2 * Copyright (c) 2003 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
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.
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.
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
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30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 #include "gssapi_locl.h"
36 RCSID("$Id: sequence.c,v 1.5 2005/04/27 17:49:43 lha Exp $");
38 #define DEFAULT_JITTER_WINDOW 20
40 struct gss_msg_order {
44 OM_uint32 jitter_window;
54 _gssapi_msg_order_create(OM_uint32 *minor_status,
55 struct gss_msg_order **o,
58 OM_uint32 jitter_window,
63 if (jitter_window == 0)
64 jitter_window = DEFAULT_JITTER_WINDOW;
66 len = jitter_window * sizeof((*o)->elem[0]);
68 len -= sizeof((*o)->elem[0]);
72 *minor_status = ENOMEM;
78 (*o)->first_seq = seq_num;
79 (*o)->jitter_window = jitter_window;
80 (*o)->elem[0] = seq_num - 1;
83 return GSS_S_COMPLETE;
87 _gssapi_msg_order_destroy(struct gss_msg_order **m)
91 return GSS_S_COMPLETE;
95 elem_set(struct gss_msg_order *o, unsigned int slot, OM_uint32 val)
97 o->elem[slot % o->jitter_window] = val;
101 elem_insert(struct gss_msg_order *o,
102 unsigned int after_slot,
105 assert(o->jitter_window > after_slot);
107 if (o->length > after_slot)
108 memmove(&o->elem[after_slot + 1], &o->elem[after_slot],
109 (o->length - after_slot - 1) * sizeof(o->elem[0]));
111 elem_set(o, after_slot, seq_num);
113 if (o->length < o->jitter_window)
117 /* rule 1: expected sequence number */
118 /* rule 2: > expected sequence number */
119 /* rule 3: seqnum < seqnum(first) */
120 /* rule 4+5: seqnum in [seqnum(first),seqnum(last)] */
123 _gssapi_msg_order_check(struct gss_msg_order *o, OM_uint32 seq_num)
129 return GSS_S_COMPLETE;
131 if ((o->flags & (GSS_C_REPLAY_FLAG|GSS_C_SEQUENCE_FLAG)) == 0)
132 return GSS_S_COMPLETE;
134 /* check if the packet is the next in order */
135 if (o->elem[0] == seq_num - 1) {
136 elem_insert(o, 0, seq_num);
137 return GSS_S_COMPLETE;
140 r = (o->flags & (GSS_C_REPLAY_FLAG|GSS_C_SEQUENCE_FLAG))==GSS_C_REPLAY_FLAG;
142 /* sequence number larger then largest sequence number
143 * or smaller then the first sequence number */
144 if (seq_num > o->elem[0]
145 || seq_num < o->first_seq
148 elem_insert(o, 0, seq_num);
150 return GSS_S_COMPLETE;
152 return GSS_S_GAP_TOKEN;
156 assert(o->length > 0);
158 /* sequence number smaller the first sequence number */
159 if (seq_num < o->elem[o->length - 1]) {
161 return(GSS_S_OLD_TOKEN);
163 return(GSS_S_UNSEQ_TOKEN);
166 if (seq_num == o->elem[o->length - 1]) {
167 return GSS_S_DUPLICATE_TOKEN;
170 for (i = 0; i < o->length - 1; i++) {
171 if (o->elem[i] == seq_num)
172 return GSS_S_DUPLICATE_TOKEN;
173 if (o->elem[i + 1] < seq_num && o->elem[i] < seq_num) {
174 elem_insert(o, i, seq_num);
176 return GSS_S_COMPLETE;
178 return GSS_S_UNSEQ_TOKEN;
182 return GSS_S_FAILURE;
186 _gssapi_msg_order_f(OM_uint32 flags)
188 return flags & (GSS_C_SEQUENCE_FLAG|GSS_C_REPLAY_FLAG);