1gnutls_srp_set_server_credentials_gfnuungtcnltusit_olsnsr(p3_)set_server_credentials_function(3)
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NAME

6       gnutls_srp_set_server_credentials_function - API function
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SYNOPSIS

9       #include <gnutls/gnutls.h>
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11       void  gnutls_srp_set_server_credentials_function(gnutls_srp_server_cre‐
12       dentials_t             cred,     gnutls_srp_server_credentials_function
13       * func);
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ARGUMENTS

16       gnutls_srp_server_credentials_t         cred
17                   is a gnutls_srp_server_credentials_t type.
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19       gnutls_srp_server_credentials_function         * func
20                   is the callback function
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DESCRIPTION

23       This  function can be used to set a callback to retrieve the user's SRP
24       credentials.  The callback's function form is:
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26       int (*callback)(gnutls_session_t, const char* username,  gnutls_datum_t
27       *salt,    gnutls_datum_t    *verifier,    gnutls_datum_t    *generator,
28       gnutls_datum_t *prime);
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30        username contains the actual username.  The  salt ,  verifier ,   gen‐
31       erator and  prime must be filled in using the gnutls_malloc(). For con‐
32       venience  prime and  generator may also be one of the static parameters
33       defined in gnutls.h.
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35       Initially,  the  data  field  is NULL in every gnutls_datum_t structure
36       that the callback has to fill in. When  the  callback  is  done  GnuTLS
37       deallocates  all of those buffers which are non-NULL, regardless of the
38       return value.
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40       In order to prevent attackers from guessing valid usernames, if a  user
41       does  not  exist,  g  and  n  values should be filled in using a random
42       user's parameters. In that case the callback must  return  the  special
43       value  (1).   See gnutls_srp_set_server_fake_salt_seed too.  If this is
44       not required for your application, return a negative  number  from  the
45       callback to abort the handshake.
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47       The  callback  function  will  only  be called once per handshake.  The
48       callback function should return 0 on success,  while  -1  indicates  an
49       error.
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REPORTING BUGS

52       Report bugs to <bugs@gnutls.org>.
53       Home page: https://www.gnutls.org
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57       Copyright © 2001-2019 Free Software Foundation, Inc., and others.
58       Copying  and  distribution  of this file, with or without modification,
59       are permitted in any medium  without  royalty  provided  the  copyright
60       notice and this notice are preserved.
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SEE ALSO

63       The  full  documentation  for gnutls is maintained as a Texinfo manual.
64       If the /usr/share/doc/gnutls/ directory does not contain the HTML  form
65       visit
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67       https://www.gnutls.org/manual/
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69gnutls                           gnut3l.s6_.s8rp_set_server_credentials_function(3)
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