1 /*
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  * krb5_decrypt_tkt_part() function.
28  */
29 
30 #include <k5-int.h>
31 
32 /*
33  Decrypts dec_ticket->enc_part
34  using *srv_key, and places result in dec_ticket->enc_part2.
35  The storage of dec_ticket->enc_part2 will be allocated before return.
36 
37  returns errors from encryption routines, system errors
38 
39 */
40 
41 /*ARGSUSED*/
42 krb5_error_code KRB5_CALLCONV
krb5_decrypt_tkt_part(krb5_context context,const krb5_keyblock * srv_key,register krb5_ticket * ticket)43 krb5_decrypt_tkt_part(krb5_context context, const krb5_keyblock *srv_key, register krb5_ticket *ticket)
44 {
45     krb5_enc_tkt_part *dec_tkt_part;
46     krb5_data scratch;
47     krb5_error_code retval;
48 
49     if (!krb5_c_valid_enctype(ticket->enc_part.enctype))
50 	return KRB5_PROG_ETYPE_NOSUPP;
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 #define clean_scratch() {memset(scratch.data, 0, scratch.length); \
65 free(scratch.data);}
66 
67     /*  now decode the decrypted stuff */
68     retval = decode_krb5_enc_tkt_part(&scratch, &dec_tkt_part);
69     if (!retval) {
70 	ticket->enc_part2 = dec_tkt_part;
71     }
72     clean_scratch();
73     return retval;
74 }
75