source4/auth/gensec/cyrus_sasl.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Connect GENSEC to an external SASL lib
   5
   6    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2006
   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    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "lib/tsocket/tsocket.h"
  24 #include "auth/credentials/credentials.h"
  25 #include "auth/gensec/gensec.h"
  26 #include "auth/gensec/gensec_proto.h"
  27 #include "auth/gensec/gensec_toplevel_proto.h"
  28 #include <sasl/sasl.h>
  29
  30 NTSTATUS gensec_sasl_init(void);
  31
  32 struct gensec_sasl_state {
  33         sasl_conn_t *conn;
  34         int step;
  35         bool wrap;
  36 };
  37
  38 static NTSTATUS sasl_nt_status(int sasl_ret)
  39 {
  40         switch (sasl_ret) {
  41         case SASL_CONTINUE:
  42                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
  43         case SASL_NOMEM:
  44                 return NT_STATUS_NO_MEMORY;
  45         case SASL_BADPARAM:
  46         case SASL_NOMECH:
  47                 return NT_STATUS_INVALID_PARAMETER;
  48         case SASL_BADMAC:
  49                 return NT_STATUS_ACCESS_DENIED;
  50         case SASL_OK:
  51                 return NT_STATUS_OK;
  52         default:
  53                 return NT_STATUS_UNSUCCESSFUL;
  54         }
  55 }
  56
  57 static int gensec_sasl_get_user(void *context, int id,
  58                                 const char **result, unsigned *len)
  59 {
  60         struct gensec_security *gensec_security = talloc_get_type(context, struct gensec_security);
  61         const char *username = cli_credentials_get_username(gensec_get_credentials(gensec_security));
  62         if (id != SASL_CB_USER && id != SASL_CB_AUTHNAME) {
  63                 return SASL_FAIL;
  64         }
  65
  66         *result = username;
  67         return SASL_OK;
  68 }
  69
  70 static int gensec_sasl_get_realm(void *context, int id,
  71                                  const char **availrealms,
  72                                  const char **result)
  73 {
  74         struct gensec_security *gensec_security = talloc_get_type(context, struct gensec_security);
  75         const char *realm = cli_credentials_get_realm(gensec_get_credentials(gensec_security));
  76         int i;
  77         if (id != SASL_CB_GETREALM) {
  78                 return SASL_FAIL;
  79         }
  80
  81         for (i=0; availrealms && availrealms[i]; i++) {
  82                 if (strcasecmp_m(realm, availrealms[i]) == 0) {
  83                         result[i] = availrealms[i];
  84                         return SASL_OK;
  85                 }
  86         }
  87         /* None of the realms match, so lets not specify one */
  88         *result = "";
  89         return SASL_OK;
  90 }
  91
  92 static int gensec_sasl_get_password(sasl_conn_t *conn, void *context, int id,
  93                              sasl_secret_t **psecret)
  94 {
  95         struct gensec_security *gensec_security = talloc_get_type(context, struct gensec_security);
  96         const char *password = cli_credentials_get_password(gensec_get_credentials(gensec_security));
  97
  98         sasl_secret_t *secret;
  99         if (!password) {
 100                 *psecret = NULL;
 101                 return SASL_OK;
 102         }
 103         secret = talloc_size(gensec_security, sizeof(sasl_secret_t)+strlen(password)+1);
 104         if (!secret) {
 105                 return SASL_NOMEM;
 106         }
 107         secret->len = strlen(password);
 108         strlcpy((char*)secret->data, password, secret->len+1);
 109         *psecret = secret;
 110         return SASL_OK;
 111 }
 112
 113 static int gensec_sasl_dispose(struct gensec_sasl_state *gensec_sasl_state)
 114 {
 115         sasl_dispose(&gensec_sasl_state->conn);
 116         return SASL_OK;
 117 }
 118
 119 static NTSTATUS gensec_sasl_client_start(struct gensec_security *gensec_security)
 120 {
 121         struct gensec_sasl_state *gensec_sasl_state;
 122         const char *service = gensec_get_target_service(gensec_security);
 123         const char *target_name = gensec_get_target_hostname(gensec_security);
 124         const struct tsocket_address *tlocal_addr = gensec_get_local_address(gensec_security);
 125         const struct tsocket_address *tremote_addr = gensec_get_remote_address(gensec_security);
 126         char *local_addr = NULL;
 127         char *remote_addr = NULL;
 128         int sasl_ret;
 129
 130         sasl_callback_t *callbacks;
 131
 132         gensec_sasl_state = talloc_zero(gensec_security, struct gensec_sasl_state);
 133         if (!gensec_sasl_state) {
 134                 return NT_STATUS_NO_MEMORY;
 135         }
 136
 137         callbacks = talloc_array(gensec_sasl_state, sasl_callback_t, 5);
 138         callbacks[0].id = SASL_CB_USER;
 139         callbacks[0].proc = gensec_sasl_get_user;
 140         callbacks[0].context = gensec_security;
 141
 142         callbacks[1].id =  SASL_CB_AUTHNAME;
 143         callbacks[1].proc = gensec_sasl_get_user;
 144         callbacks[1].context = gensec_security;
 145
 146         callbacks[2].id = SASL_CB_GETREALM;
 147         callbacks[2].proc = gensec_sasl_get_realm;
 148         callbacks[2].context = gensec_security;
 149
 150         callbacks[3].id = SASL_CB_PASS;
 151         callbacks[3].proc = gensec_sasl_get_password;
 152         callbacks[3].context = gensec_security;
 153
 154         callbacks[4].id = SASL_CB_LIST_END;
 155         callbacks[4].proc = NULL;
 156         callbacks[4].context = NULL;
 157
 158         gensec_security->private_data = gensec_sasl_state;
 159
 160         if (tlocal_addr) {
 161                 local_addr = talloc_asprintf(gensec_sasl_state,
 162                                 "%s;%d",
 163                                 tsocket_address_inet_addr_string(tlocal_addr, gensec_sasl_state),
 164                                 tsocket_address_inet_port(tlocal_addr));
 165         }
 166
 167         if (tremote_addr) {
 168                 remote_addr = talloc_asprintf(gensec_sasl_state,
 169                                 "%s;%d",
 170                                 tsocket_address_inet_addr_string(tremote_addr, gensec_sasl_state),
 171                                 tsocket_address_inet_port(tremote_addr));
 172         }
 173         gensec_sasl_state->step = 0;
 174
 175         sasl_ret = sasl_client_new(service,
 176                                    target_name,
 177                                    local_addr, remote_addr, callbacks, 0,
 178                                    &gensec_sasl_state->conn);
 179
 180         if (sasl_ret == SASL_OK) {
 181                 sasl_security_properties_t props;
 182                 talloc_set_destructor(gensec_sasl_state, gensec_sasl_dispose);
 183
 184                 ZERO_STRUCT(props);
 185                 if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 186                         props.min_ssf = 1;
 187                         props.max_ssf = 1;
 188                         props.maxbufsize = 65536;
 189                         gensec_sasl_state->wrap = true;
 190                 }
 191                 if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 192                         props.min_ssf = 40;
 193                         props.max_ssf = UINT_MAX;
 194                         props.maxbufsize = 65536;
 195                         gensec_sasl_state->wrap = true;
 196                 }
 197
 198                 sasl_ret = sasl_setprop(gensec_sasl_state->conn, SASL_SEC_PROPS, &props);
 199         }
 200         if (sasl_ret != SASL_OK) {
 201                 DEBUG(1, ("GENSEC SASL: client_new failed: %s\n", sasl_errdetail(gensec_sasl_state->conn)));
 202         }
 203         return sasl_nt_status(sasl_ret);
 204 }
 205
 206 static NTSTATUS gensec_sasl_update(struct gensec_security *gensec_security,
 207                                    TALLOC_CTX *out_mem_ctx,
 208                                    struct tevent_context *ev,
 209                                    const DATA_BLOB in, DATA_BLOB *out)
 210 {
 211         struct gensec_sasl_state *gensec_sasl_state = talloc_get_type(gensec_security->private_data,
 212                                                                       struct gensec_sasl_state);
 213         int sasl_ret;
 214         const char *out_data;
 215         unsigned int out_len;
 216
 217         if (gensec_sasl_state->step == 0) {
 218                 const char *mech;
 219                 sasl_ret = sasl_client_start(gensec_sasl_state->conn, gensec_security->ops->sasl_name,
 220                                              NULL, &out_data, &out_len, &mech);
 221         } else {
 222                 sasl_ret = sasl_client_step(gensec_sasl_state->conn,
 223                                             (char*)in.data, in.length, NULL,
 224                                             &out_data, &out_len);
 225         }
 226         if (sasl_ret == SASL_OK || sasl_ret == SASL_CONTINUE) {
 227                 *out = data_blob_talloc(out_mem_ctx, out_data, out_len);
 228         } else {
 229                 DEBUG(1, ("GENSEC SASL: step %d update failed: %s\n", gensec_sasl_state->step,
 230                           sasl_errdetail(gensec_sasl_state->conn)));
 231         }
 232         gensec_sasl_state->step++;
 233         return sasl_nt_status(sasl_ret);
 234 }
 235
 236 static NTSTATUS gensec_sasl_unwrap_packets(struct gensec_security *gensec_security,
 237                                         TALLOC_CTX *out_mem_ctx,
 238                                         const DATA_BLOB *in,
 239                                         DATA_BLOB *out,
 240                                         size_t *len_processed)
 241 {
 242         struct gensec_sasl_state *gensec_sasl_state = talloc_get_type(gensec_security->private_data,
 243                                                                       struct gensec_sasl_state);
 244         const char *out_data;
 245         unsigned int out_len;
 246
 247         int sasl_ret = sasl_decode(gensec_sasl_state->conn,
 248                                    (char*)in->data, in->length, &out_data,
 249                                    &out_len);
 250         if (sasl_ret == SASL_OK) {
 251                 *out = data_blob_talloc(out_mem_ctx, out_data, out_len);
 252                 *len_processed = in->length;
 253         } else {
 254                 DEBUG(1, ("GENSEC SASL: unwrap failed: %s\n", sasl_errdetail(gensec_sasl_state->conn)));
 255         }
 256         return sasl_nt_status(sasl_ret);
 257
 258 }
 259
 260 static NTSTATUS gensec_sasl_wrap_packets(struct gensec_security *gensec_security,
 261                                         TALLOC_CTX *out_mem_ctx,
 262                                         const DATA_BLOB *in,
 263                                         DATA_BLOB *out,
 264                                         size_t *len_processed)
 265 {
 266         struct gensec_sasl_state *gensec_sasl_state = talloc_get_type(gensec_security->private_data,
 267                                                                       struct gensec_sasl_state);
 268         const char *out_data;
 269         unsigned int out_len;
 270         unsigned len_permitted;
 271         int sasl_ret = sasl_getprop(gensec_sasl_state->conn, SASL_SSF,
 272                         (const void**)&len_permitted);
 273         if (sasl_ret != SASL_OK) {
 274                 return sasl_nt_status(sasl_ret);
 275         }
 276         len_permitted = MIN(len_permitted, in->length);
 277
 278         sasl_ret = sasl_encode(gensec_sasl_state->conn,
 279                                (char*)in->data, len_permitted, &out_data,
 280                                &out_len);
 281         if (sasl_ret == SASL_OK) {
 282                 *out = data_blob_talloc(out_mem_ctx, out_data, out_len);
 283                 *len_processed = in->length;
 284         } else {
 285                 DEBUG(1, ("GENSEC SASL: wrap failed: %s\n", sasl_errdetail(gensec_sasl_state->conn)));
 286         }
 287         return sasl_nt_status(sasl_ret);
 288 }
 289
 290 /* Try to figure out what features we actually got on the connection */
 291 static bool gensec_sasl_have_feature(struct gensec_security *gensec_security,
 292                                      uint32_t feature)
 293 {
 294         struct gensec_sasl_state *gensec_sasl_state = talloc_get_type(gensec_security->private_data,
 295                                                                       struct gensec_sasl_state);
 296         sasl_ssf_t ssf;
 297         int sasl_ret;
 298
 299         /* If we did not elect to wrap, then we have neither sign nor seal, no matter what the SSF claims */
 300         if (!gensec_sasl_state->wrap) {
 301                 return false;
 302         }
 303
 304         sasl_ret = sasl_getprop(gensec_sasl_state->conn, SASL_SSF,
 305                         (const void**)&ssf);
 306         if (sasl_ret != SASL_OK) {
 307                 return false;
 308         }
 309         if (feature & GENSEC_FEATURE_SIGN) {
 310                 if (ssf == 0) {
 311                         return false;
 312                 }
 313                 if (ssf >= 1) {
 314                         return true;
 315                 }
 316         }
 317         if (feature & GENSEC_FEATURE_SEAL) {
 318                 if (ssf <= 1) {
 319                         return false;
 320                 }
 321                 if (ssf > 1) {
 322                         return true;
 323                 }
 324         }
 325         return false;
 326 }
 327
 328 /* This could in theory work with any SASL mech */
 329 static const struct gensec_security_ops gensec_sasl_security_ops = {
 330         .name             = "sasl-DIGEST-MD5",
 331         .sasl_name        = "DIGEST-MD5",
 332         .client_start     = gensec_sasl_client_start,
 333         .update           = gensec_sasl_update,
 334         .wrap_packets     = gensec_sasl_wrap_packets,
 335         .unwrap_packets   = gensec_sasl_unwrap_packets,
 336         .have_feature     = gensec_sasl_have_feature,
 337         .enabled          = true,
 338         .priority         = GENSEC_SASL
 339 };
 340
 341 static int gensec_sasl_log(void *context,
 342                     int sasl_log_level,
 343                     const char *message)
 344 {
 345         int dl;
 346         switch (sasl_log_level) {
 347         case SASL_LOG_NONE:
 348                 dl = 0;
 349                 break;
 350         case SASL_LOG_ERR:
 351                 dl = 1;
 352                 break;
 353         case SASL_LOG_FAIL:
 354                 dl = 2;
 355                 break;
 356         case SASL_LOG_WARN:
 357                 dl = 3;
 358                 break;
 359         case SASL_LOG_NOTE:
 360                 dl = 5;
 361                 break;
 362         case SASL_LOG_DEBUG:
 363                 dl = 10;
 364                 break;
 365         case SASL_LOG_TRACE:
 366                 dl = 11;
 367                 break;
 368 #if DEBUG_PASSWORD
 369         case SASL_LOG_PASS:
 370                 dl = 100;
 371                 break;
 372 #endif
 373         default:
 374                 dl = 0;
 375                 break;
 376         }
 377         DEBUG(dl, ("gensec_sasl: %s\n", message));
 378
 379         return SASL_OK;
 380 }
 381
 382 NTSTATUS gensec_sasl_init(void)
 383 {
 384         NTSTATUS ret;
 385         int sasl_ret;
 386 #if 0
 387         int i;
 388         const char **sasl_mechs;
 389 #endif
 390
 391         static const sasl_callback_t callbacks[] = {
 392                 {
 393                         .id = SASL_CB_LOG,
 394                         .proc = gensec_sasl_log,
 395                         .context = NULL,
 396                 },
 397                 {
 398                         .id = SASL_CB_LIST_END,
 399                         .proc = gensec_sasl_log,
 400                         .context = NULL,
 401                 }
 402         };
 403         sasl_ret = sasl_client_init(callbacks);
 404
 405         if (sasl_ret == SASL_NOMECH) {
 406                 /* Nothing to do here */
 407                 return NT_STATUS_OK;
 408         }
 409
 410         if (sasl_ret != SASL_OK) {
 411                 return sasl_nt_status(sasl_ret);
 412         }
 413
 414         /* For now, we just register DIGEST-MD5 */
 415 #if 1
 416         ret = gensec_register(&gensec_sasl_security_ops);
 417         if (!NT_STATUS_IS_OK(ret)) {
 418                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 419                          gensec_sasl_security_ops.name));
 420                 return ret;
 421         }
 422 #else
 423         sasl_mechs = sasl_global_listmech();
 424         for (i = 0; sasl_mechs && sasl_mechs[i]; i++) {
 425                 const struct gensec_security_ops *oldmech;
 426                 struct gensec_security_ops *newmech;
 427                 oldmech = gensec_security_by_sasl_name(NULL, sasl_mechs[i]);
 428                 if (oldmech) {
 429                         continue;
 430                 }
 431                 newmech = talloc(talloc_autofree_context(), struct gensec_security_ops);
 432                 if (!newmech) {
 433                         return NT_STATUS_NO_MEMORY;
 434                 }
 435                 *newmech = gensec_sasl_security_ops;
 436                 newmech->sasl_name = talloc_strdup(newmech, sasl_mechs[i]);
 437                 newmech->name = talloc_asprintf(newmech, "sasl-%s", sasl_mechs[i]);
 438                 if (!newmech->sasl_name || !newmech->name) {
 439                         return NT_STATUS_NO_MEMORY;
 440                 }
 441
 442                 ret = gensec_register(newmech);
 443                 if (!NT_STATUS_IS_OK(ret)) {
 444                         DEBUG(0,("Failed to register '%s' gensec backend!\n",
 445                                  gensec_sasl_security_ops.name));
 446                         return ret;
 447                 }
 448         }
 449 #endif
 450         return NT_STATUS_OK;
 451 }