1 /* $NetBSD: sequence.c,v 1.1.1.2 2014/04/24 12:45:29 pettai Exp $ */
2
3 /*
4 * Copyright (c) 2003 - 2006 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 "gsskrb5_locl.h"
37
38 #define DEFAULT_JITTER_WINDOW 20
39
40 struct gss_msg_order {
41 OM_uint32 flags;
42 OM_uint32 start;
43 OM_uint32 length;
44 OM_uint32 jitter_window;
45 OM_uint32 first_seq;
46 OM_uint32 elem[1];
47 };
48
49
50 /*
51 *
52 */
53
54 static OM_uint32
msg_order_alloc(OM_uint32 * minor_status,struct gss_msg_order ** o,OM_uint32 jitter_window)55 msg_order_alloc(OM_uint32 *minor_status,
56 struct gss_msg_order **o,
57 OM_uint32 jitter_window)
58 {
59 size_t len;
60
61 len = jitter_window * sizeof((*o)->elem[0]);
62 len += sizeof(**o);
63 len -= sizeof((*o)->elem[0]);
64
65 *o = calloc(1, len);
66 if (*o == NULL) {
67 *minor_status = ENOMEM;
68 return GSS_S_FAILURE;
69 }
70
71 *minor_status = 0;
72 return GSS_S_COMPLETE;
73 }
74
75 /*
76 *
77 */
78
79 OM_uint32
_gssapi_msg_order_create(OM_uint32 * minor_status,struct gss_msg_order ** o,OM_uint32 flags,OM_uint32 seq_num,OM_uint32 jitter_window,int use_64)80 _gssapi_msg_order_create(OM_uint32 *minor_status,
81 struct gss_msg_order **o,
82 OM_uint32 flags,
83 OM_uint32 seq_num,
84 OM_uint32 jitter_window,
85 int use_64)
86 {
87 OM_uint32 ret;
88
89 if (jitter_window == 0)
90 jitter_window = DEFAULT_JITTER_WINDOW;
91
92 ret = msg_order_alloc(minor_status, o, jitter_window);
93 if(ret != GSS_S_COMPLETE)
94 return ret;
95
96 (*o)->flags = flags;
97 (*o)->length = 0;
98 (*o)->first_seq = seq_num;
99 (*o)->jitter_window = jitter_window;
100 (*o)->elem[0] = seq_num - 1;
101
102 *minor_status = 0;
103 return GSS_S_COMPLETE;
104 }
105
106 OM_uint32
_gssapi_msg_order_destroy(struct gss_msg_order ** m)107 _gssapi_msg_order_destroy(struct gss_msg_order **m)
108 {
109 free(*m);
110 *m = NULL;
111 return GSS_S_COMPLETE;
112 }
113
114 static void
elem_set(struct gss_msg_order * o,unsigned int slot,OM_uint32 val)115 elem_set(struct gss_msg_order *o, unsigned int slot, OM_uint32 val)
116 {
117 o->elem[slot % o->jitter_window] = val;
118 }
119
120 static void
elem_insert(struct gss_msg_order * o,unsigned int after_slot,OM_uint32 seq_num)121 elem_insert(struct gss_msg_order *o,
122 unsigned int after_slot,
123 OM_uint32 seq_num)
124 {
125 assert(o->jitter_window > after_slot);
126
127 if (o->length > after_slot)
128 memmove(&o->elem[after_slot + 1], &o->elem[after_slot],
129 (o->length - after_slot - 1) * sizeof(o->elem[0]));
130
131 elem_set(o, after_slot, seq_num);
132
133 if (o->length < o->jitter_window)
134 o->length++;
135 }
136
137 /* rule 1: expected sequence number */
138 /* rule 2: > expected sequence number */
139 /* rule 3: seqnum < seqnum(first) */
140 /* rule 4+5: seqnum in [seqnum(first),seqnum(last)] */
141
142 OM_uint32
_gssapi_msg_order_check(struct gss_msg_order * o,OM_uint32 seq_num)143 _gssapi_msg_order_check(struct gss_msg_order *o, OM_uint32 seq_num)
144 {
145 OM_uint32 r;
146 size_t i;
147
148 if (o == NULL)
149 return GSS_S_COMPLETE;
150
151 if ((o->flags & (GSS_C_REPLAY_FLAG|GSS_C_SEQUENCE_FLAG)) == 0)
152 return GSS_S_COMPLETE;
153
154 /* check if the packet is the next in order */
155 if (o->elem[0] == seq_num - 1) {
156 elem_insert(o, 0, seq_num);
157 return GSS_S_COMPLETE;
158 }
159
160 r = (o->flags & (GSS_C_REPLAY_FLAG|GSS_C_SEQUENCE_FLAG))==GSS_C_REPLAY_FLAG;
161
162 /* sequence number larger then largest sequence number
163 * or smaller then the first sequence number */
164 if (seq_num > o->elem[0]
165 || seq_num < o->first_seq
166 || o->length == 0)
167 {
168 elem_insert(o, 0, seq_num);
169 if (r) {
170 return GSS_S_COMPLETE;
171 } else {
172 return GSS_S_GAP_TOKEN;
173 }
174 }
175
176 assert(o->length > 0);
177
178 /* sequence number smaller the first sequence number */
179 if (seq_num < o->elem[o->length - 1]) {
180 if (r)
181 return(GSS_S_OLD_TOKEN);
182 else
183 return(GSS_S_UNSEQ_TOKEN);
184 }
185
186 if (seq_num == o->elem[o->length - 1]) {
187 return GSS_S_DUPLICATE_TOKEN;
188 }
189
190 for (i = 0; i < o->length - 1; i++) {
191 if (o->elem[i] == seq_num)
192 return GSS_S_DUPLICATE_TOKEN;
193 if (o->elem[i + 1] < seq_num && o->elem[i] < seq_num) {
194 elem_insert(o, i, seq_num);
195 if (r)
196 return GSS_S_COMPLETE;
197 else
198 return GSS_S_UNSEQ_TOKEN;
199 }
200 }
201
202 return GSS_S_FAILURE;
203 }
204
205 OM_uint32
_gssapi_msg_order_f(OM_uint32 flags)206 _gssapi_msg_order_f(OM_uint32 flags)
207 {
208 return flags & (GSS_C_SEQUENCE_FLAG|GSS_C_REPLAY_FLAG);
209 }
210
211 /*
212 * Translate `o` into inter-process format and export in to `sp'.
213 */
214
215 krb5_error_code
_gssapi_msg_order_export(krb5_storage * sp,struct gss_msg_order * o)216 _gssapi_msg_order_export(krb5_storage *sp, struct gss_msg_order *o)
217 {
218 krb5_error_code kret;
219 OM_uint32 i;
220
221 kret = krb5_store_int32(sp, o->flags);
222 if (kret)
223 return kret;
224 kret = krb5_store_int32(sp, o->start);
225 if (kret)
226 return kret;
227 kret = krb5_store_int32(sp, o->length);
228 if (kret)
229 return kret;
230 kret = krb5_store_int32(sp, o->jitter_window);
231 if (kret)
232 return kret;
233 kret = krb5_store_int32(sp, o->first_seq);
234 if (kret)
235 return kret;
236
237 for (i = 0; i < o->jitter_window; i++) {
238 kret = krb5_store_int32(sp, o->elem[i]);
239 if (kret)
240 return kret;
241 }
242
243 return 0;
244 }
245
246 OM_uint32
_gssapi_msg_order_import(OM_uint32 * minor_status,krb5_storage * sp,struct gss_msg_order ** o)247 _gssapi_msg_order_import(OM_uint32 *minor_status,
248 krb5_storage *sp,
249 struct gss_msg_order **o)
250 {
251 OM_uint32 ret;
252 krb5_error_code kret;
253 int32_t i, flags, start, length, jitter_window, first_seq;
254
255 kret = krb5_ret_int32(sp, &flags);
256 if (kret)
257 goto failed;
258 kret = krb5_ret_int32(sp, &start);
259 if (kret)
260 goto failed;
261 kret = krb5_ret_int32(sp, &length);
262 if (kret)
263 goto failed;
264 kret = krb5_ret_int32(sp, &jitter_window);
265 if (kret)
266 goto failed;
267 kret = krb5_ret_int32(sp, &first_seq);
268 if (kret)
269 goto failed;
270
271 ret = msg_order_alloc(minor_status, o, jitter_window);
272 if (ret != GSS_S_COMPLETE)
273 return ret;
274
275 (*o)->flags = flags;
276 (*o)->start = start;
277 (*o)->length = length;
278 (*o)->jitter_window = jitter_window;
279 (*o)->first_seq = first_seq;
280
281 for( i = 0; i < jitter_window; i++ ) {
282 kret = krb5_ret_int32(sp, (int32_t*)&((*o)->elem[i]));
283 if (kret)
284 goto failed;
285 }
286
287 *minor_status = 0;
288 return GSS_S_COMPLETE;
289
290 failed:
291 _gssapi_msg_order_destroy(o);
292 *minor_status = kret;
293 return GSS_S_FAILURE;
294 }
295