source/libsmb/spnego.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    RFC2478 Compliant SPNEGO implementation
   5
   6    Copyright (C) Jim McDonough <jmcd@us.ibm.com>   2003
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24 #include "includes.h"
  25
  26 #undef DBGC_CLASS
  27 #define DBGC_CLASS DBGC_AUTH
  28
  29 static BOOL read_negTokenInit(ASN1_DATA *asn1, negTokenInit_t *token)
  30 {
  31         ZERO_STRUCTP(token);
  32
  33         asn1_start_tag(asn1, ASN1_CONTEXT(0));
  34         asn1_start_tag(asn1, ASN1_SEQUENCE(0));
  35
  36         while (!asn1->has_error && 0 < asn1_tag_remaining(asn1)) {
  37                 int i;
  38
  39                 switch (asn1->data[asn1->ofs]) {
  40                 /* Read mechTypes */
  41                 case ASN1_CONTEXT(0):
  42                         asn1_start_tag(asn1, ASN1_CONTEXT(0));
  43                         asn1_start_tag(asn1, ASN1_SEQUENCE(0));
  44
  45                         token->mechTypes = malloc(sizeof(*token->mechTypes));
  46                         for (i = 0; !asn1->has_error &&
  47                                      0 < asn1_tag_remaining(asn1); i++) {
  48                                 token->mechTypes =
  49                                         realloc(token->mechTypes, (i + 2) *
  50                                                 sizeof(*token->mechTypes));
  51                                 asn1_read_OID(asn1, token->mechTypes + i);
  52                         }
  53                         token->mechTypes[i] = NULL;
  54
  55                         asn1_end_tag(asn1);
  56                         asn1_end_tag(asn1);
  57                         break;
  58                 /* Read reqFlags */
  59                 case ASN1_CONTEXT(1):
  60                         asn1_start_tag(asn1, ASN1_CONTEXT(1));
  61                         asn1_read_Integer(asn1, &token->reqFlags);
  62                         token->reqFlags |= SPNEGO_REQ_FLAG;
  63                         asn1_end_tag(asn1);
  64                         break;
  65                 /* Read mechToken */
  66                 case ASN1_CONTEXT(2):
  67                         asn1_start_tag(asn1, ASN1_CONTEXT(2));
  68                         asn1_read_OctetString(asn1, &token->mechToken);
  69                         asn1_end_tag(asn1);
  70                         break;
  71                 /* Read mecListMIC */
  72                 case ASN1_CONTEXT(3):
  73                         asn1_start_tag(asn1, ASN1_CONTEXT(3));
  74                         if (asn1->data[asn1->ofs] == ASN1_OCTET_STRING) {
  75                                 asn1_read_OctetString(asn1,
  76                                                       &token->mechListMIC);
  77                         } else {
  78                                 /* RFC 2478 says we have an Octet String here,
  79                                    but W2k sends something different... */
  80                                 char *mechListMIC;
  81                                 asn1_push_tag(asn1, ASN1_SEQUENCE(0));
  82                                 asn1_push_tag(asn1, ASN1_CONTEXT(0));
  83                                 asn1_read_GeneralString(asn1, &mechListMIC);
  84                                 asn1_pop_tag(asn1);
  85                                 asn1_pop_tag(asn1);
  86
  87                                 token->mechListMIC =
  88                                         data_blob(mechListMIC, strlen(mechListMIC));
  89                                 SAFE_FREE(mechListMIC);
  90                         }
  91                         asn1_end_tag(asn1);
  92                         break;
  93                 default:
  94                         asn1->has_error = True;
  95                         break;
  96                 }
  97         }
  98
  99         asn1_end_tag(asn1);
 100         asn1_end_tag(asn1);
 101
 102         return !asn1->has_error;
 103 }
 104
 105 static BOOL write_negTokenInit(ASN1_DATA *asn1, negTokenInit_t *token)
 106 {
 107         asn1_push_tag(asn1, ASN1_CONTEXT(0));
 108         asn1_push_tag(asn1, ASN1_SEQUENCE(0));
 109
 110         /* Write mechTypes */
 111         if (token->mechTypes && *token->mechTypes) {
 112                 int i;
 113
 114                 asn1_push_tag(asn1, ASN1_CONTEXT(0));
 115                 asn1_push_tag(asn1, ASN1_SEQUENCE(0));
 116                 for (i = 0; token->mechTypes[i]; i++) {
 117                         asn1_write_OID(asn1, token->mechTypes[i]);
 118                 }
 119                 asn1_pop_tag(asn1);
 120                 asn1_pop_tag(asn1);
 121         }
 122
 123         /* write reqFlags */
 124         if (token->reqFlags & SPNEGO_REQ_FLAG) {
 125                 int flags = token->reqFlags & ~SPNEGO_REQ_FLAG;
 126
 127                 asn1_push_tag(asn1, ASN1_CONTEXT(1));
 128                 asn1_write_Integer(asn1, flags);
 129                 asn1_pop_tag(asn1);
 130         }
 131
 132         /* write mechToken */
 133         if (token->mechToken.data) {
 134                 asn1_push_tag(asn1, ASN1_CONTEXT(2));
 135                 asn1_write_OctetString(asn1, token->mechToken.data,
 136                                        token->mechToken.length);
 137                 asn1_pop_tag(asn1);
 138         }
 139
 140         /* write mechListMIC */
 141         if (token->mechListMIC.data) {
 142                 asn1_push_tag(asn1, ASN1_CONTEXT(3));
 143 #if 0
 144                 /* This is what RFC 2478 says ... */
 145                 asn1_write_OctetString(asn1, token->mechListMIC.data,
 146                                        token->mechListMIC.length);
 147 #else
 148                 /* ... but unfortunately this is what Windows
 149                    sends/expects */
 150                 asn1_push_tag(asn1, ASN1_SEQUENCE(0));
 151                 asn1_push_tag(asn1, ASN1_CONTEXT(0));
 152                 asn1_push_tag(asn1, ASN1_GENERAL_STRING);
 153                 asn1_write(asn1, token->mechListMIC.data,
 154                            token->mechListMIC.length);
 155                 asn1_pop_tag(asn1);
 156                 asn1_pop_tag(asn1);
 157                 asn1_pop_tag(asn1);
 158 #endif
 159                 asn1_pop_tag(asn1);
 160         }
 161
 162         asn1_pop_tag(asn1);
 163         asn1_pop_tag(asn1);
 164
 165         return !asn1->has_error;
 166 }
 167
 168 static BOOL read_negTokenTarg(ASN1_DATA *asn1, negTokenTarg_t *token)
 169 {
 170         ZERO_STRUCTP(token);
 171
 172         asn1_start_tag(asn1, ASN1_CONTEXT(1));
 173         asn1_start_tag(asn1, ASN1_SEQUENCE(0));
 174
 175         while (!asn1->has_error && 0 < asn1_tag_remaining(asn1)) {
 176                 switch (asn1->data[asn1->ofs]) {
 177                 case ASN1_CONTEXT(0):
 178                         asn1_start_tag(asn1, ASN1_CONTEXT(0));
 179                         asn1_start_tag(asn1, ASN1_ENUMERATED);
 180                         asn1_read_uint8(asn1, &token->negResult);
 181                         asn1_end_tag(asn1);
 182                         asn1_end_tag(asn1);
 183                         break;
 184                 case ASN1_CONTEXT(1):
 185                         asn1_start_tag(asn1, ASN1_CONTEXT(1));
 186                         asn1_read_OID(asn1, &token->supportedMech);
 187                         asn1_end_tag(asn1);
 188                         break;
 189                 case ASN1_CONTEXT(2):
 190                         asn1_start_tag(asn1, ASN1_CONTEXT(2));
 191                         asn1_read_OctetString(asn1, &token->responseToken);
 192                         asn1_end_tag(asn1);
 193                         break;
 194                 case ASN1_CONTEXT(3):
 195                         asn1_start_tag(asn1, ASN1_CONTEXT(3));
 196                         asn1_read_OctetString(asn1, &token->mechListMIC);
 197                         asn1_end_tag(asn1);
 198                         break;
 199                 default:
 200                         asn1->has_error = True;
 201                         break;
 202                 }
 203         }
 204
 205         asn1_end_tag(asn1);
 206         asn1_end_tag(asn1);
 207
 208         return !asn1->has_error;
 209 }
 210
 211 static BOOL write_negTokenTarg(ASN1_DATA *asn1, negTokenTarg_t *token)
 212 {
 213         asn1_push_tag(asn1, ASN1_CONTEXT(1));
 214         asn1_push_tag(asn1, ASN1_SEQUENCE(0));
 215
 216         asn1_push_tag(asn1, ASN1_CONTEXT(0));
 217         asn1_write_enumerated(asn1, token->negResult);
 218         asn1_pop_tag(asn1);
 219
 220         if (token->supportedMech) {
 221                 asn1_push_tag(asn1, ASN1_CONTEXT(1));
 222                 asn1_write_OID(asn1, token->supportedMech);
 223                 asn1_pop_tag(asn1);
 224         }
 225
 226         if (token->responseToken.data) {
 227                 asn1_push_tag(asn1, ASN1_CONTEXT(2));
 228                 asn1_write_OctetString(asn1, token->responseToken.data,
 229                                        token->responseToken.length);
 230                 asn1_pop_tag(asn1);
 231         }
 232
 233         if (token->mechListMIC.data) {
 234                 asn1_push_tag(asn1, ASN1_CONTEXT(3));
 235                 asn1_write_OctetString(asn1, token->mechListMIC.data,
 236                                       token->mechListMIC.length);
 237                 asn1_pop_tag(asn1);
 238         }
 239
 240         asn1_pop_tag(asn1);
 241         asn1_pop_tag(asn1);
 242
 243         return !asn1->has_error;
 244 }
 245
 246 ssize_t read_spnego_data(DATA_BLOB data, SPNEGO_DATA *token)
 247 {
 248         ASN1_DATA asn1;
 249         ssize_t ret = -1;
 250
 251         ZERO_STRUCTP(token);
 252         ZERO_STRUCT(asn1);
 253         asn1_load(&asn1, data);
 254
 255         switch (asn1.data[asn1.ofs]) {
 256         case ASN1_APPLICATION(0):
 257                 asn1_start_tag(&asn1, ASN1_APPLICATION(0));
 258                 asn1_check_OID(&asn1, OID_SPNEGO);
 259                 if (read_negTokenInit(&asn1, &token->negTokenInit)) {
 260                         token->type = SPNEGO_NEG_TOKEN_INIT;
 261                 }
 262                 asn1_end_tag(&asn1);
 263                 break;
 264         case ASN1_CONTEXT(1):
 265                 if (read_negTokenTarg(&asn1, &token->negTokenTarg)) {
 266                         token->type = SPNEGO_NEG_TOKEN_TARG;
 267                 }
 268                 break;
 269         default:
 270                 break;
 271         }
 272
 273         if (!asn1.has_error) ret = asn1.ofs;
 274         asn1_free(&asn1);
 275
 276         return ret;
 277 }
 278
 279 ssize_t write_spnego_data(DATA_BLOB *blob, SPNEGO_DATA *spnego)
 280 {
 281         ASN1_DATA asn1;
 282         ssize_t ret = -1;
 283
 284         ZERO_STRUCT(asn1);
 285
 286         switch (spnego->type) {
 287         case SPNEGO_NEG_TOKEN_INIT:
 288                 asn1_push_tag(&asn1, ASN1_APPLICATION(0));
 289                 asn1_write_OID(&asn1, OID_SPNEGO);
 290                 write_negTokenInit(&asn1, &spnego->negTokenInit);
 291                 asn1_pop_tag(&asn1);
 292                 break;
 293         case SPNEGO_NEG_TOKEN_TARG:
 294                 write_negTokenTarg(&asn1, &spnego->negTokenTarg);
 295                 break;
 296         default:
 297                 asn1.has_error = True;
 298                 break;
 299         }
 300
 301         if (!asn1.has_error) {
 302                 *blob = data_blob(asn1.data, asn1.length);
 303                 ret = asn1.ofs;
 304         }
 305         asn1_free(&asn1);
 306
 307         return ret;
 308 }
 309
 310 BOOL free_spnego_data(SPNEGO_DATA *spnego)
 311 {
 312         BOOL ret = True;
 313
 314         if (!spnego) goto out;
 315
 316         switch(spnego->type) {
 317         case SPNEGO_NEG_TOKEN_INIT:
 318                 if (spnego->negTokenInit.mechTypes) {
 319                         int i;
 320                         for (i = 0; spnego->negTokenInit.mechTypes[i]; i++) {
 321                                 free(spnego->negTokenInit.mechTypes[i]);
 322                         }
 323                         free(spnego->negTokenInit.mechTypes);
 324                 }
 325                 data_blob_free(&spnego->negTokenInit.mechToken);
 326                 data_blob_free(&spnego->negTokenInit.mechListMIC);
 327                 break;
 328         case SPNEGO_NEG_TOKEN_TARG:
 329                 if (spnego->negTokenTarg.supportedMech) {
 330                         free(spnego->negTokenTarg.supportedMech);
 331                 }
 332                 data_blob_free(&spnego->negTokenTarg.responseToken);
 333                 data_blob_free(&spnego->negTokenTarg.mechListMIC);
 334                 break;
 335         default:
 336                 ret = False;
 337                 break;
 338         }
 339         ZERO_STRUCTP(spnego);
 340 out:
 341         return ret;
 342 }
 343