source3/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 3 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, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "includes.h"
  24
  25 #undef DBGC_CLASS
  26 #define DBGC_CLASS DBGC_AUTH
  27
  28 static bool read_negTokenInit(ASN1_DATA *asn1, negTokenInit_t *token)
  29 {
  30         ZERO_STRUCTP(token);
  31
  32         asn1_start_tag(asn1, ASN1_CONTEXT(0));
  33         asn1_start_tag(asn1, ASN1_SEQUENCE(0));
  34
  35         while (!asn1->has_error && 0 < asn1_tag_remaining(asn1)) {
  36                 int i;
  37
  38                 switch (asn1->data[asn1->ofs]) {
  39                 /* Read mechTypes */
  40                 case ASN1_CONTEXT(0):
  41                         asn1_start_tag(asn1, ASN1_CONTEXT(0));
  42                         asn1_start_tag(asn1, ASN1_SEQUENCE(0));
  43
  44                         token->mechTypes = TALLOC_P(talloc_autofree_context(), const char *);
  45                         for (i = 0; !asn1->has_error &&
  46                                      0 < asn1_tag_remaining(asn1); i++) {
  47                                 const char *p_oid = NULL;
  48                                 token->mechTypes =
  49                                         TALLOC_REALLOC_ARRAY(talloc_autofree_context(),
  50                                                 token->mechTypes, const char *, i + 2);
  51                                 if (!token->mechTypes) {
  52                                         asn1->has_error = True;
  53                                         return False;
  54                                 }
  55                                 asn1_read_OID(asn1, talloc_autofree_context(), &p_oid);
  56                                 token->mechTypes[i] = p_oid;
  57                         }
  58                         token->mechTypes[i] = NULL;
  59
  60                         asn1_end_tag(asn1);
  61                         asn1_end_tag(asn1);
  62                         break;
  63                 /* Read reqFlags */
  64                 case ASN1_CONTEXT(1):
  65                         asn1_start_tag(asn1, ASN1_CONTEXT(1));
  66                         asn1_read_Integer(asn1, &token->reqFlags);
  67                         token->reqFlags |= SPNEGO_REQ_FLAG;
  68                         asn1_end_tag(asn1);
  69                         break;
  70                 /* Read mechToken */
  71                 case ASN1_CONTEXT(2):
  72                         asn1_start_tag(asn1, ASN1_CONTEXT(2));
  73                         asn1_read_OctetString(asn1,
  74                                 talloc_autofree_context(), &token->mechToken);
  75                         asn1_end_tag(asn1);
  76                         break;
  77                 /* Read mecListMIC */
  78                 case ASN1_CONTEXT(3):
  79                         asn1_start_tag(asn1, ASN1_CONTEXT(3));
  80                         if (asn1->data[asn1->ofs] == ASN1_OCTET_STRING) {
  81                                 asn1_read_OctetString(asn1, talloc_autofree_context(),
  82                                                       &token->mechListMIC);
  83                         } else {
  84                                 /* RFC 2478 says we have an Octet String here,
  85                                    but W2k sends something different... */
  86                                 char *mechListMIC;
  87                                 asn1_push_tag(asn1, ASN1_SEQUENCE(0));
  88                                 asn1_push_tag(asn1, ASN1_CONTEXT(0));
  89                                 asn1_read_GeneralString(asn1,
  90                                         talloc_autofree_context(), &mechListMIC);
  91                                 asn1_pop_tag(asn1);
  92                                 asn1_pop_tag(asn1);
  93
  94                                 token->mechListMIC =
  95                                         data_blob(mechListMIC, strlen(mechListMIC));
  96                                 TALLOC_FREE(mechListMIC);
  97                         }
  98                         asn1_end_tag(asn1);
  99                         break;
 100                 default:
 101                         asn1->has_error = True;
 102                         break;
 103                 }
 104         }
 105
 106         asn1_end_tag(asn1);
 107         asn1_end_tag(asn1);
 108
 109         return !asn1->has_error;
 110 }
 111
 112 static bool write_negTokenInit(ASN1_DATA *asn1, negTokenInit_t *token)
 113 {
 114         asn1_push_tag(asn1, ASN1_CONTEXT(0));
 115         asn1_push_tag(asn1, ASN1_SEQUENCE(0));
 116
 117         /* Write mechTypes */
 118         if (token->mechTypes && *token->mechTypes) {
 119                 int i;
 120
 121                 asn1_push_tag(asn1, ASN1_CONTEXT(0));
 122                 asn1_push_tag(asn1, ASN1_SEQUENCE(0));
 123                 for (i = 0; token->mechTypes[i]; i++) {
 124                         asn1_write_OID(asn1, token->mechTypes[i]);
 125                 }
 126                 asn1_pop_tag(asn1);
 127                 asn1_pop_tag(asn1);
 128         }
 129
 130         /* write reqFlags */
 131         if (token->reqFlags & SPNEGO_REQ_FLAG) {
 132                 int flags = token->reqFlags & ~SPNEGO_REQ_FLAG;
 133
 134                 asn1_push_tag(asn1, ASN1_CONTEXT(1));
 135                 asn1_write_Integer(asn1, flags);
 136                 asn1_pop_tag(asn1);
 137         }
 138
 139         /* write mechToken */
 140         if (token->mechToken.data) {
 141                 asn1_push_tag(asn1, ASN1_CONTEXT(2));
 142                 asn1_write_OctetString(asn1, token->mechToken.data,
 143                                        token->mechToken.length);
 144                 asn1_pop_tag(asn1);
 145         }
 146
 147         /* write mechListMIC */
 148         if (token->mechListMIC.data) {
 149                 asn1_push_tag(asn1, ASN1_CONTEXT(3));
 150 #if 0
 151                 /* This is what RFC 2478 says ... */
 152                 asn1_write_OctetString(asn1, token->mechListMIC.data,
 153                                        token->mechListMIC.length);
 154 #else
 155                 /* ... but unfortunately this is what Windows
 156                    sends/expects */
 157                 asn1_push_tag(asn1, ASN1_SEQUENCE(0));
 158                 asn1_push_tag(asn1, ASN1_CONTEXT(0));
 159                 asn1_push_tag(asn1, ASN1_GENERAL_STRING);
 160                 asn1_write(asn1, token->mechListMIC.data,
 161                            token->mechListMIC.length);
 162                 asn1_pop_tag(asn1);
 163                 asn1_pop_tag(asn1);
 164                 asn1_pop_tag(asn1);
 165 #endif
 166                 asn1_pop_tag(asn1);
 167         }
 168
 169         asn1_pop_tag(asn1);
 170         asn1_pop_tag(asn1);
 171
 172         return !asn1->has_error;
 173 }
 174
 175 static bool read_negTokenTarg(ASN1_DATA *asn1, negTokenTarg_t *token)
 176 {
 177         ZERO_STRUCTP(token);
 178
 179         asn1_start_tag(asn1, ASN1_CONTEXT(1));
 180         asn1_start_tag(asn1, ASN1_SEQUENCE(0));
 181
 182         while (!asn1->has_error && 0 < asn1_tag_remaining(asn1)) {
 183                 switch (asn1->data[asn1->ofs]) {
 184                 case ASN1_CONTEXT(0):
 185                         asn1_start_tag(asn1, ASN1_CONTEXT(0));
 186                         asn1_start_tag(asn1, ASN1_ENUMERATED);
 187                         asn1_read_uint8(asn1, &token->negResult);
 188                         asn1_end_tag(asn1);
 189                         asn1_end_tag(asn1);
 190                         break;
 191                 case ASN1_CONTEXT(1): {
 192                         const char *mech = NULL;
 193                         asn1_start_tag(asn1, ASN1_CONTEXT(1));
 194                         asn1_read_OID(asn1, talloc_autofree_context(), &mech);
 195                         asn1_end_tag(asn1);
 196                         token->supportedMech = CONST_DISCARD(char *, mech);
 197                         }
 198                         break;
 199                 case ASN1_CONTEXT(2):
 200                         asn1_start_tag(asn1, ASN1_CONTEXT(2));
 201                         asn1_read_OctetString(asn1,
 202                                 talloc_autofree_context(), &token->responseToken);
 203                         asn1_end_tag(asn1);
 204                         break;
 205                 case ASN1_CONTEXT(3):
 206                         asn1_start_tag(asn1, ASN1_CONTEXT(3));
 207                         asn1_read_OctetString(asn1,
 208                                 talloc_autofree_context(), &token->mechListMIC);
 209                         asn1_end_tag(asn1);
 210                         break;
 211                 default:
 212                         asn1->has_error = True;
 213                         break;
 214                 }
 215         }
 216
 217         asn1_end_tag(asn1);
 218         asn1_end_tag(asn1);
 219
 220         return !asn1->has_error;
 221 }
 222
 223 static bool write_negTokenTarg(ASN1_DATA *asn1, negTokenTarg_t *token)
 224 {
 225         asn1_push_tag(asn1, ASN1_CONTEXT(1));
 226         asn1_push_tag(asn1, ASN1_SEQUENCE(0));
 227
 228         asn1_push_tag(asn1, ASN1_CONTEXT(0));
 229         asn1_write_enumerated(asn1, token->negResult);
 230         asn1_pop_tag(asn1);
 231
 232         if (token->supportedMech) {
 233                 asn1_push_tag(asn1, ASN1_CONTEXT(1));
 234                 asn1_write_OID(asn1, token->supportedMech);
 235                 asn1_pop_tag(asn1);
 236         }
 237
 238         if (token->responseToken.data) {
 239                 asn1_push_tag(asn1, ASN1_CONTEXT(2));
 240                 asn1_write_OctetString(asn1, token->responseToken.data,
 241                                        token->responseToken.length);
 242                 asn1_pop_tag(asn1);
 243         }
 244
 245         if (token->mechListMIC.data) {
 246                 asn1_push_tag(asn1, ASN1_CONTEXT(3));
 247                 asn1_write_OctetString(asn1, token->mechListMIC.data,
 248                                       token->mechListMIC.length);
 249                 asn1_pop_tag(asn1);
 250         }
 251
 252         asn1_pop_tag(asn1);
 253         asn1_pop_tag(asn1);
 254
 255         return !asn1->has_error;
 256 }
 257
 258 ssize_t read_spnego_data(DATA_BLOB data, SPNEGO_DATA *token)
 259 {
 260         ASN1_DATA *asn1;
 261         ssize_t ret = -1;
 262
 263         ZERO_STRUCTP(token);
 264
 265         asn1 = asn1_init(talloc_tos());
 266         if (asn1 == NULL) {
 267                 return -1;
 268         }
 269
 270         asn1_load(asn1, data);
 271
 272         switch (asn1->data[asn1->ofs]) {
 273         case ASN1_APPLICATION(0):
 274                 asn1_start_tag(asn1, ASN1_APPLICATION(0));
 275                 asn1_check_OID(asn1, OID_SPNEGO);
 276                 if (read_negTokenInit(asn1, &token->negTokenInit)) {
 277                         token->type = SPNEGO_NEG_TOKEN_INIT;
 278                 }
 279                 asn1_end_tag(asn1);
 280                 break;
 281         case ASN1_CONTEXT(1):
 282                 if (read_negTokenTarg(asn1, &token->negTokenTarg)) {
 283                         token->type = SPNEGO_NEG_TOKEN_TARG;
 284                 }
 285                 break;
 286         default:
 287                 break;
 288         }
 289
 290         if (!asn1->has_error) ret = asn1->ofs;
 291         asn1_free(asn1);
 292
 293         return ret;
 294 }
 295
 296 ssize_t write_spnego_data(DATA_BLOB *blob, SPNEGO_DATA *spnego)
 297 {
 298         ASN1_DATA *asn1;
 299         ssize_t ret = -1;
 300
 301         asn1 = asn1_init(talloc_tos());
 302         if (asn1 == NULL) {
 303                 return -1;
 304         }
 305
 306         switch (spnego->type) {
 307         case SPNEGO_NEG_TOKEN_INIT:
 308                 asn1_push_tag(asn1, ASN1_APPLICATION(0));
 309                 asn1_write_OID(asn1, OID_SPNEGO);
 310                 write_negTokenInit(asn1, &spnego->negTokenInit);
 311                 asn1_pop_tag(asn1);
 312                 break;
 313         case SPNEGO_NEG_TOKEN_TARG:
 314                 write_negTokenTarg(asn1, &spnego->negTokenTarg);
 315                 break;
 316         default:
 317                 asn1->has_error = True;
 318                 break;
 319         }
 320
 321         if (!asn1->has_error) {
 322                 *blob = data_blob(asn1->data, asn1->length);
 323                 ret = asn1->ofs;
 324         }
 325         asn1_free(asn1);
 326
 327         return ret;
 328 }
 329
 330 bool free_spnego_data(SPNEGO_DATA *spnego)
 331 {
 332         bool ret = True;
 333
 334         if (!spnego) goto out;
 335
 336         switch(spnego->type) {
 337         case SPNEGO_NEG_TOKEN_INIT:
 338                 if (spnego->negTokenInit.mechTypes) {
 339                         int i;
 340                         for (i = 0; spnego->negTokenInit.mechTypes[i]; i++) {
 341                                 talloc_free(CONST_DISCARD(char *,spnego->negTokenInit.mechTypes[i]));
 342                         }
 343                         talloc_free(spnego->negTokenInit.mechTypes);
 344                 }
 345                 data_blob_free(&spnego->negTokenInit.mechToken);
 346                 data_blob_free(&spnego->negTokenInit.mechListMIC);
 347                 break;
 348         case SPNEGO_NEG_TOKEN_TARG:
 349                 if (spnego->negTokenTarg.supportedMech) {
 350                         talloc_free(spnego->negTokenTarg.supportedMech);
 351                 }
 352                 data_blob_free(&spnego->negTokenTarg.responseToken);
 353                 data_blob_free(&spnego->negTokenTarg.mechListMIC);
 354                 break;
 355         default:
 356                 ret = False;
 357                 break;
 358         }
 359         ZERO_STRUCTP(spnego);
 360 out:
 361         return ret;
 362 }