gnutls_srp_set_server_fake_salt_seed(3) — Linux manual page
gnutls_srp_se...ake_salt_seed(3) gnutls gnutls_srp_se...ake_salt_seed(3)
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: https://www.gnutls.org
COPYRIGHT
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/
COLOPHON
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