Fixed extraction bug

cthackers · Mar 14, 2024 · bd83f19 · bd83f19
1 parent 4a684a2
commit bd83f19
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Showing 4 changed files with 29 additions and 51 deletions.
diff --git a/headers/entryHeader.js b/headers/entryHeader.js
@@ -170,60 +170,39 @@ module.exports = function () {
         },
 
         get realDataOffset() {
-            return _offset + Constants.LOCHDR + _fnameLen + _extraLen;
+            return _offset + Constants.LOCHDR + _dataHeader.fnameLen + _dataHeader.extraLen;
         },
 
         get dataHeader() {
+            return _dataHeader;
+        },
+
+        loadDataHeaderFromBinary: function (/*Buffer*/ input) {
+            var data = input.slice(_offset, _offset + Constants.LOCHDR);
+            // 30 bytes and should start with "PK\003\004"
+            if (data.readUInt32LE(0) !== Constants.LOCSIG) {
+                throw new Error(Utils.Errors.INVALID_LOC);
+            }
             _dataHeader = {
                 // version needed to extract
-                version: _version,
+                version: data.readUInt16LE(Constants.LOCVER),
                 // general purpose bit flag
-                flags: _flags,
+                flags: data.readUInt16LE(Constants.LOCFLG),
                 // compression method
-                method: _method,
+                method: data.readUInt16LE(Constants.LOCHOW),
                 // modification time (2 bytes time, 2 bytes date)
-                time: _time,
+                time: data.readUInt32LE(Constants.LOCTIM),
                 // uncompressed file crc-32 value
-                crc: _crc,
+                crc: data.readUInt32LE(Constants.LOCCRC),
                 // compressed size
-                compressedSize: _compressedSize,
+                compressedSize: data.readUInt32LE(Constants.LOCSIZ),
                 // uncompressed size
-                size: _size,
+                size: data.readUInt32LE(Constants.LOCLEN),
                 // filename length
-                fnameLen: _fnameLen,
+                fnameLen: data.readUInt16LE(Constants.LOCNAM),
                 // extra field length
-                extraLen: _extraLen
+                extraLen: data.readUInt16LE(Constants.LOCEXT)
             };
-
-            return _dataHeader;
-        },
-
-        loadDataHeaderFromBinary: function (/*Buffer*/ input) {
-            var data = input.slice(_offset, _offset + Constants.LOCHDR);
-            // 30 bytes and should start with "PK\003\004"
-            if (data.readUInt32LE(0) !== Constants.LOCSIG) {
-                throw new Error(Utils.Errors.INVALID_LOC);
-            }
-
-            // version needed to extract
-            _version = data.readUInt16LE(Constants.LOCVER);
-            // general purpose bit flag
-            _flags = data.readUInt16LE(Constants.LOCFLG);
-            // compression method
-            _method = data.readUInt16LE(Constants.LOCHOW);
-            // modification time (2 bytes time, 2 bytes date)
-            _time = data.readUInt32LE(Constants.LOCTIM);
-            // uncompressed file crc-32 value
-            _crc = data.readUInt32LE(Constants.LOCCRC);
-            // compressed size
-            _compressedSize = data.readUInt32LE(Constants.LOCSIZ);
-            // uncompressed size
-            _size = data.readUInt32LE(Constants.LOCLEN);
-            // filename length
-            _fnameLen = data.readUInt16LE(Constants.LOCNAM);
-            // extra field length
-            _extraLen = data.readUInt16LE(Constants.LOCEXT);
-
         },
 
         loadFromBinary: function (/*Buffer*/ data) {

diff --git a/package-lock.json b/package-lock.json
diff --git a/package.json b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "adm-zip",
-  "version": "0.5.11",
+  "version": "0.5.12",
   "description": "Javascript implementation of zip for nodejs with support for electron original-fs. Allows user to create or extract zip files both in memory or to/from disk",
   "scripts": {
     "test": "mocha -R spec",

diff --git a/zipEntry.js b/zipEntry.js
@@ -15,8 +15,7 @@ module.exports = function (/*Buffer*/ input) {
         if (!input || !Buffer.isBuffer(input)) {
             return Buffer.alloc(0);
         }
-        //Scanning a local file headers is not necessary (except in the case of corrupted archives)
-        if(!_entryHeader.compressedSize) _entryHeader.loadDataHeaderFromBinary(input);
+        _entryHeader.loadDataHeaderFromBinary(input);
         return input.slice(_entryHeader.realDataOffset, _entryHeader.realDataOffset + _entryHeader.compressedSize);
     }