xref: /freebsd/crypto/heimdal/lib/krb5/mk_rep.c (revision 5521ff5a4d1929056e7ffc982fac3341ca54df7c)
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_rep.c,v 1.19 2001/05/14 06:14:49 assar Exp $");
37 
38 krb5_error_code
39 krb5_mk_rep(krb5_context context,
40 	    krb5_auth_context auth_context,
41 	    krb5_data *outbuf)
42 {
43   krb5_error_code ret;
44   AP_REP ap;
45   EncAPRepPart body;
46   u_char *buf = NULL;
47   size_t buf_size;
48   size_t len;
49   krb5_crypto crypto;
50 
51   ap.pvno = 5;
52   ap.msg_type = krb_ap_rep;
53 
54   memset (&body, 0, sizeof(body));
55 
56   body.ctime = auth_context->authenticator->ctime;
57   body.cusec = auth_context->authenticator->cusec;
58   body.subkey = NULL;
59   if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
60     krb5_generate_seq_number (context,
61 			      auth_context->keyblock,
62 			      &auth_context->local_seqnumber);
63     body.seq_number = malloc (sizeof(*body.seq_number));
64     if (body.seq_number == NULL) {
65 	krb5_set_error_string (context, "malloc: out of memory");
66 	return ENOMEM;
67     }
68     *(body.seq_number) = auth_context->local_seqnumber;
69   } else
70     body.seq_number = NULL;
71 
72   ap.enc_part.etype = auth_context->keyblock->keytype;
73   ap.enc_part.kvno  = NULL;
74 
75   buf_size = length_EncAPRepPart(&body);
76   buf = malloc (buf_size);
77   if (buf == NULL) {
78       free_EncAPRepPart (&body);
79       krb5_set_error_string (context, "malloc: out of memory");
80       return ENOMEM;
81   }
82 
83   ret = krb5_encode_EncAPRepPart (context,
84 				  buf + buf_size - 1,
85 				  buf_size,
86 				  &body,
87 				  &len);
88 
89   free_EncAPRepPart (&body);
90   ret = krb5_crypto_init(context, auth_context->keyblock,
91 			 0 /* ap.enc_part.etype */, &crypto);
92   if (ret) {
93       free (buf);
94       return ret;
95   }
96   ret = krb5_encrypt (context,
97 		      crypto,
98 		      KRB5_KU_AP_REQ_ENC_PART,
99 		      buf + buf_size - len,
100 		      len,
101 		      &ap.enc_part.cipher);
102   krb5_crypto_destroy(context, crypto);
103   if (ret) {
104       free(buf);
105       return ret;
106   }
107 
108   buf_size = length_AP_REP(&ap);
109   buf = realloc(buf, buf_size);
110   if(buf == NULL) {
111       free_AP_REP (&ap);
112       krb5_set_error_string (context, "malloc: out of memory");
113       return ENOMEM;
114   }
115   ret = encode_AP_REP (buf + buf_size - 1, buf_size, &ap, &len);
116 
117   free_AP_REP (&ap);
118 
119   if(len != buf_size)
120       krb5_abortx(context, "krb5_mk_rep: encoded length != calculated length");
121   outbuf->data = buf;
122   outbuf->length = len;
123   return 0;
124 }
125