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/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/* lib/krb5/krb/gen_save_subkey.c */
/*
* Copyright 2009 by the Massachusetts Institute of Technology.
* All Rights Reserved.
*
* Export of this software from the United States of America may
* require a specific license from the United States Government.
* It is the responsibility of any person or organization contemplating
* export to obtain such a license before exporting.
*
* WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
* distribute this software and its documentation for any purpose and
* without fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright notice and
* this permission notice appear in supporting documentation, and that
* the name of M.I.T. not be used in advertising or publicity pertaining
* to distribution of the software without specific, written prior
* permission. Furthermore if you modify this software you must label
* your software as modified software and not distribute it in such a
* fashion that it might be confused with the original M.I.T. software.
* M.I.T. makes no representations about the suitability of
* this software for any purpose. It is provided "as is" without express
* or implied warranty.
*/
#include "k5-int.h"
#include "int-proto.h"
#include "auth_con.h"
krb5_error_code
k5_generate_and_save_subkey(krb5_context context,
krb5_auth_context auth_context,
krb5_keyblock *keyblock, krb5_enctype enctype)
{
/* Provide some more fodder for random number code.
This isn't strong cryptographically; the point here is not
to guarantee randomness, but to make it less likely that multiple
sessions could pick the same subkey. */
struct {
krb5_int32 sec, usec;
} rnd_data;
krb5_data d;
krb5_error_code retval;
krb5_keyblock *kb = NULL;
if (krb5_crypto_us_timeofday(&rnd_data.sec, &rnd_data.usec) == 0) {
d.length = sizeof(rnd_data);
d.data = (char *) &rnd_data;
krb5_c_random_add_entropy(context, KRB5_C_RANDSOURCE_TIMING, &d);
}
retval = krb5_generate_subkey_extended(context, keyblock, enctype, &kb);
if (retval)
return retval;
retval = krb5_auth_con_setsendsubkey(context, auth_context, kb);
if (retval)
goto cleanup;
retval = krb5_auth_con_setrecvsubkey(context, auth_context, kb);
if (retval)
goto cleanup;
cleanup:
if (retval) {
(void) krb5_auth_con_setsendsubkey(context, auth_context, NULL);
(void) krb5_auth_con_setrecvsubkey(context, auth_context, NULL);
}
krb5_free_keyblock(context, kb);
return retval;
}
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