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Diffstat (limited to 'data/extensions/uBlock0@raymondhill.net/js/urlskip.js')
| -rw-r--r-- | data/extensions/uBlock0@raymondhill.net/js/urlskip.js | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/data/extensions/uBlock0@raymondhill.net/js/urlskip.js b/data/extensions/uBlock0@raymondhill.net/js/urlskip.js new file mode 100644 index 0000000..360a3dd --- /dev/null +++ b/data/extensions/uBlock0@raymondhill.net/js/urlskip.js @@ -0,0 +1,165 @@ +/******************************************************************************* + + uBlock Origin - a comprehensive, efficient content blocker + Copyright (C) 2022-present Raymond Hill + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see {http://www.gnu.org/licenses/}. + + Home: https://github.com/gorhill/uBlock +*/ + +/** + * @trustedOption urlskip + * + * @description + * Extract a URL from another URL according to one or more transformation steps, + * thereby skipping over intermediate network request(s) to remote servers. + * Requires a trusted source. + * + * @param steps + * A serie of space-separated directives representing the transformation steps + * to perform to extract the final URL to which a network request should be + * redirected. + * + * Supported directives: + * + * `?name`: extract the value of parameter `name` as the current string. + * + * `&i`: extract the name of the parameter at position `i` as the current + * string. The position is 1-based. + * + * `#`: extract the hash as the current string. + * + * `/.../`: extract the first capture group of a regex as the current string. + * + * `+https`: prepend the current string with `https://`. + * + * `-base64`: decode the current string as a base64-encoded string. + * + * `-safebase64`: decode the current string as a safe base64-encoded string. + * + * `-uricomponent`: decode the current string as a URI encoded string. + * + * `-blocked`: allow the redirection of blocked requests. By default, blocked + * requests can't by urlskip'ed. + * + * At any given step, the currently extracted string may not necessarily be + * a valid URL, and more transformation steps may be needed to obtain a valid + * URL once all the steps are applied. + * + * An unsupported step or a failed step will abort the transformation and no + * redirection will be performed. + * + * The final step is expected to yield a valid URL. If the result is not a + * valid URL, no redirection will be performed. + * + * @example + * ||example.com/path/to/tracker$urlskip=?url + * ||example.com/path/to/tracker$urlskip=?url ?to + * ||pixiv.net/jump.php?$urlskip=&1 + * ||podtrac.com/pts/redirect.mp3/$urlskip=/\/redirect\.mp3\/(.*?\.mp3\b)/ +https + * + * */ + +export function urlSkip(url, blocked, steps, directive = {}) { + try { + let redirectBlocked = false; + let urlout = url; + for ( const step of steps ) { + const urlin = urlout; + const c0 = step.charCodeAt(0); + // Extract from hash + if ( c0 === 0x23 && step === '#' ) { // # + const pos = urlin.indexOf('#'); + urlout = pos !== -1 ? urlin.slice(pos+1) : ''; + continue; + } + // Extract from URL parameter name at position i + if ( c0 === 0x26 ) { // & + const i = (parseInt(step.slice(1)) || 0) - 1; + if ( i < 0 ) { return; } + const url = new URL(urlin); + if ( i >= url.searchParams.size ) { return; } + const params = Array.from(url.searchParams.keys()); + urlout = decodeURIComponent(params[i]); + continue; + } + // Enforce https + if ( c0 === 0x2B && step === '+https' ) { // + + const s = urlin.replace(/^https?:\/\//, ''); + if ( /^[\w-]:\/\//.test(s) ) { return; } + urlout = `https://${s}`; + continue; + } + // Decode + if ( c0 === 0x2D ) { // - + // Base64 + if ( step === '-base64' ) { + urlout = self.atob(urlin); + continue; + } + // Safe Base64 + if ( step === '-safebase64' ) { + if ( urlSkip.safeBase64Replacer === undefined ) { + urlSkip.safeBase64Map = { '-': '+', '_': '/' }; + urlSkip.safeBase64Replacer = s => urlSkip.safeBase64Map[s]; + } + urlout = urlin.replace(/[-_]/g, urlSkip.safeBase64Replacer); + urlout = self.atob(urlout); + continue; + } + // URI component + if ( step === '-uricomponent' ) { + urlout = decodeURIComponent(urlin); + continue; + } + // Enable skip of blocked requests + if ( step === '-blocked' ) { + redirectBlocked = true; + continue; + } + } + // Regex extraction from first capture group + if ( c0 === 0x2F ) { // / + const re = directive.cache ?? new RegExp(step.slice(1, -1)); + if ( directive.cache === null ) { + directive.cache = re; + } + const match = re.exec(urlin); + if ( match === null ) { return; } + if ( match.length <= 1 ) { return; } + urlout = match[1]; + continue; + } + // Extract from URL parameter + if ( c0 === 0x3F ) { // ? + urlout = (new URL(urlin)).searchParams.get(step.slice(1)); + if ( urlout === null ) { return; } + if ( urlout.includes(' ') ) { + urlout = urlout.replace(/ /g, '%20'); + } + continue; + } + // Unknown directive + return; + } + const urlfinal = new URL(urlout); + if ( urlfinal.protocol !== 'https:' ) { + if ( urlfinal.protocol !== 'http:' ) { return; } + } + if ( blocked && redirectBlocked !== true ) { return; } + return urlout; + } catch { + } +} |