rlm@1: // Crypto/RarAes.cpp
rlm@1: // Note: you must include MyAes.cpp to project to initialize AES tables
rlm@1: 
rlm@1: #include "StdAfx.h"
rlm@1: 
rlm@1: #include "RarAes.h"
rlm@1: #include "Sha1.h"
rlm@1: 
rlm@1: namespace NCrypto {
rlm@1: namespace NRar29 {
rlm@1: 
rlm@1: CDecoder::CDecoder():
rlm@1:   _thereIsSalt(false),
rlm@1:   _needCalculate(true),
rlm@1:   _rar350Mode(false)
rlm@1: {
rlm@1:   for (int i = 0; i < sizeof(_salt); i++)
rlm@1:     _salt[i] = 0;
rlm@1: }
rlm@1: 
rlm@1: STDMETHODIMP CDecoder::SetDecoderProperties2(const Byte *data, UInt32 size)
rlm@1: {
rlm@1:   bool thereIsSaltPrev = _thereIsSalt;
rlm@1:   _thereIsSalt = false;
rlm@1:   if (size == 0)
rlm@1:     return S_OK;
rlm@1:   if (size < 8)
rlm@1:     return E_INVALIDARG;
rlm@1:   _thereIsSalt = true;
rlm@1:   bool same = false;
rlm@1:   if (_thereIsSalt == thereIsSaltPrev)
rlm@1:   {
rlm@1:     same = true;
rlm@1:     if (_thereIsSalt)
rlm@1:     {
rlm@1:       for (int i = 0; i < sizeof(_salt); i++)
rlm@1:         if (_salt[i] != data[i])
rlm@1:         {
rlm@1:           same = false;
rlm@1:           break;
rlm@1:         }
rlm@1:     }
rlm@1:   }
rlm@1:   for (int i = 0; i < sizeof(_salt); i++)
rlm@1:     _salt[i] = data[i];
rlm@1:   if (!_needCalculate && !same)
rlm@1:     _needCalculate = true;
rlm@1:   return S_OK;
rlm@1: }
rlm@1: 
rlm@1: static const int kMaxPasswordLength = 127 * 2;
rlm@1: 
rlm@1: STDMETHODIMP CDecoder::CryptoSetPassword(const Byte *data, UInt32 size)
rlm@1: {
rlm@1:   if (size > kMaxPasswordLength)
rlm@1:     size = kMaxPasswordLength;
rlm@1:   bool same = false;
rlm@1:   if (size == buffer.GetCapacity())
rlm@1:   {
rlm@1:     same = true;
rlm@1:     for (UInt32 i = 0; i < size; i++)
rlm@1:       if (data[i] != buffer[i])
rlm@1:       {
rlm@1:         same = false;
rlm@1:         break;
rlm@1:       }
rlm@1:   }
rlm@1:   if (!_needCalculate && !same)
rlm@1:     _needCalculate = true;
rlm@1:   buffer.SetCapacity(size);
rlm@1:   memcpy(buffer, data, size);
rlm@1:   return S_OK;
rlm@1: }
rlm@1: 
rlm@1: STDMETHODIMP CDecoder::Init()
rlm@1: {
rlm@1:   Calculate();
rlm@1:   Aes_SetKeyDecode(&Aes.aes, aesKey, kRarAesKeySize);
rlm@1:   AesCbc_Init(&Aes, aesInit);
rlm@1:   return S_OK;
rlm@1: }
rlm@1: 
rlm@1: STDMETHODIMP_(UInt32) CDecoder::Filter(Byte *data, UInt32 size)
rlm@1: {
rlm@1:   return (UInt32)AesCbc_Decode(&Aes, data, size);
rlm@1: }
rlm@1: 
rlm@1: void CDecoder::Calculate()
rlm@1: {
rlm@1:   if (_needCalculate)
rlm@1:   {
rlm@1:     const int kSaltSize = 8;
rlm@1:     
rlm@1:     Byte rawPassword[kMaxPasswordLength + kSaltSize];
rlm@1:     
rlm@1:     memcpy(rawPassword, buffer, buffer.GetCapacity());
rlm@1:     
rlm@1:     size_t rawLength = buffer.GetCapacity();
rlm@1:     
rlm@1:     if (_thereIsSalt)
rlm@1:     {
rlm@1:       memcpy(rawPassword + rawLength, _salt, kSaltSize);
rlm@1:       rawLength += kSaltSize;
rlm@1:     }
rlm@1:     
rlm@1:     NSha1::CContext sha;
rlm@1:     sha.Init();
rlm@1: 
rlm@1:     // seems rar reverts hash for sha.
rlm@1:     const int hashRounds = 0x40000;
rlm@1:     int i;
rlm@1:     for (i = 0; i < hashRounds; i++)
rlm@1:     {
rlm@1:       sha.Update(rawPassword, rawLength, _rar350Mode);
rlm@1:       Byte pswNum[3] = { (Byte)i, (Byte)(i >> 8), (Byte)(i >> 16) };
rlm@1:       sha.Update(pswNum, 3, _rar350Mode);
rlm@1:       if (i % (hashRounds / 16) == 0)
rlm@1:       {
rlm@1:         NSha1::CContext shaTemp = sha;
rlm@1:         Byte digest[NSha1::kDigestSize];
rlm@1:         shaTemp.Final(digest);
rlm@1:         aesInit[i / (hashRounds / 16)] = (Byte)digest[4 * 4 + 3];
rlm@1:       }
rlm@1:     }
rlm@1:     /*
rlm@1:     // it's test message for sha
rlm@1:     const char *message = "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq";
rlm@1:     sha.Update((const Byte *)message, strlen(message));
rlm@1:     */
rlm@1:     Byte digest[20];
rlm@1:     sha.Final(digest);
rlm@1:     for (i = 0; i < 4; i++)
rlm@1:       for (int j = 0; j < 4; j++)
rlm@1:         aesKey[i * 4 + j] = (digest[i * 4 + 3 - j]);
rlm@1:   }
rlm@1:   _needCalculate = false;
rlm@1: }
rlm@1: 
rlm@1: }}