xref: /freebsd/crypto/heimdal/lib/krb5/mk_priv.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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_priv(krb5_context context,
38 	     krb5_auth_context auth_context,
39 	     const krb5_data *userdata,
40 	     krb5_data *outbuf,
41 	     krb5_replay_data *outdata)
42 {
43     krb5_error_code ret;
44     KRB_PRIV s;
45     EncKrbPrivPart part;
46     u_char *buf = NULL;
47     size_t buf_size;
48     size_t len = 0;
49     krb5_crypto crypto;
50     krb5_keyblock *key;
51     krb5_replay_data rdata;
52 
53     if ((auth_context->flags &
54 	 (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE)) &&
55 	outdata == NULL)
56 	return KRB5_RC_REQUIRED; /* XXX better error, MIT returns this */
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     memset(&rdata, 0, sizeof(rdata));
66 
67     part.user_data = *userdata;
68 
69     krb5_us_timeofday (context, &rdata.timestamp, &rdata.usec);
70 
71     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) {
72 	part.timestamp = &rdata.timestamp;
73 	part.usec      = &rdata.usec;
74     } else {
75 	part.timestamp = NULL;
76 	part.usec      = NULL;
77     }
78 
79     if (auth_context->flags & KRB5_AUTH_CONTEXT_RET_TIME) {
80 	outdata->timestamp = rdata.timestamp;
81 	outdata->usec = rdata.usec;
82     }
83 
84     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
85 	rdata.seq = auth_context->local_seqnumber;
86 	part.seq_number = &rdata.seq;
87     } else
88 	part.seq_number = NULL;
89 
90     if (auth_context->flags & KRB5_AUTH_CONTEXT_RET_SEQUENCE)
91 	outdata->seq = auth_context->local_seqnumber;
92 
93     part.s_address = auth_context->local_address;
94     part.r_address = auth_context->remote_address;
95 
96     krb5_data_zero (&s.enc_part.cipher);
97 
98     ASN1_MALLOC_ENCODE(EncKrbPrivPart, buf, buf_size, &part, &len, ret);
99     if (ret)
100 	goto fail;
101     if (buf_size != len)
102 	krb5_abortx(context, "internal error in ASN.1 encoder");
103 
104     s.pvno = 5;
105     s.msg_type = krb_priv;
106     s.enc_part.etype = key->keytype;
107     s.enc_part.kvno = NULL;
108 
109     ret = krb5_crypto_init(context, key, 0, &crypto);
110     if (ret) {
111 	free (buf);
112 	return ret;
113     }
114     ret = krb5_encrypt (context,
115 			crypto,
116 			KRB5_KU_KRB_PRIV,
117 			buf + buf_size - len,
118 			len,
119 			&s.enc_part.cipher);
120     krb5_crypto_destroy(context, crypto);
121     if (ret) {
122 	free(buf);
123 	return ret;
124     }
125     free(buf);
126 
127 
128     ASN1_MALLOC_ENCODE(KRB_PRIV, buf, buf_size, &s, &len, ret);
129     if (ret)
130 	goto fail;
131     if (buf_size != len)
132 	krb5_abortx(context, "internal error in ASN.1 encoder");
133 
134     krb5_data_free (&s.enc_part.cipher);
135 
136     ret = krb5_data_copy(outbuf, buf + buf_size - len, len);
137     if (ret) {
138 	krb5_set_error_message(context, ENOMEM,
139 			       N_("malloc: out of memory", ""));
140 	free(buf);
141 	return ENOMEM;
142     }
143     free (buf);
144     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE)
145 	auth_context->local_seqnumber =
146 	    (auth_context->local_seqnumber + 1) & 0xFFFFFFFF;
147     return 0;
148 
149   fail:
150     free (buf);
151     krb5_data_free (&s.enc_part.cipher);
152     return ret;
153 }
154