1 files changed, 88 insertions, 0 deletions
diff --git a/src/libs/7zip/win/CPP/7zip/Crypto/ZipCrypto.cpp b/src/libs/7zip/win/CPP/7zip/Crypto/ZipCrypto.cpp
new file mode 100644
index 000000000..baaaf98e3
--- /dev/null
+++ b/src/libs/7zip/win/CPP/7zip/Crypto/ZipCrypto.cpp
@@ -0,0 +1,88 @@
+// Crypto/ZipCrypto.cpp
+
+#include "StdAfx.h"
+
+#include "../../../C/7zCrc.h"
+
+#include "../Common/StreamUtils.h"
+
+#include "RandGen.h"
+#include "ZipCrypto.h"
+
+namespace NCrypto {
+namespace NZip {
+
+void CCipher::UpdateKeys(Byte b)
+{
+  Keys[0] = CRC_UPDATE_BYTE(Keys[0], b);
+  Keys[1] = (Keys[1] + (Keys[0] & 0xFF)) * 0x8088405 + 1;
+  Keys[2] = CRC_UPDATE_BYTE(Keys[2], (Byte)(Keys[1] >> 24));
+}
+
+STDMETHODIMP CCipher::CryptoSetPassword(const Byte *password, UInt32 passwordLen)
+{
+  Keys[0] = 0x12345678;
+  Keys[1] = 0x23456789;
+  Keys[2] = 0x34567890;
+  UInt32 i;
+  for (i = 0; i < passwordLen; i++)
+    UpdateKeys(password[i]);
+  for (i = 0; i < 3; i++)
+    Keys2[i] = Keys[i];
+  return S_OK;
+}
+
+STDMETHODIMP CCipher::Init()
+{
+  return S_OK;
+}
+
+Byte CCipher::DecryptByteSpec()
+{
+  UInt32 temp = Keys[2] | 2;
+  return (Byte)((temp * (temp ^ 1)) >> 8);
+}
+
+HRESULT CEncoder::WriteHeader(ISequentialOutStream *outStream, UInt32 crc)
+{
+  Byte h[kHeaderSize];
+  g_RandomGenerator.Generate(h, kHeaderSize - 2);
+  h[kHeaderSize - 1] = (Byte)(crc >> 24);
+  h[kHeaderSize - 2] = (Byte)(crc >> 16);
+  RestoreKeys();
+  Filter(h, kHeaderSize);
+  return WriteStream(outStream, h, kHeaderSize);
+}
+
+STDMETHODIMP_(UInt32) CEncoder::Filter(Byte *data, UInt32 size)
+{
+  for (UInt32 i = 0; i < size; i++)
+  {
+    Byte b = data[i];
+    data[i] = (Byte)(b ^ DecryptByteSpec());;
+    UpdateKeys(b);
+  }
+  return size;
+}
+
+HRESULT CDecoder::ReadHeader(ISequentialInStream *inStream)
+{
+  Byte h[kHeaderSize];
+  RINOK(ReadStream_FAIL(inStream, h, kHeaderSize));
+  RestoreKeys();
+  Filter(h, kHeaderSize);
+  return S_OK;
+}
+
+STDMETHODIMP_(UInt32) CDecoder::Filter(Byte *data, UInt32 size)
+{
+  for (UInt32 i = 0; i < size; i++)
+  {
+    Byte c = (Byte)(data[i] ^ DecryptByteSpec());
+    UpdateKeys(c);
+    data[i] = c;
+  }
+  return size;
+}
+
+}}