gnutls_srp_set_server_credentials_function(3) — Linux manual page



NAME         top

       gnutls_srp_set_server_credentials_function - API function

SYNOPSIS         top

       #include <gnutls/gnutls.h>

       cred, gnutls_srp_server_credentials_function         * func);

ARGUMENTS         top

       gnutls_srp_server_credentials_t         cred
                   is a gnutls_srp_server_credentials_t type.

       gnutls_srp_server_credentials_function         * func
                   is the callback function

DESCRIPTION         top

       This function can be used to set a callback to retrieve the
       user's SRP credentials.  The callback's function form is:

       int (*callback)(gnutls_session_t, const char* username,
       gnutls_datum_t *salt, gnutls_datum_t *verifier, gnutls_datum_t
       *generator, gnutls_datum_t *prime);

        username contains the actual username.  The  salt ,  verifier ,
       generator and  prime must be filled in using the gnutls_malloc().
       For convenience  prime and  generator may also be one of the
       static parameters defined in gnutls.h.

       Initially, the data field is NULL in every gnutls_datum_t
       structure that the callback has to fill in. When the callback is
       done GnuTLS deallocates all of those buffers which are non-NULL,
       regardless of the return value.

       In order to prevent attackers from guessing valid usernames, if a
       user does not exist, g and n values should be filled in using a
       random user's parameters. In that case the callback must return
       the special value (1).  See gnutls_srp_set_server_fake_salt_seed
       too.  If this is not required for your application, return a
       negative number from the callback to abort the handshake.

       The callback function will only be called once per handshake.
       The callback function should return 0 on success, while -1
       indicates an error.

REPORTING BUGS         top

       Report bugs to <>.
       Home page:

COPYRIGHT         top

       Copyright © 2001- Free Software Foundation, Inc., and others.
       Copying and distribution of this file, with or without
       modification, are permitted in any medium without royalty
       provided the copyright notice and this notice are preserved.

SEE ALSO         top

       The full documentation for gnutls is maintained as a Texinfo
       manual.  If the /usr/share/doc/gnutls/ directory does not contain
       the HTML form visit 

COLOPHON         top

       This page is part of the GnuTLS (GnuTLS Transport Layer Security
       Library) project.  Information about the project can be found at
       ⟨⟩.  If you have a bug report for this
       manual page, send it to  This page was obtained
       from the tarball gnutls-3.7.8.tar.xz fetched from
       ⟨⟩ on 2022-12-17.  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
       the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to

gnutls                     gnutls_3s.r7p._8set_server_credentials_function(3)