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| author | Tomas Bzatek <tbzatek@users.sourceforge.net> | 2008-06-08 11:04:43 +0200 |
|---|---|---|
| committer | Tomas Bzatek <tbzatek@users.sourceforge.net> | 2008-06-08 11:04:43 +0200 |
| commit | 16f738ecee689c6feb2acb7e4ef4d9bb4144ae7d (patch) | |
| tree | 3d22f54f7298f81b18ed66d05a62fa8bfab359ab /zip/ZipArchive/ZipCrc32Cryptograph.cpp | |
| download | tuxcmd-modules-release-0.6.36-dev.tar.xz | |
Initial commitv0.6.36release-0.6.36-dev
Diffstat (limited to 'zip/ZipArchive/ZipCrc32Cryptograph.cpp')
| -rw-r--r-- | zip/ZipArchive/ZipCrc32Cryptograph.cpp | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/zip/ZipArchive/ZipCrc32Cryptograph.cpp b/zip/ZipArchive/ZipCrc32Cryptograph.cpp new file mode 100644 index 0000000..50a0e2b --- /dev/null +++ b/zip/ZipArchive/ZipCrc32Cryptograph.cpp @@ -0,0 +1,81 @@ +////////////////////////////////////////////////////////////////////////////////
+// This source file is part of the ZipArchive library source distribution and
+// is Copyrighted 2000 - 2007 by Artpol Software - Tadeusz Dracz
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License
+// as published by the Free Software Foundation; either version 2
+// of the License, or (at your option) any later version.
+//
+// For the licensing details refer to the License.txt file.
+//
+// Web Site: http://www.artpol-software.com
+////////////////////////////////////////////////////////////////////////////////
+
+#include "stdafx.h"
+#include "ZipCrc32Cryptograph.h"
+
+bool CZipCrc32Cryptograph::InitDecode(CZipAutoBuffer& password, CZipFileHeader& currentFile, CZipStorage& storage)
+{
+ CryptInitKeys(password);
+ CZipAutoBuffer buf(ZIPARCHIVE_ENCR_HEADER_LEN);
+ storage.Read(buf, ZIPARCHIVE_ENCR_HEADER_LEN, false);
+ BYTE b = 0;
+ for (int i = 0; i < ZIPARCHIVE_ENCR_HEADER_LEN; i++)
+ {
+ b = buf[i]; // only temporary
+ CryptDecode((char&)b);
+ }
+ // check the last byte
+ return currentFile.IsDataDescriptor() ?
+ (BYTE(currentFile.m_uModTime >> 8) == b) : (BYTE(currentFile.m_uCrc32 >> 24) == b);
+}
+
+void CZipCrc32Cryptograph::InitEncode(CZipAutoBuffer& password, CZipFileHeader& currentFile, CZipStorage& storage)
+{
+ CZipAutoBuffer buf(ZIPARCHIVE_ENCR_HEADER_LEN);
+ // use pseudo-crc since we don't know it yet
+ CryptInitKeys(password);
+ srand(UINT(time(NULL)));
+ // genereate pseudo-random sequence
+ char c;
+ char* buffer = (char*)buf;
+ for (int i = 0; i < ZIPARCHIVE_ENCR_HEADER_LEN - 2; i++)
+ {
+ int t1 = rand();
+ c = (char)((t1 >> 6) & 0xFF);
+ if (!c)
+ c = (char)(t1 & 0xFF);
+ CryptEncode(c);
+ buffer[i] = c;
+
+ }
+ long iCrc = (long)currentFile.m_uModTime << 16;
+ c = (char)((iCrc >> 16) & 0xFF);
+ CryptEncode(c);
+ buffer[ZIPARCHIVE_ENCR_HEADER_LEN - 2] = c;
+ c = (char)((iCrc >> 24) & 0xFF);
+ CryptEncode(c);
+ buffer[ZIPARCHIVE_ENCR_HEADER_LEN - 1] = c;
+ storage.Write(buf, ZIPARCHIVE_ENCR_HEADER_LEN, false);
+ currentFile.m_uComprSize += ZIPARCHIVE_ENCR_HEADER_LEN;
+}
+
+void CZipCrc32Cryptograph::CryptInitKeys(CZipAutoBuffer& password)
+{
+ m_keys[0] = 305419896L;
+ m_keys[1] = 591751049L;
+ m_keys[2] = 878082192L;
+ for (DWORD i = 0; i < password.GetSize(); i++)
+ CryptUpdateKeys(password[i]);
+}
+
+void CZipCrc32Cryptograph::CryptUpdateKeys(char c)
+{
+ m_keys[0] = CryptCRC32(m_keys[0], c);
+ m_keys[1] += m_keys[0] & 0xff;
+ m_keys[1] = m_keys[1] * 134775813L + 1;
+ c = char(m_keys[1] >> 24);
+ m_keys[2] = CryptCRC32(m_keys[2], c);
+}
+
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