'use strict';
var StringReader = require('./stringReader');
var utils = require('./utils');
var CompressedObject = require('./compressedObject');
var jszipProto = require('./object');
var support = require('./support');
var MADE_BY_DOS = 0x00;
var MADE_BY_UNIX = 0x03;
// class ZipEntry {{{
/**
* An entry in the zip file.
* @constructor
* @param {Object} options Options of the current file.
* @param {Object} loadOptions Options for loading the stream.
*/
function ZipEntry(options, loadOptions) {
this.options = options;
this.loadOptions = loadOptions;
}
ZipEntry.prototype = {
/**
* say if the file is encrypted.
* @return {boolean} true if the file is encrypted, false otherwise.
*/
isEncrypted: function() {
// bit 1 is set
return (this.bitFlag & 0x0001) === 0x0001;
},
/**
* say if the file has utf-8 filename/comment.
* @return {boolean} true if the filename/comment is in utf-8, false otherwise.
*/
useUTF8: function() {
// bit 11 is set
return (this.bitFlag & 0x0800) === 0x0800;
},
/**
* Prepare the function used to generate the compressed content from this ZipFile.
* @param {DataReader} reader the reader to use.
* @param {number} from the offset from where we should read the data.
* @param {number} length the length of the data to read.
* @return {Function} the callback to get the compressed content (the type depends of the DataReader class).
*/
prepareCompressedContent: function(reader, from, length) {
return function() {
var previousIndex = reader.index;
reader.setIndex(from);
var compressedFileData = reader.readData(length);
reader.setIndex(previousIndex);
return compressedFileData;
};
},
/**
* Prepare the function used to generate the uncompressed content from this ZipFile.
* @param {DataReader} reader the reader to use.
* @param {number} from the offset from where we should read the data.
* @param {number} length the length of the data to read.
* @param {JSZip.compression} compression the compression used on this file.
* @param {number} uncompressedSize the uncompressed size to expect.
* @return {Function} the callback to get the uncompressed content (the type depends of the DataReader class).
*/
prepareContent: function(reader, from, length, compression, uncompressedSize) {
return function() {
var compressedFileData = utils.transformTo(compression.uncompressInputType, this.getCompressedContent());
var uncompressedFileData = compression.uncompress(compressedFileData);
if (uncompressedFileData.length !== uncompressedSize) {
throw new Error("Bug : uncompressed data size mismatch");
}
return uncompressedFileData;
};
},
/**
* Read the local part of a zip file and add the info in this object.
* @param {DataReader} reader the reader to use.
*/
readLocalPart: function(reader) {
var compression, localExtraFieldsLength;
// we already know everything from the central dir !
// If the central dir data are false, we are doomed.
// On the bright side, the local part is scary : zip64, data descriptors, both, etc.
// The less data we get here, the more reliable this should be.
// Let's skip the whole header and dash to the data !
reader.skip(22);
// in some zip created on windows, the filename stored in the central dir contains \ instead of /.
// Strangely, the filename here is OK.
// I would love to treat these zip files as corrupted (see http://www.info-zip.org/FAQ.html#backslashes
// or APPNOTE#4.4.17.1, "All slashes MUST be forward slashes '/'") but there are a lot of bad zip generators...
// Search "unzip mismatching "local" filename continuing with "central" filename version" on
// the internet.
//
// I think I see the logic here : the central directory is used to display
// content and the local directory is used to extract the files. Mixing / and \
// may be used to display \ to windows users and use / when extracting the files.
// Unfortunately, this lead also to some issues : http://seclists.org/fulldisclosure/2009/Sep/394
this.fileNameLength = reader.readInt(2);
localExtraFieldsLength = reader.readInt(2); // can't be sure this will be the same as the central dir
this.fileName = reader.readData(this.fileNameLength);
reader.skip(localExtraFieldsLength);
if (this.compressedSize == -1 || this.uncompressedSize == -1) {
throw new Error("Bug or corrupted zip : didn't get enough informations from the central directory " + "(compressedSize == -1 || uncompressedSize == -1)");
}
compression = utils.findCompression(this.compressionMethod);
if (compression === null) { // no compression found
throw new Error("Corrupted zip : compression " + utils.pretty(this.compressionMethod) + " unknown (inner file : " + utils.transformTo("string", this.fileName) + ")");
}
this.decompressed = new CompressedObject();
this.decompressed.compressedSize = this.compressedSize;
this.decompressed.uncompressedSize = this.uncompressedSize;
this.decompressed.crc32 = this.crc32;
this.decompressed.compressionMethod = this.compressionMethod;
this.decompressed.getCompressedContent = this.prepareCompressedContent(reader, reader.index, this.compressedSize, compression);
this.decompressed.getContent = this.prepareContent(reader, reader.index, this.compressedSize, compression, this.uncompressedSize);
// we need to compute the crc32...
if (this.loadOptions.checkCRC32) {
this.decompressed = utils.transformTo("string", this.decompressed.getContent());
if (jszipProto.crc32(this.decompressed) !== this.crc32) {
throw new Error("Corrupted zip : CRC32 mismatch");
}
}
},
/**
* Read the central part of a zip file and add the info in this object.
* @param {DataReader} reader the reader to use.
*/
readCentralPart: function(reader) {
this.versionMadeBy = reader.readInt(2);
this.versionNeeded = reader.readInt(2);
this.bitFlag = reader.readInt(2);
this.compressionMethod = reader.readString(2);
this.date = reader.readDate();
this.crc32 = reader.readInt(4);
this.compressedSize = reader.readInt(4);
this.uncompressedSize = reader.readInt(4);
this.fileNameLength = reader.readInt(2);
this.extraFieldsLength = reader.readInt(2);
this.fileCommentLength = reader.readInt(2);
this.diskNumberStart = reader.readInt(2);
this.internalFileAttributes = reader.readInt(2);
this.externalFileAttributes = reader.readInt(4);
this.localHeaderOffset = reader.readInt(4);
if (this.isEncrypted()) {
throw new Error("Encrypted zip are not supported");
}
this.fileName = reader.readData(this.fileNameLength);
this.readExtraFields(reader);
this.parseZIP64ExtraField(reader);
this.fileComment = reader.readData(this.fileCommentLength);
},
/**
* Parse the external file attributes and get the unix/dos permissions.
*/
processAttributes: function () {
this.unixPermissions = null;
this.dosPermissions = null;
var madeBy = this.versionMadeBy >> 8;
// Check if we have the DOS directory flag set.
// We look for it in the DOS and UNIX permissions
// but some unknown platform could set it as a compatibility flag.
this.dir = this.externalFileAttributes & 0x0010 ? true : false;
if(madeBy === MADE_BY_DOS) {
// first 6 bits (0 to 5)
this.dosPermissions = this.externalFileAttributes & 0x3F;
}
if(madeBy === MADE_BY_UNIX) {
this.unixPermissions = (this.externalFileAttributes >> 16) & 0xFFFF;
// the octal permissions are in (this.unixPermissions & 0x01FF).toString(8);
}
// fail safe : if the name ends with a / it probably means a folder
if (!this.dir && this.fileNameStr.slice(-1) === '/') {
this.dir = true;
}
},
/**
* Parse the ZIP64 extra field and merge the info in the current ZipEntry.
* @param {DataReader} reader the reader to use.
*/
parseZIP64ExtraField: function(reader) {
if (!this.extraFields[0x0001]) {
return;
}
// should be something, preparing the extra reader
var extraReader = new StringReader(this.extraFields[0x0001].value);
// I really hope that these 64bits integer can fit in 32 bits integer, because js
// won't let us have more.
if (this.uncompressedSize === utils.MAX_VALUE_32BITS) {
this.uncompressedSize = extraReader.readInt(8);
}
if (this.compressedSize === utils.MAX_VALUE_32BITS) {
this.compressedSize = extraReader.readInt(8);
}
if (this.localHeaderOffset === utils.MAX_VALUE_32BITS) {
this.localHeaderOffset = extraReader.readInt(8);
}
if (this.diskNumberStart === utils.MAX_VALUE_32BITS) {
this.diskNumberStart = extraReader.readInt(4);
}
},
/**
* Read the central part of a zip file and add the info in this object.
* @param {DataReader} reader the reader to use.
*/
readExtraFields: function(reader) {
var start = reader.index,
extraFieldId,
extraFieldLength,
extraFieldValue;
this.extraFields = this.extraFields || {};
while (reader.index < start + this.extraFieldsLength) {
extraFieldId = reader.readInt(2);
extraFieldLength = reader.readInt(2);
extraFieldValue = reader.readString(extraFieldLength);
this.extraFields[extraFieldId] = {
id: extraFieldId,
length: extraFieldLength,
value: extraFieldValue
};
}
},
/**
* Apply an UTF8 transformation if needed.
*/
handleUTF8: function() {
var decodeParamType = support.uint8array ? "uint8array" : "array";
if (this.useUTF8()) {
this.fileNameStr = jszipProto.utf8decode(this.fileName);
this.fileCommentStr = jszipProto.utf8decode(this.fileComment);
} else {
var upath = this.findExtraFieldUnicodePath();
if (upath !== null) {
this.fileNameStr = upath;
} else {
var fileNameByteArray = utils.transformTo(decodeParamType, this.fileName);
this.fileNameStr = this.loadOptions.decodeFileName(fileNameByteArray);
}
var ucomment = this.findExtraFieldUnicodeComment();
if (ucomment !== null) {
this.fileCommentStr = ucomment;
} else {
var commentByteArray = utils.transformTo(decodeParamType, this.fileComment);
this.fileCommentStr = this.loadOptions.decodeFileName(commentByteArray);
}
}
},
/**
* Find the unicode path declared in the extra field, if any.
* @return {String} the unicode path, null otherwise.
*/
findExtraFieldUnicodePath: function() {
var upathField = this.extraFields[0x7075];
if (upathField) {
var extraReader = new StringReader(upathField.value);
// wrong version
if (extraReader.readInt(1) !== 1) {
return null;
}
// the crc of the filename changed, this field is out of date.
if (jszipProto.crc32(this.fileName) !== extraReader.readInt(4)) {
return null;
}
return jszipProto.utf8decode(extraReader.readString(upathField.length - 5));
}
return null;
},
/**
* Find the unicode comment declared in the extra field, if any.
* @return {String} the unicode comment, null otherwise.
*/
findExtraFieldUnicodeComment: function() {
var ucommentField = this.extraFields[0x6375];
if (ucommentField) {
var extraReader = new StringReader(ucommentField.value);
// wrong version
if (extraReader.readInt(1) !== 1) {
return null;
}
// the crc of the comment changed, this field is out of date.
if (jszipProto.crc32(this.fileComment) !== extraReader.readInt(4)) {
return null;
}
return jszipProto.utf8decode(extraReader.readString(ucommentField.length - 5));
}
return null;
}
};
module.exports = ZipEntry;
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