source/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 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    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 #include "includes.h"
  24 #include "auth/auth.h"
  25 #include "auth/credentials/credentials.h"
  26 #include "auth/gensec/gensec.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(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 0;
 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 *local_socket_addr = gensec_get_my_addr(gensec_security);
 122         struct socket_address *remote_socket_addr = gensec_get_peer_addr(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 (local_socket_addr) {
 158                 local_addr = talloc_asprintf(gensec_sasl_state,
 159                                              "%s;%d",
 160                                              local_socket_addr->addr,
 161                                              local_socket_addr->port);
 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                                             in.data, in.length, NULL, &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                                    in->data, in->length, &out_data, &out_len);
 243         if (sasl_ret == SASL_OK) {
 244                 *out = data_blob_talloc(out_mem_ctx, out_data, out_len);
 245                 *len_processed = in->length;
 246         } else {
 247                 DEBUG(1, ("GENSEC SASL: unwrap failed: %s\n", sasl_errdetail(gensec_sasl_state->conn)));
 248         }
 249         return sasl_nt_status(sasl_ret);
 250
 251 }
 252 static NTSTATUS gensec_sasl_wrap_packets(struct gensec_security *gensec_security,
 253                                         TALLOC_CTX *out_mem_ctx,
 254                                         const DATA_BLOB *in,
 255                                         DATA_BLOB *out,
 256                                         size_t *len_processed)
 257 {
 258         struct gensec_sasl_state *gensec_sasl_state = talloc_get_type(gensec_security->private_data,
 259                                                                       struct gensec_sasl_state);
 260         const char *out_data;
 261         unsigned int out_len;
 262
 263         int sasl_ret = sasl_encode(gensec_sasl_state->conn,
 264                                    in->data, in->length, &out_data, &out_len);
 265         if (sasl_ret == SASL_OK) {
 266                 *out = data_blob_talloc(out_mem_ctx, out_data, out_len);
 267                 *len_processed = in->length;
 268         } else {
 269                 DEBUG(1, ("GENSEC SASL: wrap failed: %s\n", sasl_errdetail(gensec_sasl_state->conn)));
 270         }
 271         return sasl_nt_status(sasl_ret);
 272 }
 273
 274 /* Try to figure out what features we actually got on the connection */
 275 static BOOL gensec_sasl_have_feature(struct gensec_security *gensec_security,
 276                                      uint32_t feature)
 277 {
 278         struct gensec_sasl_state *gensec_sasl_state = talloc_get_type(gensec_security->private_data,
 279                                                                       struct gensec_sasl_state);
 280         sasl_ssf_t ssf;
 281         int sasl_ret = sasl_getprop(gensec_sasl_state->conn, SASL_SSF, &ssf);
 282         if (sasl_ret != SASL_OK) {
 283                 return False;
 284         }
 285         if (feature & GENSEC_FEATURE_SIGN) {
 286                 if (ssf == 0) {
 287                         return False;
 288                 }
 289                 if (ssf >= 1) {
 290                         return True;
 291                 }
 292         }
 293         if (feature & GENSEC_FEATURE_SEAL) {
 294                 if (ssf <= 1) {
 295                         return False;
 296                 }
 297                 if (ssf > 1) {
 298                         return True;
 299                 }
 300         }
 301         return False;
 302 }
 303
 304 /* This could in theory work with any SASL mech */
 305 static const struct gensec_security_ops gensec_sasl_security_ops = {
 306         .name             = "sasl-DIGEST-MD5",
 307         .sasl_name        = "DIGEST-MD5",
 308         .client_start     = gensec_sasl_client_start,
 309         .update           = gensec_sasl_update,
 310         .wrap_packets     = gensec_sasl_wrap_packets,
 311         .unwrap_packets   = gensec_sasl_unwrap_packets,
 312         .have_feature     = gensec_sasl_have_feature,
 313         .enabled          = True,
 314         .priority         = GENSEC_SASL
 315 };
 316
 317 int gensec_sasl_log(void *context,
 318                     int sasl_log_level,
 319                     const char *message)
 320 {
 321         int debug_level;
 322         switch (sasl_log_level) {
 323         case SASL_LOG_NONE:
 324                 debug_level = 0;
 325                 break;
 326         case SASL_LOG_ERR:
 327                 debug_level = 1;
 328                 break;
 329         case SASL_LOG_FAIL:
 330                 debug_level = 2;
 331                 break;
 332         case SASL_LOG_WARN:
 333                 debug_level = 3;
 334                 break;
 335         case SASL_LOG_NOTE:
 336                 debug_level = 5;
 337                 break;
 338         case SASL_LOG_DEBUG:
 339                 debug_level = 10;
 340                 break;
 341         case SASL_LOG_TRACE:
 342                 debug_level = 11;
 343                 break;
 344 #if DEBUG_PASSWORD
 345         case SASL_LOG_PASS:
 346                 debug_level = 100;
 347                 break;
 348 #endif
 349         default:
 350                 debug_level = 0;
 351                 break;
 352         }
 353         DEBUG(debug_level, ("gensec_sasl: %s\n", message));
 354
 355         return SASL_OK;
 356 }
 357
 358 NTSTATUS gensec_sasl_init(void)
 359 {
 360         NTSTATUS ret;
 361         int sasl_ret, i;
 362         const char **sasl_mechs;
 363
 364         static const sasl_callback_t callbacks[] = {
 365                 {
 366                         .id = SASL_CB_LOG,
 367                         .proc = gensec_sasl_log,
 368                         .context = NULL,
 369                 },
 370                 {
 371                         .id = SASL_CB_LIST_END,
 372                         .proc = gensec_sasl_log,
 373                         .context = NULL,
 374                 }
 375         };
 376         sasl_ret = sasl_client_init(callbacks);
 377
 378         if (sasl_ret == SASL_NOMECH) {
 379                 /* Nothing to do here */
 380                 return NT_STATUS_OK;
 381         }
 382
 383         if (sasl_ret != SASL_OK) {
 384                 return sasl_nt_status(sasl_ret);
 385         }
 386
 387         /* For now, we just register DIGEST-MD5 */
 388 #if 1
 389         ret = gensec_register(&gensec_sasl_security_ops);
 390         if (!NT_STATUS_IS_OK(ret)) {
 391                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 392                          gensec_sasl_security_ops.name));
 393                 return ret;
 394         }
 395 #else
 396         sasl_mechs = sasl_global_listmech();
 397         for (i = 0; sasl_mechs && sasl_mechs[i]; i++) {
 398                 const struct gensec_security_ops *oldmech;
 399                 struct gensec_security_ops *newmech;
 400                 oldmech = gensec_security_by_sasl_name(NULL, sasl_mechs[i]);
 401                 if (oldmech) {
 402                         continue;
 403                 }
 404                 newmech = talloc(talloc_autofree_context(), struct gensec_security_ops);
 405                 if (!newmech) {
 406                         return NT_STATUS_NO_MEMORY;
 407                 }
 408                 *newmech = gensec_sasl_security_ops;
 409                 newmech->sasl_name = talloc_strdup(newmech, sasl_mechs[i]);
 410                 newmech->name = talloc_asprintf(newmech, "sasl-%s", sasl_mechs[i]);
 411                 if (!newmech->sasl_name || !newmech->name) {
 412                         return NT_STATUS_NO_MEMORY;
 413                 }
 414
 415                 ret = gensec_register(newmech);
 416                 if (!NT_STATUS_IS_OK(ret)) {
 417                         DEBUG(0,("Failed to register '%s' gensec backend!\n",
 418                                  gensec_sasl_security_ops.name));
 419                         return ret;
 420                 }
 421         }
 422 #endif
 423         return NT_STATUS_OK;
 424 }