CHAP secrets, CHAP passwords and IPSEC preshared keys can be specified as a text string or as a sequence of hexadecimal values. ...

CHAP secrets, CHAP passwords and IPSEC preshared keys can be specified as a text string or as a sequence of hexadecimal values. The value specified on the command line is always considered a string unless the first two characters 0x in which case it is considered a hexadecimal value.  For example 0x12345678 specifies a 4 byte secret