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