hexstr2bin

Converts a hexadecimal string hex into an array of bytes.

The optional separator ':' may be used between single or pairs of hexadecimal characters, eg "00:11" or "0:1". Any "0x" at the beginning of hex is ignored. hex may not start or end with ':'.

Parameters:

hex	a string of hexadecimal characters with optional ':' separators

Returns:

the converted bytes, or null on error