sign_and_verify
failed |= sign_and_verify("default method", evp_priv, evp_pub);
failed |= sign_and_verify("app data sign method", evp_priv, evp_pub);
failed |= sign_and_verify("ex data verify method", evp_priv, evp_pub);
failed |= sign_and_verify("both sides bogus", evp_priv, evp_pub);