NAME

       gnutls_srp_set_server_fake_salt_seed - API function

SYNOPSIS

       #include <gnutls/gnutls.h>

       void  gnutls_srp_set_server_fake_salt_seed(gnutls_srp_server_credentials_t  cred,  const gnutls_datum_t *
       seed, unsigned int salt_length);

ARGUMENTS

       gnutls_srp_server_credentials_t cred
                   is a gnutls_srp_server_credentials_t type

       const gnutls_datum_t * seed
                   is the seed data, only needs to be valid until the function returns; size of the seed must be
                   greater than zero

       unsigned int salt_length
                   is the length of the generated fake salts

DESCRIPTION

       This function sets the seed that is used to generate salts for invalid (non-existent) usernames.

       In  order to prevent attackers from guessing valid usernames, when a user does not exist gnutls generates
       a salt and a verifier and proceeds with the protocol as usual.  The authentication will ultimately  fail,
       but the client cannot tell whether the username is valid (exists) or invalid.

       If  an  attacker  learns the seed, given a salt (which is part of the handshake) which was generated when
       the seed was in use, it can tell whether or not the authentication failed because of an unknown username.
       This seed cannot be used to reveal application data or passwords.

        salt_length  should  represent the salt length your application uses.  Generating fake salts longer than
       20 bytes is not supported.

       By default the seed is a random value, different each time a gnutls_srp_server_credentials_t is allocated
       and fake salts are 16 bytes long.

SINCE

       3.3.0

REPORTING BUGS

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

COPYRIGHT

       Copyright © 2001-2021 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

       http://www.gnutls.org/manual/