Function ConvertHexToBytes

src/string.cpp:570–593

* Convert a hex-string to a byte-array, while validating it was actually hex. * * @param hex The hex-string to convert. * @param bytes The byte-array to write the result to. * * @note The length of the hex-string has to be exactly twice that of the length * of the byte-array, otherwise conversion will fail. * * @return True iff the hex-string was valid and the conversion succeeded. */

 * @return True iff the hex-string was valid and the conversion succeeded.
 */
bool ConvertHexToBytes(std::string_view hex, std::span<uint8_t> bytes)
{
	if (bytes.size() != hex.size() / 2) {
		return false;
	}

	/* Hex-string lengths are always divisible by 2. */
	if (hex.size() % 2 != 0) {
		return false;
	}

	for (size_t i = 0; i < hex.size() / 2; i++) {
		auto hi = ConvertHexNibbleToByte(hex[i * 2]);
		auto lo = ConvertHexNibbleToByte(hex[i * 2 + 1]);

		if (hi < 0 || lo < 0) {
			return false;
		}

		bytes[i] = (hi << 4) | lo;
	}

	return true;
}

#ifdef WITH_UNISCRIBE