NAME
asn_modinv - modular inverse
SYNOPSIS
string asn_modinv(string a, string m)
DESCRIPTION
Compute the inverse of a 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, or
if there is no inverse.