NAME
asn_add - add two arbitrary size numbers
SYNOPSIS
string asn_add(string a, string b, string m)
DESCRIPTION
Compute the sum of a and b modulo m. The modulus must be larger than
zero.
Arbitrary size numbers are encoded as strings, most significant byte
first. The most significant bit in the first byte, when set, indicates
that the number is negative and encoded in two's complement.
ERRORS
An error will result if the modulus is less than or equal to zero.