1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/win32/7zip/7z/CPP/7zip/Crypto/ZipStrong.cpp	Sat Mar 03 10:31:27 2012 -0600
     1.3 @@ -0,0 +1,180 @@
     1.4 +// Crypto/ZipStrong.cpp
     1.5 +
     1.6 +#include "StdAfx.h"
     1.7 +
     1.8 +extern "C"
     1.9 +{
    1.10 +#include "../../../C/7zCrc.h"
    1.11 +#include "../../../C/CpuArch.h"
    1.12 +}
    1.13 +
    1.14 +#include "../Common/StreamUtils.h"
    1.15 +
    1.16 +#include "MyAES.h"
    1.17 +#include "Sha1.h"
    1.18 +#include "ZipStrong.h"
    1.19 +
    1.20 +namespace NCrypto {
    1.21 +namespace NZipStrong {
    1.22 +
    1.23 +static const UInt16 kAES128 = 0x660E;
    1.24 +
    1.25 +// DeriveKey* function is similar to CryptDeriveKey() from Windows.
    1.26 +// But MSDN tells that we need such scheme only if
    1.27 +// "the required key length is longer than the hash value"
    1.28 +// but ZipStrong uses it always.
    1.29 +
    1.30 +static void DeriveKey2(const Byte *digest, Byte c, Byte *dest)
    1.31 +{
    1.32 +  Byte buf[64];
    1.33 +  memset(buf, c, 64);
    1.34 +  for (unsigned i = 0; i < NSha1::kDigestSize; i++)
    1.35 +    buf[i] ^= digest[i];
    1.36 +  NSha1::CContext sha;
    1.37 +  sha.Init();
    1.38 +  sha.Update(buf, 64);
    1.39 +  sha.Final(dest);
    1.40 +}
    1.41 + 
    1.42 +static void DeriveKey(NSha1::CContext &sha, Byte *key)
    1.43 +{
    1.44 +  Byte digest[NSha1::kDigestSize];
    1.45 +  sha.Final(digest);
    1.46 +  Byte temp[NSha1::kDigestSize * 2];
    1.47 +  DeriveKey2(digest, 0x36, temp);
    1.48 +  DeriveKey2(digest, 0x5C, temp + NSha1::kDigestSize);
    1.49 +  memcpy(key, temp, 32);
    1.50 +}
    1.51 +
    1.52 +void CKeyInfo::SetPassword(const Byte *data, UInt32 size)
    1.53 +{
    1.54 +  NSha1::CContext sha;
    1.55 +  sha.Init();
    1.56 +  sha.Update(data, size);
    1.57 +  DeriveKey(sha, MasterKey);
    1.58 +}
    1.59 +
    1.60 +STDMETHODIMP CBaseCoder::CryptoSetPassword(const Byte *data, UInt32 size)
    1.61 +{
    1.62 +  _key.SetPassword(data, size);
    1.63 +  return S_OK;
    1.64 +}
    1.65 +
    1.66 +STDMETHODIMP CBaseCoder::Init()
    1.67 +{
    1.68 +  return S_OK;
    1.69 +}
    1.70 +
    1.71 +HRESULT CDecoder::ReadHeader(ISequentialInStream *inStream, UInt32 /* crc */, UInt64 /* unpackSize */)
    1.72 +{
    1.73 +  Byte temp[4];
    1.74 +  RINOK(ReadStream_FALSE(inStream, temp, 2));
    1.75 +  _ivSize = GetUi16(temp);
    1.76 +  if (_ivSize == 0)
    1.77 +  {
    1.78 +    return E_NOTIMPL;
    1.79 +    /*
    1.80 +    SetUi32(_iv, crc);
    1.81 +    for (int i = 0; i < 8; i++)
    1.82 +     _iv[4 + i] = (Byte)(unpackSize >> (8 * i));
    1.83 +    SetUi32(_iv + 12, 0);
    1.84 +    */
    1.85 +  }
    1.86 +  else if (_ivSize == 16)
    1.87 +  {
    1.88 +    RINOK(ReadStream_FALSE(inStream, _iv, _ivSize));
    1.89 +  }
    1.90 +  else
    1.91 +    return E_NOTIMPL;
    1.92 +  RINOK(ReadStream_FALSE(inStream, temp, 4));
    1.93 +  _remSize = GetUi32(temp);
    1.94 +  if (_remSize > _buf.GetCapacity())
    1.95 +  {
    1.96 +    _buf.Free();
    1.97 +    _buf.SetCapacity(_remSize);
    1.98 +  }
    1.99 +  return ReadStream_FALSE(inStream, _buf, _remSize);
   1.100 +}
   1.101 +
   1.102 +HRESULT CDecoder::CheckPassword(bool &passwOK)
   1.103 +{
   1.104 +  passwOK = false;
   1.105 +  if (_remSize < 10)
   1.106 +    return E_NOTIMPL;
   1.107 +  Byte *p = _buf;
   1.108 +  UInt16 format = GetUi16(p);
   1.109 +  if (format != 3)
   1.110 +    return E_NOTIMPL;
   1.111 +  UInt16 algId  = GetUi16(p + 2);
   1.112 +  if (algId < kAES128)
   1.113 +    return E_NOTIMPL;
   1.114 +  algId -= kAES128;
   1.115 +  if (algId > 2)
   1.116 +    return E_NOTIMPL;
   1.117 +  UInt16 bitLen = GetUi16(p + 4);
   1.118 +  UInt16 flags  = GetUi16(p + 6);
   1.119 +  if (algId * 64 + 128 != bitLen)
   1.120 +    return E_NOTIMPL;
   1.121 +  _key.KeySize = 16 + algId * 8;
   1.122 +  if ((flags & 1) == 0)
   1.123 +    return E_NOTIMPL;
   1.124 +  UInt32 rdSize = GetUi16(p + 8);
   1.125 +  UInt32 pos = 10;
   1.126 +  Byte *rd = p + pos;
   1.127 +  pos += rdSize;
   1.128 +  if (pos + 4 > _remSize)
   1.129 +    return E_NOTIMPL;
   1.130 +  UInt32 reserved = GetUi32(p + pos);
   1.131 +  pos += 4;
   1.132 +  if (reserved != 0)
   1.133 +    return E_NOTIMPL;
   1.134 +  if (pos + 2 > _remSize)
   1.135 +    return E_NOTIMPL;
   1.136 +  UInt32 validSize = GetUi16(p + pos);
   1.137 +  pos += 2;
   1.138 +  Byte *validData = p + pos;
   1.139 +  if (pos + validSize != _remSize)
   1.140 +    return E_NOTIMPL;
   1.141 +
   1.142 +  if (!_aesFilter)
   1.143 +    _aesFilter = new CAesCbcDecoder;
   1.144 +
   1.145 +  CMyComPtr<ICryptoProperties> cp;
   1.146 +  RINOK(_aesFilter.QueryInterface(IID_ICryptoProperties, &cp));
   1.147 +  {
   1.148 +    RINOK(cp->SetKey(_key.MasterKey, _key.KeySize));
   1.149 +    RINOK(cp->SetInitVector(_iv, 16));
   1.150 +    _aesFilter->Init();
   1.151 +    if (_aesFilter->Filter(rd, rdSize) != rdSize)
   1.152 +      return E_NOTIMPL;
   1.153 +  }
   1.154 +
   1.155 +  Byte fileKey[32];
   1.156 +  NSha1::CContext sha;
   1.157 +  sha.Init();
   1.158 +  sha.Update(_iv, 16);
   1.159 +  sha.Update(rd, rdSize - 16); // we don't use last 16 bytes (PAD bytes)
   1.160 +  DeriveKey(sha, fileKey);
   1.161 +  
   1.162 +  RINOK(cp->SetKey(fileKey, _key.KeySize));
   1.163 +  RINOK(cp->SetInitVector(_iv, 16));
   1.164 +  _aesFilter->Init();
   1.165 +  if (_aesFilter->Filter(validData, validSize) != validSize)
   1.166 +    return E_NOTIMPL;
   1.167 +
   1.168 +  if (validSize < 4)
   1.169 +    return E_NOTIMPL;
   1.170 +  validSize -= 4;
   1.171 +  if (GetUi32(validData + validSize) != CrcCalc(validData, validSize))
   1.172 +    return S_OK;
   1.173 +  passwOK = true;
   1.174 +  _aesFilter->Init();
   1.175 +  return S_OK;
   1.176 +}
   1.177 +
   1.178 +STDMETHODIMP_(UInt32) CDecoder::Filter(Byte *data, UInt32 size)
   1.179 +{
   1.180 +  return _aesFilter->Filter(data, size);
   1.181 +}
   1.182 +
   1.183 +}}