VPatch 3.0

git-svn-id: https://svn.code.sf.net/p/nsis/code/NSIS/trunk@4271 212acab6-be3b-0410-9dea-997c60f758d6

Contrib/VPatch/Source/GenPat/Checksums.cpp

@@ -0,0 +1,120 @@
+//---------------------------------------------------------------------------
+// Checksums.cpp
+//---------------------------------------------------------------------------
+//                           -=* VPatch *=-
+//---------------------------------------------------------------------------
+// Copyright (C) 2001-2005 Koen van de Sande / Van de Sande Productions
+//---------------------------------------------------------------------------
+// Website: http://www.tibed.net/vpatch
+//
+// This software is provided 'as-is', without any express or implied
+// warranty.  In no event will the authors be held liable for any damages
+// arising from the use of this software.
+//
+// Permission is granted to anyone to use this software for any purpose,
+// including commercial applications, and to alter it and redistribute it
+// freely, subject to the following restrictions:
+//
+// 1. The origin of this software must not be misrepresented; you must not
+//    claim that you wrote the original software. If you use this software
+//    in a product, an acknowledgment in the product documentation would be
+//    appreciated but is not required.
+// 2. Altered source versions must be plainly marked as such, and must not be
+//    misrepresented as being the original software.
+// 3. This notice may not be removed or altered from any source distribution.
+
+#include "Checksums.h"
+
+/* ------------------------ CRC32 checksum calculation ----------------- */
+
+uint32_t CRCTable[256];
+bool bInitCRC = false;
+
+void InitCRC() {
+  int i, j; unsigned long c;
+  for (c = i = 0; i < 256; c = ++i) {
+    for (j = 0; j < 8; j++) {
+      if (c & 1)	c = (c>>1) ^ 0xEDB88320;
+      else		c >>= 1;
+    }
+    CRCTable[i] = c;
+  }
+  bInitCRC = true;
+}
+
+crc32_t streamCRC32(bistream& data) {
+  if(!bInitCRC) InitCRC();
+
+  const int CRCBLOCKSIZE = 16384;
+
+  uint8_t block[CRCBLOCKSIZE];
+  unsigned int read;
+  uint8_t *p;
+
+  crc32_t crc = 0xFFFFFFFF;
+  while(data.good()) {
+    data.read(reinterpret_cast<char*>(block), CRCBLOCKSIZE);
+    read = data.gcount();
+    for (p = block; p < block + read; p++)
+      crc = CRCTable[(crc & 0xFF) ^ *p] ^ (crc >> 8);
+  }
+  crc = (crc ^ 0xFFFFFFFF);
+  return crc;
+}
+
+/* ------------------------ MD5 checksum calculation ----------------- */
+
+void streamMD5(bistream& data, md5_byte_t digest[16]) {
+  const int MD5BLOCKSIZE = 16384;
+  uint8_t md5block[MD5BLOCKSIZE];
+  unsigned int read;
+
+  md5_state_t state;
+
+  md5_init(&state);
+
+  while(data.good()) {
+    data.read(reinterpret_cast<char*>(md5block), MD5BLOCKSIZE);
+    read = data.gcount();
+    md5_append(&state, md5block, read);
+  }
+
+  md5_finish(&state, digest);
+}
+
+TChecksum::TChecksum(std::string& fileName) : mode(MD5) {
+  bifstream data;
+  data.open(fileName.c_str(), ios::binary | ios::in);
+  data.seekg(0, ios::beg);
+  crc = streamCRC32(data);
+  data.close();
+
+  bifstream data2;
+  data2.open(fileName.c_str(), ios::binary | ios::in);
+  data2.seekg(0, ios::beg);
+  streamMD5(data2, digest);
+  data2.close();
+}
+
+void TChecksum::loadMD5(md5_byte_t newdigest[16]) {
+  mode = MD5;
+  for(int i = 0; i < 16; i++) {
+    digest[i] = newdigest[i];
+  }
+}
+void TChecksum::loadCRC32(crc32_t newcrc) {
+  mode = CRC32;
+  crc = newcrc;
+}
+bool TChecksum::operator==(const TChecksum& b) {
+  if(mode != b.mode) throw "Checksums in different mode: MD5/CRC32";
+  if(mode == MD5) {
+    for(int md5index = 0; md5index < 16; md5index++) {
+      if(digest[md5index] != b.digest[md5index]) break;
+      if(md5index == 15) return true;
+    }
+    return false;
+  } else {
+    return (crc == b.crc);
+  }
+}