1 /* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
2 /* lib/krb5/krb/decode_kdc.c */
3 /*
4 * Copyright 1990 by the Massachusetts Institute of Technology.
5 * All Rights Reserved.
6 *
7 * Export of this software from the United States of America may
8 * require a specific license from the United States Government.
9 * It is the responsibility of any person or organization contemplating
10 * export to obtain such a license before exporting.
11 *
12 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
13 * distribute this software and its documentation for any purpose and
14 * without fee is hereby granted, provided that the above copyright
15 * notice appear in all copies and that both that copyright notice and
16 * this permission notice appear in supporting documentation, and that
17 * the name of M.I.T. not be used in advertising or publicity pertaining
18 * to distribution of the software without specific, written prior
19 * permission. Furthermore if you modify this software you must label
20 * your software as modified software and not distribute it in such a
21 * fashion that it might be confused with the original M.I.T. software.
22 * M.I.T. makes no representations about the suitability of
23 * this software for any purpose. It is provided "as is" without express
24 * or implied warranty.
25 */
26
27 #include "k5-int.h"
28 #include "int-proto.h"
29 #include "fast.h"
30
31 /*
32 Takes a KDC_REP message and decrypts encrypted part using etype and
33 *key, putting result in *rep.
34 dec_rep->client,ticket,session,last_req,server,caddrs
35 are all set to allocated storage which should be freed by the caller
36 when finished with the response.
37
38 If the response isn't a KDC_REP (tgs or as), it returns an error from
39 the decoding routines.
40
41 returns errors from encryption routines, system errors
42 */
43
44 krb5_error_code
krb5int_decode_tgs_rep(krb5_context context,struct krb5int_fast_request_state * fast_state,krb5_data * enc_rep,const krb5_keyblock * key,krb5_keyusage usage,krb5_kdc_rep ** dec_rep_out)45 krb5int_decode_tgs_rep(krb5_context context,
46 struct krb5int_fast_request_state *fast_state,
47 krb5_data *enc_rep, const krb5_keyblock *key,
48 krb5_keyusage usage, krb5_kdc_rep **dec_rep_out)
49 {
50 krb5_error_code retval;
51 krb5_kdc_rep *dec_rep = NULL;
52 krb5_keyblock *strengthen_key = NULL, tgs_key;
53
54 tgs_key.contents = NULL;
55 if (krb5_is_as_rep(enc_rep))
56 retval = decode_krb5_as_rep(enc_rep, &dec_rep);
57 else if (krb5_is_tgs_rep(enc_rep))
58 retval = decode_krb5_tgs_rep(enc_rep, &dec_rep);
59 else
60 retval = KRB5KRB_AP_ERR_MSG_TYPE;
61 if (retval)
62 goto cleanup;
63
64 retval = krb5int_fast_process_response(context, fast_state, dec_rep,
65 &strengthen_key);
66 if (retval == KRB5_ERR_FAST_REQUIRED)
67 retval = 0;
68 else if (retval)
69 goto cleanup;
70 retval = krb5int_fast_reply_key(context, strengthen_key, key, &tgs_key);
71 if (retval)
72 goto cleanup;
73
74 retval = krb5_kdc_rep_decrypt_proc(context, &tgs_key, &usage, dec_rep);
75 if (retval)
76 goto cleanup;
77
78 *dec_rep_out = dec_rep;
79 dec_rep = NULL;
80
81 cleanup:
82 krb5_free_kdc_rep(context, dec_rep);
83 krb5_free_keyblock(context, strengthen_key);
84 krb5_free_keyblock_contents(context, &tgs_key);
85 return retval;
86 }
87