xref: /freebsd/crypto/krb5/src/lib/krb5/krb/decrypt_tk.c (revision 7f2fe78b9dd5f51c821d771b63d2e096f6fd49e9)
1 /* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
2 /* lib/krb5/krb/decrypt_tk.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 
29 /*
30   Decrypts dec_ticket->enc_part
31   using *srv_key, and places result in dec_ticket->enc_part2.
32   The storage of dec_ticket->enc_part2 will be allocated before return.
33 
34   returns errors from encryption routines, system errors
35 
36 */
37 
38 krb5_error_code KRB5_CALLCONV
krb5_decrypt_tkt_part(krb5_context context,const krb5_keyblock * srv_key,krb5_ticket * ticket)39 krb5_decrypt_tkt_part(krb5_context context, const krb5_keyblock *srv_key,
40                       krb5_ticket *ticket)
41 {
42     krb5_enc_tkt_part *dec_tkt_part;
43     krb5_data scratch;
44     krb5_error_code retval;
45 
46     if (!krb5_c_valid_enctype(ticket->enc_part.enctype))
47         return KRB5_PROG_ETYPE_NOSUPP;
48 
49     if (!krb5_is_permitted_enctype(context, ticket->enc_part.enctype))
50         return KRB5_NOPERM_ETYPE;
51 
52     scratch.length = ticket->enc_part.ciphertext.length;
53     if (!(scratch.data = malloc(ticket->enc_part.ciphertext.length)))
54         return(ENOMEM);
55 
56     /* call the encryption routine */
57     if ((retval = krb5_c_decrypt(context, srv_key,
58                                  KRB5_KEYUSAGE_KDC_REP_TICKET, 0,
59                                  &ticket->enc_part, &scratch))) {
60         free(scratch.data);
61         return retval;
62     }
63 
64     /*  now decode the decrypted stuff */
65     retval = decode_krb5_enc_tkt_part(&scratch, &dec_tkt_part);
66     if (!retval) {
67         ticket->enc_part2 = dec_tkt_part;
68     }
69     zapfree(scratch.data, scratch.length);
70     return retval;
71 }
72