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