We give this as a lowercase, sha256 hexadecimal digest of the string:
TYPE + "." + BASE64(modulus as bytes) + "." + BASE64(exponent as bytes)
Where TYPE in all our cases up until now at least are "RSA"
// "RSA." + base64(pubkey.modulus_as_bytes) + "." + base64(pubkey.exponent_as_bytes)
// We don't want the base64 string to be the "url encoding" version because it is not
// as common in programming libraries. And we want it to be base64 encoded since ASCII
- // representation avoids any problems with NULL etc. in less forgiving languages.
+ // representation avoids any problems with NULL etc. in less forgiving languages and also
+ // just easier to debug...
return strtolower(hash('sha256', $this->toString(false, false)));
}