OSSL_SIGNATURE_PARAM_MGF1_DIGEST
p = OSSL_PARAM_locate(params, OSSL_SIGNATURE_PARAM_MGF1_DIGEST);
OSSL_PARAM_utf8_string(OSSL_SIGNATURE_PARAM_MGF1_DIGEST, NULL, 0),
p = OSSL_PARAM_locate_const(params, OSSL_SIGNATURE_PARAM_MGF1_DIGEST);
OSSL_PARAM_utf8_string(OSSL_SIGNATURE_PARAM_MGF1_DIGEST, NULL, 0),
OSSL_PARAM_utf8_string(OSSL_SIGNATURE_PARAM_MGF1_DIGEST, NULL, 0),