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- var Utils = require("./util"),
- Headers = require("./headers"),
- Constants = Utils.Constants,
- Methods = require("./methods");
- module.exports = function (/** object */ options, /*Buffer*/ input) {
- var _centralHeader = new Headers.EntryHeader(),
- _entryName = Buffer.alloc(0),
- _comment = Buffer.alloc(0),
- _isDirectory = false,
- uncompressedData = null,
- _extra = Buffer.alloc(0),
- _extralocal = Buffer.alloc(0),
- _efs = true;
- // assign options
- const opts = options;
- const decoder = typeof opts.decoder === "object" ? opts.decoder : Utils.decoder;
- _efs = decoder.hasOwnProperty("efs") ? decoder.efs : false;
- function getCompressedDataFromZip() {
- //if (!input || !Buffer.isBuffer(input)) {
- if (!input || !(input instanceof Uint8Array)) {
- return Buffer.alloc(0);
- }
- _extralocal = _centralHeader.loadLocalHeaderFromBinary(input);
- return input.slice(_centralHeader.realDataOffset, _centralHeader.realDataOffset + _centralHeader.compressedSize);
- }
- function crc32OK(data) {
- // if bit 3 (0x08) of the general-purpose flags field is set, then the CRC-32 and file sizes are not known when the local header is written
- if (!_centralHeader.flags_desc) {
- if (Utils.crc32(data) !== _centralHeader.localHeader.crc) {
- return false;
- }
- } else {
- const descriptor = {};
- const dataEndOffset = _centralHeader.realDataOffset + _centralHeader.compressedSize;
- // no descriptor after compressed data, instead new local header
- if (input.readUInt32LE(dataEndOffset) == Constants.LOCSIG || input.readUInt32LE(dataEndOffset) == Constants.CENSIG) {
- throw Utils.Errors.DESCRIPTOR_NOT_EXIST();
- }
- // get decriptor data
- if (input.readUInt32LE(dataEndOffset) == Constants.EXTSIG) {
- // descriptor with signature
- descriptor.crc = input.readUInt32LE(dataEndOffset + Constants.EXTCRC);
- descriptor.compressedSize = input.readUInt32LE(dataEndOffset + Constants.EXTSIZ);
- descriptor.size = input.readUInt32LE(dataEndOffset + Constants.EXTLEN);
- } else if (input.readUInt16LE(dataEndOffset + 12) === 0x4b50) {
- // descriptor without signature (we check is new header starting where we expect)
- descriptor.crc = input.readUInt32LE(dataEndOffset + Constants.EXTCRC - 4);
- descriptor.compressedSize = input.readUInt32LE(dataEndOffset + Constants.EXTSIZ - 4);
- descriptor.size = input.readUInt32LE(dataEndOffset + Constants.EXTLEN - 4);
- } else {
- throw Utils.Errors.DESCRIPTOR_UNKNOWN();
- }
- // check data integrity
- if (descriptor.compressedSize !== _centralHeader.compressedSize || descriptor.size !== _centralHeader.size || descriptor.crc !== _centralHeader.crc) {
- throw Utils.Errors.DESCRIPTOR_FAULTY();
- }
- if (Utils.crc32(data) !== descriptor.crc) {
- return false;
- }
- // @TODO: zip64 bit descriptor fields
- // if bit 3 is set and any value in local header "zip64 Extended information" extra field are set 0 (place holder)
- // then 64-bit descriptor format is used instead of 32-bit
- // central header - "zip64 Extended information" extra field should store real values and not place holders
- }
- return true;
- }
- function decompress(/*Boolean*/ async, /*Function*/ callback, /*String, Buffer*/ pass) {
- if (typeof callback === "undefined" && typeof async === "string") {
- pass = async;
- async = void 0;
- }
- if (_isDirectory) {
- if (async && callback) {
- callback(Buffer.alloc(0), Utils.Errors.DIRECTORY_CONTENT_ERROR()); //si added error.
- }
- return Buffer.alloc(0);
- }
- var compressedData = getCompressedDataFromZip();
- if (compressedData.length === 0) {
- // File is empty, nothing to decompress.
- if (async && callback) callback(compressedData);
- return compressedData;
- }
- if (_centralHeader.encrypted) {
- if ("string" !== typeof pass && !Buffer.isBuffer(pass)) {
- throw Utils.Errors.INVALID_PASS_PARAM();
- }
- compressedData = Methods.ZipCrypto.decrypt(compressedData, _centralHeader, pass);
- }
- var data = Buffer.alloc(_centralHeader.size);
- switch (_centralHeader.method) {
- case Utils.Constants.STORED:
- compressedData.copy(data);
- if (!crc32OK(data)) {
- if (async && callback) callback(data, Utils.Errors.BAD_CRC()); //si added error
- throw Utils.Errors.BAD_CRC();
- } else {
- //si added otherwise did not seem to return data.
- if (async && callback) callback(data);
- return data;
- }
- case Utils.Constants.DEFLATED:
- var inflater = new Methods.Inflater(compressedData, _centralHeader.size);
- if (!async) {
- const result = inflater.inflate(data);
- result.copy(data, 0);
- if (!crc32OK(data)) {
- throw Utils.Errors.BAD_CRC(`"${decoder.decode(_entryName)}"`);
- }
- return data;
- } else {
- inflater.inflateAsync(function (result) {
- result.copy(result, 0);
- if (callback) {
- if (!crc32OK(result)) {
- callback(result, Utils.Errors.BAD_CRC()); //si added error
- } else {
- callback(result);
- }
- }
- });
- }
- break;
- default:
- if (async && callback) callback(Buffer.alloc(0), Utils.Errors.UNKNOWN_METHOD());
- throw Utils.Errors.UNKNOWN_METHOD();
- }
- }
- function compress(/*Boolean*/ async, /*Function*/ callback) {
- if ((!uncompressedData || !uncompressedData.length) && Buffer.isBuffer(input)) {
- // no data set or the data wasn't changed to require recompression
- if (async && callback) callback(getCompressedDataFromZip());
- return getCompressedDataFromZip();
- }
- if (uncompressedData.length && !_isDirectory) {
- var compressedData;
- // Local file header
- switch (_centralHeader.method) {
- case Utils.Constants.STORED:
- _centralHeader.compressedSize = _centralHeader.size;
- compressedData = Buffer.alloc(uncompressedData.length);
- uncompressedData.copy(compressedData);
- if (async && callback) callback(compressedData);
- return compressedData;
- default:
- case Utils.Constants.DEFLATED:
- var deflater = new Methods.Deflater(uncompressedData);
- if (!async) {
- var deflated = deflater.deflate();
- _centralHeader.compressedSize = deflated.length;
- return deflated;
- } else {
- deflater.deflateAsync(function (data) {
- compressedData = Buffer.alloc(data.length);
- _centralHeader.compressedSize = data.length;
- data.copy(compressedData);
- callback && callback(compressedData);
- });
- }
- deflater = null;
- break;
- }
- } else if (async && callback) {
- callback(Buffer.alloc(0));
- } else {
- return Buffer.alloc(0);
- }
- }
- function readUInt64LE(buffer, offset) {
- return (buffer.readUInt32LE(offset + 4) << 4) + buffer.readUInt32LE(offset);
- }
- function parseExtra(data) {
- try {
- var offset = 0;
- var signature, size, part;
- while (offset + 4 < data.length) {
- signature = data.readUInt16LE(offset);
- offset += 2;
- size = data.readUInt16LE(offset);
- offset += 2;
- part = data.slice(offset, offset + size);
- offset += size;
- if (Constants.ID_ZIP64 === signature) {
- parseZip64ExtendedInformation(part);
- }
- }
- } catch (error) {
- throw Utils.Errors.EXTRA_FIELD_PARSE_ERROR();
- }
- }
- //Override header field values with values from the ZIP64 extra field
- function parseZip64ExtendedInformation(data) {
- var size, compressedSize, offset, diskNumStart;
- if (data.length >= Constants.EF_ZIP64_SCOMP) {
- size = readUInt64LE(data, Constants.EF_ZIP64_SUNCOMP);
- if (_centralHeader.size === Constants.EF_ZIP64_OR_32) {
- _centralHeader.size = size;
- }
- }
- if (data.length >= Constants.EF_ZIP64_RHO) {
- compressedSize = readUInt64LE(data, Constants.EF_ZIP64_SCOMP);
- if (_centralHeader.compressedSize === Constants.EF_ZIP64_OR_32) {
- _centralHeader.compressedSize = compressedSize;
- }
- }
- if (data.length >= Constants.EF_ZIP64_DSN) {
- offset = readUInt64LE(data, Constants.EF_ZIP64_RHO);
- if (_centralHeader.offset === Constants.EF_ZIP64_OR_32) {
- _centralHeader.offset = offset;
- }
- }
- if (data.length >= Constants.EF_ZIP64_DSN + 4) {
- diskNumStart = data.readUInt32LE(Constants.EF_ZIP64_DSN);
- if (_centralHeader.diskNumStart === Constants.EF_ZIP64_OR_16) {
- _centralHeader.diskNumStart = diskNumStart;
- }
- }
- }
- return {
- get entryName() {
- return decoder.decode(_entryName);
- },
- get rawEntryName() {
- return _entryName;
- },
- set entryName(val) {
- _entryName = Utils.toBuffer(val, decoder.encode);
- var lastChar = _entryName[_entryName.length - 1];
- _isDirectory = lastChar === 47 || lastChar === 92;
- _centralHeader.fileNameLength = _entryName.length;
- },
- get efs() {
- if (typeof _efs === "function") {
- return _efs(this.entryName);
- } else {
- return _efs;
- }
- },
- get extra() {
- return _extra;
- },
- set extra(val) {
- _extra = val;
- _centralHeader.extraLength = val.length;
- parseExtra(val);
- },
- get comment() {
- return decoder.decode(_comment);
- },
- set comment(val) {
- _comment = Utils.toBuffer(val, decoder.encode);
- _centralHeader.commentLength = _comment.length;
- if (_comment.length > 0xffff) throw Utils.Errors.COMMENT_TOO_LONG();
- },
- get name() {
- var n = decoder.decode(_entryName);
- return _isDirectory
- ? n
- .substr(n.length - 1)
- .split("/")
- .pop()
- : n.split("/").pop();
- },
- get isDirectory() {
- return _isDirectory;
- },
- getCompressedData: function () {
- return compress(false, null);
- },
- getCompressedDataAsync: function (/*Function*/ callback) {
- compress(true, callback);
- },
- setData: function (value) {
- uncompressedData = Utils.toBuffer(value, Utils.decoder.encode);
- if (!_isDirectory && uncompressedData.length) {
- _centralHeader.size = uncompressedData.length;
- _centralHeader.method = Utils.Constants.DEFLATED;
- _centralHeader.crc = Utils.crc32(value);
- _centralHeader.changed = true;
- } else {
- // folders and blank files should be stored
- _centralHeader.method = Utils.Constants.STORED;
- }
- },
- getData: function (pass) {
- if (_centralHeader.changed) {
- return uncompressedData;
- } else {
- return decompress(false, null, pass);
- }
- },
- getDataAsync: function (/*Function*/ callback, pass) {
- if (_centralHeader.changed) {
- callback(uncompressedData);
- } else {
- decompress(true, callback, pass);
- }
- },
- set attr(attr) {
- _centralHeader.attr = attr;
- },
- get attr() {
- return _centralHeader.attr;
- },
- set header(/*Buffer*/ data) {
- _centralHeader.loadFromBinary(data);
- },
- get header() {
- return _centralHeader;
- },
- packCentralHeader: function () {
- _centralHeader.flags_efs = this.efs;
- _centralHeader.extraLength = _extra.length;
- // 1. create header (buffer)
- var header = _centralHeader.centralHeaderToBinary();
- var addpos = Utils.Constants.CENHDR;
- // 2. add file name
- _entryName.copy(header, addpos);
- addpos += _entryName.length;
- // 3. add extra data
- _extra.copy(header, addpos);
- addpos += _centralHeader.extraLength;
- // 4. add file comment
- _comment.copy(header, addpos);
- return header;
- },
- packLocalHeader: function () {
- let addpos = 0;
- _centralHeader.flags_efs = this.efs;
- _centralHeader.extraLocalLength = _extralocal.length;
- // 1. construct local header Buffer
- const localHeaderBuf = _centralHeader.localHeaderToBinary();
- // 2. localHeader - crate header buffer
- const localHeader = Buffer.alloc(localHeaderBuf.length + _entryName.length + _centralHeader.extraLocalLength);
- // 2.1 add localheader
- localHeaderBuf.copy(localHeader, addpos);
- addpos += localHeaderBuf.length;
- // 2.2 add file name
- _entryName.copy(localHeader, addpos);
- addpos += _entryName.length;
- // 2.3 add extra field
- _extralocal.copy(localHeader, addpos);
- addpos += _extralocal.length;
- return localHeader;
- },
- toJSON: function () {
- const bytes = function (nr) {
- return "<" + ((nr && nr.length + " bytes buffer") || "null") + ">";
- };
- return {
- entryName: this.entryName,
- name: this.name,
- comment: this.comment,
- isDirectory: this.isDirectory,
- header: _centralHeader.toJSON(),
- compressedData: bytes(input),
- data: bytes(uncompressedData)
- };
- },
- toString: function () {
- return JSON.stringify(this.toJSON(), null, "\t");
- }
- };
- };
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