Function codec_decode

Source/codec.cpp:92–128

} // namespace

std::size_t codec_decode(byte *pbSrcDst, std::size_t size, const char *pszPassword)
{
	uint32_t buf[BlockSize];
	uint32_t dst[SHA1HashSize];

	SHA1Context context = CodecInitKey(pszPassword);
	if (size <= SignatureSize)
		return 0;
	size -= SignatureSize;
	if (size % BlockSize != 0)
		return 0;
	for (size_t i = 0; i < size; pbSrcDst += BlockSizeBytes, i += BlockSizeBytes) {
		memcpy(buf, pbSrcDst, BlockSizeBytes);
		ByteSwapBlock(buf);
		SHA1Result(context, dst);
		XorBlock(dst, buf);
		SHA1Calculate(context, buf);
		ByteSwapBlock(buf);
		memcpy(pbSrcDst, buf, BlockSizeBytes);
	}

	memset(buf, 0, sizeof(buf));
	const CodecSignature sig = GetCodecSignature(pbSrcDst);
	if (sig.error > 0) {
		return 0;
	}

	SHA1Result(context, dst);
	if (sig.checksum != dst[0]) {
		LogError("Checksum mismatch signature={} vs calculated={}", sig.checksum, dst[0]);
		memset(dst, 0, sizeof(dst));
		return 0;
	}

	size += sig.lastChunkSize - BlockSizeBytes;
	return size;
}

std::size_t codec_get_encoded_len(std::size_t dwSrcBytes)
{