diff-updater.js (9843B) - View raw
/******************************************************************************* uBlock Origin - a comprehensive, efficient content blocker Copyright (C) 2014-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 */ // This module can be dynamically loaded or spun off as a worker. /******************************************************************************/ const patches = new Map(); const encoder = new TextEncoder(); const reFileName = /([^/]+?)(?:#.+)?$/; const EMPTYLINE = ''; /******************************************************************************/ const suffleArray = arr => { const out = arr.slice(); for ( let i = 0, n = out.length; i < n; i++ ) { const j = Math.floor(Math.random() * n); if ( j === i ) { continue; } [ out[j], out[i] ] = [ out[i], out[j] ]; } return out; }; const basename = url => { const match = reFileName.exec(url); return match && match[1] || ''; }; const resolveURL = (path, url) => { try { return new URL(path, url); } catch { } }; const expectedTimeFromPatch = assetDetails => { const match = /(\d+)\.(\d+)\.(\d+)\.(\d+)/.exec(assetDetails.patchPath); if ( match === null ) { return 0; } const date = new Date(); date.setUTCFullYear( parseInt(match[1], 10), parseInt(match[2], 10) - 1, parseInt(match[3], 10) ); date.setUTCHours(0, parseInt(match[4], 10), 0, 0); return date.getTime() + assetDetails.diffExpires; }; function parsePatch(patch) { const patchDetails = new Map(); const diffLines = patch.split('\n'); let i = 0, n = diffLines.length; while ( i < n ) { const line = diffLines[i++]; if ( line.startsWith('diff ') === false ) { continue; } const fields = line.split(/\s+/); const diffBlock = {}; for ( let j = 0; j < fields.length; j++ ) { const field = fields[j]; const pos = field.indexOf(':'); if ( pos === -1 ) { continue; } const name = field.slice(0, pos); if ( name === '' ) { continue; } const value = field.slice(pos+1); switch ( name ) { case 'name': case 'checksum': diffBlock[name] = value; break; case 'lines': diffBlock.lines = parseInt(value, 10); break; default: break; } } if ( diffBlock.name === undefined ) { return; } if ( isNaN(diffBlock.lines) || diffBlock.lines <= 0 ) { return; } if ( diffBlock.checksum === undefined ) { return; } patchDetails.set(diffBlock.name, diffBlock); diffBlock.diff = diffLines.slice(i, i + diffBlock.lines).join('\n'); i += diffBlock.lines; } if ( patchDetails.size === 0 ) { return; } return patchDetails; } function applyPatch(text, diff) { // Inspired from (Perl) "sub _patch" at: // https://twiki.org/p/pub/Codev/RcsLite/RcsLite.pm // Apparently authored by John Talintyre in Jan. 2002 // https://twiki.org/cgi-bin/view/Codev/RcsLite const lines = text.split('\n'); const diffLines = diff.split('\n'); let iAdjust = 0; let iDiff = 0, nDiff = diffLines.length; while ( iDiff < nDiff ) { const diffLine = diffLines[iDiff++]; if ( diffLine === '' ) { break; } const diffParsed = /^([ad])(\d+) (\d+)$/.exec(diffLine); if ( diffParsed === null ) { return; } const op = diffParsed[1]; const iOp = parseInt(diffParsed[2], 10); const nOp = parseInt(diffParsed[3], 10); const iOpAdj = iOp + iAdjust; if ( iOpAdj > lines.length ) { return; } // Delete lines if ( op === 'd' ) { lines.splice(iOpAdj-1, nOp); iAdjust -= nOp; continue; } // Add lines: Don't use splice() to avoid stack limit issues for ( let i = 0; i < nOp; i++ ) { lines.push(EMPTYLINE); } lines.copyWithin(iOpAdj+nOp, iOpAdj); for ( let i = 0; i < nOp; i++ ) { lines[iOpAdj+i] = diffLines[iDiff+i]; } iAdjust += nOp; iDiff += nOp; } return lines.join('\n'); } function hasPatchDetails(assetDetails) { const { patchPath } = assetDetails; const patchFile = basename(patchPath); return patchFile !== '' && patches.has(patchFile); } /******************************************************************************/ // Async async function applyPatchAndValidate(assetDetails, diffDetails) { const { text } = assetDetails; const { diff, checksum } = diffDetails; const textAfter = applyPatch(text, diff); if ( typeof textAfter !== 'string' ) { assetDetails.error = 'baddiff'; return false; } const crypto = globalThis.crypto; if ( typeof crypto !== 'object' ) { assetDetails.error = 'nocrypto'; return false; } const arrayin = encoder.encode(textAfter); const arraybuffer = await crypto.subtle.digest('SHA-1', arrayin); const arrayout = new Uint8Array(arraybuffer); const sha1Full = Array.from(arrayout).map(i => i.toString(16).padStart(2, '0') ).join(''); if ( sha1Full.startsWith(checksum) === false ) { assetDetails.error = `badchecksum: expected ${checksum}, computed ${sha1Full.slice(0, checksum.length)}`; return false; } assetDetails.text = textAfter; return true; } async function fetchPatchDetailsFromCDNs(assetDetails) { const { patchPath, cdnURLs, patchURLs } = assetDetails; if ( Array.isArray(cdnURLs) === false ) { return null; } if ( cdnURLs.length === 0 ) { return null; } for ( const cdnURL of suffleArray(patchURLs || cdnURLs) ) { const patchURL = resolveURL(patchPath, cdnURL); if ( patchURL === undefined ) { continue; } const response = await fetch(patchURL).catch(reason => { console.error(reason, patchURL); }); if ( response === undefined ) { continue; } if ( response.status === 404 ) { break; } if ( response.ok !== true ) { continue; } const patchText = await response.text(); const patchDetails = parsePatch(patchText); if ( patchURL.hash.length > 1 ) { assetDetails.diffName = patchURL.hash.slice(1); patchURL.hash = ''; } return { patchURL: patchURL.href, patchSize: `${(patchText.length / 1000).toFixed(1)} KB`, patchDetails, }; } return null; } async function fetchPatchDetails(assetDetails) { const { patchPath } = assetDetails; const patchFile = basename(patchPath); if ( patchFile === '' ) { return null; } if ( patches.has(patchFile) ) { return patches.get(patchFile); } const patchDetailsPromise = fetchPatchDetailsFromCDNs(assetDetails); patches.set(patchFile, patchDetailsPromise); return patchDetailsPromise; } async function fetchAndApplyAllPatches(assetDetails) { if ( assetDetails.fetch === false ) { if ( hasPatchDetails(assetDetails) === false ) { assetDetails.status = 'nodiff'; return assetDetails; } } // uBO-specific, to avoid pointless fetches which are likely to fail // because the patch has not yet been created const patchTime = expectedTimeFromPatch(assetDetails); if ( patchTime > Date.now() ) { assetDetails.status = 'nopatch-yet'; return assetDetails; } const patchData = await fetchPatchDetails(assetDetails); if ( patchData === null ) { assetDetails.status = (Date.now() - patchTime) < (4 * assetDetails.diffExpires) ? 'nopatch-yet' : 'nopatch'; return assetDetails; } const { patchDetails } = patchData; if ( patchDetails instanceof Map === false ) { assetDetails.status = 'nodiff'; return assetDetails; } const diffDetails = patchDetails.get(assetDetails.diffName); if ( diffDetails === undefined ) { assetDetails.status = 'nodiff'; return assetDetails; } if ( assetDetails.text === undefined ) { assetDetails.status = 'needtext'; return assetDetails; } const outcome = await applyPatchAndValidate(assetDetails, diffDetails); if ( outcome !== true ) { return assetDetails; } assetDetails.status = 'updated'; assetDetails.patchURL = patchData.patchURL; assetDetails.patchSize = patchData.patchSize; return assetDetails; } /******************************************************************************/ const self = globalThis; self.onmessage = ev => { const message = ev.data || {}; switch ( message.what ) { case 'update': fetchAndApplyAllPatches(message).then(response => { self.postMessage(response); }).catch(error => { self.postMessage({ what: 'broken', error }); }); break; } }; self.postMessage({ what: 'ready' }); /******************************************************************************/