MD *type, unsigned char *md,
                unsigned int *len);
ASN1_OCTET_STRING *X509_digest_sig(const X509 *cert,
                                   EVP_MD **md_used, int *md_is_fallback);

int X509_CRL_digest(const X509_CRL *data, const EVP_MD *type, unsigned char *md,
                    unsigned int *len);

int X509_pubkey_digest(const X509 *data, const EVP_MD *type,
                       unsigned char *md, unsigned int *len);

int X509_REQ_digest(const X509_REQ *data, const EVP_MD *type,
          