SilcBool silc_auth_verify(SilcAuthPayload payload,
                          SilcAuthMethod auth_method,
                          const void *auth_data, SilcUInt32 auth_data_len,
                          SilcHash hash, const void *id, SilcIdType type);

    Verifies the authentication data directly from the Authentication
    Payload. Supports all authentication methods. If the authentication
    method is passphrase based then the `auth_data' and `auth_data_len'
    are the passphrase and its length.  The passphrase MUST be UTF-8
    encoded.  If the method is public key authentication then the
    `auth_data' is the SilcPublicKey and the `auth_data_len' is ignored.