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NAME | SYNOPSIS | ARGUMENTS | DESCRIPTION | SINCE | REPORTING BUGS | COPYRIGHT | SEE ALSO | COLOPHON |
gnutls_srp_set_server_fake_salt_seed(3)lsls_srp_set_server_fake_salt_seed(3)
gnutls_srp_set_server_fake_salt_seed - API function
#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);
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
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.
3.3.0
Report bugs to <bugs@gnutls.org>.
Home page: http://www.gnutls.org
Copyright © 2001-2017 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.
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http://www.gnutls.org/manual/
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gnutls 3.g5n.u9tls_srp_set_server_fake_salt_seed(3)