xref: /freebsd/crypto/heimdal/lib/krb5/mk_priv.c (revision 884a2a699669ec61e2366e3e358342dbc94be24a)
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 
36 RCSID("$Id: mk_priv.c 16680 2006-02-01 12:39:26Z lha $");
37 
38 
39 krb5_error_code KRB5_LIB_FUNCTION
40 krb5_mk_priv(krb5_context context,
41 	     krb5_auth_context auth_context,
42 	     const krb5_data *userdata,
43 	     krb5_data *outbuf,
44 	     krb5_replay_data *outdata)
45 {
46     krb5_error_code ret;
47     KRB_PRIV s;
48     EncKrbPrivPart part;
49     u_char *buf = NULL;
50     size_t buf_size;
51     size_t len;
52     krb5_crypto crypto;
53     krb5_keyblock *key;
54     krb5_replay_data rdata;
55 
56     if ((auth_context->flags &
57 	 (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE)) &&
58 	outdata == NULL)
59 	return KRB5_RC_REQUIRED; /* XXX better error, MIT returns this */
60 
61     if (auth_context->local_subkey)
62 	key = auth_context->local_subkey;
63     else if (auth_context->remote_subkey)
64 	key = auth_context->remote_subkey;
65     else
66 	key = auth_context->keyblock;
67 
68     memset(&rdata, 0, sizeof(rdata));
69 
70     part.user_data = *userdata;
71 
72     krb5_us_timeofday (context, &rdata.timestamp, &rdata.usec);
73 
74     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) {
75 	part.timestamp = &rdata.timestamp;
76 	part.usec      = &rdata.usec;
77     } else {
78 	part.timestamp = NULL;
79 	part.usec      = NULL;
80     }
81 
82     if (auth_context->flags & KRB5_AUTH_CONTEXT_RET_TIME) {
83 	outdata->timestamp = rdata.timestamp;
84 	outdata->usec = rdata.usec;
85     }
86 
87     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
88 	rdata.seq = auth_context->local_seqnumber;
89 	part.seq_number = &rdata.seq;
90     } else
91 	part.seq_number = NULL;
92 
93     if (auth_context->flags & KRB5_AUTH_CONTEXT_RET_SEQUENCE)
94 	outdata->seq = auth_context->local_seqnumber;
95 
96     part.s_address = auth_context->local_address;
97     part.r_address = auth_context->remote_address;
98 
99     krb5_data_zero (&s.enc_part.cipher);
100 
101     ASN1_MALLOC_ENCODE(EncKrbPrivPart, buf, buf_size, &part, &len, ret);
102     if (ret)
103 	goto fail;
104     if (buf_size != len)
105 	krb5_abortx(context, "internal error in ASN.1 encoder");
106 
107     s.pvno = 5;
108     s.msg_type = krb_priv;
109     s.enc_part.etype = key->keytype;
110     s.enc_part.kvno = NULL;
111 
112     ret = krb5_crypto_init(context, key, 0, &crypto);
113     if (ret) {
114 	free (buf);
115 	return ret;
116     }
117     ret = krb5_encrypt (context,
118 			crypto,
119 			KRB5_KU_KRB_PRIV,
120 			buf + buf_size - len,
121 			len,
122 			&s.enc_part.cipher);
123     krb5_crypto_destroy(context, crypto);
124     if (ret) {
125 	free(buf);
126 	return ret;
127     }
128     free(buf);
129 
130 
131     ASN1_MALLOC_ENCODE(KRB_PRIV, buf, buf_size, &s, &len, ret);
132     if (ret)
133 	goto fail;
134     if (buf_size != len)
135 	krb5_abortx(context, "internal error in ASN.1 encoder");
136 
137     krb5_data_free (&s.enc_part.cipher);
138 
139     ret = krb5_data_copy(outbuf, buf + buf_size - len, len);
140     if (ret) {
141 	krb5_set_error_string (context, "malloc: out of memory");
142 	free(buf);
143 	return ENOMEM;
144     }
145     free (buf);
146     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE)
147 	auth_context->local_seqnumber =
148 	    (auth_context->local_seqnumber + 1) & 0xFFFFFFFF;
149     return 0;
150 
151   fail:
152     free (buf);
153     krb5_data_free (&s.enc_part.cipher);
154     return ret;
155 }
156