oracular (3) gnutls_srp_set_server_credentials_function.3.gz

Provided by: gnutls-doc_3.8.6-2ubuntu1.1_all bug

NAME
       gnutls_srp_set_server_credentials_function - API function


SYNOPSIS
       #include <gnutls/gnutls.h>

       void           gnutls_srp_set_server_credentials_function(gnutls_srp_server_credentials_t           cred,
       gnutls_srp_server_credentials_function * func);


ARGUMENTS
       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
       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
       Report bugs to <bugs@gnutls.org>.
       Home page: https://www.gnutls.org


       Copyright © 2001-2023 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
       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

       https://www.gnutls.org/manual/