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