xref: /freebsd/crypto/heimdal/lib/krb5/mk_safe.c (revision 2a4a1db342263067035ce69a4017c645da63455d)
1 /*
2  * Copyright (c) 1997 - 2001 Kungliga Tekniska H�gskolan
3  * (Royal Institute of Technology, Stockholm, Sweden).
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  *
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * 3. Neither the name of the Institute nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include <krb5_locl.h>
35 
36 RCSID("$Id: mk_safe.c,v 1.27 2001/06/18 02:45:15 assar Exp $");
37 
38 krb5_error_code
39 krb5_mk_safe(krb5_context context,
40 	     krb5_auth_context auth_context,
41 	     const krb5_data *userdata,
42 	     krb5_data *outbuf,
43 	     /*krb5_replay_data*/ void *outdata)
44 {
45   krb5_error_code ret;
46   KRB_SAFE s;
47   int32_t sec, usec;
48   KerberosTime sec2;
49   int usec2;
50   u_char *buf = NULL;
51   void *tmp;
52   size_t buf_size;
53   size_t len;
54   u_int32_t tmp_seq;
55   krb5_crypto crypto;
56   krb5_keyblock *key;
57 
58   if (auth_context->local_subkey)
59       key = auth_context->local_subkey;
60   else if (auth_context->remote_subkey)
61       key = auth_context->remote_subkey;
62   else
63       key = auth_context->keyblock;
64 
65   s.pvno = 5;
66   s.msg_type = krb_safe;
67 
68   s.safe_body.user_data = *userdata;
69   krb5_us_timeofday (context, &sec, &usec);
70 
71   sec2                   = sec;
72   s.safe_body.timestamp  = &sec2;
73   usec2                  = usec2;
74   s.safe_body.usec       = &usec2;
75   if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
76       tmp_seq = auth_context->local_seqnumber;
77       s.safe_body.seq_number = &tmp_seq;
78   } else
79       s.safe_body.seq_number = NULL;
80 
81   s.safe_body.s_address = auth_context->local_address;
82   s.safe_body.r_address = auth_context->remote_address;
83 
84   s.cksum.cksumtype       = 0;
85   s.cksum.checksum.data   = NULL;
86   s.cksum.checksum.length = 0;
87 
88   buf_size = length_KRB_SAFE(&s);
89   buf = malloc(buf_size + 128); /* add some for checksum */
90   if(buf == NULL) {
91       krb5_set_error_string (context, "malloc: out of memory");
92       return ENOMEM;
93   }
94   ret = encode_KRB_SAFE (buf + buf_size - 1, buf_size, &s, &len);
95   if (ret) {
96       free (buf);
97       return ret;
98   }
99   ret = krb5_crypto_init(context, key, 0, &crypto);
100   if (ret) {
101       free (buf);
102       return ret;
103   }
104   ret = krb5_create_checksum(context,
105 			     crypto,
106 			     KRB5_KU_KRB_SAFE_CKSUM,
107 			     0,
108 			     buf + buf_size - len,
109 			     len,
110 			     &s.cksum);
111   krb5_crypto_destroy(context, crypto);
112   if (ret) {
113       free (buf);
114       return ret;
115   }
116 
117   buf_size = length_KRB_SAFE(&s);
118   tmp = realloc(buf, buf_size);
119   if(tmp == NULL) {
120       free(buf);
121       krb5_set_error_string (context, "malloc: out of memory");
122       return ENOMEM;
123   }
124   buf = tmp;
125 
126   ret = encode_KRB_SAFE (buf + buf_size - 1, buf_size, &s, &len);
127   free_Checksum (&s.cksum);
128 
129   outbuf->length = len;
130   outbuf->data   = malloc (len);
131   if (outbuf->data == NULL) {
132       free (buf);
133       krb5_set_error_string (context, "malloc: out of memory");
134       return ENOMEM;
135   }
136   memcpy (outbuf->data, buf + buf_size - len, len);
137   free (buf);
138   if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE)
139       auth_context->local_seqnumber =
140 	  (auth_context->local_seqnumber + 1) & 0xFFFFFFFF;
141   return 0;
142 }
143