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                                    const DATA_BLOB in, DATA_BLOB *out)
 209 {
 210         struct gensec_sasl_state *gensec_sasl_state = talloc_get_type(gensec_security->private_data,
 211                                                                       struct gensec_sasl_state);
 212         int sasl_ret;
 213         const char *out_data;
 214         unsigned int out_len;
 215
 216         if (gensec_sasl_state->step == 0) {
 217                 const char *mech;
 218                 sasl_ret = sasl_client_start(gensec_sasl_state->conn, gensec_security->ops->sasl_name,
 219                                              NULL, &out_data, &out_len, &mech);
 220         } else {
 221                 sasl_ret = sasl_client_step(gensec_sasl_state->conn,
 222                                             (char*)in.data, in.length, NULL,
 223                                             &out_data, &out_len);
 224         }
 225         if (sasl_ret == SASL_OK || sasl_ret == SASL_CONTINUE) {
 226                 *out = data_blob_talloc(out_mem_ctx, out_data, out_len);
 227         } else {
 228                 DEBUG(1, ("GENSEC SASL: step %d update failed: %s\n", gensec_sasl_state->step,
 229                           sasl_errdetail(gensec_sasl_state->conn)));
 230         }
 231         gensec_sasl_state->step++;
 232         return sasl_nt_status(sasl_ret);
 233 }
 234
 235 static NTSTATUS gensec_sasl_unwrap_packets(struct gensec_security *gensec_security,
 236                                         TALLOC_CTX *out_mem_ctx,
 237                                         const DATA_BLOB *in,
 238                                         DATA_BLOB *out,
 239                                         size_t *len_processed)
 240 {
 241         struct gensec_sasl_state *gensec_sasl_state = talloc_get_type(gensec_security->private_data,
 242                                                                       struct gensec_sasl_state);
 243         const char *out_data;
 244         unsigned int out_len;
 245
 246         int sasl_ret = sasl_decode(gensec_sasl_state->conn,
 247                                    (char*)in->data, in->length, &out_data,
 248                                    &out_len);
 249         if (sasl_ret == SASL_OK) {
 250                 *out = data_blob_talloc(out_mem_ctx, out_data, out_len);
 251                 *len_processed = in->length;
 252         } else {
 253                 DEBUG(1, ("GENSEC SASL: unwrap failed: %s\n", sasl_errdetail(gensec_sasl_state->conn)));
 254         }
 255         return sasl_nt_status(sasl_ret);
 256
 257 }
 258
 259 static NTSTATUS gensec_sasl_wrap_packets(struct gensec_security *gensec_security,
 260                                         TALLOC_CTX *out_mem_ctx,
 261                                         const DATA_BLOB *in,
 262                                         DATA_BLOB *out,
 263                                         size_t *len_processed)
 264 {
 265         struct gensec_sasl_state *gensec_sasl_state = talloc_get_type(gensec_security->private_data,
 266                                                                       struct gensec_sasl_state);
 267         const char *out_data;
 268         unsigned int out_len;
 269         unsigned len_permitted;
 270         int sasl_ret = sasl_getprop(gensec_sasl_state->conn, SASL_SSF,
 271                         (const void**)&len_permitted);
 272         if (sasl_ret != SASL_OK) {
 273                 return sasl_nt_status(sasl_ret);
 274         }
 275         len_permitted = MIN(len_permitted, in->length);
 276
 277         sasl_ret = sasl_encode(gensec_sasl_state->conn,
 278                                (char*)in->data, len_permitted, &out_data,
 279                                &out_len);
 280         if (sasl_ret == SASL_OK) {
 281                 *out = data_blob_talloc(out_mem_ctx, out_data, out_len);
 282                 *len_processed = in->length;
 283         } else {
 284                 DEBUG(1, ("GENSEC SASL: wrap failed: %s\n", sasl_errdetail(gensec_sasl_state->conn)));
 285         }
 286         return sasl_nt_status(sasl_ret);
 287 }
 288
 289 /* Try to figure out what features we actually got on the connection */
 290 static bool gensec_sasl_have_feature(struct gensec_security *gensec_security,
 291                                      uint32_t feature)
 292 {
 293         struct gensec_sasl_state *gensec_sasl_state = talloc_get_type(gensec_security->private_data,
 294                                                                       struct gensec_sasl_state);
 295         sasl_ssf_t ssf;
 296         int sasl_ret;
 297
 298         /* If we did not elect to wrap, then we have neither sign nor seal, no matter what the SSF claims */
 299         if (!gensec_sasl_state->wrap) {
 300                 return false;
 301         }
 302
 303         sasl_ret = sasl_getprop(gensec_sasl_state->conn, SASL_SSF,
 304                         (const void**)&ssf);
 305         if (sasl_ret != SASL_OK) {
 306                 return false;
 307         }
 308         if (feature & GENSEC_FEATURE_SIGN) {
 309                 if (ssf == 0) {
 310                         return false;
 311                 }
 312                 if (ssf >= 1) {
 313                         return true;
 314                 }
 315         }
 316         if (feature & GENSEC_FEATURE_SEAL) {
 317                 if (ssf <= 1) {
 318                         return false;
 319                 }
 320                 if (ssf > 1) {
 321                         return true;
 322                 }
 323         }
 324         return false;
 325 }
 326
 327 /* This could in theory work with any SASL mech */
 328 static const struct gensec_security_ops gensec_sasl_security_ops = {
 329         .name             = "sasl-DIGEST-MD5",
 330         .sasl_name        = "DIGEST-MD5",
 331         .client_start     = gensec_sasl_client_start,
 332         .update           = gensec_sasl_update,
 333         .wrap_packets     = gensec_sasl_wrap_packets,
 334         .unwrap_packets   = gensec_sasl_unwrap_packets,
 335         .have_feature     = gensec_sasl_have_feature,
 336         .enabled          = true,
 337         .priority         = GENSEC_SASL
 338 };
 339
 340 static int gensec_sasl_log(void *context,
 341                     int sasl_log_level,
 342                     const char *message)
 343 {
 344         int dl;
 345         switch (sasl_log_level) {
 346         case SASL_LOG_NONE:
 347                 dl = 0;
 348                 break;
 349         case SASL_LOG_ERR:
 350                 dl = 1;
 351                 break;
 352         case SASL_LOG_FAIL:
 353                 dl = 2;
 354                 break;
 355         case SASL_LOG_WARN:
 356                 dl = 3;
 357                 break;
 358         case SASL_LOG_NOTE:
 359                 dl = 5;
 360                 break;
 361         case SASL_LOG_DEBUG:
 362                 dl = 10;
 363                 break;
 364         case SASL_LOG_TRACE:
 365                 dl = 11;
 366                 break;
 367 #if DEBUG_PASSWORD
 368         case SASL_LOG_PASS:
 369                 dl = 100;
 370                 break;
 371 #endif
 372         default:
 373                 dl = 0;
 374                 break;
 375         }
 376         DEBUG(dl, ("gensec_sasl: %s\n", message));
 377
 378         return SASL_OK;
 379 }
 380
 381 NTSTATUS gensec_sasl_init(void)
 382 {
 383         NTSTATUS ret;
 384         int sasl_ret;
 385 #if 0
 386         int i;
 387         const char **sasl_mechs;
 388 #endif
 389
 390         static const sasl_callback_t callbacks[] = {
 391                 {
 392                         .id = SASL_CB_LOG,
 393                         .proc = gensec_sasl_log,
 394                         .context = NULL,
 395                 },
 396                 {
 397                         .id = SASL_CB_LIST_END,
 398                         .proc = gensec_sasl_log,
 399                         .context = NULL,
 400                 }
 401         };
 402         sasl_ret = sasl_client_init(callbacks);
 403
 404         if (sasl_ret == SASL_NOMECH) {
 405                 /* Nothing to do here */
 406                 return NT_STATUS_OK;
 407         }
 408
 409         if (sasl_ret != SASL_OK) {
 410                 return sasl_nt_status(sasl_ret);
 411         }
 412
 413         /* For now, we just register DIGEST-MD5 */
 414 #if 1
 415         ret = gensec_register(&gensec_sasl_security_ops);
 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 #else
 422         sasl_mechs = sasl_global_listmech();
 423         for (i = 0; sasl_mechs && sasl_mechs[i]; i++) {
 424                 const struct gensec_security_ops *oldmech;
 425                 struct gensec_security_ops *newmech;
 426                 oldmech = gensec_security_by_sasl_name(NULL, sasl_mechs[i]);
 427                 if (oldmech) {
 428                         continue;
 429                 }
 430                 newmech = talloc(talloc_autofree_context(), struct gensec_security_ops);
 431                 if (!newmech) {
 432                         return NT_STATUS_NO_MEMORY;
 433                 }
 434                 *newmech = gensec_sasl_security_ops;
 435                 newmech->sasl_name = talloc_strdup(newmech, sasl_mechs[i]);
 436                 newmech->name = talloc_asprintf(newmech, "sasl-%s", sasl_mechs[i]);
 437                 if (!newmech->sasl_name || !newmech->name) {
 438                         return NT_STATUS_NO_MEMORY;
 439                 }
 440
 441                 ret = gensec_register(newmech);
 442                 if (!NT_STATUS_IS_OK(ret)) {
 443                         DEBUG(0,("Failed to register '%s' gensec backend!\n",
 444                                  gensec_sasl_security_ops.name));
 445                         return ret;
 446                 }
 447         }
 448 #endif
 449         return NT_STATUS_OK;
 450 }