1 /* 2 * Copyright (c) 2003 - 2006 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/gsskrb5_locl.h" 35 36 RCSID("$Id: sequence.c 18334 2006-10-07 22:16:04Z lha $"); 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 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 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 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 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 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 143 _gssapi_msg_order_check(struct gss_msg_order *o, OM_uint32 seq_num) 144 { 145 OM_uint32 r; 146 int 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 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 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 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 ret = krb5_ret_int32(sp, &start); 259 if (kret) 260 goto failed; 261 ret = krb5_ret_int32(sp, &length); 262 if (kret) 263 goto failed; 264 ret = krb5_ret_int32(sp, &jitter_window); 265 if (kret) 266 goto failed; 267 ret = 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