 
173 |     string feature = argv[1];
174 |     vector<string> args;
175 |     for (int i = 2; i < argc; i++) {
176 |         args.push_back(argv[i]);
177 |     }
178 | 
179 |     if (feature == "help") {
180 |         help(args);
181 |     } else if (feature == "list") {
182 |         list(args);
183 |     } else if(feature == "unpackAll"){
184 |         unpackAll(args);
185 |     } else if(feature == "unpack"){
186 |         unpack(args);
187 |     } else if(feature == "manifest"){
188 |         manifest(args);
189 |     } else if(feature == "pack") {
190 |         pack(args);
191 |     }else{
192 |         cout << "Error: Invalid feature specified" << endl;
193 |         printHelp();
194 |         return 1;
195 |     }
196 | 
197 |     return 0;
198 | }
199 | 
200 | 


--------------------------------------------------------------------------------
/cpp/main.exe:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/gitMenv/UEcastoc/7e8112e4d7617522d60bda812dca11949d6a77cc/cpp/main.exe


--------------------------------------------------------------------------------
/dllAPI.go:
--------------------------------------------------------------------------------
  1 | package main
  2 | 
  3 | // #include <stdio.h>
  4 | // #include <stdlib.h>
  5 | import "C"
  6 | import (
  7 | 	"embed" // for the .pak file
  8 | 	"encoding/json"
  9 | 	"fmt"
 10 | 	"io/fs"
 11 | 	"io/ioutil"
 12 | 	"os"
 13 | 	"path/filepath"
 14 | 	"strings"
 15 | 	"unsafe"
 16 | )
 17 | 
 18 | // The functions that use cgo stuff from C libraries must be used in the file
 19 | // that contains the main function.
 20 | var staticErr string
 21 | 
 22 | //go:embed req/Packed_P.pak
 23 | var embeddedFiles embed.FS
 24 | 
 25 | //export packGameFiles
 26 | func packGameFiles(dirPath *C.char, manifestPath *C.char, outFile *C.char, compressionMethod *C.char, AESKey *C.char) C.int {
 27 | 	dir := C.GoString(dirPath)
 28 | 	dir, err := filepath.Abs(dir)
 29 | 	if err != nil {
 30 | 		staticErr = err.Error()
 31 | 		return C.int(-1)
 32 | 	}
 33 | 	manifestFile := C.GoString(manifestPath)
 34 | 	outPath := C.GoString(outFile)
 35 | 	outPath = strings.TrimSuffix(outPath, filepath.Ext(outPath)) // remove any extension
 36 | 	compression := "None"
 37 | 	if compressionMethod != nil {
 38 | 		compression = C.GoString(compressionMethod)
 39 | 	}
 40 | 	aes := convertAES(AESKey)
 41 | 	if len(aes) != 0 && len(aes) != 32 {
 42 | 		staticErr = "AES key length should be 32, or none at all"
 43 | 	}
 44 | 	manifest, err := readManifest(manifestFile)
 45 | 	if err != nil {
 46 | 		staticErr = err.Error()
 47 | 		return C.int(-1)
 48 | 	}
 49 | 	n, err := packToCasToc(dir, manifest, outPath, compression, aes)
 50 | 	if err != nil {
 51 | 		staticErr = err.Error()
 52 | 		return C.int(-1)
 53 | 	}
 54 | 	// write the embedded .pak file
 55 | 	embedded, _ := embeddedFiles.ReadFile("req/Packed_P.pak")
 56 | 	os.WriteFile(outPath+".pak", embedded, os.ModePerm)
 57 | 	return C.int(n - 1) // correction for dependencies file
 58 | }
 59 | 
 60 | //export freeStringList
 61 | func freeStringList(stringlist **C.char, n C.int) {
 62 | 	for i := 0; i < int(n); i++ {
 63 | 		toFreeString := *(**C.char)(unsafe.Pointer(uintptr(unsafe.Pointer(stringlist)) + uintptr(i)*unsafe.Sizeof(*stringlist)))
 64 | 		C.free(unsafe.Pointer(toFreeString))
 65 | 	}
 66 | 	C.free(unsafe.Pointer(stringlist))
 67 | }
 68 | 
 69 | //export listGameFiles
 70 | func listGameFiles(utocFile *C.char, n *C.int, AESKey *C.char) (strlist **C.char) {
 71 | 	utocFname := C.GoString(utocFile)
 72 | 	aes := convertAES(AESKey)
 73 | 
 74 | 	d, err := parseUtocFile(utocFname, aes)
 75 | 	if err != nil {
 76 | 		staticErr = err.Error()
 77 | 		*n = C.int(-1)
 78 | 		return nil
 79 | 	}
 80 | 
 81 | 	filepaths := []string{}
 82 | 	for _, v := range d.files {
 83 | 		if v.filepath == DepFileName {
 84 | 			continue
 85 | 		}
 86 | 		filepaths = append(filepaths, v.filepath)
 87 | 	}
 88 | 	// each line a new string
 89 | 	*n = C.int(len(filepaths))
 90 | 	return strSliceToC(&filepaths)
 91 | }
 92 | 
 93 | //export getError
 94 | func getError() (err *C.char) {
 95 | 	return C.CString(staticErr)
 96 | }
 97 | 
 98 | //export createManifestFile
 99 | func createManifestFile(utocFile *C.char, ucasFile *C.char, outputFile *C.char, AESKey *C.char) C.int {
100 | 	//TODO: check if the "dependencies" part works for more games, and if it's even required.
101 | 	utocFname := C.GoString(utocFile)
102 | 	ucasFname := C.GoString(ucasFile)
103 | 	outputFname := C.GoString(outputFile)
104 | 	aes := convertAES(AESKey)
105 | 
106 | 	d, err := parseUtocFile(utocFname, aes)
107 | 	if err != nil {
108 | 		staticErr = err.Error()
109 | 		return C.int(-1)
110 | 	}
111 | 	
112 | 	if d.hdr.isEncrypted(){
113 | 		tmpFile, err := os.CreateTemp("", "tmp")
114 | 		if err != nil {
115 | 			staticErr = err.Error()
116 | 			return C.int(-1)
117 | 		}
118 | 		ucasBytes, err := ioutil.ReadFile(ucasFname)
119 | 		if err != nil {
120 | 			staticErr = err.Error()
121 | 			return C.int(-1)
122 | 		}
123 | 		decryptedBytes, err := decryptAES(&ucasBytes, aes)
124 | 		if err != nil {
125 | 			staticErr = err.Error()
126 | 			return C.int(-1)
127 | 		}
128 | 		tmpFile.Write(*decryptedBytes)
129 | 		ucasFname = tmpFile.Name()
130 | 		err = tmpFile.Close()
131 | 		if err != nil {
132 | 			fmt.Println("err:", err)
133 | 			return C.int(-1)
134 | 		}
135 | 		defer os.Remove(tmpFile.Name())
136 | 	}
137 | 	manifest, err := d.constructManifest(ucasFname)
138 | 	if err != nil {
139 | 		staticErr = err.Error()
140 | 		return C.int(-1)
141 | 	}
142 | 	b, err := json.MarshalIndent(manifest, "", "  ") // indent for readability
143 | 	if err != nil {
144 | 		staticErr = err.Error()
145 | 		return C.int(-1)
146 | 	}
147 | 	err = ioutil.WriteFile(outputFname, b, fs.ModePerm)
148 | 	if err != nil {
149 | 		staticErr = err.Error()
150 | 		return C.int(-1)
151 | 	}
152 | 
153 | 	return C.int(0)
154 | }
155 | 
156 | //export unpackAllGameFiles
157 | func unpackAllGameFiles(utocFile *C.char, ucasFile *C.char, outputDirectory *C.char, AESKey *C.char) C.int {
158 | 	reg := C.CString("/*")
159 | 	x := unpackGameFiles(utocFile, ucasFile, outputDirectory, reg, AESKey)
160 | 	C.free(unsafe.Pointer(reg)) // free the string that I made myself
161 | 	return x
162 | }
163 | 
164 | //export unpackGameFiles
165 | func unpackGameFiles(utocFile *C.char, ucasFile *C.char, outputDirectory *C.char, regex *C.char, AESKey *C.char) C.int {
166 | 	utocFname := C.GoString(utocFile)
167 | 	ucasFname := C.GoString(ucasFile)
168 | 	outDir := C.GoString(outputDirectory)
169 | 	reg := C.GoString(regex)
170 | 	aes := convertAES(AESKey)
171 | 
172 | 	d, err := parseUtocFile(utocFname, aes)
173 | 	if err != nil {
174 | 		staticErr = err.Error()
175 | 		return C.int(-1)
176 | 	}
177 | 	// ucas may also be encrypted; create temporary file and place decrypted version there
178 | 	// let the ucasreader read from the temporary file
179 | 	if d.hdr.isEncrypted() {
180 | 		tmpFile, err := os.CreateTemp("", "tmp")
181 | 		if err != nil {
182 | 			staticErr = err.Error()
183 | 			return C.int(-1)
184 | 		}
185 | 		ucasBytes, err := ioutil.ReadFile(ucasFname)
186 | 		if err != nil {
187 | 			staticErr = err.Error()
188 | 			return C.int(-1)
189 | 		}
190 | 		decryptedBytes, err := decryptAES(&ucasBytes, aes)
191 | 		if err != nil {
192 | 			staticErr = err.Error()
193 | 			return C.int(-1)
194 | 		}
195 | 		tmpFile.Write(*decryptedBytes)
196 | 		ucasFname = tmpFile.Name()
197 | 		err = tmpFile.Close()
198 | 		if err != nil {
199 | 			fmt.Println("err:", err)
200 | 			return C.int(-1)
201 | 		}
202 | 		defer os.Remove(tmpFile.Name())
203 | 	}
204 | 
205 | 	// we need the parsed .utoc file to unpack the files that are included in the .ucas file.
206 | 	numberOfFiles, err := d.unpackUcasFiles(ucasFname, outDir, reg)
207 | 	if err != nil {
208 | 		staticErr = err.Error()
209 | 		return C.int(-1)
210 | 	}
211 | 	return C.int(numberOfFiles)
212 | }
213 | 
214 | // main function is required for creating a DLL.
215 | func main() {}
216 | 


--------------------------------------------------------------------------------
/fIoStoreStructs.go:
--------------------------------------------------------------------------------
  1 | package main
  2 | 
  3 | import (
  4 | 	"encoding/binary"
  5 | 	"fmt"
  6 | 	"strconv"
  7 | )
  8 | 
  9 | type FIoContainerID uint64
 10 | type FIoStoreTocEntryMetaFlags uint8
 11 | type FString string // just a string I guess? But fancier...
 12 | type FName string
 13 | 
 14 | const (
 15 | 	NoneMetaFlag FIoStoreTocEntryMetaFlags = iota
 16 | 	CompressedMetaFlag
 17 | 	MemoryMappedMetaFlag
 18 | )
 19 | 
 20 | type FIoDirectoryIndexEntry struct {
 21 | 	Name             uint32
 22 | 	FirstChildEntry  uint32
 23 | 	NextSiblingEntry uint32
 24 | 	FirstFileEntry   uint32
 25 | }
 26 | 
 27 | type FIoFileIndexEntry struct {
 28 | 	Name          uint32
 29 | 	NextFileEntry uint32
 30 | 	UserData      uint32
 31 | }
 32 | 
 33 | type FIoChunkID struct {
 34 | 	ID      uint64 // 8 bytes
 35 | 	Index   uint16 // 2 bytes
 36 | 	Padding uint8  // 1 byte
 37 | 	Type    uint8  // 1 byte
 38 | }
 39 | 
 40 | type DirIndexWrapper struct {
 41 | 	dirs     *[]*FIoDirectoryIndexEntry
 42 | 	files    *[]*FIoFileIndexEntry
 43 | 	strTable *map[string]int
 44 | 	strSlice *[]string
 45 | }
 46 | 
 47 | func (r *FIoDirectoryIndexEntry) AddFile(fpathSections []string, fIndex uint32, structure *DirIndexWrapper) {
 48 | 	if len(fpathSections) == 0 {
 49 | 		return
 50 | 	}
 51 | 	if len(fpathSections) == 1 {
 52 | 		// only one item, add file and return; base case
 53 | 		fname := fpathSections[0]
 54 | 		newFile := FIoFileIndexEntry{
 55 | 			Name:          uint32((*(*structure).strTable)[fname]),
 56 | 			NextFileEntry: NoneEntry,
 57 | 			UserData:      fIndex,
 58 | 		}
 59 | 		newEntryIndex := uint32(len(*(*structure).files))
 60 | 		*(*structure).files = append(*(*structure).files, &newFile)
 61 | 
 62 | 		if (*r).FirstFileEntry == NoneEntry {
 63 | 			(*r).FirstFileEntry = newEntryIndex
 64 | 		} else {
 65 | 			fentry := &(*(*structure).files)[(*r).FirstFileEntry]
 66 | 			// filenames (with their path) are unique and will always be added
 67 | 			for (*fentry).NextFileEntry != NoneEntry {
 68 | 				fentry = &(*(*structure).files)[(*fentry).NextFileEntry]
 69 | 			}
 70 | 			(*fentry).NextFileEntry = newEntryIndex
 71 | 		}
 72 | 		return
 73 | 	}
 74 | 	// recursive case; find directory if present, otherwise add.
 75 | 	var currDir *FIoDirectoryIndexEntry
 76 | 	currDirName := fpathSections[0]
 77 | 	currDirNameIndex := uint32((*(*structure).strTable)[currDirName])
 78 | 
 79 | 	possibleNewEntryIndex := uint32(len(*(*structure).dirs))
 80 | 	if (*r).FirstChildEntry == NoneEntry {
 81 | 		newDirEntry := FIoDirectoryIndexEntry{
 82 | 			Name:             currDirNameIndex,
 83 | 			FirstChildEntry:  NoneEntry,
 84 | 			NextSiblingEntry: NoneEntry,
 85 | 			FirstFileEntry:   NoneEntry,
 86 | 		}
 87 | 		(*r).FirstChildEntry = possibleNewEntryIndex
 88 | 		*(*structure).dirs = append(*(*structure).dirs, &newDirEntry)
 89 | 		currDir = &newDirEntry
 90 | 	} else {
 91 | 		dentry := &(*(*structure).dirs)[(*r).FirstChildEntry]
 92 | 
 93 | 		for (*dentry).Name != currDirNameIndex {
 94 | 			if (*dentry).NextSiblingEntry != NoneEntry {
 95 | 				dentry = &(*(*structure).dirs)[(*dentry).NextSiblingEntry]
 96 | 			} else {
 97 | 				break
 98 | 			}
 99 | 		}
100 | 		if (*dentry).Name == currDirNameIndex {
101 | 			// directory found
102 | 			currDir = (*dentry)
103 | 		} else {
104 | 			// add new directory
105 | 			newDirEntry := FIoDirectoryIndexEntry{
106 | 				Name:             currDirNameIndex,
107 | 				FirstChildEntry:  NoneEntry,
108 | 				NextSiblingEntry: NoneEntry,
109 | 				FirstFileEntry:   NoneEntry,
110 | 			}
111 | 			(*dentry).NextSiblingEntry = possibleNewEntryIndex
112 | 			*(*structure).dirs = append(*(*structure).dirs, &newDirEntry)
113 | 			currDir = &newDirEntry
114 | 		}
115 | 	}
116 | 	(*currDir).AddFile(fpathSections[1:], fIndex, structure)
117 | }
118 | 
119 | func (c *FIoChunkID) ToHexString() string {
120 | 	return fmt.Sprintf("%016x%04x%02x%02x", c.ID, c.Index, c.Padding, c.Type)
121 | }
122 | 
123 | func FromHexString(s string) FIoChunkID {
124 | 	var c FIoChunkID
125 | 	v, _ := strconv.ParseUint(s[:16], 16, 64)
126 | 	c.ID = uint64(v)
127 | 	idx, _ := strconv.ParseUint(s[16:20], 16, 16)
128 | 	c.Index = uint16(idx)
129 | 	b, _ := strconv.ParseUint(s[20:22], 16, 8)
130 | 	c.Padding = uint8(b)
131 | 	b, _ = strconv.ParseUint(s[22:], 16, 8)
132 | 	c.Type = uint8(b)
133 | 	return c
134 | }
135 | 
136 | type FIoStoreTocCompressedBlockEntry struct {
137 | 	Offset            [5]uint8
138 | 	CompressedSize    [3]uint8
139 | 	UncompressedSize  [3]uint8
140 | 	CompressionMethod uint8
141 | }
142 | type FIoOffsetAndLength struct {
143 | 	Offset [5]uint8
144 | 	Length [5]uint8
145 | }
146 | 
147 | type FIoStoreTocEntryMeta struct {
148 | 	ChunkHash FIoChunkHash
149 | 	Flags     FIoStoreTocEntryMetaFlags
150 | }
151 | 
152 | type FIoChunkHash struct {
153 | 	Hash    [20]uint8 //SHA1
154 | 	Padding [12]uint8
155 | }
156 | 
157 | func normalize(s []byte) []byte {
158 | 	return append(s, make([]byte, 8-len(s))...)
159 | }
160 | func (f *FIoOffsetAndLength) GetOffset() uint64 {
161 | 	return uint64(f.Offset[4]) |
162 | 		(uint64(f.Offset[3]) << 8) |
163 | 		(uint64(f.Offset[2]) << 16) |
164 | 		(uint64(f.Offset[1]) << 24) |
165 | 		(uint64(f.Offset[0]) << 32)
166 | }
167 | func (f *FIoOffsetAndLength) GetLength() uint64 {
168 | 	return uint64(f.Length[4]) |
169 | 		(uint64(f.Length[3]) << 8) |
170 | 		(uint64(f.Length[2]) << 16) |
171 | 		(uint64(f.Length[1]) << 24) |
172 | 		(uint64(f.Length[0]) << 32)
173 | }
174 | func (f *FIoOffsetAndLength) SetOffset(offset uint64) {
175 | 	f.Offset[0] = uint8(offset >> 32)
176 | 	f.Offset[1] = uint8(offset >> 24)
177 | 	f.Offset[2] = uint8(offset >> 16)
178 | 	f.Offset[3] = uint8(offset >> 8)
179 | 	f.Offset[4] = uint8(offset >> 0)
180 | }
181 | func (f *FIoOffsetAndLength) SetLength(length uint64) {
182 | 	f.Length[0] = uint8(length >> 32)
183 | 	f.Length[1] = uint8(length >> 24)
184 | 	f.Length[2] = uint8(length >> 16)
185 | 	f.Length[3] = uint8(length >> 8)
186 | 	f.Length[4] = uint8(length >> 0)
187 | }
188 | 
189 | func (f *FIoStoreTocCompressedBlockEntry) GetOffset() uint64 {
190 | 	return binary.LittleEndian.Uint64(normalize(f.Offset[:]))
191 | }
192 | 
193 | func (f *FIoStoreTocCompressedBlockEntry) GetCompressedSize() uint32 {
194 | 	return binary.LittleEndian.Uint32(normalize(f.CompressedSize[:]))
195 | }
196 | func (f *FIoStoreTocCompressedBlockEntry) GetUncompressedSize() uint32 {
197 | 	return binary.LittleEndian.Uint32(normalize(f.UncompressedSize[:]))
198 | }
199 | 
200 | func (f *FIoStoreTocCompressedBlockEntry) SetOffset(offset uint64) {
201 | 	r := make([]byte, 5)
202 | 	for i := uint64(0); i < 5; i++ {
203 | 		r[i] = byte((offset >> (i * 8)) & 0xff)
204 | 	}
205 | 	copy(f.Offset[:], r)
206 | }
207 | func (f *FIoStoreTocCompressedBlockEntry) SetUncompressedSize(size uint32) {
208 | 	f.UncompressedSize[0] = uint8(size >> 0)
209 | 	f.UncompressedSize[1] = uint8(size >> 8)
210 | 	f.UncompressedSize[2] = uint8(size >> 16)
211 | }
212 | func (f *FIoStoreTocCompressedBlockEntry) SetCompressedSize(size uint32) {
213 | 	f.CompressedSize[0] = uint8(size >> 0)
214 | 	f.CompressedSize[1] = uint8(size >> 8)
215 | 	f.CompressedSize[2] = uint8(size >> 16)
216 | }
217 | 


--------------------------------------------------------------------------------
/go.mod:
--------------------------------------------------------------------------------
 1 | module github.com/gitMenv/UEcastoc
 2 | 
 3 | go 1.18
 4 | 
 5 | require (
 6 | 	github.com/new-world-tools/go-oodle v0.1.2
 7 | 	github.com/pierrec/lz4 v2.6.1+incompatible
 8 | 	github.com/pierrec/lz4/v4 v4.1.17
 9 | )
10 | 
11 | require (
12 | 	github.com/frankban/quicktest v1.14.4 // indirect
13 | 	github.com/itchio/lzma v0.0.0-20190703113020-d3e24e3e3d49 // indirect
14 | )
15 | 


--------------------------------------------------------------------------------
/go.sum:
--------------------------------------------------------------------------------
 1 | github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 2 | github.com/frankban/quicktest v1.14.4 h1:g2rn0vABPOOXmZUj+vbmUp0lPoXEMuhTpIluN0XL9UY=
 3 | github.com/frankban/quicktest v1.14.4/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
 4 | github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
 5 | github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 6 | github.com/itchio/lzma v0.0.0-20190703113020-d3e24e3e3d49 h1:+YrBMf3rkLjkT10zIHyVE4S7ma4hqvfjl6XgnzZwS6o=
 7 | github.com/itchio/lzma v0.0.0-20190703113020-d3e24e3e3d49/go.mod h1:avNrevQMli1pYPsz1+HIHMvx95pk6O+6otbWqCZPeZI=
 8 | github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 9 | github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
10 | github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
11 | github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
12 | github.com/new-world-tools/go-oodle v0.1.2 h1:KDZNiiN0TnkOcuncXQtlnteZQYD2samuv6H3phq2DCA=
13 | github.com/new-world-tools/go-oodle v0.1.2/go.mod h1:G8hCx5mlsQBT8xCYARaiIIyHgt0FI32LLpSN5/DryQM=
14 | github.com/pierrec/lz4 v2.6.1+incompatible h1:9UY3+iC23yxF0UfGaYrGplQ+79Rg+h/q9FV9ix19jjM=
15 | github.com/pierrec/lz4 v2.6.1+incompatible/go.mod h1:pdkljMzZIN41W+lC3N2tnIh5sFi+IEE17M5jbnwPHcY=
16 | github.com/pierrec/lz4/v4 v4.1.17 h1:kV4Ip+/hUBC+8T6+2EgburRtkE9ef4nbY3f4dFhGjMc=
17 | github.com/pierrec/lz4/v4 v4.1.17/go.mod h1:gZWDp/Ze/IJXGXf23ltt2EXimqmTUXEy0GFuRQyBid4=
18 | github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
19 | github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
20 | github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
21 | 


--------------------------------------------------------------------------------
/helpers.go:
--------------------------------------------------------------------------------
 1 | package main
 2 | 
 3 | import (
 4 | 	"crypto/aes"
 5 | 	"crypto/rand"
 6 | 	"crypto/sha1"
 7 | 	"encoding/binary"
 8 | 	"encoding/hex"
 9 | 	"strings"
10 | 	"unsafe"
11 | )
12 | import "C"
13 | 
14 | func strSliceToC(list *[]string) **C.char {
15 | 	strlist := *list
16 | 	n := len(strlist)
17 | 	// create an unsafe pointer with sufficient space on the stack
18 | 	strs := C.malloc(C.size_t(n) * C.size_t(unsafe.Sizeof(uintptr(0))))
19 | 	// fill the array with strings by offsetting the unsafe pointers with the size of the char pointers
20 | 	for i := 0; i < int(n); i++ {
21 | 		*(**C.char)(unsafe.Pointer(uintptr(strs) + uintptr(i)*unsafe.Sizeof(*(**C.char)(strs)))) = C.CString(strlist[i])
22 | 	}
23 | 	return (**C.char)(strs)
24 | }
25 | 
26 | func convertAES(AES *C.char) []byte {
27 | 	s := ""
28 | 	if AES != nil {
29 | 		s = C.GoString(AES)
30 | 	}
31 | 	// go string to []byte
32 | 	s = strings.TrimPrefix(s, "0x")
33 | 	s = strings.TrimPrefix(s, "0X")
34 | 
35 | 	b, _ := hex.DecodeString(s)
36 | 	return b
37 | }
38 | 
39 | func decryptAES(ciphertext *[]byte, AES []byte) (*[]byte, error) {
40 | 	block, err := aes.NewCipher(AES)
41 | 	if err != nil {
42 | 		return nil, err
43 | 	}
44 | 	dst := make([]byte, len(*ciphertext))
45 | 	for i := 0; i < len(dst); i += block.BlockSize() {
46 | 		block.Decrypt(dst[i:], (*ciphertext)[i:])
47 | 	}
48 | 	return &dst, nil
49 | }
50 | func encryptAES(plaintext *[]byte, AES []byte) (*[]byte, error) {
51 | 	block, err := aes.NewCipher(AES)
52 | 	if err != nil {
53 | 		return nil, err
54 | 	}
55 | 	dst := make([]byte, len(*plaintext))
56 | 	for i := 0; i < len(dst); i += block.BlockSize() {
57 | 		block.Encrypt(dst[i:], (*plaintext)[i:])
58 | 	}
59 | 	return &dst, nil
60 | }
61 | 
62 | func sha1Hash(fdata *[]byte) *FIoChunkHash {
63 | 	hasher := sha1.New()
64 | 	hasher.Write(*fdata)
65 | 	fileHash := hasher.Sum(nil)
66 | 
67 | 	var hash FIoChunkHash
68 | 	copy(hash.Hash[:], fileHash[:20])
69 | 	hash.Padding = [12]byte{} // explicitly set to 0
70 | 	return &hash
71 | }
72 | 
73 | func getRandomBytes(n int) []byte {
74 | 	ret := make([]byte, n)
75 | 	rand.Read(ret)
76 | 	return ret
77 | }
78 | 
79 | // A string must have a preamble of the strlen and a nullbyte at the end.
80 | // this function returns the string in the "FString" format.
81 | func stringToFString(str string) []byte {
82 | 	strlen := uint32(len(str) + 1) // include nullbyte
83 | 	fstring := make([]byte, int(strlen)+binary.Size(strlen))
84 | 	binary.LittleEndian.PutUint32(fstring, strlen)
85 | 	for i := 0; i < len(str); i++ {
86 | 		fstring[4+i] = str[i]
87 | 	}
88 | 	fstring[len(fstring)-1] = 0
89 | 	return fstring
90 | }
91 | 
92 | func uint32ToBytes(a *uint32) *[]byte {
93 | 	t := make([]byte, 4)
94 | 	binary.LittleEndian.PutUint32(t, *a)
95 | 	return &t
96 | }
97 | 


--------------------------------------------------------------------------------
/manifest.go:
--------------------------------------------------------------------------------
  1 | package main
  2 | 
  3 | import (
  4 | 	"bytes"
  5 | 	"encoding/binary"
  6 | 	"encoding/json"
  7 | 	"io"
  8 | 	"os"
  9 | 	"sort"
 10 | )
 11 | 
 12 | // This file is used to extract dependency data from the .ucas file.
 13 | // Not all fields are completely clear to me, so some of this must be saved somewhere to reconstruct the file later.
 14 | // I can imagine that if the dependencies are missing, something will go wrong.
 15 | // In short, this is "MAGIC" and I have no idea how or why it even works.
 16 | 
 17 | const DepFileName = "dependencies"
 18 | 
 19 | // Dependencies contains data extracted from the dependencies section in the .ucas file.
 20 | // An instance of this will be used to convert back to this section.
 21 | type Dependencies struct {
 22 | 	ThisPackageID         uint64 `json:"packageID"`
 23 | 	ChunkIDToDependencies map[uint64]FileDependency
 24 | }
 25 | 
 26 | type FileDependency struct {
 27 | 	FileSize      uint64   `json:"uncompressedSize"`
 28 | 	ExportObjects uint32   `json:"exportObjects"`
 29 | 	MostlyOne     uint32   `json:"requiredValueSomehow"`
 30 | 	SomeIndex     uint64   `json:"uniqueIndex"`
 31 | 	Dependencies  []uint64 `json:"dependencies"` // lists the ID of each dependency
 32 | }
 33 | 
 34 | type DepsHeader struct {
 35 | 	ThisPackageID    uint64
 36 | 	NumberOfIDs      uint64
 37 | 	IDSize           uint32  // always 8
 38 | 	Padding          [4]byte // value is in hex, LE, 00 00 64 C1
 39 | 	ZeroBytes        [4]byte
 40 | 	NumberOfIDsAgain uint32 // whether this means an offset or?
 41 | }
 42 | type DepLinks struct {
 43 | 	FileSize      uint64 // uncompressed file size
 44 | 	ExportObjects uint32 // number of Export Objects
 45 | 	MostlyOne     uint32 // this is either 1, 2 or 3, but most often 1.
 46 | 
 47 | 	// All entries have a unique value for this field, starting at 0
 48 | 	// It does skip some numbers, so I'm not sure what this means.
 49 | 	// Looks like some kind of index though
 50 | 	SomeIndex          uint64
 51 | 	DependencyPackages uint32 // number of dependency packages that this connection has
 52 | 	Offset             uint32 // an offset to point to the dependency packages
 53 | }
 54 | 
 55 | type parseDependencies struct {
 56 | 	Hdr              DepsHeader
 57 | 	IDs              []uint64
 58 | 	FileLength       uint32 // file length from this offset
 59 | 	Conns            []DepLinks
 60 | 	OffsetAfterConss int64
 61 | 	Deps             []uint64
 62 | 	IDToConn         map[uint64]DepLinks
 63 | }
 64 | 
 65 | type Manifest struct {
 66 | 	Files []ManifestFile `json:"Files,omitempty"` // in the .utoc file
 67 | 	Deps  Dependencies   `json:"Dependencies,omitempty"`
 68 | 	// Packages []UcasPackages `json:"Packages,omitempty"` // the "dependencies" in .ucas file???
 69 | }
 70 | type UcasPackages struct {
 71 | 	PathName             string   `json:"Name"`
 72 | 	ExportBundleChunkIds []string `json:"ExportBundleChunkIds,omitempty"`
 73 | 	BulkDataChunkIds     []string `json:"BulkDataChunkIds,omitempty"`
 74 | }
 75 | type ManifestFile struct {
 76 | 	Filepath string `json:"Path"`
 77 | 	ChunkID  string `json:"ChunkId"`
 78 | }
 79 | 
 80 | func (u *UTocData) constructManifest(ucasPath string) (m Manifest, err error) {
 81 | 	for _, v := range u.files {
 82 | 		mf := ManifestFile{Filepath: v.filepath, ChunkID: v.chunkID.ToHexString()}
 83 | 		m.Files = append(m.Files, mf)
 84 | 	}
 85 | 	// files part has been added, now decode the dependencies
 86 | 	data, err := u.unpackDependencies(ucasPath)
 87 | 	if err != nil {
 88 | 		return m, err
 89 | 	}
 90 | 	x, err := ParseDependencies(*data)
 91 | 	m.Deps = *x
 92 | 	return m, err
 93 | }
 94 | 
 95 | func readManifest(manifestPath string) (*Manifest, error) {
 96 | 	b, err := os.ReadFile(manifestPath)
 97 | 	if err != nil {
 98 | 		return nil, err
 99 | 	}
100 | 	var manifest Manifest
101 | 	err = json.Unmarshal(b, &manifest)
102 | 	return &manifest, err
103 | }
104 | 
105 | func (s *parseDependencies) extractDependencies() *Dependencies {
106 | 	d := Dependencies{}
107 | 	d.ThisPackageID = s.Hdr.ThisPackageID
108 | 	d.ChunkIDToDependencies = make(map[uint64]FileDependency)
109 | 	for i, id := range s.IDs {
110 | 		fd := FileDependency{
111 | 			FileSize:      s.Conns[i].FileSize,
112 | 			ExportObjects: s.Conns[i].ExportObjects,
113 | 			MostlyOne:     s.Conns[i].MostlyOne,
114 | 			SomeIndex:     s.Conns[i].SomeIndex,
115 | 		}
116 | 		idx := s.Conns[i].Offset / 8
117 | 		for j := 0; j < int(s.Conns[i].DependencyPackages); j++ {
118 | 			fd.Dependencies = append(fd.Dependencies, s.Deps[idx+uint32(j)])
119 | 		}
120 | 		d.ChunkIDToDependencies[id] = fd
121 | 	}
122 | 	return &d
123 | }
124 | 
125 | // Deparses the Dependencies struct exactly as how it was parsed
126 | // This was checked using a simple diff tool.
127 | func (d *Dependencies) Deparse() *[]byte {
128 | 	// deparse by writing all file portions to this buffer
129 | 	buf := bytes.NewBuffer([]byte{})
130 | 
131 | 	// write hdr
132 | 	hdr := DepsHeader{
133 | 		ThisPackageID:    d.ThisPackageID,
134 | 		NumberOfIDs:      uint64(len(d.ChunkIDToDependencies)),
135 | 		IDSize:           8,
136 | 		Padding:          [4]byte{0x00, 0x00, 0x64, 0xC1},
137 | 		ZeroBytes:        [4]byte{},
138 | 		NumberOfIDsAgain: uint32(len(d.ChunkIDToDependencies)),
139 | 	}
140 | 	binary.Write(buf, binary.LittleEndian, hdr)
141 | 
142 | 	// write list of IDs
143 | 	ids := []uint64{}
144 | 	totalNumberOfDependencies := 0
145 | 	for k := range d.ChunkIDToDependencies {
146 | 		ids = append(ids, k)
147 | 		totalNumberOfDependencies += len(d.ChunkIDToDependencies[k].Dependencies)
148 | 	}
149 | 	// these IDs are stored in order in this file, so sort here and use this ordering
150 | 	sort.Slice(ids, func(i, j int) bool {
151 | 		return ids[i] < ids[j]
152 | 	})
153 | 	for _, id := range ids {
154 | 		binary.Write(buf, binary.LittleEndian, id)
155 | 	}
156 | 	// write file length from this point onwards
157 | 	var x DepLinks
158 | 	var flength uint32 = uint32(len(d.ChunkIDToDependencies)*binary.Size(x) + totalNumberOfDependencies*8)
159 | 	binary.Write(buf, binary.LittleEndian, flength)
160 | 
161 | 	// write list of DepLinks entries
162 | 	endOfDeps := flength - uint32(totalNumberOfDependencies*8)
163 | 	depsToWrite := []uint64{}
164 | 
165 | 	for i, id := range ids {
166 | 		entry := d.ChunkIDToDependencies[id]
167 | 		link := DepLinks{
168 | 			FileSize:           entry.FileSize,
169 | 			ExportObjects:      entry.ExportObjects,
170 | 			MostlyOne:          entry.MostlyOne,
171 | 			SomeIndex:          entry.SomeIndex,
172 | 			DependencyPackages: uint32(len(entry.Dependencies)),
173 | 			Offset:             0, // 0 by default, must be calculated otherwise
174 | 		}
175 | 
176 | 		if link.DependencyPackages != 0 {
177 | 			// some math to write the correct offsets
178 | 			offsetFieldOffset := i*binary.Size(link) + 16 + 8
179 | 			target := int(endOfDeps) + len(depsToWrite)*8
180 | 			depsToWrite = append(depsToWrite, entry.Dependencies...)
181 | 			link.Offset = uint32(target - offsetFieldOffset)
182 | 		}
183 | 		binary.Write(buf, binary.LittleEndian, link)
184 | 	}
185 | 
186 | 	// write Dependencies to be written
187 | 	for _, depLink := range depsToWrite {
188 | 		binary.Write(buf, binary.LittleEndian, depLink)
189 | 	}
190 | 
191 | 	// write 8 nullbytes
192 | 	var nulls uint64 = 0
193 | 	binary.Write(buf, binary.LittleEndian, nulls)
194 | 
195 | 	b := buf.Bytes()
196 | 	return &b
197 | }
198 | 
199 | func ParseDependencies(b []byte) (*Dependencies, error) {
200 | 	s := parseDependencies{}
201 | 	s.IDToConn = make(map[uint64]DepLinks)
202 | 	reader := bytes.NewReader(b)
203 | 	err := binary.Read(reader, binary.LittleEndian, &s.Hdr)
204 | 	if err != nil {
205 | 		return nil, err
206 | 	}
207 | 	for i := 0; i < int(s.Hdr.NumberOfIDs); i++ {
208 | 		var newID uint64
209 | 		binary.Read(reader, binary.LittleEndian, &newID)
210 | 		s.IDs = append(s.IDs, newID)
211 | 	}
212 | 	binary.Read(reader, binary.LittleEndian, &s.FileLength)
213 | 	curr, _ := reader.Seek(0, io.SeekCurrent)
214 | 	var x DepLinks
215 | 	s.OffsetAfterConss = curr + int64(s.Hdr.NumberOfIDs)*int64(binary.Size(x))
216 | 	for i := 0; i < int(s.Hdr.NumberOfIDs); i++ {
217 | 		var conn DepLinks
218 | 		binary.Read(reader, binary.LittleEndian, &conn)
219 | 		// adjust so that this offset can be used to index the resulting array of connections...
220 | 		if conn.Offset != 0 {
221 | 			curr, _ := reader.Seek(0, io.SeekCurrent)
222 | 			conn.Offset = uint32(curr) + conn.Offset - uint32(s.OffsetAfterConss) - 8
223 | 		}
224 | 		s.IDToConn[s.IDs[i]] = conn
225 | 		s.Conns = append(s.Conns, conn)
226 | 	}
227 | 	s.OffsetAfterConss, err = reader.Seek(0, io.SeekCurrent)
228 | 	if err != nil {
229 | 		return nil, err
230 | 	}
231 | 
232 | 	// parse the remainder of the file as IDs I guess?
233 | 	toParse := s.FileLength - uint32(s.Hdr.NumberOfIDs)*uint32(binary.Size(s.Conns[0]))
234 | 	for i := 0; i < int(toParse); i += 8 {
235 | 		var id uint64
236 | 		binary.Read(reader, binary.LittleEndian, &id)
237 | 		s.Deps = append(s.Deps, id)
238 | 	}
239 | 	return s.extractDependencies(), nil
240 | }
241 | 


--------------------------------------------------------------------------------
/pack.go:
--------------------------------------------------------------------------------
  1 | package main
  2 | 
  3 | import (
  4 | 	"bytes"
  5 | 	"encoding/binary"
  6 | 	"errors"
  7 | 	"fmt"
  8 | 	"os"
  9 | 	"path/filepath"
 10 | 	"strings"
 11 | )
 12 | 
 13 | const (
 14 | 	CompSize              = 0x10000 // default size of a compression block. Haven't seen any others
 15 | 	PackUtocVersion       = 3       //3 is PartitionSize, 2 is DirectoryIndex according to https://github.com/FabianFG/CUE4Parse/blob/master/CUE4Parse/UE4/IO/Objects/FIoStoreTocHeader.cs
 16 | 	CompressionNameLength = 32
 17 | )
 18 | 
 19 | func listFilesInDir(dir string, pathToChunkID *map[string]FIoChunkID) (*[]GameFileMetaData, error) {
 20 | 	var files []GameFileMetaData
 21 | 	err := filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
 22 | 		if err != nil {
 23 | 			return err
 24 | 		}
 25 | 		// only add if it's a file
 26 | 		if info.IsDir() {
 27 | 			return nil
 28 | 		}
 29 | 		mountedPath, err := filepath.Abs(path)
 30 | 		if err != nil {
 31 | 			return err
 32 | 		}
 33 | 		fmt.Println("mountedpath: ", mountedPath)
 34 | 		mountedPath = strings.TrimPrefix(mountedPath, dir)
 35 | 		mountedPath = strings.ReplaceAll(mountedPath, "\\", "/") // ensure path dividors are as expected and not Windows
 36 | 		var offlen FIoOffsetAndLength
 37 | 		offlen.SetLength(uint64(info.Size()))
 38 | 
 39 | 		chidData, ok := (*pathToChunkID)[mountedPath]
 40 | 		if !ok {
 41 | 			return errors.New("a problem occurred while constructing the file. Did you use the correct manifest file?")
 42 | 		}
 43 | 		newEntry := GameFileMetaData{
 44 | 			filepath: mountedPath,
 45 | 			chunkID:  chidData,
 46 | 			offlen:   offlen,
 47 | 		}
 48 | 		fmt.Println("trimmed: ", mountedPath)
 49 | 		files = append(files, newEntry)
 50 | 		return nil
 51 | 	})
 52 | 
 53 | 	return &files, err
 54 | }
 55 | 
 56 | // This function does way too much. It does the following;
 57 | // 	- reads all files that must be packed
 58 | //  - compresses all the files as specified
 59 | //  - records all metadata of packing, required for the program.
 60 | //  - writes the compressed files to the .ucas file - not yet encrypted!
 61 | func packFilesToUcas(files *[]GameFileMetaData, m *Manifest, dir string, outFilename string, compression string) error {
 62 | 
 63 | 	/* manually add the "dependencies" section here */
 64 | 	// only include the dependencies that are present
 65 | 	subsetDependencies := make(map[uint64]FileDependency)
 66 | 	for _, v := range *files {
 67 | 		// all values are ChunkIDs
 68 | 		subsetDependencies[v.chunkID.ID] = (*m).Deps.ChunkIDToDependencies[v.chunkID.ID]
 69 | 	}
 70 | 	(*m).Deps.ChunkIDToDependencies = subsetDependencies
 71 | 
 72 | 	// find uint64 of depfile
 73 | 	depHexString := ""
 74 | 	for _, v := range (*m).Files {
 75 | 		if v.Filepath == DepFileName {
 76 | 			depHexString = v.ChunkID
 77 | 		}
 78 | 	}
 79 | 
 80 | 	compMethodNumber := uint8(0)
 81 | 	if strings.ToLower(compression) != "none" {
 82 | 		compMethodNumber = 1
 83 | 	}
 84 | 	compFun := getCompressionFunction(compression)
 85 | 	if compFun == nil {
 86 | 		return errors.New("could not find compression method. Please use none, oodle or zlib")
 87 | 	}
 88 | 
 89 | 	// create the new file in a new directory
 90 | 	directory := filepath.Dir(outFilename)
 91 | 	os.MkdirAll(directory, 0700)
 92 | 	f, err := os.OpenFile(outFilename+".ucas", os.O_CREATE|os.O_WRONLY, 0644)
 93 | 	if err != nil {
 94 | 		return err
 95 | 	}
 96 | 	defer f.Close() // all file data is written in this function
 97 | 
 98 | 	for i := 0; i < len(*files); i++ {
 99 | 		b, err := os.ReadFile(dir + (*files)[i].filepath)
100 | 
101 | 		// sorry, this is a little cursed
102 | 		if err != nil && (*files)[i].filepath != DepFileName {
103 | 			return err
104 | 		}
105 | 		// if the file doesnt exist, but the filepath indicates it's the dependency file...
106 | 		if (*files)[i].filepath == DepFileName {
107 | 			// attempt to deparse, fix filepath, set chunkid
108 | 			b = *(*m).Deps.Deparse()
109 | 			(*files)[i].filepath = ""
110 | 			(*files)[i].chunkID = FromHexString(depHexString)
111 | 		}
112 | 		(*files)[i].offlen.SetLength(uint64(len(b)))
113 | 		if i == 0 {
114 | 			(*files)[i].offlen.SetOffset(0)
115 | 		} else {
116 | 			offset := (*files)[i-1].offlen.GetOffset() + (*files)[i-1].offlen.GetLength()
117 | 			offset = ((offset + CompSize - 1) / CompSize) * CompSize // align to 0x1000
118 | 			(*files)[i].offlen.SetOffset(offset)
119 | 		}
120 | 		(*files)[i].metadata.ChunkHash = *sha1Hash(&b)
121 | 		(*files)[i].metadata.Flags = 1 // not sure what this should be?
122 | 
123 | 		// now perform compression, write per compressed block to ucas file
124 | 		for len(b) != 0 {
125 | 			var chunk []byte
126 | 			var block FIoStoreTocCompressedBlockEntry
127 | 			chunkLen := len(b)
128 | 			if chunkLen > CompSize {
129 | 				chunkLen = CompSize
130 | 			}
131 | 			chunk = b[:chunkLen]
132 | 			cChunkPtr, err := compFun(&chunk)
133 | 			if err != nil {
134 | 				return err
135 | 			}
136 | 			compressedChunk := *cChunkPtr
137 | 
138 | 			block.CompressionMethod = compMethodNumber
139 | 			currOffset, _ := f.Seek(0, os.SEEK_CUR)
140 | 			block.SetOffset(uint64(currOffset))
141 | 			block.SetUncompressedSize(uint32(chunkLen))
142 | 			block.SetCompressedSize(uint32(len(compressedChunk)))
143 | 			// align this compessedChunk to 0x10 with random bytes as padding
144 | 			compressedChunk = append(compressedChunk, getRandomBytes((0x10-(len(compressedChunk)%0x10))&(0x10-1))...)
145 | 			b = b[chunkLen:]
146 | 
147 | 			(*files)[i].compressionBlocks = append((*files)[i].compressionBlocks, block)
148 | 
149 | 			// write chunk to the new .ucas file
150 | 			f.Write(compressedChunk)
151 | 		}
152 | 		fmt.Println("Packed: ", (*files)[i].filepath)
153 | 	}
154 | 	return nil
155 | }
156 | 
157 | func (w *DirIndexWrapper) ToBytes() *[]byte {
158 | 	buf := bytes.NewBuffer([]byte{})
159 | 
160 | 	dirCount := uint32(len(*w.dirs))
161 | 	fileCount := uint32(len(*w.files))
162 | 	strCount := uint32(len(*w.strSlice))
163 | 	// mount point string
164 | 	mountPointStr := stringToFString(MountPoint)
165 | 	buf.Write(mountPointStr)
166 | 
167 | 	// directory index entries
168 | 	buf.Write(*uint32ToBytes(&dirCount))
169 | 	for _, directoryEntry := range *w.dirs {
170 | 		binary.Write(buf, binary.LittleEndian, *directoryEntry)
171 | 	}
172 | 
173 | 	// file index entries
174 | 	buf.Write(*uint32ToBytes(&fileCount))
175 | 	for _, fileEntry := range *w.files {
176 | 		binary.Write(buf, binary.LittleEndian, *fileEntry)
177 | 	}
178 | 
179 | 	// string table
180 | 	buf.Write(*uint32ToBytes(&strCount))
181 | 	for _, str := range *w.strSlice {
182 | 		buf.Write(stringToFString(str))
183 | 	}
184 | 	output := buf.Bytes()
185 | 	return &output
186 | }
187 | 
188 | func deparseDirectoryIndex(files *[]GameFileMetaData) *[]byte {
189 | 	var wrapper DirIndexWrapper
190 | 	var dirIndexEntries []*FIoDirectoryIndexEntry
191 | 	var fileIndexEntries []*FIoFileIndexEntry
192 | 
193 | 	// first, create unique slice of strings
194 | 	strmap := make(map[string]bool)
195 | 	for _, v := range *files {
196 | 		dirfiles := strings.Split(v.filepath, "/")
197 | 		if dirfiles[0] == "" {
198 | 			dirfiles = dirfiles[1:]
199 | 		}
200 | 		for _, str := range dirfiles {
201 | 			strmap[str] = true
202 | 		}
203 | 	}
204 | 	strSlice := []string{}
205 | 	for k, _ := range strmap {
206 | 		strSlice = append(strSlice, k)
207 | 	}
208 | 	// of this, create a map for quick lookup
209 | 	strIdx := make(map[string]int)
210 | 	for i, v := range strSlice {
211 | 		strIdx[v] = i
212 | 	}
213 | 	root := FIoDirectoryIndexEntry{
214 | 		Name:             NoneEntry,
215 | 		FirstChildEntry:  NoneEntry,
216 | 		NextSiblingEntry: NoneEntry,
217 | 		FirstFileEntry:   NoneEntry,
218 | 	}
219 | 	dirIndexEntries = append(dirIndexEntries, &root)
220 | 	wrapper.dirs = &dirIndexEntries
221 | 	wrapper.files = &fileIndexEntries
222 | 	wrapper.strTable = &strIdx
223 | 	wrapper.strSlice = &strSlice
224 | 
225 | 	for i, v := range *files {
226 | 		fpathSections := strings.Split(v.filepath, "/")
227 | 		if fpathSections[0] == "" {
228 | 			fpathSections = fpathSections[1:]
229 | 		}
230 | 		root.AddFile(fpathSections, uint32(i), &wrapper)
231 | 	}
232 | 
233 | 	return wrapper.ToBytes()
234 | }
235 | 
236 | func constructUtocFile(files *[]GameFileMetaData, compression string, AESKey []byte) (*[]byte, error) {
237 | 	var udata UTocData
238 | 	newContainerFlags := uint8(IndexedContainerFlag)
239 | 
240 | 	compressionMethods := []string{"None"}
241 | 	if strings.ToLower(compression) != "none" {
242 | 		compressionMethods = append(compressionMethods, compression)
243 | 		newContainerFlags |= uint8(CompressedContainerFlag)
244 | 	}
245 | 
246 | 	if len(AESKey) != 0 {
247 | 		newContainerFlags |= uint8(EncryptedContainerFlag)
248 | 	}
249 | 	compressedBlocksCount := uint32(0)
250 | 	var containerIndex int
251 | 	// fmt.Printf("%+v\n", files)
252 | 	for i, v := range *files {
253 | 		compressedBlocksCount += uint32(len(v.compressionBlocks))
254 | 		// fmt.Println("containerIndex:", v.chunkID.Type)
255 | 		// should be the right type for this container/dependencies/whatever-its-called-chunk
256 | 		if v.chunkID.Type == 10 {
257 | 			containerIndex = i
258 | 			// fmt.Println("containerIndex:", containerIndex)
259 | 		}
260 | 	}
261 | 
262 | 	dirIndexBytes := deparseDirectoryIndex(files)
263 | 	// the container uint64 must be unique and new from any other ID from within the file.
264 | 	// There is a low probability that there is a collision with any other uint64 that is already in the file.
265 | 	// When this happens, the mod won't work without any apparent reason, so this would be the first place to start investigating.
266 | 	var magic [16]byte
267 | 	for i := 0; i < len(MagicUtoc); i++ {
268 | 		magic[i] = MagicUtoc[i]
269 | 	}
270 | 	// setting the required header fields
271 | 	udata.hdr = UTocHeader{
272 | 		Magic:                       magic,
273 | 		Version:                     3, // like the Grounded files
274 | 		HeaderSize:                  uint32(binary.Size(udata.hdr)),
275 | 		EntryCount:                  uint32(len(*files)),
276 | 		CompressedBlockEntryCount:   compressedBlocksCount,
277 | 		CompressedBlockEntrySize:    12,
278 | 		CompressionMethodNameCount:  uint32(len(compressionMethods) - 1), // "extra" methods, other than "none"
279 | 		CompressionMethodNameLength: CompressionNameLength,
280 | 		CompressionBlockSize:        CompSize,
281 | 		DirectoryIndexSize:          uint32(len(*dirIndexBytes)), // number of bytes in the dirIndex
282 | 		ContainerID:                 FIoContainerID((*files)[containerIndex].chunkID.ID),
283 | 		ContainerFlags:              EIoContainerFlags(newContainerFlags),
284 | 		PartitionSize:               0xffffffffffffffff,
285 | 		PartitionCount:              1,
286 | 	}
287 | 
288 | 	buf := bytes.NewBuffer([]byte{})
289 | 	// write header
290 | 	binary.Write(buf, binary.LittleEndian, udata.hdr)
291 | 
292 | 	// write chunk IDs
293 | 	for _, v := range *files {
294 | 		binary.Write(buf, binary.LittleEndian, v.chunkID)
295 | 	}
296 | 
297 | 	// write Offset and lengths
298 | 	for _, v := range *files {
299 | 		binary.Write(buf, binary.LittleEndian, v.offlen)
300 | 	}
301 | 
302 | 	// write compression blocks
303 | 	for _, v := range *files {
304 | 		for _, b := range v.compressionBlocks {
305 | 			binary.Write(buf, binary.LittleEndian, b)
306 | 		}
307 | 	}
308 | 
309 | 	// write compression methods, but skip "none"
310 | 	for _, compMethod := range compressionMethods {
311 | 		if strings.ToLower(compMethod) == "none" {
312 | 			continue
313 | 		}
314 | 		capitalized := strings.Title(compMethod)
315 | 		bname := make([]byte, 32)
316 | 		for i := 0; i < len(capitalized); i++ {
317 | 			bname[i] = capitalized[i]
318 | 		}
319 | 		binary.Write(buf, binary.LittleEndian, bname)
320 | 	}
321 | 
322 | 	// write directory index
323 | 	binary.Write(buf, binary.LittleEndian, dirIndexBytes)
324 | 
325 | 	// write chunk metas
326 | 	for _, v := range *files {
327 | 		binary.Write(buf, binary.LittleEndian, v.metadata)
328 | 	}
329 | 	output := buf.Bytes()
330 | 
331 | 	return &output, nil
332 | }
333 | 
334 | // returns the GameFileMetaData of the dependencies file
335 | func packToCasToc(dir string, m *Manifest, outFilename string, compression string, aes []byte) (int, error) {
336 | 
337 | 	var offlen FIoOffsetAndLength
338 | 	var fdata []GameFileMetaData
339 | 	var newEntry GameFileMetaData
340 | 	for _, v := range (*m).Files {
341 | 		var p string = filepath.Join(dir, v.Filepath)
342 | 		if info, err := os.Stat(p); err == nil {
343 | 			// fmt.Println("exists", v.Filepath)
344 | 			offlen.SetLength(uint64(info.Size()))
345 | 		} else if errors.Is(err, os.ErrNotExist) && v.Filepath == DepFileName {
346 | 			//dependencies file doesnt exist, but still needs to be parsed so add it here anyways!
347 | 			// fmt.Println("exin't", v.Filepath)
348 | 			offlen.SetLength(0) //will be fixed in a later function
349 | 		}
350 | 		newEntry = GameFileMetaData{
351 | 			filepath: v.Filepath,
352 | 			chunkID:  FromHexString(v.ChunkID),
353 | 			offlen:   offlen,
354 | 		}
355 | 		fdata = append(fdata, newEntry)
356 | 	}
357 | 
358 | 	// fmt.Printf("%+v\n", pathToChunkID)
359 | 	// first aggregate flat list of all the files that are in the dir
360 | 	// the resulting slice must keep its indices structure.
361 | 	// fdata, err := listFilesInDir(dir, &pathToChunkID)
362 | 	// if err != nil {
363 | 	// 	return 0, err
364 | 	// }
365 | 
366 | 	// read each file and place them in a newly created .ucas file with the desired compression method
367 | 	// get the required data such as compression sizes and hashes;
368 | 	err := packFilesToUcas(&fdata, m, dir, outFilename, compression)
369 | 	if err != nil {
370 | 		return 0, err
371 | 	}
372 | 
373 | 	// .ucas file has been written now; encrypt with aes if desired (why would you?)
374 | 	if len(aes) != 0 {
375 | 		b, err := os.ReadFile(outFilename + ".ucas")
376 | 		if err != nil {
377 | 			return 0, err
378 | 		}
379 | 		encrypted, err := encryptAES(&b, aes)
380 | 		if err != nil {
381 | 			return 0, err
382 | 		}
383 | 		err = os.WriteFile(outFilename+".ucas", *encrypted, os.ModePerm)
384 | 		if err != nil {
385 | 			return 0, err
386 | 		}
387 | 	}
388 | 
389 | 	// .utoc file must be generated, especially the directory index, which is the hardest part.
390 | 	utocBytes, err := constructUtocFile(&fdata, compression, aes)
391 | 	if err != nil {
392 | 		return 0, err
393 | 	}
394 | 	err = os.WriteFile(outFilename+".utoc", *utocBytes, os.ModePerm)
395 | 	return len(fdata), err
396 | }
397 | 


--------------------------------------------------------------------------------
/req/Packed_P.pak:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/gitMenv/UEcastoc/7e8112e4d7617522d60bda812dca11949d6a77cc/req/Packed_P.pak


--------------------------------------------------------------------------------
/ucas.go:
--------------------------------------------------------------------------------
 1 | package main
 2 | 
 3 | import (
 4 | 	"errors"
 5 | 	"fmt"
 6 | 	"os"
 7 | 	"path/filepath"
 8 | 	"regexp"
 9 | )
10 | 
11 | func (d *UTocData) unpackFile(fdata *GameFileMetaData, blockData *[][]byte, outDir string) error {
12 | 	os.MkdirAll(outDir, 0700)
13 | 	bdata := *blockData
14 | 	outputData := []byte{}
15 | 	for i := 0; i < len(bdata); i++ {
16 | 		method := d.compressionMethods[fdata.compressionBlocks[i].CompressionMethod]
17 | 		decomp := getDecompressionFunction(method)
18 | 		if decomp == nil {
19 | 			return errors.New(fmt.Sprintf("decompression method %s not known", method))
20 | 		}
21 | 		newData, err := decomp(&(bdata[i]), fdata.compressionBlocks[i].GetUncompressedSize())
22 | 		if err != nil {
23 | 			return err
24 | 		}
25 | 		outputData = append(outputData, (*newData)...)
26 | 	}
27 | 	// ensure path exists to the file
28 | 	fpath := filepath.Clean(outDir + fdata.filepath)
29 | 	directory := filepath.Dir(fpath)
30 | 
31 | 	os.MkdirAll(directory, 0700)
32 | 	// write the actual data to the new file
33 | 	err := os.WriteFile(fpath, outputData, 0644)
34 | 
35 | 	return err
36 | }
37 | 
38 | func (d *UTocData) matchRegex(regex string) *[]GameFileMetaData {
39 | 	filesToUnpack := []GameFileMetaData{}
40 | 	for _, v := range d.files {
41 | 		match, err := regexp.MatchString(regex, v.filepath)
42 | 		if err != nil {
43 | 			return &filesToUnpack
44 | 		}
45 | 		// exclude special "dependencies" file, as it's not meant to be directly unpacked
46 | 		// for unpacking that file, have a look at the function to construct the manifest!
47 | 		if match && v.filepath != DepFileName {
48 | 			filesToUnpack = append(filesToUnpack, v)
49 | 		}
50 | 	}
51 | 	return &filesToUnpack
52 | }
53 | 
54 | func (d *UTocData) unpackUcasFiles(ucasPath string, outDir string, regex string) (filesUnpacked int, err error) {
55 | 	outDir += d.mountPoint // adjust for mountpoint
56 | 	filesUnpacked = 0
57 | 	// read the file
58 | 	openUcas, err := os.Open(ucasPath)
59 | 	if err != nil {
60 | 		return filesUnpacked, err
61 | 	}
62 | 	defer openUcas.Close()
63 | 
64 | 	filesToUnpack := *(d.matchRegex(regex))
65 | 	// each "file" is built from compression blocks
66 | 	// extract those compression blocks from the .ucas file and use those for unpacking
67 | 	// Since there's one place where the .ucas file is actually read, it can act as a work divider.
68 | 	// that may make it possible to make it run multithreaded in the future!
69 | 	for _, v := range filesToUnpack {
70 | 		var compressionblockData [][]byte
71 | 		for _, b := range v.compressionBlocks {
72 | 			_, err = openUcas.Seek(int64(b.GetOffset()), 0)
73 | 			if err != nil {
74 | 				return filesUnpacked, err
75 | 			}
76 | 			buf := make([]byte, b.GetCompressedSize())
77 | 			readBytes, err := openUcas.Read(buf)
78 | 			if err != nil {
79 | 				return filesUnpacked, err
80 | 			}
81 | 			if uint32(readBytes) != b.GetCompressedSize() {
82 | 				return filesUnpacked, errors.New("could not read the correct size")
83 | 			}
84 | 			compressionblockData = append(compressionblockData, buf)
85 | 		}
86 | 		// all separate blocks collected for file unpacking
87 | 		err = d.unpackFile(&v, &compressionblockData, outDir)
88 | 		if err != nil {
89 | 			return filesUnpacked, err
90 | 		}
91 | 		filesUnpacked++
92 | 	}
93 | 	return len(filesToUnpack), nil
94 | }
95 | 


--------------------------------------------------------------------------------
/utoc.go:
--------------------------------------------------------------------------------
  1 | package main
  2 | 
  3 | import (
  4 | 	"bytes"
  5 | 	"encoding/binary"
  6 | 	"errors"
  7 | 	"fmt"
  8 | 	"io/ioutil"
  9 | 	"os"
 10 | 	"strings"
 11 | )
 12 | 
 13 | const (
 14 | 	MagicUtoc       string = "-==--==--==--==-"
 15 | 	UnrealSignature string = "\xC1\x83\x2A\x9E"
 16 | 	MountPoint      string = "../../../"
 17 | 	NoneEntry       uint32 = 0xffffffff
 18 | )
 19 | const (
 20 | 	VersionInvalid                 uint8 = iota
 21 | 	VersionInitial                       = iota
 22 | 	VersionDirectoryIndex                = iota
 23 | 	VersionPartitionSize                 = iota
 24 | 	VersionPerfectHash                   = iota
 25 | 	VersionPerfectHashWithOverflow       = iota
 26 | 	VersionLatest                        = iota
 27 | )
 28 | 
 29 | type EIoContainerFlags uint8
 30 | 
 31 | const (
 32 | 	NoneContainerFlag       EIoContainerFlags = 0
 33 | 	CompressedContainerFlag                   = 1 << 0
 34 | 	EncryptedContainerFlag                    = 1 << 1
 35 | 	SignedContainerFlag                       = 1 << 2
 36 | 	IndexedContainerFlag                      = 1 << 3
 37 | )
 38 | 
 39 | type FGuid struct {
 40 | 	A, B, C, D uint32
 41 | }
 42 | 
 43 | type UTocHeader struct {
 44 | 	Magic                            [16]byte
 45 | 	Version                          uint8    // Current options are Initial(1), DirectoryIndex(2), PartitionSize(3)
 46 | 	Reserved0                        [3]uint8 // actually a uint8 and uint16
 47 | 	HeaderSize                       uint32   // value is 144
 48 | 	EntryCount                       uint32
 49 | 	CompressedBlockEntryCount        uint32
 50 | 	CompressedBlockEntrySize         uint32 // they say "For sanity checking"
 51 | 	CompressionMethodNameCount       uint32
 52 | 	CompressionMethodNameLength      uint32
 53 | 	CompressionBlockSize             uint32
 54 | 	DirectoryIndexSize               uint32
 55 | 	PartitionCount                   uint32 // should be 0
 56 | 	ContainerID                      FIoContainerID
 57 | 	EncryptionKeyGuid                FGuid
 58 | 	ContainerFlags                   EIoContainerFlags
 59 | 	Reserved1                        [3]byte
 60 | 	TocChunkPerfectHashSeedsCount    uint32
 61 | 	PartitionSize                    uint64
 62 | 	TocChunksWithoutPerfectHashCount uint32
 63 | 	Reserved2                        [44]byte
 64 | }
 65 | 
 66 | func (h *UTocHeader) isEncrypted() bool {
 67 | 	return h.ContainerFlags&EncryptedContainerFlag != 0
 68 | }
 69 | 
 70 | // ucas file consists of files. For each file, there is an entry with this data.
 71 | // It states where you can find which file in the ucas file.
 72 | type GameFileMetaData struct {
 73 | 	filepath          string
 74 | 	chunkID           FIoChunkID
 75 | 	offlen            FIoOffsetAndLength
 76 | 	compressionBlocks []FIoStoreTocCompressedBlockEntry
 77 | 	metadata          FIoStoreTocEntryMeta
 78 | }
 79 | 
 80 | type UTocData struct {
 81 | 	hdr                UTocHeader
 82 | 	mountPoint         string
 83 | 	files              []GameFileMetaData
 84 | 	compressionMethods []string
 85 | }
 86 | 
 87 | type GameFilePathData struct {
 88 | 	fpath    string
 89 | 	userData uint32
 90 | }
 91 | 
 92 | func (u *UTocData) unpackDependencies(ucasPath string) (*[]byte, error) {
 93 | 	// find dependency file independent of index
 94 | 	var depfile GameFileMetaData
 95 | 	// depfile := u.files[len(u.files)-1]
 96 | 	for _, f := range u.files {
 97 | 		if f.filepath == DepFileName {
 98 | 			depfile = f
 99 | 		}
100 | 	}
101 | 	if depfile.filepath != DepFileName {
102 | 		fmt.Println(depfile.filepath)
103 | 		return nil, errors.New("could not derive dependencies")
104 | 	}
105 | 	// open ucas file
106 | 	openUcas, err := os.Open(ucasPath)
107 | 	if err != nil {
108 | 		return nil, err
109 | 	}
110 | 	var compressionblockData [][]byte
111 | 	for _, b := range depfile.compressionBlocks {
112 | 		_, err = openUcas.Seek(int64(b.GetOffset()), 0)
113 | 		if err != nil {
114 | 			return nil, err
115 | 		}
116 | 		buf := make([]byte, b.GetCompressedSize())
117 | 		readBytes, err := openUcas.Read(buf)
118 | 		if err != nil {
119 | 			return nil, err
120 | 		}
121 | 		if uint32(readBytes) != b.GetCompressedSize() {
122 | 			return nil, errors.New("could not read the correct size")
123 | 		}
124 | 		compressionblockData = append(compressionblockData, buf)
125 | 	}
126 | 	// all separate blocks collected for file unpacking
127 | 	outputData := []byte{}
128 | 	for i := 0; i < len(compressionblockData); i++ {
129 | 		method := u.compressionMethods[depfile.compressionBlocks[i].CompressionMethod]
130 | 		decomp := getDecompressionFunction(method)
131 | 		if decomp == nil {
132 | 			return nil, errors.New(fmt.Sprintf("decompression method %s not known", method))
133 | 		}
134 | 		newData, err := decomp(&(compressionblockData[i]), depfile.compressionBlocks[i].GetUncompressedSize())
135 | 		if err != nil {
136 | 			return nil, err
137 | 		}
138 | 		outputData = append(outputData, (*newData)...)
139 | 	}
140 | 	return &outputData, nil
141 | }
142 | 
143 | func recursiveDirExplorer(parentPath string, pDir uint32, outputList *[]GameFilePathData,
144 | 	strTable *[]string, dirs *[]FIoDirectoryIndexEntry, files *[]FIoFileIndexEntry) {
145 | 
146 | 	dirIdx := (*dirs)[pDir].FirstChildEntry
147 | 	fileIdx := (*dirs)[pDir].FirstFileEntry
148 | 	if dirIdx == NoneEntry && fileIdx == NoneEntry { // base case
149 | 		return
150 | 	}
151 | 
152 | 	for dirIdx != NoneEntry {
153 | 		dirEntry := (*dirs)[dirIdx]
154 | 		newDirName := parentPath + "/" + (*strTable)[dirEntry.Name]
155 | 		recursiveDirExplorer(newDirName, dirIdx, outputList, strTable, dirs, files)
156 | 		dirIdx = dirEntry.NextSiblingEntry
157 | 	}
158 | 	for fileIdx != NoneEntry {
159 | 		fileEntry := (*files)[fileIdx]
160 | 		filepath := parentPath + "/" + (*strTable)[fileEntry.Name]
161 | 		(*outputList) = append((*outputList), GameFilePathData{fpath: filepath, userData: fileEntry.UserData})
162 | 		fileIdx = fileEntry.NextFileEntry
163 | 	}
164 | }
165 | 
166 | // returned is a slice of filepaths in the correct order.
167 | // meaning that the indices correspond to their file-index userData field.
168 | func parseDirectoryIndex(r *bytes.Reader, numberOfChunks int) (mountpoint string, filepaths *[]string) {
169 | 	var size, dirCount, fileCount, stringCount uint32
170 | 	var dirs []FIoDirectoryIndexEntry
171 | 	var files []FIoFileIndexEntry
172 | 	var strTable []string
173 | 
174 | 	// mount point string
175 | 	binary.Read(r, binary.LittleEndian, &size)
176 | 	mntPt := make([]byte, size)
177 | 	binary.Read(r, binary.LittleEndian, &mntPt)
178 | 	mountPointName := string(mntPt[:len(mntPt)-1])
179 | 	if !strings.HasPrefix(mountPointName, MountPoint) {
180 | 		return "", nil
181 | 	}
182 | 	mountpoint = strings.TrimPrefix(mountPointName, MountPoint)
183 | 	var dirEntry FIoDirectoryIndexEntry
184 | 	binary.Read(r, binary.LittleEndian, &dirCount)
185 | 	for i := 0; uint32(i) < dirCount; i++ {
186 | 		binary.Read(r, binary.LittleEndian, &dirEntry)
187 | 		dirs = append(dirs, dirEntry)
188 | 	}
189 | 
190 | 	var fileEntry FIoFileIndexEntry
191 | 	binary.Read(r, binary.LittleEndian, &fileCount)
192 | 	for i := 0; uint32(i) < fileCount; i++ {
193 | 		binary.Read(r, binary.LittleEndian, &fileEntry)
194 | 		files = append(files, fileEntry)
195 | 	}
196 | 
197 | 	binary.Read(r, binary.LittleEndian, &stringCount)
198 | 	for i := 0; uint32(i) < stringCount; i++ {
199 | 		binary.Read(r, binary.LittleEndian, &size)
200 | 		newString := make([]byte, size)
201 | 		binary.Read(r, binary.LittleEndian, &newString)
202 | 		strTable = append(strTable, string(newString[:len(newString)-1]))
203 | 	}
204 | 	if dirs[0].Name != NoneEntry {
205 | 		return "", nil
206 | 	}
207 | 
208 | 	var gamefilePaths []GameFilePathData
209 | 
210 | 	recursiveDirExplorer("", 0, &gamefilePaths, &strTable, &dirs, &files)
211 | 
212 | 	// order the filepaths according to their userdata
213 | 	orderedPaths := make([]string, numberOfChunks)
214 | 	for _, v := range gamefilePaths {
215 | 		orderedPaths[v.userData] = v.fpath
216 | 	}
217 | 
218 | 	return mountpoint, &orderedPaths
219 | }
220 | 
221 | func parseUtocHeader(r *bytes.Reader) (hdr UTocHeader, err error) {
222 | 	// read the header of the .utoc file
223 | 	err = binary.Read(r, binary.LittleEndian, &hdr)
224 | 	if err != nil {
225 | 		return hdr, err
226 | 	}
227 | 	if string(hdr.Magic[:]) != MagicUtoc {
228 | 		return hdr, errors.New("magic word of .utoc file was not found")
229 | 	}
230 | 	if hdr.Version < VersionDirectoryIndex {
231 | 		return hdr, errors.New("utoc version is outdated")
232 | 	}
233 | 	if hdr.Version > VersionLatest {
234 | 		return hdr, errors.New("too new utoc version")
235 | 	}
236 | 
237 | 	if hdr.Version < VersionPartitionSize {
238 | 		hdr.PartitionCount = 1
239 | 		hdr.PartitionSize = 0xffffffffffffffff // limit of uint64
240 | 		fmt.Println("Warning: this is a version of the utoc file format that may not be supported yet")
241 | 	}
242 | 	if hdr.CompressedBlockEntrySize != 12 { // must be sizeof FIoStoreTocCompressedBlockEntry
243 | 		return hdr, errors.New("compressed block entry size was incorrect")
244 | 	}
245 | 
246 | 	if hdr.ContainerFlags != 0 && uint8(hdr.ContainerFlags)&SignedContainerFlag != 0 {
247 | 		// the reference project may contain flags here, but no idea what it should do...
248 | 		return hdr, errors.New("the unreal engine dictates that this is an error. No idea why (yet)... Sorry!")
249 | 	}
250 | 
251 | 	return hdr, nil
252 | }
253 | 
254 | // the UTocData can be used to extract all information from the ucas files
255 | func parseUtocFile(utocFile string, aesKey []byte) (*UTocData, error) {
256 | 	var udata UTocData
257 | 	b, err := ioutil.ReadFile(utocFile)
258 | 	if err != nil {
259 | 		return nil, err
260 | 	}
261 | 	r := bytes.NewReader(b)
262 | 
263 | 	udata.hdr, err = parseUtocHeader(r)
264 | 	if err != nil {
265 | 		return nil, err
266 | 	}
267 | 	if udata.hdr.isEncrypted() {
268 | 		if len(aesKey) == 0 {
269 | 			return &udata, errors.New("encrypted file, but no AES key was provided! Please pass the aes key as a string in hexadecimal format")
270 | 		}
271 | 	}
272 | 
273 | 	// parse the following four sections of the file
274 | 	var chunkIDs []FIoChunkID
275 | 	var offlengths []FIoOffsetAndLength
276 | 	var perfectHashSeeds []uint32
277 | 	var withoutPerfectHashes []uint32
278 | 	var compressionBlocks []FIoStoreTocCompressedBlockEntry
279 | 	var filepaths []string
280 | 	var metas []FIoStoreTocEntryMeta
281 | 
282 | 	// following the header is a list of chunk IDs.
283 | 	var chunkID FIoChunkID
284 | 	for i := 0; i < int(udata.hdr.EntryCount); i++ {
285 | 		binary.Read(r, binary.LittleEndian, &chunkID)
286 | 		chunkIDs = append(chunkIDs, chunkID)
287 | 	}
288 | 
289 | 	var offlen FIoOffsetAndLength
290 | 	for i := 0; i < int(udata.hdr.EntryCount); i++ {
291 | 		binary.Read(r, binary.LittleEndian, &offlen)
292 | 		offlengths = append(offlengths, offlen)
293 | 	}
294 | 	// if there are Perfect Hash Seeds ?? then these must be parsed before the compression blocks
295 | 	var hashSeed uint32
296 | 	for i := 0; i < int(udata.hdr.TocChunkPerfectHashSeedsCount); i++ {
297 | 		binary.Read(r, binary.LittleEndian, &hashSeed)
298 | 		perfectHashSeeds = append(perfectHashSeeds, hashSeed)
299 | 	}
300 | 	// same goes for the chunks without perfect hashes???
301 | 	for i := 0; i < int(udata.hdr.TocChunksWithoutPerfectHashCount); i++ {
302 | 		binary.Read(r, binary.LittleEndian, &hashSeed)
303 | 		withoutPerfectHashes = append(withoutPerfectHashes, hashSeed)
304 | 	}
305 | 
306 | 	// read compression blocks
307 | 	var cBlock FIoStoreTocCompressedBlockEntry
308 | 	for i := 0; i < int(udata.hdr.CompressedBlockEntryCount); i++ {
309 | 		binary.Read(r, binary.LittleEndian, &cBlock)
310 | 		compressionBlocks = append(compressionBlocks, cBlock)
311 | 	}
312 | 	// read compression methods
313 | 	udata.compressionMethods = append(udata.compressionMethods, "None")
314 | 
315 | 	method := make([]byte, udata.hdr.CompressionMethodNameLength)
316 | 	for i := 0; i < int(udata.hdr.CompressionMethodNameCount); i++ {
317 | 		binary.Read(r, binary.LittleEndian, &method)
318 | 		udata.compressionMethods = append(udata.compressionMethods, string(bytes.Trim([]byte(method[:]), "\x00")))
319 | 	}
320 | 
321 | 	// read directory index, but only if the containerFlags states that is present. TODO?
322 | 	dirIndexBuffer := make([]byte, udata.hdr.DirectoryIndexSize)
323 | 	binary.Read(r, binary.LittleEndian, &dirIndexBuffer) // normal reader is advanced here as well
324 | 
325 | 	if udata.hdr.isEncrypted() {
326 | 		plaintext, err := decryptAES(&dirIndexBuffer, aesKey)
327 | 		if err != nil {
328 | 			return &udata, err
329 | 		}
330 | 		dirIndexBuffer = *plaintext
331 | 	}
332 | 	dirReader := bytes.NewReader(dirIndexBuffer)
333 | 
334 | 	mntPt, fpaths := parseDirectoryIndex(dirReader, len(chunkIDs))
335 | 	udata.mountPoint = mntPt
336 | 	if fpaths == nil {
337 | 		return &udata, errors.New("something went wrong parsing the directory index!")
338 | 	}
339 | 	filepaths = *fpaths
340 | 
341 | 	// read file chunk metas
342 | 	var meta FIoStoreTocEntryMeta
343 | 	for i := 0; i < int(udata.hdr.EntryCount); i++ {
344 | 		binary.Read(r, binary.LittleEndian, &meta)
345 | 		metas = append(metas, meta)
346 | 	}
347 | 	//temporary dependency "file" because it isn't always the last chunk
348 | 	var foundDeps bool
349 | 	var path string
350 | 	// aggregate file data
351 | 	for i, v := range filepaths {
352 | 		startBlock := offlengths[i].GetOffset() / uint64(udata.hdr.CompressionBlockSize)
353 | 		// hacky way of rounding the length to the next multiple of the compressionblocksize and intcasting
354 | 		endBlock := startBlock + (offlengths[i].GetLength()+(uint64(udata.hdr.CompressionBlockSize)-1))/uint64(udata.hdr.CompressionBlockSize)
355 | 		blocks := compressionBlocks[startBlock:endBlock]
356 | 		if v == "" {
357 | 			// check for "dependencies" chunk via type instead of assuming it's last.
358 | 			// in the sample im running this on, the chunkID matches with the one in the header.
359 | 			if chunkIDs[i].Type != 10 && uint64(udata.hdr.ContainerID) != chunkIDs[i].ID {
360 | 				// if the name is empty, the type is 10, and the chunkID doesnt match, then it's not the dependencies
361 | 				continue
362 | 			}
363 | 			foundDeps = true
364 | 			path = DepFileName
365 | 		} else {
366 | 			path = v
367 | 		}
368 | 		udata.files = append(udata.files, GameFileMetaData{
369 | 			filepath:          path,
370 | 			chunkID:           chunkIDs[i],
371 | 			offlen:            offlengths[i],
372 | 			compressionBlocks: blocks,
373 | 			metadata:          metas[i],
374 | 		})
375 | 	}
376 | 	if !foundDeps {
377 | 		return &udata, errors.New("couldn't find dependencies")
378 | 	}
379 | 	// the final file in the list will have filepath "dependencies"
380 | 	// //manually stick this on at the end for compatibility?
381 | 	// udata.files = append(udata.files, deps)
382 | 	return &udata, nil
383 | }
384 | 


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