- fatal("auth_rsa_generate_challenge: BN_CTX_new() failed");
- BN_mod(challenge, challenge, key->rsa->n, ctx);
+ fatal("auth_rsa_generate_challenge: BN_CTX_new failed");
+ if (BN_mod(challenge, challenge, key->rsa->n, ctx) == 0)
+ fatal("auth_rsa_generate_challenge: BN_mod failed");