Function codec_decode

Source/codec.cpp:12–54

};

int codec_decode(BYTE *pbSrcDst, DWORD size, char *pszPassword)
{
	char buf[128];
	char dst[SHA1HashSize];
	int i;
	CodecSignature *sig;

	codec_init_key(0, pszPassword);
	if (size <= 8)
		return 0;
	size = size - 8;
	if (size % 64 != 0)
		return 0;
	for (i = size; i != 0; pbSrcDst += 64, i -= 64) {
		memcpy(buf, pbSrcDst, 64);
		SHA1Result(0, dst);
		for (int j = 0; j < 64; j++) {
			buf[j] ^= dst[j % SHA1HashSize];
		}
		SHA1Calculate(0, buf, NULL);
		memset(dst, 0, sizeof(dst));
		memcpy(pbSrcDst, buf, 64);
	}

	memset(buf, 0, sizeof(buf));
	sig = (CodecSignature *)pbSrcDst;
	if (sig->error > 0) {
		goto error;
	}

	SHA1Result(0, dst);
	if (sig->checksum != *(DWORD *)dst) {
		memset(dst, 0, sizeof(dst));
		goto error;
	}

	size += sig->last_chunk_size - 64;
	SHA1Clear();
	return size;
error:
	SHA1Clear();
	return 0;
}

void codec_init_key(int unused, char *pszPassword)
{