HashResult BCryptHashImpl::Calculate(Aws::IStream& stream)
{
if (!IsValid())
{
return HashResult();
}
std::lock_guard<std::mutex> locker(m_algorithmMutex);
auto startingPos = stream.tellg();
bool success = HashStream(stream);
if (success)
{
stream.clear();
}
stream.seekg(startingPos, stream.beg);
if (!success)
{
return HashResult();
}
return HashResult(ByteBuffer(m_hashBuffer, m_hashBufferLength));
}
HashResult MD5CommonCryptoImpl::Calculate(Aws::IStream& stream)
{
CC_MD5_CTX md5;
CC_MD5_Init(&md5);
auto currentPos = stream.tellg();
stream.seekg(0, stream.beg);
char streamBuffer[Aws::Utils::Crypto::Hash::INTERNAL_HASH_STREAM_BUFFER_SIZE];
while(stream.good())
{
stream.read(streamBuffer, Aws::Utils::Crypto::Hash::INTERNAL_HASH_STREAM_BUFFER_SIZE);
auto bytesRead = stream.gcount();
if(bytesRead > 0)
{
CC_MD5_Update(&md5, streamBuffer, static_cast<CC_LONG>(bytesRead));
}
}
stream.clear();
stream.seekg(currentPos, stream.beg);
ByteBuffer hash(CC_MD5_DIGEST_LENGTH);
CC_MD5_Final(hash.GetUnderlyingData(), &md5);
return HashResult(std::move(hash));
}
HashResult Sha256CommonCryptoImpl::Calculate(Aws::IStream& stream)
{
CC_SHA256_CTX sha256;
CC_SHA256_Init(&sha256);
unsigned currentPos = stream.tellg();
stream.seekg(0, stream.beg);
char streamBuffer[Aws::Utils::Crypto::Hash::INTERNAL_HASH_STREAM_BUFFER_SIZE];
while(stream.good())
{
stream.read(streamBuffer, Aws::Utils::Crypto::Hash::INTERNAL_HASH_STREAM_BUFFER_SIZE);
auto bytesRead = stream.gcount();
if(bytesRead > 0)
{
CC_SHA256_Update(&sha256, streamBuffer, bytesRead);
}
}
stream.clear();
stream.seekg(currentPos, stream.beg);
ByteBuffer hash(CC_SHA256_DIGEST_LENGTH);
CC_SHA256_Final(hash.GetUnderlyingData(), &sha256);
return HashResult(std::move(hash));
}
bool BCryptHashImpl::HashStream(Aws::IStream& stream)
{
BCryptHashContext context(m_algorithmHandle, m_hashObject, m_hashObjectLength);
if (!context.IsValid())
{
AWS_LOG_ERROR(logTag, "Error creating hash handle.");
return false;
}
char streamBuffer[Aws::Utils::Crypto::Hash::INTERNAL_HASH_STREAM_BUFFER_SIZE];
NTSTATUS status = 0;
stream.seekg(0, stream.beg);
while (stream.good())
{
stream.read(streamBuffer, Aws::Utils::Crypto::Hash::INTERNAL_HASH_STREAM_BUFFER_SIZE);
std::streamsize bytesRead = stream.gcount();
if (bytesRead > 0)
{
status = BCryptHashData(context.m_hashHandle, (PBYTE)streamBuffer, (ULONG)bytesRead, 0);
if (!NT_SUCCESS(status))
{
AWS_LOG_ERROR(logTag, "Error computing hash.");
return false;
}
}
}
if (!stream.eof())
{
return false;
}
status = BCryptFinishHash(context.m_hashHandle, m_hashBuffer, m_hashBufferLength, 0);
if (!NT_SUCCESS(status))
{
AWS_LOG_ERROR(logTag, "Error obtaining computed hash");
return false;
}
return true;
}
