├── .gitignore ├── go.mod ├── .github ├── build └── workflows │ ├── release.yml │ └── main.yml ├── go.sum ├── README.md ├── main.go └── LICENSE /.gitignore: -------------------------------------------------------------------------------- 1 | .env 2 | .vscode 3 | .mypy_cache 4 | .notes.md 5 | -------------------------------------------------------------------------------- /go.mod: -------------------------------------------------------------------------------- 1 | module pan-net.cloud/security/artifactory-pypi-scanner 2 | 3 | go 1.14 4 | 5 | require ( 6 | github.com/PuerkitoBio/goquery v1.6.1 7 | golang.org/x/net v0.0.0-20200707034311-ab3426394381 // indirect 8 | ) 9 | -------------------------------------------------------------------------------- /.github/build: -------------------------------------------------------------------------------- 1 | #!/usr/bin/env sh 2 | 3 | go get github.com/mitchellh/gox 4 | gox -output "artifactory-pypi-scanner_{{.OS}}_{{.Arch}}" 5 | for file in artifactory-pypi-scanner*; do 6 | sha256sum "$file" > "${file}.sha256sum" 7 | done 8 | -------------------------------------------------------------------------------- /.github/workflows/release.yml: -------------------------------------------------------------------------------- 1 | on: 2 | release: 3 | types: [created] 4 | name: Release 5 | jobs: 6 | generate: 7 | name: Create release-artifacts 8 | runs-on: ubuntu-latest 9 | steps: 10 | - name: Checkout the repository 11 | uses: actions/checkout@master 12 | - name: Generate the artifacts 13 | uses: skx/github-action-build@master 14 | - name: Upload the artifacts 15 | uses: skx/github-action-publish-binaries@master 16 | env: 17 | GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} 18 | with: 19 | args: 'artifactory-pypi-scanner*' 20 | -------------------------------------------------------------------------------- /.github/workflows/main.yml: -------------------------------------------------------------------------------- 1 | on: [push, pull_request] 2 | name: Build and lint 3 | jobs: 4 | lint: 5 | name: Lint 6 | runs-on: ubuntu-latest 7 | steps: 8 | - name: Install Go 9 | uses: actions/setup-go@v2 10 | with: 11 | go-version: 1.15 12 | 13 | - name: Checkout code 14 | uses: actions/checkout@v2 15 | 16 | - name: Lint code 17 | run: | 18 | go get -u golang.org/x/lint/golint 19 | golint . 20 | build: 21 | name: Build 22 | runs-on: ubuntu-latest 23 | needs: [lint] 24 | steps: 25 | - name: Set up Go 26 | uses: actions/setup-go@v2 27 | with: 28 | go-version: 1.15 29 | 30 | - name: Check out code 31 | uses: actions/checkout@v2 32 | 33 | - name: Build 34 | run: go build . 35 | -------------------------------------------------------------------------------- /go.sum: -------------------------------------------------------------------------------- 1 | github.com/PuerkitoBio/goquery v1.6.1 h1:FgjbQZKl5HTmcn4sKBgvx8vv63nhyhIpv7lJpFGCWpk= 2 | github.com/PuerkitoBio/goquery v1.6.1/go.mod h1:GsLWisAFVj4WgDibEWF4pvYnkVQBpKBKeU+7zCJoLcc= 3 | github.com/andybalholm/cascadia v1.1.0 h1:BuuO6sSfQNFRu1LppgbD25Hr2vLYW25JvxHs5zzsLTo= 4 | github.com/andybalholm/cascadia v1.1.0/go.mod h1:GsXiBklL0woXo1j/WYWtSYYC4ouU9PqHO0sqidkEA4Y= 5 | golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w= 6 | golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto= 7 | golang.org/x/net v0.0.0-20180218175443-cbe0f9307d01/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4= 8 | golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg= 9 | golang.org/x/net v0.0.0-20200202094626-16171245cfb2/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s= 10 | golang.org/x/net v0.0.0-20200707034311-ab3426394381 h1:VXak5I6aEWmAXeQjA+QSZzlgNrpq9mjcfDemuexIKsU= 11 | golang.org/x/net v0.0.0-20200707034311-ab3426394381/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA= 12 | golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY= 13 | golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs= 14 | golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs= 15 | golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg= 16 | golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ= 17 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # Artifactory PyPI Scanner 2 | [![Go Report Card](https://goreportcard.com/badge/github.com/pan-net-security/artifactory-pypi-scanner)](https://goreportcard.com/report/github.com/pan-net-security/artifactory-pypi-scanner) [![Build Status](https://github.com/pan-net-security/artifactory-pypi-scanner/workflows/Build%20and%20lint/badge.svg?branch=master&event=push)](https://github.com/pan-net-security/artifactory-pypi-scanner/actions?query=workflow%3A%22Build+and+lint%22) 3 | 4 | `artifactory-pypi-scanner` lists all Python packages in a [jfrog artifactory](https://jfrog.com/artifactory/) instance. Checks whether they're present on [PyPI](https://pypi.org/) and creates new ones with the same name if they do not exist on PyPI. 5 | 6 | ## But why? 7 | 8 | When `pip` searches for packages, it searches PyPI first and other repositories next. This creates a security issue which was described [here](https://github.com/pypa/pip/issues/8606). Let's say we have a package in an internal repository. Someone can upload a package containing malicious code with the same name to PyPI. When downloading the package users will download the malicious package. To prevent this package injection we create a placeholder on PyPI. 9 | 10 | ### OK, but haven't I just performed a package injection on myself? 11 | 12 | Well yes, actually but no. If the package version is not specified, `pip` tries to get the latest version possible. By creating a package with a low enough version (`0.0.47`) on PyPI, we make sure that `pip` downloads the package from internal repositories. 13 | 14 | > Be nice and prefix your package name with, e.g. name of your organization, not to clutter PyPI 15 | 16 | 17 | ## Installation 18 | 19 | You can build it from source or download pre-build binaries from [releases](https://github.com/pan-net-security/artifactory-pypi-scanner/releases). 20 | ```sh 21 | go get github.com/pan-net-security/artifactory-pypi-scanner 22 | ``` 23 | 24 | ## Configuration 25 | 26 | `artifactory-pypi-scanner` is configured by environmental variables. All variables are mandatory. 27 | 28 | - `ARTIFACTORY_URL` 29 | - `PYPI_UPLOAD_URL` - used for uploading packages via [legacy](https://warehouse.readthedocs.io/api-reference/legacy/#upload-api) endpoint 30 | - `PYPI_URL` - used for checking presence of package via [json](https://warehouse.readthedocs.io/api-reference/json/#get--pypi--project_name--json) endpoint 31 | - `PYPI_EMAIL` - used for checking authors of conflicting packages 32 | - `PYPI_TOKEN` - API token, not a password 33 | 34 | ## Example 35 | 36 | `artifactory-pypi-scanner` outputs JSON since it is easily consumable by other services. 37 | 38 | ``` 39 | $ artifactory-pypi-scanner | jq 40 | { 41 | "error": "", 42 | "artifactoryPackages": 3, 43 | "pypiPlaceholders": 2, 44 | "repositoryResults": [ 45 | { 46 | "error": "", 47 | "url": "https://af.example.com/artifactory//repository1-pypi-local", 48 | "packageResults": [ 49 | { 50 | "error": "", 51 | "name": "package1", 52 | "isOurs": false, 53 | "created": false 54 | } 55 | ] 56 | }, 57 | { 58 | "error": "", 59 | "url": "https://af.example.com/artifactory//repository2-pypi-local", 60 | "packageResults": [ 61 | { 62 | "error": "", 63 | "name": "package2", 64 | "isOurs": true, 65 | "created": false 66 | }, 67 | { 68 | "error": "", 69 | "name": "package3", 70 | "isOurs": true, 71 | "created": true 72 | } 73 | ] 74 | } 75 | ] 76 | } 77 | ``` 78 | -------------------------------------------------------------------------------- /main.go: -------------------------------------------------------------------------------- 1 | package main 2 | 3 | import ( 4 | "archive/tar" 5 | "bytes" 6 | "compress/gzip" 7 | "crypto/md5" 8 | "encoding/json" 9 | "fmt" 10 | "io" 11 | "io/ioutil" 12 | "log" 13 | "mime/multipart" 14 | "net/http" 15 | "net/url" 16 | "os" 17 | "strings" 18 | "time" 19 | 20 | "github.com/PuerkitoBio/goquery" 21 | ) 22 | 23 | // PackageVersion is default version for python packages 24 | const PackageVersion = "0.0.47" 25 | const setupPy = `from setuptools import setup 26 | 27 | setup(name='%s', version='%s', author_email='%s') 28 | ` 29 | const pkgInfo = `Metadata-Version: 1.0 30 | Name: %s 31 | Version: %s 32 | Summary: UNKNOWN 33 | Home-page: UNKNOWN 34 | Author: UNKNOWN 35 | Author-email: %s 36 | License: UNKNOWN 37 | Description: UNKNOWN 38 | Platform: UNKNOWN` 39 | 40 | type client struct { 41 | http *http.Client 42 | artifacoryURL string 43 | repositoriesURI string 44 | pypiPackageInfoURI string 45 | pypiPackageUploadURI string 46 | pypiEmail string 47 | pypiToken string 48 | pypiURL string 49 | pypiUploadURL string 50 | } 51 | 52 | type scannerResult struct { 53 | Err string `json:"error"` 54 | ArtifactoryPackages int `json:"artifactoryPackages"` 55 | PypiPlaceholders int `json:"pypiPlaceholders"` 56 | RepositoryResults []repositoryResult `json:"repositoryResults"` 57 | } 58 | 59 | type repositoryResult struct { 60 | Err string `json:"error"` 61 | URL string `json:"url"` 62 | PackageResults []packageResult `json:"packageResults"` 63 | } 64 | 65 | type packageResult struct { 66 | Err string `json:"error"` 67 | Name string `json:"name"` 68 | IsOurs bool `json:"isOurs"` 69 | Created bool `json:"created"` 70 | } 71 | 72 | type packages []struct { 73 | URL string `json:"url"` 74 | } 75 | 76 | type packageInfo struct { 77 | Info struct { 78 | AuthorEmail string `json:"author_email"` 79 | } `json:"info"` 80 | } 81 | 82 | func (c client) getRepositoryURLs() ([]string, error) { 83 | params := url.Values{} 84 | params.Add("type", "local") 85 | params.Add("packageType", "pypi") 86 | 87 | req, err := http.NewRequest("GET", fmt.Sprintf(c.repositoriesURI, c.artifacoryURL), nil) 88 | if err != nil { 89 | return nil, fmt.Errorf("failed to build request: %s", err) 90 | } 91 | 92 | req.URL.RawQuery = params.Encode() 93 | resp, err := c.http.Do(req) 94 | if err != nil { 95 | return nil, fmt.Errorf("failed to send request: %s", err) 96 | } 97 | defer resp.Body.Close() 98 | 99 | packages := packages{} 100 | if err := json.NewDecoder(resp.Body).Decode(&packages); err != nil { 101 | return nil, fmt.Errorf("failed to decode response: %s", err) 102 | } 103 | 104 | var repositoryURLs []string 105 | for _, item := range packages { 106 | repositoryURLs = append(repositoryURLs, item.URL) 107 | } 108 | return repositoryURLs, nil 109 | } 110 | 111 | func (c client) getPackageNamesFromArtifactory(repositoryURL string) ([]string, error) { 112 | log.Printf("Scanning: %s\n", repositoryURL) 113 | var packages []string 114 | 115 | url, err := url.Parse(repositoryURL) 116 | if err != nil { 117 | return nil, fmt.Errorf("invalid package url: %s", err) 118 | } 119 | 120 | simpleAPIURL := fmt.Sprintf("%s://%s%s/.pypi/simple.html", url.Scheme, url.Hostname(), url.Path) 121 | req, err := http.NewRequest("GET", fmt.Sprintf(simpleAPIURL), nil) 122 | if err != nil { 123 | return nil, fmt.Errorf("failed to create request: %s", err) 124 | } 125 | 126 | resp, err := c.http.Do(req) 127 | if err != nil { 128 | return nil, fmt.Errorf("failed to send request: %s", err) 129 | } 130 | defer resp.Body.Close() 131 | 132 | doc, err := goquery.NewDocumentFromReader(resp.Body) 133 | if err != nil { 134 | return nil, fmt.Errorf("failed to parse document: %s", err) 135 | } 136 | 137 | doc.Find("a").Each(func(i int, s *goquery.Selection) { 138 | text := s.Text() 139 | requires, exists := s.Attr("data-requires-python") 140 | // artifactory has a bug when it leaks anchor attributes to the inner 141 | // text. this filters out anchors with malformed inner texts 142 | if !exists || requires == "" || !strings.Contains(text, requires[1:]) { 143 | packages = append(packages, text) 144 | } 145 | }) 146 | 147 | if len(packages) == 0 { 148 | return nil, fmt.Errorf("no package found at %s", simpleAPIURL) 149 | } 150 | 151 | return packages, nil 152 | } 153 | 154 | func (c client) chechIfPackageIsOurs(packageName string) (bool, error) { 155 | req, err := http.NewRequest("GET", fmt.Sprintf(c.pypiPackageInfoURI, c.pypiURL, packageName), nil) 156 | if err != nil { 157 | return false, fmt.Errorf("failed to create request: %s", err) 158 | } 159 | 160 | resp, err := c.http.Do(req) 161 | if err != nil { 162 | return false, fmt.Errorf("failed to get %s from PyPI: %s", packageName, err) 163 | } 164 | defer resp.Body.Close() 165 | 166 | packageInfo := packageInfo{} 167 | if err := json.NewDecoder(resp.Body).Decode(&packageInfo); err != nil { 168 | return false, fmt.Errorf("failed to decode response from PyPI: %s", err) 169 | } 170 | 171 | log.Printf("%s has '%s' as author", packageName, packageInfo.Info.AuthorEmail) 172 | return strings.EqualFold(packageInfo.Info.AuthorEmail, c.pypiEmail), nil 173 | } 174 | 175 | func (c client) createPackage(name string) ([]byte, error) { 176 | var buf bytes.Buffer 177 | gz := gzip.NewWriter(&buf) 178 | tarball := tar.NewWriter(gz) 179 | 180 | pgkInfoContent := []byte(fmt.Sprintf(pkgInfo, name, PackageVersion, c.pypiEmail)) 181 | setupPyContent := []byte(fmt.Sprintf(setupPy, name, PackageVersion, c.pypiEmail)) 182 | 183 | files := map[string][]byte{ 184 | fmt.Sprintf("%s-%s/PKG-INFO", name, PackageVersion): pgkInfoContent, 185 | fmt.Sprintf("%s-%s/setup.py", name, PackageVersion): setupPyContent, 186 | fmt.Sprintf("%s-%s/%s.egg-info/PKG-INFO", name, PackageVersion, name): pgkInfoContent, 187 | } 188 | 189 | for name, content := range files { 190 | header := tar.Header{ 191 | Name: name, 192 | Mode: 0600, 193 | Size: int64(len(content)), 194 | Typeflag: tar.TypeReg, 195 | } 196 | if err := tarball.WriteHeader(&header); err != nil { 197 | tarball.Close() 198 | gz.Close() 199 | return nil, fmt.Errorf("unable to tar header of %s: %s", name, err) 200 | } 201 | if _, err := tarball.Write(content); err != nil { 202 | tarball.Close() 203 | gz.Close() 204 | return nil, fmt.Errorf("unable to tar content of %s: %s", name, err) 205 | } 206 | 207 | } 208 | 209 | if err := tarball.Close(); err != nil { 210 | return nil, err 211 | } 212 | if err := gz.Close(); err != nil { 213 | return nil, err 214 | } 215 | return buf.Bytes(), nil 216 | } 217 | 218 | func (c client) uploadPackage(name string) error { 219 | body := &bytes.Buffer{} 220 | writer := multipart.NewWriter(body) 221 | defer writer.Close() 222 | 223 | fileWritter, err := writer.CreateFormFile("content", fmt.Sprintf("%s-%s.tar.gz", name, PackageVersion)) 224 | if err != nil { 225 | return fmt.Errorf("failed to add dist to request: %s", err) 226 | } 227 | 228 | packageTar, err := c.createPackage(name) 229 | if err != nil { 230 | return fmt.Errorf("unable to create %s.tar.gz: %s", name, err) 231 | } 232 | 233 | if _, err := io.Copy(fileWritter, bytes.NewReader(packageTar)); err != nil { 234 | return fmt.Errorf("unable to copy package tar multipart writter") 235 | } 236 | 237 | for fieldName, fieldValue := range map[string]string{ 238 | ":action": "file_upload", 239 | "protocol_version": "1", 240 | "filetype": "sdist", 241 | "pyversion": "source", 242 | "name": name, 243 | "metadata_version": "1.0", 244 | "author_email": c.pypiEmail, 245 | "version": PackageVersion, 246 | "md5_digest": fmt.Sprintf("%x", md5.Sum(packageTar)), 247 | } { 248 | field, err := writer.CreateFormField(fieldName) 249 | if err != nil { 250 | return fmt.Errorf("failed to create form field for %s: %s", fieldName, err) 251 | } 252 | if _, err := field.Write([]byte(fieldValue)); err != nil { 253 | return fmt.Errorf("failed to write field %s: %s", fieldName, err) 254 | } 255 | } 256 | 257 | uploadURL := fmt.Sprintf(c.pypiPackageUploadURI, c.pypiUploadURL) 258 | req, err := http.NewRequest("POST", uploadURL, body) 259 | if err != nil { 260 | return fmt.Errorf("failed to create request to %s: %s", uploadURL, err) 261 | } 262 | 263 | req.Header.Add("Content-Type", writer.FormDataContentType()) 264 | req.SetBasicAuth("__token__", c.pypiToken) 265 | resp, err := c.http.Do(req) 266 | if err != nil { 267 | return fmt.Errorf("failed to create PyPI package: %s", err) 268 | } 269 | 270 | if resp.StatusCode != 200 { 271 | body, err := ioutil.ReadAll(resp.Body) 272 | if err != nil { 273 | body = []byte("[none]") 274 | } 275 | return fmt.Errorf("Invalid response from PyPI received: %d. Body: %s", resp.StatusCode, body) 276 | } 277 | return nil 278 | } 279 | 280 | func (c client) handlePackage(name string, resultChan chan<- packageResult) { 281 | result := packageResult{Name: name} 282 | 283 | isOurs, err := c.chechIfPackageIsOurs(name) 284 | result.IsOurs = isOurs 285 | if err == nil { 286 | // this means that package exists at PyPI, we just report the result 287 | resultChan <- result 288 | return 289 | } 290 | 291 | log.Printf("Received error from PyPI: %s. Trying to create %s package.\n", err, name) 292 | if err := c.uploadPackage(name); err != nil { 293 | result.Err = fmt.Sprintf("unable to create package '%s': %s", name, err) 294 | resultChan <- result 295 | return 296 | } 297 | result.Created = true 298 | result.IsOurs = true 299 | resultChan <- result 300 | } 301 | 302 | func (c client) handleRepository(repositoryURL string, resultChan chan<- repositoryResult) { 303 | log.Printf("Handling %s repository\n", repositoryURL) 304 | result := repositoryResult{URL: repositoryURL} 305 | names, err := c.getPackageNamesFromArtifactory(repositoryURL) 306 | if err != nil { 307 | result.Err = fmt.Sprintf("failed to get package name: %s", err) 308 | resultChan <- result 309 | return 310 | } 311 | 312 | packageResultChan := make(chan packageResult) 313 | for _, name := range names { 314 | log.Printf("Handling package: %s", name) 315 | go c.handlePackage(name, packageResultChan) 316 | } 317 | 318 | for i := 0; i < len(names); i++ { 319 | select { 320 | case packageResult := <-packageResultChan: 321 | result.PackageResults = append(result.PackageResults, packageResult) 322 | log.Printf("Got result from package: %s", packageResult.Name) 323 | } 324 | } 325 | resultChan <- result 326 | } 327 | 328 | func (c client) run() error { 329 | scannerResult := scannerResult{} 330 | 331 | repositoryURLs, err := c.getRepositoryURLs() 332 | if err != nil { 333 | return fmt.Errorf("failed to get package URLs from AF: %s", err) 334 | } 335 | 336 | log.Printf("Got %d repositories from artifactory\n", len(repositoryURLs)) 337 | 338 | resultChan := make(chan repositoryResult) 339 | for _, url := range repositoryURLs { 340 | go c.handleRepository(url, resultChan) 341 | } 342 | 343 | for i := 0; i < len(repositoryURLs); i++ { 344 | select { 345 | case result := <-resultChan: 346 | scannerResult.RepositoryResults = append(scannerResult.RepositoryResults, result) 347 | if result.Err != "" { 348 | log.Printf("Error handling %s: %s\n", result.URL, result.Err) 349 | } 350 | log.Printf("Successfully handled %s repository\n", result.URL) 351 | for _, r := range result.PackageResults { 352 | scannerResult.ArtifactoryPackages++ 353 | if r.Created || r.IsOurs { 354 | scannerResult.PypiPlaceholders++ 355 | } 356 | } 357 | } 358 | } 359 | 360 | jsonResult, err := json.Marshal(scannerResult) 361 | if err != nil { 362 | return fmt.Errorf("unable to marshall scanner result: %s", err) 363 | } 364 | fmt.Printf("%s\n", jsonResult) 365 | return nil 366 | } 367 | 368 | func main() { 369 | client := client{ 370 | http: &http.Client{Timeout: time.Second * 10}, 371 | artifacoryURL: os.Getenv("ARTIFACTORY_URL"), 372 | repositoriesURI: "%s/artifactory/api/repositories", 373 | pypiURL: os.Getenv("PYPI_URL"), 374 | pypiUploadURL: os.Getenv("PYPI_UPLOAD_URL"), 375 | pypiEmail: os.Getenv("PYPI_EMAIL"), 376 | pypiToken: os.Getenv("PYPI_TOKEN"), 377 | pypiPackageInfoURI: "%s/pypi/%s/json", 378 | pypiPackageUploadURI: "%s/legacy/", 379 | } 380 | 381 | if err := client.run(); err != nil { 382 | log.Fatalln(err) 383 | } 384 | } 385 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | GNU GENERAL PUBLIC LICENSE 2 | Version 3, 29 June 2007 3 | 4 | Copyright (C) 2007 Free Software Foundation, Inc. 5 | Everyone is permitted to copy and distribute verbatim copies 6 | of this license document, but changing it is not allowed. 7 | 8 | Preamble 9 | 10 | The GNU General Public License is a free, copyleft license for 11 | software and other kinds of works. 12 | 13 | The licenses for most software and other practical works are designed 14 | to take away your freedom to share and change the works. By contrast, 15 | the GNU General Public License is intended to guarantee your freedom to 16 | share and change all versions of a program--to make sure it remains free 17 | software for all its users. We, the Free Software Foundation, use the 18 | GNU General Public License for most of our software; it applies also to 19 | any other work released this way by its authors. You can apply it to 20 | your programs, too. 21 | 22 | When we speak of free software, we are referring to freedom, not 23 | price. Our General Public Licenses are designed to make sure that you 24 | have the freedom to distribute copies of free software (and charge for 25 | them if you wish), that you receive source code or can get it if you 26 | want it, that you can change the software or use pieces of it in new 27 | free programs, and that you know you can do these things. 28 | 29 | To protect your rights, we need to prevent others from denying you 30 | these rights or asking you to surrender the rights. Therefore, you have 31 | certain responsibilities if you distribute copies of the software, or if 32 | you modify it: responsibilities to respect the freedom of others. 33 | 34 | For example, if you distribute copies of such a program, whether 35 | gratis or for a fee, you must pass on to the recipients the same 36 | freedoms that you received. You must make sure that they, too, receive 37 | or can get the source code. And you must show them these terms so they 38 | know their rights. 39 | 40 | Developers that use the GNU GPL protect your rights with two steps: 41 | (1) assert copyright on the software, and (2) offer you this License 42 | giving you legal permission to copy, distribute and/or modify it. 43 | 44 | For the developers' and authors' protection, the GPL clearly explains 45 | that there is no warranty for this free software. For both users' and 46 | authors' sake, the GPL requires that modified versions be marked as 47 | changed, so that their problems will not be attributed erroneously to 48 | authors of previous versions. 49 | 50 | Some devices are designed to deny users access to install or run 51 | modified versions of the software inside them, although the manufacturer 52 | can do so. This is fundamentally incompatible with the aim of 53 | protecting users' freedom to change the software. The systematic 54 | pattern of such abuse occurs in the area of products for individuals to 55 | use, which is precisely where it is most unacceptable. Therefore, we 56 | have designed this version of the GPL to prohibit the practice for those 57 | products. If such problems arise substantially in other domains, we 58 | stand ready to extend this provision to those domains in future versions 59 | of the GPL, as needed to protect the freedom of users. 60 | 61 | Finally, every program is threatened constantly by software patents. 62 | States should not allow patents to restrict development and use of 63 | software on general-purpose computers, but in those that do, we wish to 64 | avoid the special danger that patents applied to a free program could 65 | make it effectively proprietary. To prevent this, the GPL assures that 66 | patents cannot be used to render the program non-free. 67 | 68 | The precise terms and conditions for copying, distribution and 69 | modification follow. 70 | 71 | TERMS AND CONDITIONS 72 | 73 | 0. Definitions. 74 | 75 | "This License" refers to version 3 of the GNU General Public License. 76 | 77 | "Copyright" also means copyright-like laws that apply to other kinds of 78 | works, such as semiconductor masks. 79 | 80 | "The Program" refers to any copyrightable work licensed under this 81 | License. Each licensee is addressed as "you". "Licensees" and 82 | "recipients" may be individuals or organizations. 83 | 84 | To "modify" a work means to copy from or adapt all or part of the work 85 | in a fashion requiring copyright permission, other than the making of an 86 | exact copy. The resulting work is called a "modified version" of the 87 | earlier work or a work "based on" the earlier work. 88 | 89 | A "covered work" means either the unmodified Program or a work based 90 | on the Program. 91 | 92 | To "propagate" a work means to do anything with it that, without 93 | permission, would make you directly or secondarily liable for 94 | infringement under applicable copyright law, except executing it on a 95 | computer or modifying a private copy. Propagation includes copying, 96 | distribution (with or without modification), making available to the 97 | public, and in some countries other activities as well. 98 | 99 | To "convey" a work means any kind of propagation that enables other 100 | parties to make or receive copies. Mere interaction with a user through 101 | a computer network, with no transfer of a copy, is not conveying. 102 | 103 | An interactive user interface displays "Appropriate Legal Notices" 104 | to the extent that it includes a convenient and prominently visible 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 | 635 | Copyright (C) 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 . 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 | Copyright (C) 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 | . 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 | . 675 | --------------------------------------------------------------------------------