xref: /freebsd/crypto/heimdal/lib/krb5/mk_rep.c (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
1 /*
2  * Copyright (c) 1997 - 2003 Kungliga Tekniska Högskolan
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 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
37 krb5_mk_rep(krb5_context context,
38 	    krb5_auth_context auth_context,
39 	    krb5_data *outbuf)
40 {
41     krb5_error_code ret;
42     AP_REP ap;
43     EncAPRepPart body;
44     u_char *buf = NULL;
45     size_t buf_size;
46     size_t len = 0;
47     krb5_crypto crypto;
48 
49     ap.pvno = 5;
50     ap.msg_type = krb_ap_rep;
51 
52     memset (&body, 0, sizeof(body));
53 
54     body.ctime = auth_context->authenticator->ctime;
55     body.cusec = auth_context->authenticator->cusec;
56     if (auth_context->flags & KRB5_AUTH_CONTEXT_USE_SUBKEY) {
57 	if (auth_context->local_subkey == NULL) {
58 	    ret = krb5_auth_con_generatelocalsubkey(context,
59 						    auth_context,
60 						    auth_context->keyblock);
61 	    if(ret) {
62 		free_EncAPRepPart(&body);
63 		return ret;
64 	    }
65 	}
66 	ret = krb5_copy_keyblock(context, auth_context->local_subkey,
67 				 &body.subkey);
68 	if (ret) {
69 	    free_EncAPRepPart(&body);
70 	    krb5_set_error_message(context, ENOMEM,
71 				   N_("malloc: out of memory", ""));
72 	    return ENOMEM;
73 	}
74     } else
75 	body.subkey = NULL;
76     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
77 	if(auth_context->local_seqnumber == 0)
78 	    krb5_generate_seq_number (context,
79 				      auth_context->keyblock,
80 				      &auth_context->local_seqnumber);
81 	ALLOC(body.seq_number, 1);
82 	if (body.seq_number == NULL) {
83 	    krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
84 	    free_EncAPRepPart(&body);
85 	    return ENOMEM;
86 	}
87 	*(body.seq_number) = auth_context->local_seqnumber;
88     } else
89 	body.seq_number = NULL;
90 
91     ap.enc_part.etype = auth_context->keyblock->keytype;
92     ap.enc_part.kvno  = NULL;
93 
94     ASN1_MALLOC_ENCODE(EncAPRepPart, buf, buf_size, &body, &len, ret);
95     free_EncAPRepPart (&body);
96     if(ret)
97 	return ret;
98     if (buf_size != len)
99 	krb5_abortx(context, "internal error in ASN.1 encoder");
100     ret = krb5_crypto_init(context, auth_context->keyblock,
101 			   0 /* ap.enc_part.etype */, &crypto);
102     if (ret) {
103 	free (buf);
104 	return ret;
105     }
106     ret = krb5_encrypt (context,
107 			crypto,
108 			KRB5_KU_AP_REQ_ENC_PART,
109 			buf + buf_size - len,
110 			len,
111 			&ap.enc_part.cipher);
112     krb5_crypto_destroy(context, crypto);
113     free(buf);
114     if (ret)
115 	return ret;
116 
117     ASN1_MALLOC_ENCODE(AP_REP, outbuf->data, outbuf->length, &ap, &len, ret);
118     if (ret == 0 && outbuf->length != len)
119 	krb5_abortx(context, "internal error in ASN.1 encoder");
120     free_AP_REP (&ap);
121     return ret;
122 }
123