diff options
Diffstat (limited to 'CPP/7zip/Crypto/Rar5Aes.cpp')
| -rw-r--r-- | CPP/7zip/Crypto/Rar5Aes.cpp | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/CPP/7zip/Crypto/Rar5Aes.cpp b/CPP/7zip/Crypto/Rar5Aes.cpp new file mode 100644 index 00000000..648a3d4d --- /dev/null +++ b/CPP/7zip/Crypto/Rar5Aes.cpp @@ -0,0 +1,257 @@ +// Crypto/Rar5Aes.cpp + +#include "StdAfx.h" + +#include "../../../C/CpuArch.h" + +#ifndef _7ZIP_ST +#include "../../Windows/Synchronization.h" +#endif + +#include "Rar5Aes.h" + +namespace NCrypto { +namespace NRar5 { + +static const unsigned kNumIterationsLog_Max = 24; + +static const unsigned kPswCheckCsumSize = 4; +static const unsigned kCheckSize = kPswCheckSize + kPswCheckCsumSize; + +CKey::CKey(): + _needCalc(true), + _numIterationsLog(0) +{ + for (unsigned i = 0; i < sizeof(_salt); i++) + _salt[i] = 0; +} + +CDecoder::CDecoder(): CAesCbcDecoder(kAesKeySize) {} + +static unsigned ReadVarInt(const Byte *p, unsigned maxSize, UInt64 *val) +{ + unsigned i; + *val = 0; + + for (i = 0; i < maxSize;) + { + Byte b = p[i]; + if (i < 10) + *val |= (UInt64)(b & 0x7F) << (7 * i++); + if ((b & 0x80) == 0) + return i; + } + return 0; +} + +HRESULT CDecoder::SetDecoderProps(const Byte *p, unsigned size, bool includeIV, bool isService) +{ + UInt64 Version; + + unsigned num = ReadVarInt(p, size, &Version); + if (num == 0) + return E_NOTIMPL; + p += num; + size -= num; + + if (Version != 0) + return E_NOTIMPL; + + num = ReadVarInt(p, size, &Flags); + if (num == 0) + return E_NOTIMPL; + p += num; + size -= num; + + bool isCheck = IsThereCheck(); + if (size != 1 + kSaltSize + (includeIV ? AES_BLOCK_SIZE : 0) + (unsigned)(isCheck ? kCheckSize : 0)) + return E_NOTIMPL; + + if (_numIterationsLog != p[0]) + { + _numIterationsLog = p[0]; + _needCalc = true; + } + + p++; + + if (memcmp(_salt, p, kSaltSize) != 0) + { + memcpy(_salt, p, kSaltSize); + _needCalc = true; + } + + p += kSaltSize; + + if (includeIV) + { + memcpy(_iv, p, AES_BLOCK_SIZE); + p += AES_BLOCK_SIZE; + } + + _canCheck = true; + + if (isCheck) + { + memcpy(_check, p, kPswCheckSize); + CSha256 sha; + Byte digest[SHA256_DIGEST_SIZE]; + Sha256_Init(&sha); + Sha256_Update(&sha, _check, kPswCheckSize); + Sha256_Final(&sha, digest); + _canCheck = (memcmp(digest, p + kPswCheckSize, kPswCheckCsumSize) == 0); + if (_canCheck && isService) + { + // There was bug in RAR 5.21- : PswCheck field in service records ("QO") contained zeros. + // so we disable password checking for such bad records. + _canCheck = false; + for (unsigned i = 0; i < kPswCheckSize; i++) + if (p[i] != 0) + { + _canCheck = true; + break; + } + } + } + + return (_numIterationsLog <= kNumIterationsLog_Max ? S_OK : E_NOTIMPL); +} + + +void CDecoder::SetPassword(const Byte *data, size_t size) +{ + if (size != _password.Size() || memcmp(data, _password, size) != 0) + { + _needCalc = true; + _password.CopyFrom(data, size); + } +} + + +STDMETHODIMP CDecoder::Init() +{ + CalcKey_and_CheckPassword(); + RINOK(SetKey(_key, kAesKeySize)); + RINOK(SetInitVector(_iv, AES_BLOCK_SIZE)); + return CAesCbcCoder::Init(); +} + + +UInt32 CDecoder::Hmac_Convert_Crc32(UInt32 crc) const +{ + NSha256::CHmac ctx; + ctx.SetKey(_hashKey, NSha256::kDigestSize); + Byte v[4]; + SetUi32(v, crc); + ctx.Update(v, 4); + Byte h[NSha256::kDigestSize]; + ctx.Final(h); + crc = 0; + for (unsigned i = 0; i < NSha256::kDigestSize; i++) + crc ^= (UInt32)h[i] << ((i & 3) * 8); + return crc; +}; + + +void CDecoder::Hmac_Convert_32Bytes(Byte *data) const +{ + NSha256::CHmac ctx; + ctx.SetKey(_hashKey, NSha256::kDigestSize); + ctx.Update(data, NSha256::kDigestSize); + ctx.Final(data); +}; + + +#ifndef _7ZIP_ST + static CKey g_Key; + static NWindows::NSynchronization::CCriticalSection g_GlobalKeyCacheCriticalSection; + #define MT_LOCK NWindows::NSynchronization::CCriticalSectionLock lock(g_GlobalKeyCacheCriticalSection); +#else + #define MT_LOCK +#endif + +bool CDecoder::CalcKey_and_CheckPassword() +{ + if (_needCalc) + { + { + MT_LOCK + if (!g_Key._needCalc && IsKeyEqualTo(g_Key)) + { + CopyCalcedKeysFrom(g_Key); + _needCalc = false; + } + } + + if (_needCalc) + { + Byte pswCheck[SHA256_DIGEST_SIZE]; + + { + // Pbkdf HMAC-SHA-256 + + NSha256::CHmac baseCtx; + baseCtx.SetKey(_password, _password.Size()); + + NSha256::CHmac ctx = baseCtx; + ctx.Update(_salt, sizeof(_salt)); + + Byte u[NSha256::kDigestSize]; + Byte key[NSha256::kDigestSize]; + + u[0] = 0; + u[1] = 0; + u[2] = 0; + u[3] = 1; + + ctx.Update(u, 4); + ctx.Final(u); + + memcpy(key, u, NSha256::kDigestSize); + + UInt32 numIterations = ((UInt32)1 << _numIterationsLog) - 1; + + for (unsigned i = 0; i < 3; i++) + { + UInt32 j = numIterations; + + for (; j != 0; j--) + { + ctx = baseCtx; + ctx.Update(u, NSha256::kDigestSize); + ctx.Final(u); + for (unsigned s = 0; s < NSha256::kDigestSize; s++) + key[s] ^= u[s]; + } + + // RAR uses additional iterations for additional keys + memcpy((i == 0 ? _key : (i == 1 ? _hashKey : pswCheck)), key, NSha256::kDigestSize); + numIterations = 16; + } + } + + { + unsigned i; + + for (i = 0; i < kPswCheckSize; i++) + _check_Calced[i] = pswCheck[i]; + + for (i = kPswCheckSize; i < SHA256_DIGEST_SIZE; i++) + _check_Calced[i & (kPswCheckSize - 1)] ^= pswCheck[i]; + } + + _needCalc = false; + + { + MT_LOCK + g_Key = *this; + } + } + } + + if (IsThereCheck() && _canCheck) + return (memcmp(_check_Calced, _check, kPswCheckSize) == 0); + return true; +} + +}} |