1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/win32/7zip/7z/CPP/7zip/Archive/Rar/RarIn.cpp	Sat Mar 03 10:31:27 2012 -0600
     1.3 @@ -0,0 +1,513 @@
     1.4 +// Archive/RarIn.cpp
     1.5 +
     1.6 +#include "StdAfx.h"
     1.7 +
     1.8 +#include "Common/StringConvert.h"
     1.9 +#include "Common/UTFConvert.h"
    1.10 +
    1.11 +#include "RarIn.h"
    1.12 +#include "../../Common/LimitedStreams.h"
    1.13 +#include "../../Common/StreamUtils.h"
    1.14 +
    1.15 +#include "../Common/FindSignature.h"
    1.16 +
    1.17 +extern "C"
    1.18 +{
    1.19 +  #include "../../../../C/7zCrc.h"
    1.20 +}
    1.21 +
    1.22 +namespace NArchive {
    1.23 +namespace NRar {
    1.24 + 
    1.25 +void CInArchive::ThrowExceptionWithCode(
    1.26 +    CInArchiveException::CCauseType cause)
    1.27 +{
    1.28 +  throw CInArchiveException(cause);
    1.29 +}
    1.30 +
    1.31 +HRESULT CInArchive::Open(IInStream *inStream, const UInt64 *searchHeaderSizeLimit)
    1.32 +{
    1.33 +  try
    1.34 +  {
    1.35 +    Close();
    1.36 +    HRESULT res = Open2(inStream, searchHeaderSizeLimit);
    1.37 +    if (res == S_OK)
    1.38 +      return res;
    1.39 +    Close();
    1.40 +    return res;
    1.41 +  }
    1.42 +  catch(...) { Close(); throw; }
    1.43 +}
    1.44 +
    1.45 +void CInArchive::Close()
    1.46 +{
    1.47 +  m_Stream.Release();
    1.48 +}
    1.49 +
    1.50 +
    1.51 +static inline bool TestMarkerCandidate(const void *aTestBytes)
    1.52 +{
    1.53 +  for (UInt32 i = 0; i < NHeader::kMarkerSize; i++)
    1.54 +    if (((const Byte *)aTestBytes)[i] != NHeader::kMarker[i])
    1.55 +      return false;
    1.56 +  return true;
    1.57 +}
    1.58 +
    1.59 +HRESULT CInArchive::FindAndReadMarker(IInStream *stream, const UInt64 *searchHeaderSizeLimit)
    1.60 +{
    1.61 +  RINOK(FindSignatureInStream(stream,
    1.62 +      NHeader::kMarker, NHeader::kMarkerSize,
    1.63 +      searchHeaderSizeLimit, m_ArchiveStartPosition));
    1.64 +  m_Stream = stream;
    1.65 +  m_Position = m_ArchiveStartPosition + NHeader::kMarkerSize;
    1.66 +  return m_Stream->Seek(m_Position, STREAM_SEEK_SET, NULL);
    1.67 +}
    1.68 +
    1.69 +void CInArchive::ThrowUnexpectedEndOfArchiveException()
    1.70 +{
    1.71 +  ThrowExceptionWithCode(CInArchiveException::kUnexpectedEndOfArchive);
    1.72 +}
    1.73 +
    1.74 +bool CInArchive::ReadBytesAndTestSize(void *data, UInt32 size)
    1.75 +{
    1.76 +  if (m_CryptoMode)
    1.77 +  {
    1.78 +    const Byte *bufData = (const Byte *)m_DecryptedData;
    1.79 +    UInt32 bufSize = m_DecryptedDataSize;
    1.80 +    UInt32 i;
    1.81 +    for (i = 0; i < size && m_CryptoPos < bufSize; i++)
    1.82 +      ((Byte *)data)[i] = bufData[m_CryptoPos++];
    1.83 +    return (i == size);
    1.84 +  }
    1.85 +  return (ReadStream_FALSE(m_Stream, data, size) == S_OK);
    1.86 +}
    1.87 +
    1.88 +void CInArchive::ReadBytesAndTestResult(void *data, UInt32 size)
    1.89 +{
    1.90 +  if(!ReadBytesAndTestSize(data,size))
    1.91 +    ThrowUnexpectedEndOfArchiveException();
    1.92 +}
    1.93 +
    1.94 +HRESULT CInArchive::ReadBytes(void *data, UInt32 size, UInt32 *processedSize)
    1.95 +{
    1.96 +  size_t realProcessedSize = size;
    1.97 +  HRESULT result = ReadStream(m_Stream, data, &realProcessedSize);
    1.98 +  if (processedSize != NULL)
    1.99 +    *processedSize = (UInt32)realProcessedSize;
   1.100 +  AddToSeekValue(realProcessedSize);
   1.101 +  return result;
   1.102 +}
   1.103 +
   1.104 +static UInt32 CrcUpdateUInt16(UInt32 crc, UInt16 v)
   1.105 +{
   1.106 +  crc = CRC_UPDATE_BYTE(crc, (Byte)(v & 0xFF));
   1.107 +  crc = CRC_UPDATE_BYTE(crc, (Byte)((v >> 8) & 0xFF));
   1.108 +  return crc;
   1.109 +}
   1.110 +
   1.111 +static UInt32 CrcUpdateUInt32(UInt32 crc, UInt32 v)
   1.112 +{
   1.113 +  crc = CRC_UPDATE_BYTE(crc, (Byte)(v & 0xFF));
   1.114 +  crc = CRC_UPDATE_BYTE(crc, (Byte)((v >> 8) & 0xFF));
   1.115 +  crc = CRC_UPDATE_BYTE(crc, (Byte)((v >> 16) & 0xFF));
   1.116 +  crc = CRC_UPDATE_BYTE(crc, (Byte)((v >> 24) & 0xFF));
   1.117 +  return crc;
   1.118 +}
   1.119 +
   1.120 +
   1.121 +HRESULT CInArchive::Open2(IInStream *stream, const UInt64 *searchHeaderSizeLimit)
   1.122 +{
   1.123 +  m_CryptoMode = false;
   1.124 +  RINOK(stream->Seek(0, STREAM_SEEK_SET, &m_StreamStartPosition));
   1.125 +  m_Position = m_StreamStartPosition;
   1.126 +
   1.127 +  RINOK(FindAndReadMarker(stream, searchHeaderSizeLimit));
   1.128 +
   1.129 +  Byte buf[NHeader::NArchive::kArchiveHeaderSize];
   1.130 +  UInt32 processedSize;
   1.131 +  ReadBytes(buf, sizeof(buf), &processedSize);
   1.132 +  if (processedSize != sizeof(buf))
   1.133 +    return S_FALSE;
   1.134 +  m_CurData = buf;
   1.135 +  m_CurPos = 0;
   1.136 +  m_PosLimit = sizeof(buf);
   1.137 +
   1.138 +  m_ArchiveHeader.CRC = ReadUInt16();
   1.139 +  m_ArchiveHeader.Type = ReadByte();
   1.140 +  m_ArchiveHeader.Flags = ReadUInt16();
   1.141 +  m_ArchiveHeader.Size = ReadUInt16();
   1.142 +  m_ArchiveHeader.Reserved1 = ReadUInt16();
   1.143 +  m_ArchiveHeader.Reserved2 = ReadUInt32();
   1.144 +  m_ArchiveHeader.EncryptVersion = 0;
   1.145 +
   1.146 +  UInt32 crc = CRC_INIT_VAL;
   1.147 +  crc = CRC_UPDATE_BYTE(crc, m_ArchiveHeader.Type);
   1.148 +  crc = CrcUpdateUInt16(crc, m_ArchiveHeader.Flags);
   1.149 +  crc = CrcUpdateUInt16(crc, m_ArchiveHeader.Size);
   1.150 +  crc = CrcUpdateUInt16(crc, m_ArchiveHeader.Reserved1);
   1.151 +  crc = CrcUpdateUInt32(crc, m_ArchiveHeader.Reserved2);
   1.152 +
   1.153 +  if (m_ArchiveHeader.IsThereEncryptVer() && m_ArchiveHeader.Size > NHeader::NArchive::kArchiveHeaderSize)
   1.154 +  {
   1.155 +    ReadBytes(&m_ArchiveHeader.EncryptVersion, 1, &processedSize);
   1.156 +    if (processedSize != 1)
   1.157 +      return S_FALSE;
   1.158 +    crc = CRC_UPDATE_BYTE(crc, m_ArchiveHeader.EncryptVersion);
   1.159 +  }
   1.160 +
   1.161 +  if(m_ArchiveHeader.CRC != (CRC_GET_DIGEST(crc) & 0xFFFF))
   1.162 +    ThrowExceptionWithCode(CInArchiveException::kArchiveHeaderCRCError);
   1.163 +  if (m_ArchiveHeader.Type != NHeader::NBlockType::kArchiveHeader)
   1.164 +    return S_FALSE;
   1.165 +  m_ArchiveCommentPosition = m_Position;
   1.166 +  m_SeekOnArchiveComment = true;
   1.167 +  return S_OK;
   1.168 +}
   1.169 +
   1.170 +void CInArchive::SkipArchiveComment()
   1.171 +{
   1.172 +  if (!m_SeekOnArchiveComment)
   1.173 +    return;
   1.174 +  AddToSeekValue(m_ArchiveHeader.Size - m_ArchiveHeader.GetBaseSize());
   1.175 +  m_SeekOnArchiveComment = false;
   1.176 +}
   1.177 +
   1.178 +void CInArchive::GetArchiveInfo(CInArchiveInfo &archiveInfo) const
   1.179 +{
   1.180 +  archiveInfo.StartPosition = m_ArchiveStartPosition;
   1.181 +  archiveInfo.Flags = m_ArchiveHeader.Flags;
   1.182 +  archiveInfo.CommentPosition = m_ArchiveCommentPosition;
   1.183 +  archiveInfo.CommentSize = (UInt16)(m_ArchiveHeader.Size - NHeader::NArchive::kArchiveHeaderSize);
   1.184 +}
   1.185 +
   1.186 +static void DecodeUnicodeFileName(const char *name, const Byte *encName,
   1.187 +    int encSize, wchar_t *unicodeName, int maxDecSize)
   1.188 +{
   1.189 +  int encPos = 0;
   1.190 +  int decPos = 0;
   1.191 +  int flagBits = 0;
   1.192 +  Byte flags = 0;
   1.193 +  Byte highByte = encName[encPos++];
   1.194 +  while (encPos < encSize && decPos < maxDecSize)
   1.195 +  {
   1.196 +    if (flagBits == 0)
   1.197 +    {
   1.198 +      flags = encName[encPos++];
   1.199 +      flagBits = 8;
   1.200 +    }
   1.201 +    switch(flags >> 6)
   1.202 +    {
   1.203 +      case 0:
   1.204 +        unicodeName[decPos++] = encName[encPos++];
   1.205 +        break;
   1.206 +      case 1:
   1.207 +        unicodeName[decPos++] = (wchar_t)(encName[encPos++] + (highByte << 8));
   1.208 +        break;
   1.209 +      case 2:
   1.210 +        unicodeName[decPos++] = (wchar_t)(encName[encPos] + (encName[encPos + 1] << 8));
   1.211 +        encPos += 2;
   1.212 +        break;
   1.213 +      case 3:
   1.214 +        {
   1.215 +          int length = encName[encPos++];
   1.216 +          if (length & 0x80)
   1.217 +          {
   1.218 +            Byte correction = encName[encPos++];
   1.219 +            for (length = (length & 0x7f) + 2;
   1.220 +                length > 0 && decPos < maxDecSize; length--, decPos++)
   1.221 +              unicodeName[decPos] = (wchar_t)(((name[decPos] + correction) & 0xff) + (highByte << 8));
   1.222 +          }
   1.223 +          else
   1.224 +            for (length += 2; length > 0 && decPos < maxDecSize; length--, decPos++)
   1.225 +              unicodeName[decPos] = name[decPos];
   1.226 +        }
   1.227 +        break;
   1.228 +    }
   1.229 +    flags <<= 2;
   1.230 +    flagBits -= 2;
   1.231 +  }
   1.232 +  unicodeName[decPos < maxDecSize ? decPos : maxDecSize - 1] = 0;
   1.233 +}
   1.234 +
   1.235 +void CInArchive::ReadName(CItemEx &item, int nameSize)
   1.236 +{
   1.237 +  item.UnicodeName.Empty();
   1.238 +  if (nameSize > 0)
   1.239 +  {
   1.240 +    m_NameBuffer.EnsureCapacity(nameSize + 1);
   1.241 +    char *buffer = (char *)m_NameBuffer;
   1.242 +
   1.243 +    for (int i = 0; i < nameSize; i++)
   1.244 +      buffer[i] = ReadByte();
   1.245 +
   1.246 +    int mainLen;
   1.247 +    for (mainLen = 0; mainLen < nameSize; mainLen++)
   1.248 +      if (buffer[mainLen] == '\0')
   1.249 +        break;
   1.250 +    buffer[mainLen] = '\0';
   1.251 +    item.Name = buffer;
   1.252 +
   1.253 +    if(item.HasUnicodeName())
   1.254 +    {
   1.255 +      if(mainLen < nameSize)
   1.256 +      {
   1.257 +        int unicodeNameSizeMax = MyMin(nameSize, (0x400));
   1.258 +        _unicodeNameBuffer.EnsureCapacity(unicodeNameSizeMax + 1);
   1.259 +        DecodeUnicodeFileName(buffer, (const Byte *)buffer + mainLen + 1,
   1.260 +            nameSize - (mainLen + 1), _unicodeNameBuffer, unicodeNameSizeMax);
   1.261 +        item.UnicodeName = _unicodeNameBuffer;
   1.262 +      }
   1.263 +      else if (!ConvertUTF8ToUnicode(item.Name, item.UnicodeName))
   1.264 +        item.UnicodeName.Empty();
   1.265 +    }
   1.266 +  }
   1.267 +  else
   1.268 +    item.Name.Empty();
   1.269 +}
   1.270 +
   1.271 +Byte CInArchive::ReadByte()
   1.272 +{
   1.273 +  if (m_CurPos >= m_PosLimit)
   1.274 +    throw CInArchiveException(CInArchiveException::kIncorrectArchive);
   1.275 +  return m_CurData[m_CurPos++];
   1.276 +}
   1.277 +
   1.278 +UInt16 CInArchive::ReadUInt16()
   1.279 +{
   1.280 +  UInt16 value = 0;
   1.281 +  for (int i = 0; i < 2; i++)
   1.282 +  {
   1.283 +    Byte b = ReadByte();
   1.284 +    value |= (UInt16(b) << (8 * i));
   1.285 +  }
   1.286 +  return value;
   1.287 +}
   1.288 +
   1.289 +UInt32 CInArchive::ReadUInt32()
   1.290 +{
   1.291 +  UInt32 value = 0;
   1.292 +  for (int i = 0; i < 4; i++)
   1.293 +  {
   1.294 +    Byte b = ReadByte();
   1.295 +    value |= (UInt32(b) << (8 * i));
   1.296 +  }
   1.297 +  return value;
   1.298 +}
   1.299 +
   1.300 +void CInArchive::ReadTime(Byte mask, CRarTime &rarTime)
   1.301 +{
   1.302 +  rarTime.LowSecond = (Byte)(((mask & 4) != 0) ? 1 : 0);
   1.303 +  int numDigits = (mask & 3);
   1.304 +  rarTime.SubTime[0] = rarTime.SubTime[1] = rarTime.SubTime[2] = 0;
   1.305 +  for (int i = 0; i < numDigits; i++)
   1.306 +    rarTime.SubTime[3 - numDigits + i] = ReadByte();
   1.307 +}
   1.308 +
   1.309 +void CInArchive::ReadHeaderReal(CItemEx &item)
   1.310 +{
   1.311 +  item.Flags = m_BlockHeader.Flags;
   1.312 +  item.PackSize = ReadUInt32();
   1.313 +  item.Size = ReadUInt32();
   1.314 +  item.HostOS = ReadByte();
   1.315 +  item.FileCRC = ReadUInt32();
   1.316 +  item.MTime.DosTime = ReadUInt32();
   1.317 +  item.UnPackVersion = ReadByte();
   1.318 +  item.Method = ReadByte();
   1.319 +  int nameSize = ReadUInt16();
   1.320 +  item.Attrib = ReadUInt32();
   1.321 +
   1.322 +  item.MTime.LowSecond = 0;
   1.323 +  item.MTime.SubTime[0] =
   1.324 +      item.MTime.SubTime[1] =
   1.325 +      item.MTime.SubTime[2] = 0;
   1.326 +
   1.327 +  if((item.Flags & NHeader::NFile::kSize64Bits) != 0)
   1.328 +  {
   1.329 +    item.PackSize |= ((UInt64)ReadUInt32() << 32);
   1.330 +    item.Size |= ((UInt64)ReadUInt32() << 32);
   1.331 +  }
   1.332 +
   1.333 +  ReadName(item, nameSize);
   1.334 +
   1.335 +  if (item.HasSalt())
   1.336 +    for (int i = 0; i < sizeof(item.Salt); i++)
   1.337 +      item.Salt[i] = ReadByte();
   1.338 +
   1.339 +  // some rar archives have HasExtTime flag without field.
   1.340 +  if (m_CurPos < m_PosLimit && item.HasExtTime())
   1.341 +  {
   1.342 +    Byte accessMask = (Byte)(ReadByte() >> 4);
   1.343 +    Byte b = ReadByte();
   1.344 +    Byte modifMask = (Byte)(b >> 4);
   1.345 +    Byte createMask = (Byte)(b & 0xF);
   1.346 +    if ((modifMask & 8) != 0)
   1.347 +      ReadTime(modifMask, item.MTime);
   1.348 +    item.CTimeDefined = ((createMask & 8) != 0);
   1.349 +    if (item.CTimeDefined)
   1.350 +    {
   1.351 +      item.CTime.DosTime = ReadUInt32();
   1.352 +      ReadTime(createMask, item.CTime);
   1.353 +    }
   1.354 +    item.ATimeDefined = ((accessMask & 8) != 0);
   1.355 +    if (item.ATimeDefined)
   1.356 +    {
   1.357 +      item.ATime.DosTime = ReadUInt32();
   1.358 +      ReadTime(accessMask, item.ATime);
   1.359 +    }
   1.360 +  }
   1.361 +
   1.362 +  UInt16 fileHeaderWithNameSize = (UInt16)m_CurPos;
   1.363 +  
   1.364 +  item.Position = m_Position;
   1.365 +  item.MainPartSize = fileHeaderWithNameSize;
   1.366 +  item.CommentSize = (UInt16)(m_BlockHeader.HeadSize - fileHeaderWithNameSize);
   1.367 +
   1.368 +  if (m_CryptoMode)
   1.369 +    item.AlignSize = (UInt16)((16 - ((m_BlockHeader.HeadSize) & 0xF)) & 0xF);
   1.370 +  else
   1.371 +    item.AlignSize = 0;
   1.372 +  AddToSeekValue(m_BlockHeader.HeadSize);
   1.373 +}
   1.374 +
   1.375 +void CInArchive::AddToSeekValue(UInt64 addValue)
   1.376 +{
   1.377 +  m_Position += addValue;
   1.378 +}
   1.379 +
   1.380 +HRESULT CInArchive::GetNextItem(CItemEx &item, ICryptoGetTextPassword *getTextPassword)
   1.381 +{
   1.382 +  if (m_SeekOnArchiveComment)
   1.383 +    SkipArchiveComment();
   1.384 +  for (;;)
   1.385 +  {
   1.386 +    if(!SeekInArchive(m_Position))
   1.387 +      return S_FALSE;
   1.388 +    if (!m_CryptoMode && (m_ArchiveHeader.Flags &
   1.389 +        NHeader::NArchive::kBlockHeadersAreEncrypted) != 0)
   1.390 +    {
   1.391 +      m_CryptoMode = false;
   1.392 +      if (getTextPassword == 0)
   1.393 +        return S_FALSE;
   1.394 +      if(!SeekInArchive(m_Position))
   1.395 +        return S_FALSE;
   1.396 +      if (!m_RarAES)
   1.397 +      {
   1.398 +        m_RarAESSpec = new NCrypto::NRar29::CDecoder;
   1.399 +        m_RarAES = m_RarAESSpec;
   1.400 +      }
   1.401 +      m_RarAESSpec->SetRar350Mode(m_ArchiveHeader.IsEncryptOld());
   1.402 +
   1.403 +      // Salt
   1.404 +      const UInt32 kSaltSize = 8;
   1.405 +      Byte salt[kSaltSize];
   1.406 +      if(!ReadBytesAndTestSize(salt, kSaltSize))
   1.407 +        return S_FALSE;
   1.408 +      m_Position += kSaltSize;
   1.409 +      RINOK(m_RarAESSpec->SetDecoderProperties2(salt, kSaltSize))
   1.410 +      // Password
   1.411 +      CMyComBSTR password;
   1.412 +      RINOK(getTextPassword->CryptoGetTextPassword(&password))
   1.413 +      UString unicodePassword(password);
   1.414 +
   1.415 +      CByteBuffer buffer;
   1.416 +      const UInt32 sizeInBytes = unicodePassword.Length() * 2;
   1.417 +      buffer.SetCapacity(sizeInBytes);
   1.418 +      for (int i = 0; i < unicodePassword.Length(); i++)
   1.419 +      {
   1.420 +        wchar_t c = unicodePassword[i];
   1.421 +        ((Byte *)buffer)[i * 2] = (Byte)c;
   1.422 +        ((Byte *)buffer)[i * 2 + 1] = (Byte)(c >> 8);
   1.423 +      }
   1.424 +
   1.425 +      RINOK(m_RarAESSpec->CryptoSetPassword((const Byte *)buffer, sizeInBytes));
   1.426 +
   1.427 +      const UInt32 kDecryptedBufferSize = (1 << 12);
   1.428 +      if (m_DecryptedData.GetCapacity() == 0)
   1.429 +      {
   1.430 +        m_DecryptedData.SetCapacity(kDecryptedBufferSize);
   1.431 +      }
   1.432 +      RINOK(m_RarAES->Init());
   1.433 +      size_t decryptedDataSizeT = kDecryptedBufferSize;
   1.434 +      RINOK(ReadStream(m_Stream, (Byte *)m_DecryptedData, &decryptedDataSizeT));
   1.435 +      m_DecryptedDataSize = (UInt32)decryptedDataSizeT;
   1.436 +      m_DecryptedDataSize = m_RarAES->Filter((Byte *)m_DecryptedData, m_DecryptedDataSize);
   1.437 +
   1.438 +      m_CryptoMode = true;
   1.439 +      m_CryptoPos = 0;
   1.440 +    }
   1.441 +
   1.442 +    m_FileHeaderData.EnsureCapacity(7);
   1.443 +    if(!ReadBytesAndTestSize((Byte *)m_FileHeaderData, 7))
   1.444 +      return S_FALSE;
   1.445 +
   1.446 +    m_CurData = (Byte *)m_FileHeaderData;
   1.447 +    m_CurPos = 0;
   1.448 +    m_PosLimit = 7;
   1.449 +    m_BlockHeader.CRC = ReadUInt16();
   1.450 +    m_BlockHeader.Type = ReadByte();
   1.451 +    m_BlockHeader.Flags = ReadUInt16();
   1.452 +    m_BlockHeader.HeadSize = ReadUInt16();
   1.453 +
   1.454 +    if (m_BlockHeader.HeadSize < 7)
   1.455 +      ThrowExceptionWithCode(CInArchiveException::kIncorrectArchive);
   1.456 +
   1.457 +    if (m_BlockHeader.Type == NHeader::NBlockType::kEndOfArchive)
   1.458 +      return S_FALSE;
   1.459 +
   1.460 +    if (m_BlockHeader.Type == NHeader::NBlockType::kFileHeader)
   1.461 +    {
   1.462 +      m_FileHeaderData.EnsureCapacity(m_BlockHeader.HeadSize);
   1.463 +      m_CurData = (Byte *)m_FileHeaderData;
   1.464 +      m_PosLimit = m_BlockHeader.HeadSize;
   1.465 +      ReadBytesAndTestResult(m_CurData + m_CurPos, m_BlockHeader.HeadSize - 7);
   1.466 +      ReadHeaderReal(item);
   1.467 +      if ((CrcCalc(m_CurData + 2,
   1.468 +          m_BlockHeader.HeadSize - item.CommentSize - 2) & 0xFFFF) != m_BlockHeader.CRC)
   1.469 +        ThrowExceptionWithCode(CInArchiveException::kFileHeaderCRCError);
   1.470 +
   1.471 +      FinishCryptoBlock();
   1.472 +      m_CryptoMode = false;
   1.473 +      SeekInArchive(m_Position); // Move Position to compressed Data;
   1.474 +      AddToSeekValue(item.PackSize);  // m_Position points to next header;
   1.475 +      return S_OK;
   1.476 +    }
   1.477 +    if (m_CryptoMode && m_BlockHeader.HeadSize > (1 << 12))
   1.478 +      return E_FAIL; // it's for bad passwords
   1.479 +    if ((m_BlockHeader.Flags & NHeader::NBlock::kLongBlock) != 0)
   1.480 +    {
   1.481 +      m_FileHeaderData.EnsureCapacity(7 + 4);
   1.482 +      m_CurData = (Byte *)m_FileHeaderData;
   1.483 +      ReadBytesAndTestResult(m_CurData + m_CurPos, 4); // test it
   1.484 +      m_PosLimit = 7 + 4;
   1.485 +      UInt32 dataSize = ReadUInt32();
   1.486 +      AddToSeekValue(dataSize);
   1.487 +      if (m_CryptoMode && dataSize > (1 << 27))
   1.488 +        return E_FAIL; // it's for bad passwords
   1.489 +      m_CryptoPos = m_BlockHeader.HeadSize;
   1.490 +    }
   1.491 +    else
   1.492 +      m_CryptoPos = 0;
   1.493 +    AddToSeekValue(m_BlockHeader.HeadSize);
   1.494 +    FinishCryptoBlock();
   1.495 +    m_CryptoMode = false;
   1.496 +  }
   1.497 +}
   1.498 +
   1.499 +bool CInArchive::SeekInArchive(UInt64 position)
   1.500 +{
   1.501 +  UInt64 newPosition;
   1.502 +  m_Stream->Seek(position, STREAM_SEEK_SET, &newPosition);
   1.503 +  return newPosition == position;
   1.504 +}
   1.505 +
   1.506 +ISequentialInStream* CInArchive::CreateLimitedStream(UInt64 position, UInt64 size)
   1.507 +{
   1.508 +  CLimitedSequentialInStream *streamSpec = new CLimitedSequentialInStream;
   1.509 +  CMyComPtr<ISequentialInStream> inStream(streamSpec);
   1.510 +  SeekInArchive(position);
   1.511 +  streamSpec->SetStream(m_Stream);
   1.512 +  streamSpec->Init(size);
   1.513 +  return inStream.Detach();
   1.514 +}
   1.515 +
   1.516 +}}