Is there any example code on how to set up openssl engine to work with a
custom external ECDSA system?
Specifically, I have a custom "C" library which implements the following:
int external_ecdsa_initialize(); /* open connection to external
system */
int external_ecdsa_sign(const uint8_t *data, const int datalen); /*
sign data */
void external ecdsa_finalize(); /* close connection */
This library handles all of the communication with the external system
containing the ECC private key, and provides an API to generate the ECDSA
signatures. (This way, if my server is ever hacked, the attacker won't get
a copy of the external ECC private key.)
My goal is to turn this into a proper ECDSA method for OpenSSL engine, and
allow it to be used as an EVP_PKEY object, but I cannot find a way to do
this.
