source4/lib/credentials.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Copyright (C) Jelmer Vernooij 2005
   5    Copyright (C) Tim Potter 2001
   6    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005
   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 "system/filesys.h"
  25 #include "lib/cmdline/popt_common.h"
  26 #include "include/secrets.h"
  27 #include "lib/ldb/include/ldb.h"
  28
  29 /**
  30  * Create a new credentials structure
  31  * @param mem_ctx TALLOC_CTX parent for credentials structure
  32  */
  33 struct cli_credentials *cli_credentials_init(TALLOC_CTX *mem_ctx)
  34 {
  35         struct cli_credentials *cred = talloc_zero(mem_ctx, struct cli_credentials);
  36         if (!cred) {
  37                 return cred;
  38         }
  39
  40         return cred;
  41 }
  42
  43 /**
  44  * Obtain the username for this credentials context.
  45  * @param cred credentials context
  46  * @retval The username set on this context.
  47  * @note Return value will never be NULL except by programmer error.
  48  */
  49 const char *cli_credentials_get_username(struct cli_credentials *cred)
  50 {
  51         if (cred->machine_account_pending) {
  52                 cli_credentials_set_machine_account(cred);
  53         }
  54
  55         if (cred->username_obtained == CRED_CALLBACK) {
  56                 cred->username = cred->username_cb(cred);
  57                 cred->username_obtained = CRED_SPECIFIED;
  58         }
  59
  60         return cred->username;
  61 }
  62
  63 BOOL cli_credentials_set_username(struct cli_credentials *cred, const char *val, enum credentials_obtained obtained)
  64 {
  65         if (obtained >= cred->username_obtained) {
  66                 cred->username = talloc_strdup(cred, val);
  67                 cred->username_obtained = obtained;
  68                 return True;
  69         }
  70
  71         return False;
  72 }
  73
  74 /**
  75  * Obtain the password for this credentials context.
  76  * @param cred credentials context
  77  * @retval If set, the cleartext password, otherwise NULL
  78  */
  79 const char *cli_credentials_get_password(struct cli_credentials *cred)
  80 {
  81         if (cred->machine_account_pending) {
  82                 cli_credentials_set_machine_account(cred);
  83         }
  84
  85         if (cred->password_obtained == CRED_CALLBACK) {
  86                 cred->password = cred->password_cb(cred);
  87                 cred->password_obtained = CRED_SPECIFIED;
  88         }
  89
  90         return cred->password;
  91 }
  92
  93 BOOL cli_credentials_set_password(struct cli_credentials *cred, const char *val, enum credentials_obtained obtained)
  94 {
  95         if (obtained >= cred->password_obtained) {
  96                 cred->password = talloc_strdup(cred, val);
  97                 cred->password_obtained = obtained;
  98                 return True;
  99         }
 100
 101         return False;
 102 }
 103
 104 /**
 105  * Obtain the 'short' or 'NetBIOS' domain for this credentials context.
 106  * @param cred credentials context
 107  * @retval The domain set on this context.
 108  * @note Return value will never be NULL except by programmer error.
 109  */
 110 const char *cli_credentials_get_domain(struct cli_credentials *cred)
 111 {
 112         if (cred->machine_account_pending) {
 113                 cli_credentials_set_machine_account(cred);
 114         }
 115
 116         if (cred->domain_obtained == CRED_CALLBACK) {
 117                 cred->domain = cred->domain_cb(cred);
 118                 cred->domain_obtained = CRED_SPECIFIED;
 119         }
 120
 121         return cred->domain;
 122 }
 123
 124
 125 BOOL cli_credentials_set_domain(struct cli_credentials *cred, const char *val, enum credentials_obtained obtained)
 126 {
 127         if (obtained >= cred->domain_obtained) {
 128                 cred->domain = talloc_strdup(cred, val);
 129                 cred->domain_obtained = obtained;
 130                 return True;
 131         }
 132
 133         return False;
 134 }
 135
 136 /**
 137  * Obtain the Kerberos realm for this credentials context.
 138  * @param cred credentials context
 139  * @retval The realm set on this context.
 140  * @note Return value will never be NULL except by programmer error.
 141  */
 142 const char *cli_credentials_get_realm(struct cli_credentials *cred)
 143 {
 144         if (cred->machine_account_pending) {
 145                 cli_credentials_set_machine_account(cred);
 146         }
 147
 148         if (cred->realm_obtained == CRED_CALLBACK) {
 149                 cred->realm = cred->realm_cb(cred);
 150                 cred->realm_obtained = CRED_SPECIFIED;
 151         }
 152
 153         return cred->realm;
 154 }
 155
 156 /**
 157  * Obtain the user's Kerberos principal for this credentials context.
 158  * @param cred credentials context
 159  * @param mem_ctx A talloc context to return the prinipal name on.
 160  * @retval The user's Kerberos principal
 161  * @note Return value may be NULL due to out-of memeory or invalid mem_ctx
 162  */
 163 char *cli_credentials_get_principal(struct cli_credentials *cred,
 164                                     TALLOC_CTX *mem_ctx)
 165 {
 166         return talloc_asprintf(mem_ctx, "%s@%s",
 167                                cli_credentials_get_username(cred),
 168                                cli_credentials_get_realm(cred));
 169 }
 170
 171 BOOL cli_credentials_set_realm(struct cli_credentials *cred, const char *val, enum credentials_obtained obtained)
 172 {
 173         if (obtained >= cred->realm_obtained) {
 174                 cred->realm = talloc_strdup(cred, val);
 175                 cred->realm_obtained = obtained;
 176                 return True;
 177         }
 178
 179         return False;
 180 }
 181
 182 /**
 183  * Obtain the 'short' or 'NetBIOS' workstation name for this credentials context.
 184  *
 185  * @param cred credentials context
 186  * @retval The workstation name set on this context.
 187  * @note Return value will never be NULL except by programmer error.
 188  */
 189 const char *cli_credentials_get_workstation(struct cli_credentials *cred)
 190 {
 191         if (cred->workstation_obtained == CRED_CALLBACK) {
 192                 cred->workstation = cred->workstation_cb(cred);
 193                 cred->workstation_obtained = CRED_SPECIFIED;
 194         }
 195
 196         return cred->workstation;
 197 }
 198
 199 BOOL cli_credentials_set_workstation(struct cli_credentials *cred, const char *val, enum credentials_obtained obtained)
 200 {
 201         if (obtained >= cred->workstation_obtained) {
 202                 cred->workstation = talloc_strdup(cred, val);
 203                 cred->workstation_obtained = obtained;
 204                 return True;
 205         }
 206
 207         return False;
 208 }
 209
 210 /**
 211  * Read a file descriptor, and parse it for a password (eg from a file or stdin)
 212  *
 213  * @param credentials Credentials structure on which to set the password
 214  * @param fd open file descriptor to read the password from
 215  * @param obtained This enum describes how 'specified' this password is
 216  */
 217
 218 BOOL cli_credentials_parse_password_fd(struct cli_credentials *credentials, int fd, enum credentials_obtained obtained)
 219 {
 220         char *p;
 221         char pass[128];
 222
 223         for(p = pass, *p = '\0'; /* ensure that pass is null-terminated */
 224                 p && p - pass < sizeof(pass);) {
 225                 switch (read(fd, p, 1)) {
 226                 case 1:
 227                         if (*p != '\n' && *p != '\0') {
 228                                 *++p = '\0'; /* advance p, and null-terminate pass */
 229                                 break;
 230                         }
 231                 case 0:
 232                         if (p - pass) {
 233                                 *p = '\0'; /* null-terminate it, just in case... */
 234                                 p = NULL; /* then force the loop condition to become false */
 235                                 break;
 236                         } else {
 237                                 fprintf(stderr, "Error reading password from file descriptor %d: %s\n", fd, "empty password\n");
 238                                 return False;
 239                         }
 240
 241                 default:
 242                         fprintf(stderr, "Error reading password from file descriptor %d: %s\n",
 243                                         fd, strerror(errno));
 244                         return False;
 245                 }
 246         }
 247
 248         cli_credentials_set_password(credentials, pass, obtained);
 249         return True;
 250 }
 251
 252 /**
 253  * Read a named file, and parse it for a password
 254  *
 255  * @param credentials Credentials structure on which to set the password
 256  * @param file a named file to read the password from
 257  * @param obtained This enum describes how 'specified' this password is
 258  */
 259
 260 BOOL cli_credentials_parse_password_file(struct cli_credentials *credentials, const char *file, enum credentials_obtained obtained)
 261 {
 262         int fd = open(file, O_RDONLY, 0);
 263         BOOL ret;
 264
 265         if (fd < 0) {
 266                 fprintf(stderr, "Error opening PASSWD_FILE %s: %s\n",
 267                                 file, strerror(errno));
 268                 return False;
 269         }
 270
 271         ret = cli_credentials_parse_password_fd(credentials, fd, obtained);
 272
 273         close(fd);
 274
 275         return ret;
 276 }
 277
 278 /**
 279  * Read a named file, and parse it for username, domain, realm and password
 280  *
 281  * @param credentials Credentials structure on which to set the password
 282  * @param file a named file to read the details from
 283  * @param obtained This enum describes how 'specified' this password is
 284  */
 285
 286 BOOL cli_credentials_parse_file(struct cli_credentials *cred, const char *file, enum credentials_obtained obtained)
 287 {
 288         XFILE *auth;
 289         char buf[128];
 290         uint16_t len = 0;
 291         char *ptr, *val, *param;
 292
 293         if ((auth=x_fopen(file, O_RDONLY, 0)) == NULL)
 294         {
 295                 /* fail if we can't open the credentials file */
 296                 d_printf("ERROR: Unable to open credentials file!\n");
 297                 return False;
 298         }
 299
 300         while (!x_feof(auth))
 301         {
 302                 /* get a line from the file */
 303                 if (!x_fgets(buf, sizeof(buf), auth))
 304                         continue;
 305                 len = strlen(buf);
 306
 307                 if ((len) && (buf[len-1]=='\n'))
 308                 {
 309                         buf[len-1] = '\0';
 310                         len--;
 311                 }
 312                 if (len == 0)
 313                         continue;
 314
 315                 /* break up the line into parameter & value.
 316                  * will need to eat a little whitespace possibly */
 317                 param = buf;
 318                 if (!(ptr = strchr_m (buf, '=')))
 319                         continue;
 320
 321                 val = ptr+1;
 322                 *ptr = '\0';
 323
 324                 /* eat leading white space */
 325                 while ((*val!='\0') && ((*val==' ') || (*val=='\t')))
 326                         val++;
 327
 328                 if (strwicmp("password", param) == 0) {
 329                         cli_credentials_set_password(cred, val, obtained);
 330                 } else if (strwicmp("username", param) == 0) {
 331                         cli_credentials_set_username(cred, val, obtained);
 332                 } else if (strwicmp("domain", param) == 0) {
 333                         cli_credentials_set_domain(cred, val, obtained);
 334                 } else if (strwicmp("realm", param) == 0) {
 335                         cli_credentials_set_realm(cred, val, obtained);
 336                 }
 337                 memset(buf, 0, sizeof(buf));
 338         }
 339
 340         x_fclose(auth);
 341         return True;
 342 }
 343
 344
 345 /**
 346  * Given a string, typically obtained from a -U argument, parse it into domain, username, realm and password fields
 347  *
 348  * The format accepted is [domain\\]user[%password] or user[@realm][%password]
 349  *
 350  * @param credentials Credentials structure on which to set the password
 351  * @param data the string containing the username, password etc
 352  * @param obtained This enum describes how 'specified' this password is
 353  */
 354
 355 void cli_credentials_parse_string(struct cli_credentials *credentials, const char *data, enum credentials_obtained obtained)
 356 {
 357         char *uname, *p;
 358
 359         uname = talloc_strdup(credentials, data);
 360         if ((p = strchr_m(uname,'%'))) {
 361                 *p = 0;
 362                 cli_credentials_set_password(credentials, p+1, obtained);
 363         }
 364
 365         if ((p = strchr_m(uname,'@'))) {
 366                 *p = 0;
 367                 cli_credentials_set_realm(credentials, p+1, obtained);
 368         } else if ((p = strchr_m(uname,'\\')) || (p = strchr_m(uname, '/'))) {
 369                 *p = 0;
 370                 cli_credentials_set_domain(credentials, uname, obtained);
 371                 uname = p+1;
 372         }
 373         cli_credentials_set_username(credentials, uname, obtained);
 374 }
 375
 376 /**
 377  * Specifies default values for domain, workstation and realm
 378  * from the smb.conf configuration file
 379  *
 380  * @param cred Credentials structure to fill in
 381  */
 382 void cli_credentials_set_conf(struct cli_credentials *cred)
 383 {
 384         cli_credentials_set_domain(cred, lp_workgroup(), CRED_GUESSED);
 385         cli_credentials_set_workstation(cred, lp_netbios_name(), CRED_GUESSED);
 386         cli_credentials_set_realm(cred, lp_realm(), CRED_GUESSED);
 387 }
 388
 389 /**
 390  * Guess defaults for credentials from environment variables,
 391  * and from the configuration file
 392  *
 393  * @param cred Credentials structure to fill in
 394  */
 395 void cli_credentials_guess(struct cli_credentials *cred)
 396 {
 397         char *p;
 398
 399         cli_credentials_set_username(cred, "", CRED_GUESSED);
 400         cli_credentials_set_conf(cred);
 401
 402         if (getenv("LOGNAME")) {
 403                 cli_credentials_set_username(cred, getenv("LOGNAME"), CRED_GUESSED);
 404         }
 405
 406         if (getenv("USER")) {
 407                 cli_credentials_parse_string(cred, getenv("USER"), CRED_GUESSED);
 408                 if ((p = strchr_m(getenv("USER"),'%'))) {
 409                         memset(p,0,strlen(cred->password));
 410                 }
 411         }
 412
 413         if (getenv("DOMAIN")) {
 414                 cli_credentials_set_domain(cred, getenv("DOMAIN"), CRED_GUESSED);
 415         }
 416
 417         if (getenv("PASSWD")) {
 418                 cli_credentials_set_password(cred, getenv("PASSWD"), CRED_GUESSED);
 419         }
 420
 421         if (getenv("PASSWD_FD")) {
 422                 cli_credentials_parse_password_fd(cred, atoi(getenv("PASSWD_FD")), CRED_GUESSED);
 423         }
 424
 425         if (getenv("PASSWD_FILE")) {
 426                 cli_credentials_parse_password_file(cred, getenv("PASSWD_FILE"), CRED_GUESSED);
 427         }
 428 }
 429
 430 /**
 431  * Fill in credentials for the machine trust account, from the secrets database.
 432  *
 433  * @param cred Credentials structure to fill in
 434  * @retval NTSTATUS error detailing any failure
 435  */
 436 NTSTATUS cli_credentials_set_machine_account(struct cli_credentials *cred)
 437 {
 438         TALLOC_CTX *mem_ctx;
 439
 440         struct ldb_context *ldb;
 441         int ldb_ret;
 442         struct ldb_message **msgs;
 443         const char *base_dn = SECRETS_PRIMARY_DOMAIN_DN;
 444         const char *attrs[] = {
 445                 "secret",
 446                 "samAccountName",
 447                 "flatname",
 448                 "realm",
 449                 NULL
 450         };
 451
 452         const char *machine_account;
 453         const char *password;
 454         const char *domain;
 455         const char *realm;
 456
 457         /* ok, we are going to get it now, don't recurse back here */
 458         cred->machine_account_pending = False;
 459
 460         mem_ctx = talloc_named(cred, 0, "cli_credentials fetch machine password");
 461         /* Local secrets are stored in secrets.ldb */
 462         ldb = secrets_db_connect(mem_ctx);
 463         if (!ldb) {
 464                 DEBUG(1, ("Could not open secrets.ldb\n"));
 465                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 466         }
 467
 468         /* search for the secret record */
 469         ldb_ret = gendb_search(ldb,
 470                                mem_ctx, base_dn, &msgs, attrs,
 471                                SECRETS_PRIMARY_DOMAIN_FILTER,
 472                                cli_credentials_get_domain(cred));
 473         if (ldb_ret == 0) {
 474                 DEBUG(1, ("Could not find join record to domain: %s\n",
 475                           cli_credentials_get_domain(cred)));
 476                 talloc_free(mem_ctx);
 477                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 478         } else if (ldb_ret != 1) {
 479                 DEBUG(1, ("Found more than one (%d) join records to domain: %s\n",
 480                           ldb_ret, cli_credentials_get_domain(cred)));
 481                 talloc_free(mem_ctx);
 482                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 483         }
 484
 485         password = ldb_msg_find_string(msgs[0], "secret", NULL);
 486         if (!password) {
 487                 DEBUG(1, ("Could not find 'secret' in join record to domain: %s\n",
 488                           cli_credentials_get_domain(cred)));
 489                 talloc_free(mem_ctx);
 490                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 491         }
 492
 493         machine_account = ldb_msg_find_string(msgs[0], "samAccountName", NULL);
 494         if (!machine_account) {
 495                 DEBUG(1, ("Could not find 'samAccountName' in join record to domain: %s\n",
 496                           cli_credentials_get_domain(cred)));
 497                 talloc_free(mem_ctx);
 498                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 499         }
 500
 501         domain = ldb_msg_find_string(msgs[0], "flatname", NULL);
 502         if (domain) {
 503                 cli_credentials_set_domain(cred, domain, CRED_SPECIFIED);
 504         }
 505
 506         realm = ldb_msg_find_string(msgs[0], "realm", NULL);
 507         if (realm) {
 508                 cli_credentials_set_realm(cred, realm, CRED_SPECIFIED);
 509         }
 510
 511         cli_credentials_set_username(cred, machine_account, CRED_SPECIFIED);
 512         cli_credentials_set_password(cred, password, CRED_SPECIFIED);
 513         talloc_free(mem_ctx);
 514
 515         return NT_STATUS_OK;
 516 }
 517
 518 /**
 519  * Ask that when required, the credentials system will be filled with
 520  * machine trust account, from the secrets database.
 521  *
 522  * @param cred Credentials structure to fill in
 523  * @note This function is used to call the above function after, rather
 524  *       than during, popt processing.
 525  *
 526  */
 527 void cli_credentials_set_machine_account_pending(struct cli_credentials *cred)
 528 {
 529         cred->machine_account_pending = True;
 530 }
 531
 532 /**
 533  * Attach NETLOGON credentials for use with SCHANNEL
 534  */
 535
 536 void cli_credentials_set_netlogon_creds(struct cli_credentials *cred,
 537                                         struct creds_CredentialState *netlogon_creds)
 538 {
 539         cred->netlogon_creds = talloc_reference(cred, netlogon_creds);
 540 }
 541
 542 /**
 543  * Return attached NETLOGON credentials
 544  */
 545
 546 struct creds_CredentialState *cli_credentials_get_netlogon_creds(struct cli_credentials *cred)
 547 {
 548         return cred->netlogon_creds;
 549 }
 550
 551 /**
 552  * Fill in a credentials structure as the anonymous user
 553  */
 554 void cli_credentials_set_anonymous(struct cli_credentials *cred)
 555 {
 556         cli_credentials_set_username(cred, "", CRED_SPECIFIED);
 557         cli_credentials_set_domain(cred, "", CRED_SPECIFIED);
 558         cli_credentials_set_password(cred, NULL, CRED_SPECIFIED);
 559 }
 560
 561 /**
 562  * Describe a credentials context as anonymous or authenticated
 563  * @retval True if anonymous, False if a username is specified
 564  */
 565
 566 BOOL cli_credentials_is_anonymous(struct cli_credentials *cred)
 567 {
 568         const char *username = cli_credentials_get_username(cred);
 569
 570         /* Yes, it is deliberate that we die if we have a NULL pointer
 571          * here - anonymous is "", not NULL, which is 'never specified,
 572          * never guessed', ie programmer bug */
 573         if (!username[0])
 574                 return True;
 575
 576         return False;
 577 }