static const EVP_MD *rsa_algor_to_md(X509_ALGOR *alg)
{
    const EVP_MD *md;
    if (!alg)
        return EVP_sha1();
    md = EVP_get_digestbyobj(alg->algorithm);
    if (md == NULL)
        RSAerr(RSA_F_RSA_ALGOR_TO_MD, RSA_R_UNKNOWN_DIGEST);
    return md;
}
static const EVP_MD *rsa_algor_to_md(X509_ALGOR *alg)
{
    const EVP_MD *md;
    if (!alg)
        return EVP_sha1();
    md = EVP_get_digestbyobj(alg->algorithm);
    if (md == NULL)
        RSAerr(RSA_F_RSA_ALGOR_TO_MD, RSA_R_UNKNOWN_DIGEST);
    return md;
}