1/*
2 * Copyright (c) 1997 - 2003 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
36RCSID("$Id: mk_rep.c 13863 2004-05-25 21:46:46Z lha $");
37
38krb5_error_code KRB5_LIB_FUNCTION
39krb5_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    if (auth_context->flags & KRB5_AUTH_CONTEXT_USE_SUBKEY) {
59	if (auth_context->local_subkey == NULL) {
60	    ret = krb5_auth_con_generatelocalsubkey(context,
61						    auth_context,
62						    auth_context->keyblock);
63	    if(ret) {
64		krb5_set_error_string (context,
65				       "krb5_mk_rep: generating subkey");
66		free_EncAPRepPart(&body);
67		return ret;
68	    }
69	}
70	ret = krb5_copy_keyblock(context, auth_context->local_subkey,
71				 &body.subkey);
72	if (ret) {
73	    krb5_set_error_string (context,
74				   "krb5_copy_keyblock: out of memory");
75	    free_EncAPRepPart(&body);
76	    return ENOMEM;
77	}
78    } else
79	body.subkey = NULL;
80    if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
81	if(auth_context->local_seqnumber == 0)
82	    krb5_generate_seq_number (context,
83				      auth_context->keyblock,
84				      &auth_context->local_seqnumber);
85	ALLOC(body.seq_number, 1);
86	if (body.seq_number == NULL) {
87	    krb5_set_error_string (context, "malloc: out of memory");
88	    free_EncAPRepPart(&body);
89	    return ENOMEM;
90	}
91	*(body.seq_number) = auth_context->local_seqnumber;
92    } else
93	body.seq_number = NULL;
94
95    ap.enc_part.etype = auth_context->keyblock->keytype;
96    ap.enc_part.kvno  = NULL;
97
98    ASN1_MALLOC_ENCODE(EncAPRepPart, buf, buf_size, &body, &len, ret);
99    free_EncAPRepPart (&body);
100    if(ret)
101	return ret;
102    if (buf_size != len)
103	krb5_abortx(context, "internal error in ASN.1 encoder");
104    ret = krb5_crypto_init(context, auth_context->keyblock,
105			   0 /* ap.enc_part.etype */, &crypto);
106    if (ret) {
107	free (buf);
108	return ret;
109    }
110    ret = krb5_encrypt (context,
111			crypto,
112			KRB5_KU_AP_REQ_ENC_PART,
113			buf + buf_size - len,
114			len,
115			&ap.enc_part.cipher);
116    krb5_crypto_destroy(context, crypto);
117    free(buf);
118    if (ret)
119	return ret;
120
121    ASN1_MALLOC_ENCODE(AP_REP, outbuf->data, outbuf->length, &ap, &len, ret);
122    if (ret == 0 && outbuf->length != len)
123	krb5_abortx(context, "internal error in ASN.1 encoder");
124    free_AP_REP (&ap);
125    return ret;
126}
127