1 /* $NetBSD: rd_priv.c,v 1.2 2017/01/28 21:31:49 christos Exp $ */
2
3 /*
4 * Copyright (c) 1997-2007 Kungliga Tekniska Högskolan
5 * (Royal Institute of Technology, Stockholm, Sweden).
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * 3. Neither the name of the Institute nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include "krb5_locl.h"
37
38 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_rd_priv(krb5_context context,krb5_auth_context auth_context,const krb5_data * inbuf,krb5_data * outbuf,krb5_replay_data * outdata)39 krb5_rd_priv(krb5_context context,
40 krb5_auth_context auth_context,
41 const krb5_data *inbuf,
42 krb5_data *outbuf,
43 krb5_replay_data *outdata)
44 {
45 krb5_error_code ret;
46 KRB_PRIV priv;
47 EncKrbPrivPart part;
48 size_t len;
49 krb5_data plain;
50 krb5_keyblock *key;
51 krb5_crypto crypto;
52
53 krb5_data_zero(outbuf);
54
55 if ((auth_context->flags &
56 (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE)))
57 {
58 if (outdata == NULL) {
59 krb5_clear_error_message (context);
60 return KRB5_RC_REQUIRED; /* XXX better error, MIT returns this */
61 }
62 /* if these fields are not present in the priv-part, silently
63 return zero */
64 memset(outdata, 0, sizeof(*outdata));
65 }
66
67 memset(&priv, 0, sizeof(priv));
68 ret = decode_KRB_PRIV (inbuf->data, inbuf->length, &priv, &len);
69 if (ret) {
70 krb5_clear_error_message (context);
71 goto failure;
72 }
73 if (priv.pvno != 5) {
74 krb5_clear_error_message (context);
75 ret = KRB5KRB_AP_ERR_BADVERSION;
76 goto failure;
77 }
78 if (priv.msg_type != krb_priv) {
79 krb5_clear_error_message (context);
80 ret = KRB5KRB_AP_ERR_MSG_TYPE;
81 goto failure;
82 }
83
84 if (auth_context->remote_subkey)
85 key = auth_context->remote_subkey;
86 else if (auth_context->local_subkey)
87 key = auth_context->local_subkey;
88 else
89 key = auth_context->keyblock;
90
91 ret = krb5_crypto_init(context, key, 0, &crypto);
92 if (ret)
93 goto failure;
94 ret = krb5_decrypt_EncryptedData(context,
95 crypto,
96 KRB5_KU_KRB_PRIV,
97 &priv.enc_part,
98 &plain);
99 krb5_crypto_destroy(context, crypto);
100 if (ret)
101 goto failure;
102
103 ret = decode_EncKrbPrivPart (plain.data, plain.length, &part, &len);
104 krb5_data_free (&plain);
105 if (ret) {
106 krb5_clear_error_message (context);
107 goto failure;
108 }
109
110 /* check sender address */
111
112 if (part.s_address
113 && auth_context->remote_address
114 && !krb5_address_compare (context,
115 auth_context->remote_address,
116 part.s_address)) {
117 krb5_clear_error_message (context);
118 ret = KRB5KRB_AP_ERR_BADADDR;
119 goto failure_part;
120 }
121
122 /* check receiver address */
123
124 if (part.r_address
125 && auth_context->local_address
126 && !krb5_address_compare (context,
127 auth_context->local_address,
128 part.r_address)) {
129 krb5_clear_error_message (context);
130 ret = KRB5KRB_AP_ERR_BADADDR;
131 goto failure_part;
132 }
133
134 /* check timestamp */
135 if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) {
136 krb5_timestamp sec;
137
138 krb5_timeofday (context, &sec);
139 if (part.timestamp == NULL ||
140 part.usec == NULL ||
141 labs(*part.timestamp - sec) > context->max_skew) {
142 krb5_clear_error_message (context);
143 ret = KRB5KRB_AP_ERR_SKEW;
144 goto failure_part;
145 }
146 }
147
148 /* XXX - check replay cache */
149
150 /* check sequence number. since MIT krb5 cannot generate a sequence
151 number of zero but instead generates no sequence number, we accept that
152 */
153
154 if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
155 if ((part.seq_number == NULL
156 && auth_context->remote_seqnumber != 0)
157 || (part.seq_number != NULL
158 && *part.seq_number != auth_context->remote_seqnumber)) {
159 krb5_clear_error_message (context);
160 ret = KRB5KRB_AP_ERR_BADORDER;
161 goto failure_part;
162 }
163 auth_context->remote_seqnumber++;
164 }
165
166 ret = krb5_data_copy (outbuf, part.user_data.data, part.user_data.length);
167 if (ret)
168 goto failure_part;
169
170 if ((auth_context->flags &
171 (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE))) {
172 if(part.timestamp)
173 outdata->timestamp = *part.timestamp;
174 if(part.usec)
175 outdata->usec = *part.usec;
176 if(part.seq_number)
177 outdata->seq = *part.seq_number;
178 }
179
180 failure_part:
181 free_EncKrbPrivPart (&part);
182
183 failure:
184 free_KRB_PRIV (&priv);
185 return ret;
186 }
187