Zip: Use last modified time from basic header when validating zip dec…

…ryption

The last modified time used for zip decryption validation must be the
one from the basic header. If UnixTimeExtraFields are present, the
previous implementation was attempting to verify against that value
instead.
Fixed #804

src/SharpCompress/Common/Zip/Headers/DirectoryEntryHeader.cs

@@ -14,8 +14,8 @@ internal override void Read(BinaryReader reader)
         VersionNeededToExtract = reader.ReadUInt16();
         Flags = (HeaderFlags)reader.ReadUInt16();
         CompressionMethod = (ZipCompressionMethod)reader.ReadUInt16();
-        LastModifiedTime = reader.ReadUInt16();
-        LastModifiedDate = reader.ReadUInt16();
+        OriginalLastModifiedTime = LastModifiedTime = reader.ReadUInt16();
+        OriginalLastModifiedDate = LastModifiedDate = reader.ReadUInt16();
         Crc = reader.ReadUInt32();
         CompressedSize = reader.ReadUInt32();
         UncompressedSize = reader.ReadUInt32();

src/SharpCompress/Common/Zip/Headers/LocalEntryHeader.cs

@@ -13,8 +13,8 @@ internal override void Read(BinaryReader reader)
         Version = reader.ReadUInt16();
         Flags = (HeaderFlags)reader.ReadUInt16();
         CompressionMethod = (ZipCompressionMethod)reader.ReadUInt16();
-        LastModifiedTime = reader.ReadUInt16();
-        LastModifiedDate = reader.ReadUInt16();
+        OriginalLastModifiedTime = LastModifiedTime = reader.ReadUInt16();
+        OriginalLastModifiedDate = LastModifiedDate = reader.ReadUInt16();
         Crc = reader.ReadUInt32();
         CompressedSize = reader.ReadUInt32();
         UncompressedSize = reader.ReadUInt32();

src/SharpCompress/Common/Zip/Headers/ZipFileEntry.cs

@@ -67,8 +67,26 @@ internal PkwareTraditionalEncryptionData ComposeEncryptionData(Stream archiveStr
 
     internal WinzipAesEncryptionData WinzipAesEncryptionData { get; set; }
 
+    /// <summary>
+    /// The last modified date as read from the Local or Central Directory header.
+    /// </summary>
+    internal ushort OriginalLastModifiedDate { get; set; }
+
+    /// <summary>
+    /// The last modified date from the UnixTimeExtraField, if present, or the
+    /// Local or Cental Directory header, if not.
+    /// </summary>
     internal ushort LastModifiedDate { get; set; }
 
+    /// <summary>
+    /// The last modified time as read from the Local or Central Directory header.
+    /// </summary>
+    internal ushort OriginalLastModifiedTime { get; set; }
+
+    /// <summary>
+    /// The last modified time from the UnixTimeExtraField, if present, or the
+    /// Local or Cental Directory header, if not.
+    /// </summary>
     internal ushort LastModifiedTime { get; set; }
 
     internal uint Crc { get; set; }

src/SharpCompress/Common/Zip/PkwareTraditionalEncryptionData.cs

@@ -39,7 +39,7 @@ byte[] encryptionHeader
             {
                 throw new CryptographicException("The password did not match.");
             }
-            if (plainTextHeader[11] != (byte)((header.LastModifiedTime >> 8) & 0xff))
+            if (plainTextHeader[11] != (byte)((header.OriginalLastModifiedTime >> 8) & 0xff))
             {
                 throw new CryptographicException("The password did not match.");
             }