i2o_ECPublicKey
return (i2o_ECPublicKey(a->pkey.ec, pp));
penclen = i2o_ECPublicKey(ec_key, NULL);
penclen = i2o_ECPublicKey(ec_key, &p);
penclen = i2o_ECPublicKey(eckey, NULL);
penclen = i2o_ECPublicKey(eckey, &p);
int i2o_ECPublicKey(const EC_KEY *key, unsigned char **out);