entryHeader.js 12 KB

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  1. var Utils = require("../util"),
  2. Constants = Utils.Constants;
  3. /* The central directory file header */
  4. module.exports = function () {
  5. var _verMade = 20, // v2.0
  6. _version = 10, // v1.0
  7. _flags = 0,
  8. _method = 0,
  9. _time = 0,
  10. _crc = 0,
  11. _compressedSize = 0,
  12. _size = 0,
  13. _fnameLen = 0,
  14. _extraLen = 0,
  15. _comLen = 0,
  16. _diskStart = 0,
  17. _inattr = 0,
  18. _attr = 0,
  19. _offset = 0;
  20. _verMade |= Utils.isWin ? 0x0a00 : 0x0300;
  21. // Set EFS flag since filename and comment fields are all by default encoded using UTF-8.
  22. // Without it file names may be corrupted for other apps when file names use unicode chars
  23. _flags |= Constants.FLG_EFS;
  24. const _localHeader = {
  25. extraLen: 0
  26. };
  27. // casting
  28. const uint32 = (val) => Math.max(0, val) >>> 0;
  29. const uint16 = (val) => Math.max(0, val) & 0xffff;
  30. const uint8 = (val) => Math.max(0, val) & 0xff;
  31. _time = Utils.fromDate2DOS(new Date());
  32. return {
  33. get made() {
  34. return _verMade;
  35. },
  36. set made(val) {
  37. _verMade = val;
  38. },
  39. get version() {
  40. return _version;
  41. },
  42. set version(val) {
  43. _version = val;
  44. },
  45. get flags() {
  46. return _flags;
  47. },
  48. set flags(val) {
  49. _flags = val;
  50. },
  51. get flags_efs() {
  52. return (_flags & Constants.FLG_EFS) > 0;
  53. },
  54. set flags_efs(val) {
  55. if (val) {
  56. _flags |= Constants.FLG_EFS;
  57. } else {
  58. _flags &= ~Constants.FLG_EFS;
  59. }
  60. },
  61. get flags_desc() {
  62. return (_flags & Constants.FLG_DESC) > 0;
  63. },
  64. set flags_desc(val) {
  65. if (val) {
  66. _flags |= Constants.FLG_DESC;
  67. } else {
  68. _flags &= ~Constants.FLG_DESC;
  69. }
  70. },
  71. get method() {
  72. return _method;
  73. },
  74. set method(val) {
  75. switch (val) {
  76. case Constants.STORED:
  77. this.version = 10;
  78. case Constants.DEFLATED:
  79. default:
  80. this.version = 20;
  81. }
  82. _method = val;
  83. },
  84. get time() {
  85. return Utils.fromDOS2Date(this.timeval);
  86. },
  87. set time(val) {
  88. val = new Date(val);
  89. this.timeval = Utils.fromDate2DOS(val);
  90. },
  91. get timeval() {
  92. return _time;
  93. },
  94. set timeval(val) {
  95. _time = uint32(val);
  96. },
  97. get timeHighByte() {
  98. return uint8(_time >>> 8);
  99. },
  100. get crc() {
  101. return _crc;
  102. },
  103. set crc(val) {
  104. _crc = uint32(val);
  105. },
  106. get compressedSize() {
  107. return _compressedSize;
  108. },
  109. set compressedSize(val) {
  110. _compressedSize = uint32(val);
  111. },
  112. get size() {
  113. return _size;
  114. },
  115. set size(val) {
  116. _size = uint32(val);
  117. },
  118. get fileNameLength() {
  119. return _fnameLen;
  120. },
  121. set fileNameLength(val) {
  122. _fnameLen = val;
  123. },
  124. get extraLength() {
  125. return _extraLen;
  126. },
  127. set extraLength(val) {
  128. _extraLen = val;
  129. },
  130. get extraLocalLength() {
  131. return _localHeader.extraLen;
  132. },
  133. set extraLocalLength(val) {
  134. _localHeader.extraLen = val;
  135. },
  136. get commentLength() {
  137. return _comLen;
  138. },
  139. set commentLength(val) {
  140. _comLen = val;
  141. },
  142. get diskNumStart() {
  143. return _diskStart;
  144. },
  145. set diskNumStart(val) {
  146. _diskStart = uint32(val);
  147. },
  148. get inAttr() {
  149. return _inattr;
  150. },
  151. set inAttr(val) {
  152. _inattr = uint32(val);
  153. },
  154. get attr() {
  155. return _attr;
  156. },
  157. set attr(val) {
  158. _attr = uint32(val);
  159. },
  160. // get Unix file permissions
  161. get fileAttr() {
  162. return (_attr || 0) >> 16 & 0xfff;
  163. },
  164. get offset() {
  165. return _offset;
  166. },
  167. set offset(val) {
  168. _offset = uint32(val);
  169. },
  170. get encrypted() {
  171. return (_flags & Constants.FLG_ENC) === Constants.FLG_ENC;
  172. },
  173. get centralHeaderSize() {
  174. return Constants.CENHDR + _fnameLen + _extraLen + _comLen;
  175. },
  176. get realDataOffset() {
  177. return _offset + Constants.LOCHDR + _localHeader.fnameLen + _localHeader.extraLen;
  178. },
  179. get localHeader() {
  180. return _localHeader;
  181. },
  182. loadLocalHeaderFromBinary: function (/*Buffer*/ input) {
  183. var data = input.slice(_offset, _offset + Constants.LOCHDR);
  184. // 30 bytes and should start with "PK\003\004"
  185. if (data.readUInt32LE(0) !== Constants.LOCSIG) {
  186. throw Utils.Errors.INVALID_LOC();
  187. }
  188. // version needed to extract
  189. _localHeader.version = data.readUInt16LE(Constants.LOCVER);
  190. // general purpose bit flag
  191. _localHeader.flags = data.readUInt16LE(Constants.LOCFLG);
  192. // desc flag
  193. _localHeader.flags_desc = (_localHeader.flags & Constants.FLG_DESC) > 0;
  194. // compression method
  195. _localHeader.method = data.readUInt16LE(Constants.LOCHOW);
  196. // modification time (2 bytes time, 2 bytes date)
  197. _localHeader.time = data.readUInt32LE(Constants.LOCTIM);
  198. // uncompressed file crc-32 valu
  199. _localHeader.crc = data.readUInt32LE(Constants.LOCCRC);
  200. // compressed size
  201. _localHeader.compressedSize = data.readUInt32LE(Constants.LOCSIZ);
  202. // uncompressed size
  203. _localHeader.size = data.readUInt32LE(Constants.LOCLEN);
  204. // filename length
  205. _localHeader.fnameLen = data.readUInt16LE(Constants.LOCNAM);
  206. // extra field length
  207. _localHeader.extraLen = data.readUInt16LE(Constants.LOCEXT);
  208. // read extra data
  209. const extraStart = _offset + Constants.LOCHDR + _localHeader.fnameLen;
  210. const extraEnd = extraStart + _localHeader.extraLen;
  211. return input.slice(extraStart, extraEnd);
  212. },
  213. loadFromBinary: function (/*Buffer*/ data) {
  214. // data should be 46 bytes and start with "PK 01 02"
  215. if (data.length !== Constants.CENHDR || data.readUInt32LE(0) !== Constants.CENSIG) {
  216. throw Utils.Errors.INVALID_CEN();
  217. }
  218. // version made by
  219. _verMade = data.readUInt16LE(Constants.CENVEM);
  220. // version needed to extract
  221. _version = data.readUInt16LE(Constants.CENVER);
  222. // encrypt, decrypt flags
  223. _flags = data.readUInt16LE(Constants.CENFLG);
  224. // compression method
  225. _method = data.readUInt16LE(Constants.CENHOW);
  226. // modification time (2 bytes time, 2 bytes date)
  227. _time = data.readUInt32LE(Constants.CENTIM);
  228. // uncompressed file crc-32 value
  229. _crc = data.readUInt32LE(Constants.CENCRC);
  230. // compressed size
  231. _compressedSize = data.readUInt32LE(Constants.CENSIZ);
  232. // uncompressed size
  233. _size = data.readUInt32LE(Constants.CENLEN);
  234. // filename length
  235. _fnameLen = data.readUInt16LE(Constants.CENNAM);
  236. // extra field length
  237. _extraLen = data.readUInt16LE(Constants.CENEXT);
  238. // file comment length
  239. _comLen = data.readUInt16LE(Constants.CENCOM);
  240. // volume number start
  241. _diskStart = data.readUInt16LE(Constants.CENDSK);
  242. // internal file attributes
  243. _inattr = data.readUInt16LE(Constants.CENATT);
  244. // external file attributes
  245. _attr = data.readUInt32LE(Constants.CENATX);
  246. // LOC header offset
  247. _offset = data.readUInt32LE(Constants.CENOFF);
  248. },
  249. localHeaderToBinary: function () {
  250. // LOC header size (30 bytes)
  251. var data = Buffer.alloc(Constants.LOCHDR);
  252. // "PK\003\004"
  253. data.writeUInt32LE(Constants.LOCSIG, 0);
  254. // version needed to extract
  255. data.writeUInt16LE(_version, Constants.LOCVER);
  256. // general purpose bit flag
  257. data.writeUInt16LE(_flags, Constants.LOCFLG);
  258. // compression method
  259. data.writeUInt16LE(_method, Constants.LOCHOW);
  260. // modification time (2 bytes time, 2 bytes date)
  261. data.writeUInt32LE(_time, Constants.LOCTIM);
  262. // uncompressed file crc-32 value
  263. data.writeUInt32LE(_crc, Constants.LOCCRC);
  264. // compressed size
  265. data.writeUInt32LE(_compressedSize, Constants.LOCSIZ);
  266. // uncompressed size
  267. data.writeUInt32LE(_size, Constants.LOCLEN);
  268. // filename length
  269. data.writeUInt16LE(_fnameLen, Constants.LOCNAM);
  270. // extra field length
  271. data.writeUInt16LE(_localHeader.extraLen, Constants.LOCEXT);
  272. return data;
  273. },
  274. centralHeaderToBinary: function () {
  275. // CEN header size (46 bytes)
  276. var data = Buffer.alloc(Constants.CENHDR + _fnameLen + _extraLen + _comLen);
  277. // "PK\001\002"
  278. data.writeUInt32LE(Constants.CENSIG, 0);
  279. // version made by
  280. data.writeUInt16LE(_verMade, Constants.CENVEM);
  281. // version needed to extract
  282. data.writeUInt16LE(_version, Constants.CENVER);
  283. // encrypt, decrypt flags
  284. data.writeUInt16LE(_flags, Constants.CENFLG);
  285. // compression method
  286. data.writeUInt16LE(_method, Constants.CENHOW);
  287. // modification time (2 bytes time, 2 bytes date)
  288. data.writeUInt32LE(_time, Constants.CENTIM);
  289. // uncompressed file crc-32 value
  290. data.writeUInt32LE(_crc, Constants.CENCRC);
  291. // compressed size
  292. data.writeUInt32LE(_compressedSize, Constants.CENSIZ);
  293. // uncompressed size
  294. data.writeUInt32LE(_size, Constants.CENLEN);
  295. // filename length
  296. data.writeUInt16LE(_fnameLen, Constants.CENNAM);
  297. // extra field length
  298. data.writeUInt16LE(_extraLen, Constants.CENEXT);
  299. // file comment length
  300. data.writeUInt16LE(_comLen, Constants.CENCOM);
  301. // volume number start
  302. data.writeUInt16LE(_diskStart, Constants.CENDSK);
  303. // internal file attributes
  304. data.writeUInt16LE(_inattr, Constants.CENATT);
  305. // external file attributes
  306. data.writeUInt32LE(_attr, Constants.CENATX);
  307. // LOC header offset
  308. data.writeUInt32LE(_offset, Constants.CENOFF);
  309. return data;
  310. },
  311. toJSON: function () {
  312. const bytes = function (nr) {
  313. return nr + " bytes";
  314. };
  315. return {
  316. made: _verMade,
  317. version: _version,
  318. flags: _flags,
  319. method: Utils.methodToString(_method),
  320. time: this.time,
  321. crc: "0x" + _crc.toString(16).toUpperCase(),
  322. compressedSize: bytes(_compressedSize),
  323. size: bytes(_size),
  324. fileNameLength: bytes(_fnameLen),
  325. extraLength: bytes(_extraLen),
  326. commentLength: bytes(_comLen),
  327. diskNumStart: _diskStart,
  328. inAttr: _inattr,
  329. attr: _attr,
  330. offset: _offset,
  331. centralHeaderSize: bytes(Constants.CENHDR + _fnameLen + _extraLen + _comLen)
  332. };
  333. },
  334. toString: function () {
  335. return JSON.stringify(this.toJSON(), null, "\t");
  336. }
  337. };
  338. };