*
* This function will return the bits of the prime used in the last
* Diffie-Hellman authentication with the peer. Should be used for
- * both anonymous and ephemeral Diffie-Hellman.
+ * both anonymous and ephemeral Diffie-Hellman. Note that some
+ * ciphers, like RSA and DSA without DHE, does not use a
+ * Diffie-Hellman exchange, and then this function will return 0.
*
- * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise
- * an error code is returned.
+ * Returns: The Diffie-Hellman bit strength is returned, or 0 if no
+ * Diffie-Hellman exchange was done, or a negative error code on
+ * failure.
**/
int
gnutls_dh_get_prime_bits (gnutls_session_t session)