2019-09-21 16:11:55 +02:00

276 lines
8.0 KiB
JavaScript

var util = require('util');
var zlib = require('zlib');
var Stream = require('stream');
var binary = require('binary');
var Promise = require('bluebird');
var PullStream = require('./PullStream');
var NoopStream = require('./NoopStream');
var BufferStream = require('./BufferStream');
var parseExtraField = require('./parseExtraField');
var Buffer = require('./Buffer');
var parseDateTime = require('./parseDateTime');
// Backwards compatibility for node versions < 8
if (!Stream.Writable || !Stream.Writable.prototype.destroy)
Stream = require('readable-stream');
var endDirectorySignature = Buffer.alloc(4);
endDirectorySignature.writeUInt32LE(0x06054b50, 0);
function Parse(opts) {
if (!(this instanceof Parse)) {
return new Parse(opts);
}
var self = this;
self._opts = opts || { verbose: false };
PullStream.call(self, self._opts);
self.on('finish',function() {
self.emit('close');
});
self._readRecord().catch(function(e) {
if (!self.__emittedError || self.__emittedError !== e)
self.emit('error',e);
});
}
util.inherits(Parse, PullStream);
Parse.prototype._readRecord = function () {
var self = this;
return self.pull(4).then(function(data) {
if (data.length === 0)
return;
var signature = data.readUInt32LE(0);
if (signature === 0x34327243) {
return self._readCrxHeader();
}
if (signature === 0x04034b50) {
return self._readFile();
}
else if (signature === 0x02014b50) {
self.__ended = true;
return self._readCentralDirectoryFileHeader();
}
else if (signature === 0x06054b50) {
return self._readEndOfCentralDirectoryRecord();
}
else if (self.__ended) {
return self.pull(endDirectorySignature).then(function() {
return self._readEndOfCentralDirectoryRecord();
});
}
else
self.emit('error', new Error('invalid signature: 0x' + signature.toString(16)));
});
};
Parse.prototype._readCrxHeader = function() {
var self = this;
return self.pull(12).then(function(data) {
self.crxHeader = binary.parse(data)
.word32lu('version')
.word32lu('pubKeyLength')
.word32lu('signatureLength')
.vars;
return self.pull(self.crxHeader.pubKeyLength + self.crxHeader.signatureLength);
}).then(function(data) {
self.crxHeader.publicKey = data.slice(0,self.crxHeader.pubKeyLength);
self.crxHeader.signature = data.slice(self.crxHeader.pubKeyLength);
self.emit('crx-header',self.crxHeader);
return self._readRecord();
});
};
Parse.prototype._readFile = function () {
var self = this;
return self.pull(26).then(function(data) {
var vars = binary.parse(data)
.word16lu('versionsNeededToExtract')
.word16lu('flags')
.word16lu('compressionMethod')
.word16lu('lastModifiedTime')
.word16lu('lastModifiedDate')
.word32lu('crc32')
.word32lu('compressedSize')
.word32lu('uncompressedSize')
.word16lu('fileNameLength')
.word16lu('extraFieldLength')
.vars;
vars.lastModifiedDateTime = parseDateTime(vars.lastModifiedDate, vars.lastModifiedTime);
if (self.crxHeader) vars.crxHeader = self.crxHeader;
return self.pull(vars.fileNameLength).then(function(fileNameBuffer) {
var fileName = fileNameBuffer.toString('utf8');
var entry = Stream.PassThrough();
var __autodraining = false;
entry.autodrain = function() {
__autodraining = true;
var draining = entry.pipe(NoopStream());
draining.promise = function() {
return new Promise(function(resolve, reject) {
draining.on('finish',resolve);
draining.on('error',reject);
});
};
return draining;
};
entry.buffer = function() {
return BufferStream(entry);
};
entry.path = fileName;
entry.props = {};
entry.props.path = fileName;
entry.props.pathBuffer = fileNameBuffer;
entry.props.flags = {
"isUnicode": vars.flags & 0x11
};
entry.type = (vars.uncompressedSize === 0 && /[\/\\]$/.test(fileName)) ? 'Directory' : 'File';
if (self._opts.verbose) {
if (entry.type === 'Directory') {
console.log(' creating:', fileName);
} else if (entry.type === 'File') {
if (vars.compressionMethod === 0) {
console.log(' extracting:', fileName);
} else {
console.log(' inflating:', fileName);
}
}
}
return self.pull(vars.extraFieldLength).then(function(extraField) {
var extra = parseExtraField(extraField, vars);
entry.vars = vars;
entry.extra = extra;
self.emit('entry', entry);
if (self._readableState.pipesCount)
self.push(entry);
if (self._opts.verbose)
console.log({
filename:fileName,
vars: vars,
extra: extra
});
var fileSizeKnown = !(vars.flags & 0x08) || vars.compressedSize > 0,
eof;
entry.__autodraining = __autodraining; // expose __autodraining for test purposes
var inflater = (vars.compressionMethod && !__autodraining) ? zlib.createInflateRaw() : Stream.PassThrough();
if (fileSizeKnown) {
entry.size = vars.uncompressedSize;
eof = vars.compressedSize;
} else {
eof = Buffer.alloc(4);
eof.writeUInt32LE(0x08074b50, 0);
}
self.stream(eof)
.pipe(inflater)
.on('error',function(err) { self.emit('error',err);})
.pipe(entry)
.on('finish', function() {
return fileSizeKnown ? self._readRecord() : self._processDataDescriptor(entry);
});
return null; // This prevents bluebird from throwing "promise created but not returned" warnings
});
});
});
};
Parse.prototype._processDataDescriptor = function (entry) {
var self = this;
self.pull(16).then(function(data) {
var vars = binary.parse(data)
.word32lu('dataDescriptorSignature')
.word32lu('crc32')
.word32lu('compressedSize')
.word32lu('uncompressedSize')
.vars;
entry.size = vars.uncompressedSize;
self._readRecord();
});
};
Parse.prototype._readCentralDirectoryFileHeader = function () {
var self = this;
self.pull(42).then(function(data) {
var vars = binary.parse(data)
.word16lu('versionMadeBy')
.word16lu('versionsNeededToExtract')
.word16lu('flags')
.word16lu('compressionMethod')
.word16lu('lastModifiedTime')
.word16lu('lastModifiedDate')
.word32lu('crc32')
.word32lu('compressedSize')
.word32lu('uncompressedSize')
.word16lu('fileNameLength')
.word16lu('extraFieldLength')
.word16lu('fileCommentLength')
.word16lu('diskNumber')
.word16lu('internalFileAttributes')
.word32lu('externalFileAttributes')
.word32lu('offsetToLocalFileHeader')
.vars;
return self.pull(vars.fileNameLength).then(function(fileName) {
vars.fileName = fileName.toString('utf8');
return self.pull(vars.extraFieldLength);
})
.then(function(extraField) {
return self.pull(vars.fileCommentLength);
})
.then(function(fileComment) {
return self._readRecord();
});
});
};
Parse.prototype._readEndOfCentralDirectoryRecord = function() {
var self = this;
self.pull(18).then(function(data) {
var vars = binary.parse(data)
.word16lu('diskNumber')
.word16lu('diskStart')
.word16lu('numberOfRecordsOnDisk')
.word16lu('numberOfRecords')
.word32lu('sizeOfCentralDirectory')
.word32lu('offsetToStartOfCentralDirectory')
.word16lu('commentLength')
.vars;
self.pull(vars.commentLength).then(function(comment) {
comment = comment.toString('utf8');
self.end();
self.push(null);
});
});
};
Parse.prototype.promise = function() {
var self = this;
return new Promise(function(resolve,reject) {
self.on('finish',resolve);
self.on('error',reject);
});
};
module.exports = Parse;