third_party/pam_wrapper/pam_wrapper.c

   1 /*
   2  * Copyright (c) 2015 Andreas Schneider <asn@samba.org>
   3  * Copyright (c) 2015 Jakub Hrozek <jakub.hrozek@posteo.se>
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include "config.h"
  20
  21 #include <errno.h>
  22 #include <stdarg.h>
  23 #include <stdbool.h>
  24 #include <stdlib.h>
  25 #include <stdio.h>
  26 #include <string.h>
  27 #include <stdint.h>
  28 #include <sys/types.h>
  29 #include <sys/stat.h>
  30 #include <dirent.h>
  31 #include <fcntl.h>
  32 #include <unistd.h>
  33 #include <dlfcn.h>
  34 #include <libgen.h>
  35 #include <signal.h>
  36 #include <limits.h>
  37 #include <ctype.h>
  38
  39 #include <ftw.h>
  40
  41 #ifdef HAVE_SECURITY_PAM_APPL_H
  42 #include <security/pam_appl.h>
  43 #endif
  44 #ifdef HAVE_SECURITY_PAM_MODULES_H
  45 #include <security/pam_modules.h>
  46 #endif
  47 #ifdef HAVE_SECURITY_PAM_EXT_H
  48 #include <security/pam_ext.h>
  49 #endif
  50
  51 #include "pwrap_compat.h"
  52
  53 #ifdef HAVE_GCC_THREAD_LOCAL_STORAGE
  54 # define PWRAP_THREAD __thread
  55 #else
  56 # define PWRAP_THREAD
  57 #endif
  58
  59 #ifdef HAVE_CONSTRUCTOR_ATTRIBUTE
  60 #define CONSTRUCTOR_ATTRIBUTE __attribute__ ((constructor))
  61 #else
  62 #define CONSTRUCTOR_ATTRIBUTE
  63 #endif /* HAVE_CONSTRUCTOR_ATTRIBUTE */
  64
  65 #ifdef HAVE_DESTRUCTOR_ATTRIBUTE
  66 #define DESTRUCTOR_ATTRIBUTE __attribute__ ((destructor))
  67 #else
  68 #define DESTRUCTOR_ATTRIBUTE
  69 #endif /* HAVE_DESTRUCTOR_ATTRIBUTE */
  70
  71 #ifdef HAVE_ADDRESS_SANITIZER_ATTRIBUTE
  72 #define DO_NOT_SANITIZE_ADDRESS_ATTRIBUTE __attribute__((no_sanitize_address))
  73 #else /* DO_NOT_SANITIZE_ADDRESS_ATTRIBUTE */
  74 #define DO_NOT_SANITIZE_ADDRESS_ATTRIBUTE
  75 #endif /* DO_NOT_SANITIZE_ADDRESS_ATTRIBUTE */
  76
  77 /* GCC have printf type attribute check. */
  78 #ifdef HAVE_FUNCTION_ATTRIBUTE_FORMAT
  79 #define PRINTF_ATTRIBUTE(a,b) __attribute__ ((__format__ (__printf__, a, b)))
  80 #else
  81 #define PRINTF_ATTRIBUTE(a,b)
  82 #endif /* HAVE_FUNCTION_ATTRIBUTE_FORMAT */
  83
  84 #ifndef SAFE_FREE
  85 #define SAFE_FREE(x) do { if ((x) != NULL) {free(x); (x)=NULL;} } while(0)
  86 #endif
  87
  88 #ifndef discard_const
  89 #define discard_const(ptr) ((void *)((uintptr_t)(ptr)))
  90 #endif
  91
  92 #ifndef discard_const_p
  93 #define discard_const_p(type, ptr) ((type *)discard_const(ptr))
  94 #endif
  95
  96 /*****************
  97  * LOGGING
  98  *****************/
  99
 100 enum pwrap_dbglvl_e {
 101         PWRAP_LOG_ERROR = 0,
 102         PWRAP_LOG_WARN,
 103         PWRAP_LOG_DEBUG,
 104         PWRAP_LOG_TRACE
 105 };
 106
 107 static void pwrap_log(enum pwrap_dbglvl_e dbglvl,
 108                       const char *function,
 109                       const char *format, ...) PRINTF_ATTRIBUTE(3, 4);
 110 # define PWRAP_LOG(dbglvl, ...) pwrap_log((dbglvl), __func__, __VA_ARGS__)
 111
 112 static void pwrap_vlog(enum pwrap_dbglvl_e dbglvl,
 113                        const char *function,
 114                        const char *format,
 115                        va_list args) PRINTF_ATTRIBUTE(3, 0);
 116
 117 static void pwrap_vlog(enum pwrap_dbglvl_e dbglvl,
 118                        const char *function,
 119                        const char *format,
 120                        va_list args)
 121 {
 122         char buffer[1024];
 123         const char *d;
 124         unsigned int lvl = 0;
 125         const char *prefix = "PWRAP";
 126
 127         d = getenv("PAM_WRAPPER_DEBUGLEVEL");
 128         if (d != NULL) {
 129                 lvl = atoi(d);
 130         }
 131
 132         if (lvl < dbglvl) {
 133                 return;
 134         }
 135
 136         vsnprintf(buffer, sizeof(buffer), format, args);
 137
 138         switch (dbglvl) {
 139         case PWRAP_LOG_ERROR:
 140                 prefix = "PWRAP_ERROR";
 141                 break;
 142         case PWRAP_LOG_WARN:
 143                 prefix = "PWRAP_WARN";
 144                 break;
 145         case PWRAP_LOG_DEBUG:
 146                 prefix = "PWRAP_DEBUG";
 147                 break;
 148         case PWRAP_LOG_TRACE:
 149                 prefix = "PWRAP_TRACE";
 150                 break;
 151         }
 152
 153         fprintf(stderr,
 154                 "%s(%d) - %s: %s\n",
 155                 prefix,
 156                 (int)getpid(),
 157                 function,
 158                 buffer);
 159 }
 160
 161 static void pwrap_log(enum pwrap_dbglvl_e dbglvl,
 162                       const char *function,
 163                       const char *format, ...)
 164 {
 165         va_list va;
 166
 167         va_start(va, format);
 168         pwrap_vlog(dbglvl, function, format, va);
 169         va_end(va);
 170 }
 171
 172 /*****************
 173  * LIBC
 174  *****************/
 175
 176 #define LIBPAM_NAME "libpam.so.0"
 177
 178 typedef int (*__libpam_pam_start)(const char *service_name,
 179                                   const char *user,
 180                                   const struct pam_conv *pam_conversation,
 181                                   pam_handle_t **pamh);
 182
 183 typedef int (*__libpam_pam_end)(pam_handle_t *pamh, int pam_status);
 184
 185 typedef int (*__libpam_pam_authenticate)(pam_handle_t *pamh, int flags);
 186
 187 typedef int (*__libpam_pam_chauthtok)(pam_handle_t *pamh, int flags);
 188
 189 typedef int (*__libpam_pam_acct_mgmt)(pam_handle_t *pamh, int flags);
 190
 191 typedef int (*__libpam_pam_putenv)(pam_handle_t *pamh, const char *name_value);
 192
 193 typedef const char * (*__libpam_pam_getenv)(pam_handle_t *pamh, const char *name);
 194
 195 typedef char ** (*__libpam_pam_getenvlist)(pam_handle_t *pamh);
 196
 197 typedef int (*__libpam_pam_open_session)(pam_handle_t *pamh, int flags);
 198
 199 typedef int (*__libpam_pam_close_session)(pam_handle_t *pamh, int flags);
 200
 201 typedef int (*__libpam_pam_setcred)(pam_handle_t *pamh, int flags);
 202
 203 typedef int (*__libpam_pam_get_item)(const pam_handle_t *pamh,
 204                                      int item_type,
 205                                      const void **item);
 206
 207 typedef int (*__libpam_pam_set_item)(pam_handle_t *pamh,
 208                                      int item_type,
 209                                      const void *item);
 210
 211 typedef int (*__libpam_pam_get_data)(const pam_handle_t *pamh,
 212                                      const char *module_data_name,
 213                                      const void **data);
 214
 215 typedef int (*__libpam_pam_set_data)(pam_handle_t *pamh,
 216                                      const char *module_data_name,
 217                                      void *data,
 218                                      void (*cleanup)(pam_handle_t *pamh,
 219                                                      void *data,
 220                                                      int error_status));
 221
 222 typedef int (*__libpam_pam_vprompt)(pam_handle_t *pamh,
 223                                     int style,
 224                                     char **response,
 225                                     const char *fmt,
 226                                     va_list args);
 227
 228 typedef const char * (*__libpam_pam_strerror)(pam_handle_t *pamh,
 229                                               int errnum);
 230
 231 #ifdef HAVE_PAM_VSYSLOG
 232 typedef void (*__libpam_pam_vsyslog)(const pam_handle_t *pamh,
 233                                      int priority,
 234                                      const char *fmt,
 235                                      va_list args);
 236 #endif
 237
 238 #define PWRAP_SYMBOL_ENTRY(i) \
 239         union { \
 240                 __libpam_##i f; \
 241                 void *obj; \
 242         } _libpam_##i
 243
 244 struct pwrap_libpam_symbols {
 245         PWRAP_SYMBOL_ENTRY(pam_start);
 246         PWRAP_SYMBOL_ENTRY(pam_end);
 247         PWRAP_SYMBOL_ENTRY(pam_authenticate);
 248         PWRAP_SYMBOL_ENTRY(pam_chauthtok);
 249         PWRAP_SYMBOL_ENTRY(pam_acct_mgmt);
 250         PWRAP_SYMBOL_ENTRY(pam_putenv);
 251         PWRAP_SYMBOL_ENTRY(pam_getenv);
 252         PWRAP_SYMBOL_ENTRY(pam_getenvlist);
 253         PWRAP_SYMBOL_ENTRY(pam_open_session);
 254         PWRAP_SYMBOL_ENTRY(pam_close_session);
 255         PWRAP_SYMBOL_ENTRY(pam_setcred);
 256         PWRAP_SYMBOL_ENTRY(pam_get_item);
 257         PWRAP_SYMBOL_ENTRY(pam_set_item);
 258         PWRAP_SYMBOL_ENTRY(pam_get_data);
 259         PWRAP_SYMBOL_ENTRY(pam_set_data);
 260         PWRAP_SYMBOL_ENTRY(pam_vprompt);
 261         PWRAP_SYMBOL_ENTRY(pam_strerror);
 262 #ifdef HAVE_PAM_VSYSLOG
 263         PWRAP_SYMBOL_ENTRY(pam_vsyslog);
 264 #endif
 265 };
 266
 267 struct pwrap {
 268         struct {
 269                 void *handle;
 270                 struct pwrap_libpam_symbols symbols;
 271         } libpam;
 272
 273         bool enabled;
 274         bool initialised;
 275         char *config_dir;
 276         char *libpam_so;
 277 };
 278
 279 static struct pwrap pwrap;
 280
 281 /*********************************************************
 282  * PWRAP PROTOTYPES
 283  *********************************************************/
 284
 285 bool pam_wrapper_enabled(void);
 286 void pwrap_constructor(void) CONSTRUCTOR_ATTRIBUTE;
 287 void pwrap_destructor(void) DESTRUCTOR_ATTRIBUTE;
 288
 289 /*********************************************************
 290  * PWRAP LIBC LOADER FUNCTIONS
 291  *********************************************************/
 292
 293 enum pwrap_lib {
 294     PWRAP_LIBPAM,
 295 };
 296
 297 static void *pwrap_load_lib_handle(enum pwrap_lib lib)
 298 {
 299         int flags = RTLD_LAZY;
 300         void *handle = NULL;
 301
 302 #ifdef RTLD_DEEPBIND
 303         flags |= RTLD_DEEPBIND;
 304 #endif
 305
 306         switch (lib) {
 307         case PWRAP_LIBPAM:
 308                 handle = pwrap.libpam.handle;
 309                 if (handle == NULL) {
 310                         handle = dlopen(pwrap.libpam_so, flags);
 311                         if (handle != NULL) {
 312                                 PWRAP_LOG(PWRAP_LOG_DEBUG,
 313                                           "Opened %s\n", pwrap.libpam_so);
 314                                 pwrap.libpam.handle = handle;
 315                                 break;
 316                         }
 317                 }
 318                 break;
 319         }
 320
 321         if (handle == NULL) {
 322                 PWRAP_LOG(PWRAP_LOG_ERROR,
 323                           "Failed to dlopen library: %s\n",
 324                           dlerror());
 325                 exit(-1);
 326         }
 327
 328         return handle;
 329 }
 330
 331 static void *_pwrap_bind_symbol(enum pwrap_lib lib, const char *fn_name)
 332 {
 333         void *handle;
 334         void *func;
 335
 336         handle = pwrap_load_lib_handle(lib);
 337
 338         func = dlsym(handle, fn_name);
 339         if (func == NULL) {
 340                 PWRAP_LOG(PWRAP_LOG_ERROR,
 341                           "Failed to find %s: %s\n",
 342                           fn_name, dlerror());
 343                 exit(-1);
 344         }
 345
 346         return func;
 347 }
 348
 349 #define pwrap_bind_symbol_libpam(sym_name) \
 350         if (pwrap.libpam.symbols._libpam_##sym_name.obj == NULL) { \
 351                 pwrap.libpam.symbols._libpam_##sym_name.obj = \
 352                         _pwrap_bind_symbol(PWRAP_LIBPAM, #sym_name); \
 353         } \
 354
 355 /*
 356  * IMPORTANT
 357  *
 358  * Functions especially from libpam need to be loaded individually, you can't
 359  * load all at once or gdb will segfault at startup. The same applies to
 360  * valgrind and has probably something todo with with the linker.
 361  * So we need load each function at the point it is called the first time.
 362  */
 363 static int libpam_pam_start(const char *service_name,
 364                             const char *user,
 365                             const struct pam_conv *pam_conversation,
 366                             pam_handle_t **pamh)
 367 {
 368         pwrap_bind_symbol_libpam(pam_start);
 369
 370         return pwrap.libpam.symbols._libpam_pam_start.f(service_name,
 371                                                         user,
 372                                                         pam_conversation,
 373                                                         pamh);
 374 }
 375
 376 static int libpam_pam_end(pam_handle_t *pamh, int pam_status)
 377 {
 378         pwrap_bind_symbol_libpam(pam_end);
 379
 380         return pwrap.libpam.symbols._libpam_pam_end.f(pamh, pam_status);
 381 }
 382
 383 static int libpam_pam_authenticate(pam_handle_t *pamh, int flags)
 384 {
 385         pwrap_bind_symbol_libpam(pam_authenticate);
 386
 387         return pwrap.libpam.symbols._libpam_pam_authenticate.f(pamh, flags);
 388 }
 389
 390 static int libpam_pam_chauthtok(pam_handle_t *pamh, int flags)
 391 {
 392         pwrap_bind_symbol_libpam(pam_chauthtok);
 393
 394         return pwrap.libpam.symbols._libpam_pam_chauthtok.f(pamh, flags);
 395 }
 396
 397 static int libpam_pam_acct_mgmt(pam_handle_t *pamh, int flags)
 398 {
 399         pwrap_bind_symbol_libpam(pam_acct_mgmt);
 400
 401         return pwrap.libpam.symbols._libpam_pam_acct_mgmt.f(pamh, flags);
 402 }
 403
 404 static int libpam_pam_putenv(pam_handle_t *pamh, const char *name_value)
 405 {
 406         pwrap_bind_symbol_libpam(pam_putenv);
 407
 408         return pwrap.libpam.symbols._libpam_pam_putenv.f(pamh, name_value);
 409 }
 410
 411 static const char *libpam_pam_getenv(pam_handle_t *pamh, const char *name)
 412 {
 413         pwrap_bind_symbol_libpam(pam_getenv);
 414
 415         return pwrap.libpam.symbols._libpam_pam_getenv.f(pamh, name);
 416 }
 417
 418 static char **libpam_pam_getenvlist(pam_handle_t *pamh)
 419 {
 420         pwrap_bind_symbol_libpam(pam_getenvlist);
 421
 422         return pwrap.libpam.symbols._libpam_pam_getenvlist.f(pamh);
 423 }
 424
 425 static int libpam_pam_open_session(pam_handle_t *pamh, int flags)
 426 {
 427         pwrap_bind_symbol_libpam(pam_open_session);
 428
 429         return pwrap.libpam.symbols._libpam_pam_open_session.f(pamh, flags);
 430 }
 431
 432 static int libpam_pam_close_session(pam_handle_t *pamh, int flags)
 433 {
 434         pwrap_bind_symbol_libpam(pam_close_session);
 435
 436         return pwrap.libpam.symbols._libpam_pam_close_session.f(pamh, flags);
 437 }
 438
 439 static int libpam_pam_setcred(pam_handle_t *pamh, int flags)
 440 {
 441         pwrap_bind_symbol_libpam(pam_setcred);
 442
 443         return pwrap.libpam.symbols._libpam_pam_setcred.f(pamh, flags);
 444 }
 445
 446 static int libpam_pam_get_item(const pam_handle_t *pamh, int item_type, const void **item)
 447 {
 448         pwrap_bind_symbol_libpam(pam_get_item);
 449
 450         return pwrap.libpam.symbols._libpam_pam_get_item.f(pamh, item_type, item);
 451 }
 452
 453 static int libpam_pam_set_item(pam_handle_t *pamh, int item_type, const void *item)
 454 {
 455         pwrap_bind_symbol_libpam(pam_set_item);
 456
 457         return pwrap.libpam.symbols._libpam_pam_set_item.f(pamh, item_type, item);
 458 }
 459
 460 static int libpam_pam_get_data(const pam_handle_t *pamh,
 461                                const char *module_data_name,
 462                                const void **data)
 463 {
 464         pwrap_bind_symbol_libpam(pam_get_data);
 465
 466         return pwrap.libpam.symbols._libpam_pam_get_data.f(pamh,
 467                                                            module_data_name,
 468                                                            data);
 469 }
 470
 471 static int libpam_pam_set_data(pam_handle_t *pamh,
 472                                const char *module_data_name,
 473                                void *data,
 474                                void (*cleanup)(pam_handle_t *pamh,
 475                                                void *data,
 476                                                int error_status))
 477 {
 478         pwrap_bind_symbol_libpam(pam_set_data);
 479
 480         return pwrap.libpam.symbols._libpam_pam_set_data.f(pamh,
 481                                                            module_data_name,
 482                                                            data,
 483                                                            cleanup);
 484 }
 485
 486 static int libpam_pam_vprompt(pam_handle_t *pamh,
 487                               int style,
 488                               char **response,
 489                               const char *fmt,
 490                               va_list args)
 491 {
 492         pwrap_bind_symbol_libpam(pam_vprompt);
 493
 494         return pwrap.libpam.symbols._libpam_pam_vprompt.f(pamh,
 495                                                           style,
 496                                                           response,
 497                                                           fmt,
 498                                                           args);
 499 }
 500
 501 #ifdef HAVE_PAM_STRERROR_CONST
 502 static const char *libpam_pam_strerror(const pam_handle_t *pamh, int errnum)
 503 #else
 504 static const char *libpam_pam_strerror(pam_handle_t *pamh, int errnum)
 505 #endif
 506 {
 507         pwrap_bind_symbol_libpam(pam_strerror);
 508
 509         return pwrap.libpam.symbols._libpam_pam_strerror.f(discard_const_p(pam_handle_t, pamh), errnum);
 510 }
 511
 512 #ifdef HAVE_PAM_VSYSLOG
 513 static void libpam_pam_vsyslog(const pam_handle_t *pamh,
 514                                int priority,
 515                                const char *fmt,
 516                                va_list args)
 517 {
 518         pwrap_bind_symbol_libpam(pam_vsyslog);
 519
 520         pwrap.libpam.symbols._libpam_pam_vsyslog.f(pamh,
 521                                                    priority,
 522                                                    fmt,
 523                                                    args);
 524 }
 525 #endif /* HAVE_PAM_VSYSLOG */
 526
 527 /*********************************************************
 528  * PWRAP INIT
 529  *********************************************************/
 530
 531 #define BUFFER_SIZE 32768
 532
 533 /* copy file from src to dst, overwrites dst */
 534 static int p_copy(const char *src, const char *dst, mode_t mode)
 535 {
 536         int srcfd = -1;
 537         int dstfd = -1;
 538         int rc = -1;
 539         ssize_t bread, bwritten;
 540         struct stat sb;
 541         char buf[BUFFER_SIZE];
 542         int cmp;
 543
 544         cmp = strcmp(src, dst);
 545         if (cmp == 0) {
 546                 return -1;
 547         }
 548
 549         srcfd = open(src, O_RDONLY, 0);
 550         if (srcfd < 0) {
 551                 return -1;
 552         }
 553
 554         if (mode == 0) {
 555                 rc = fstat(srcfd, &sb);
 556                 if (rc != 0) {
 557                         rc = -1;
 558                         goto out;
 559                 }
 560                 mode = sb.st_mode;
 561         }
 562
 563         dstfd = open(dst, O_CREAT|O_WRONLY|O_TRUNC, mode);
 564         if (dstfd < 0) {
 565                 rc = -1;
 566                 goto out;
 567         }
 568
 569         for (;;) {
 570                 bread = read(srcfd, buf, BUFFER_SIZE);
 571                 if (bread == 0) {
 572                         /* done */
 573                         break;
 574                 } else if (bread < 0) {
 575                         errno = EIO;
 576                         rc = -1;
 577                         goto out;
 578                 }
 579
 580                 bwritten = write(dstfd, buf, bread);
 581                 if (bwritten < 0) {
 582                         errno = EIO;
 583                         rc = -1;
 584                         goto out;
 585                 }
 586
 587                 if (bread != bwritten) {
 588                         errno = EFAULT;
 589                         rc = -1;
 590                         goto out;
 591                 }
 592         }
 593
 594         rc = 0;
 595 out:
 596         if (srcfd != -1) {
 597                 close(srcfd);
 598         }
 599         if (dstfd != -1) {
 600                 close(dstfd);
 601         }
 602         if (rc < 0) {
 603                 unlink(dst);
 604         }
 605
 606         return rc;
 607 }
 608
 609 /* Do not pass any flag if not defined */
 610 #ifndef FTW_ACTIONRETVAL
 611 #define FTW_ACTIONRETVAL 0
 612 #endif
 613
 614 /* Action return values */
 615 #ifndef FTW_STOP
 616 #define FTW_STOP -1
 617 #endif
 618
 619 #ifndef FTW_CONTINUE
 620 #define FTW_CONTINUE 0
 621 #endif
 622
 623 #ifndef FTW_SKIP_SUBTREE
 624 #define FTW_SKIP_SUBTREE 0
 625 #endif
 626
 627 static int copy_ftw(const char *fpath,
 628                     const struct stat *sb,
 629                     int typeflag,
 630                     struct FTW *ftwbuf)
 631 {
 632         int rc;
 633         char buf[BUFFER_SIZE];
 634
 635         switch (typeflag) {
 636         case FTW_D:
 637         case FTW_DNR:
 638                 /* We want to copy the directories from this directory */
 639                 if (ftwbuf->level == 0) {
 640                         return FTW_CONTINUE;
 641                 }
 642                 return FTW_SKIP_SUBTREE;
 643         case FTW_F:
 644                 break;
 645         default:
 646                 return FTW_CONTINUE;
 647         }
 648
 649         rc = snprintf(buf, BUFFER_SIZE, "%s/%s", pwrap.config_dir, fpath + ftwbuf->base);
 650         if (rc >= BUFFER_SIZE) {
 651                 return FTW_STOP;
 652         }
 653
 654         PWRAP_LOG(PWRAP_LOG_TRACE, "Copying %s", fpath);
 655         rc = p_copy(fpath, buf, sb->st_mode);
 656         if (rc != 0) {
 657                 return FTW_STOP;
 658         }
 659
 660         return FTW_CONTINUE;
 661 }
 662
 663 static int copy_confdir(const char *src)
 664 {
 665         int rc;
 666
 667         PWRAP_LOG(PWRAP_LOG_DEBUG,
 668                   "Copy config files from %s to %s",
 669                   src,
 670                   pwrap.config_dir);
 671         rc = nftw(src, copy_ftw, 1, FTW_ACTIONRETVAL);
 672         if (rc != 0) {
 673                 return -1;
 674         }
 675
 676         return 0;
 677 }
 678
 679 static int p_rmdirs(const char *path);
 680
 681 static void pwrap_clean_stale_dirs(const char *dir)
 682 {
 683         size_t len = strlen(dir);
 684         char pidfile[len + 5];
 685         ssize_t rc;
 686         char buf[8] = {0};
 687         long int tmp;
 688         pid_t pid;
 689         int fd;
 690
 691         snprintf(pidfile,
 692                  sizeof(pidfile),
 693                  "%s/pid",
 694                  dir);
 695
 696         /* read the pidfile */
 697         fd = open(pidfile, O_RDONLY);
 698         if (fd < 0) {
 699                 if (errno == ENOENT) {
 700                         PWRAP_LOG(PWRAP_LOG_TRACE,
 701                                   "pidfile %s missing, nothing to do\n",
 702                                   pidfile);
 703                 } else {
 704                         PWRAP_LOG(PWRAP_LOG_ERROR,
 705                                   "Failed to open pidfile %s - error: %s",
 706                                   pidfile, strerror(errno));
 707                 }
 708                 return;
 709         }
 710
 711         rc = read(fd, buf, sizeof(buf));
 712         close(fd);
 713         if (rc < 0) {
 714                 PWRAP_LOG(PWRAP_LOG_ERROR,
 715                           "Failed to read pidfile %s - error: %s",
 716                           pidfile, strerror(errno));
 717                 return;
 718         }
 719
 720         buf[sizeof(buf) - 1] = '\0';
 721
 722         tmp = strtol(buf, NULL, 10);
 723         if (tmp == 0 || tmp > 0xFFFF || errno == ERANGE) {
 724                 PWRAP_LOG(PWRAP_LOG_ERROR,
 725                           "Failed to parse pid, buf=%s",
 726                           buf);
 727                 return;
 728         }
 729
 730         pid = (pid_t)(tmp & 0xFFFF);
 731
 732         rc = kill(pid, 0);
 733         if (rc == -1) {
 734                 PWRAP_LOG(PWRAP_LOG_TRACE,
 735                           "Remove stale pam_wrapper dir: %s",
 736                           dir);
 737                 p_rmdirs(dir);
 738         }
 739
 740         return;
 741 }
 742
 743 static int pso_copy(const char *src, const char *dst, const char *pdir, mode_t mode)
 744 {
 745         int srcfd = -1;
 746         int dstfd = -1;
 747         int rc = -1;
 748         ssize_t bread, bwritten;
 749         struct stat sb;
 750         char buf[10];
 751         int cmp;
 752         size_t to_read;
 753         bool found_slash;
 754
 755         cmp = strcmp(src, dst);
 756         if (cmp == 0) {
 757                 return -1;
 758         }
 759
 760         srcfd = open(src, O_RDONLY, 0);
 761         if (srcfd < 0) {
 762                 return -1;
 763         }
 764
 765         if (mode == 0) {
 766                 rc = fstat(srcfd, &sb);
 767                 if (rc != 0) {
 768                         rc = -1;
 769                         goto out;
 770                 }
 771                 mode = sb.st_mode;
 772         }
 773
 774         dstfd = open(dst, O_CREAT|O_WRONLY|O_TRUNC, mode);
 775         if (dstfd < 0) {
 776                 rc = -1;
 777                 goto out;
 778         }
 779
 780         found_slash = false;
 781         to_read = 1;
 782
 783         for (;;) {
 784                 bread = read(srcfd, buf, to_read);
 785                 if (bread == 0) {
 786                         /* done */
 787                         break;
 788                 } else if (bread < 0) {
 789                         errno = EIO;
 790                         rc = -1;
 791                         goto out;
 792                 }
 793
 794                 to_read = 1;
 795                 if (!found_slash && buf[0] == '/') {
 796                         found_slash = true;
 797                         to_read = 9;
 798                 }
 799
 800                 if (found_slash && bread == 9) {
 801                         cmp = memcmp(buf, "etc/pam.d", 9);
 802                         if (cmp == 0) {
 803                                 memcpy(buf, pdir + 1, 9);
 804                         }
 805                         found_slash = false;
 806                 }
 807
 808                 bwritten = write(dstfd, buf, bread);
 809                 if (bwritten < 0) {
 810                         errno = EIO;
 811                         rc = -1;
 812                         goto out;
 813                 }
 814
 815                 if (bread != bwritten) {
 816                         errno = EFAULT;
 817                         rc = -1;
 818                         goto out;
 819                 }
 820         }
 821
 822         rc = 0;
 823 out:
 824         if (srcfd != -1) {
 825                 close(srcfd);
 826         }
 827         if (dstfd != -1) {
 828                 close(dstfd);
 829         }
 830         if (rc < 0) {
 831                 unlink(dst);
 832         }
 833
 834         return rc;
 835 }
 836
 837 static void pwrap_init(void)
 838 {
 839         char tmp_config_dir[] = "/tmp/pam.X";
 840         size_t len = strlen(tmp_config_dir);
 841         const char *env;
 842         struct stat sb;
 843         int rc;
 844         unsigned i;
 845         char pam_library[128] = { 0 };
 846         char libpam_path[1024] = { 0 };
 847         ssize_t ret;
 848         FILE *pidfile;
 849         char pidfile_path[1024] = { 0 };
 850         char letter;
 851
 852         if (!pam_wrapper_enabled()) {
 853                 return;
 854         }
 855
 856         if (pwrap.initialised) {
 857                 return;
 858         }
 859
 860         /*
 861          * The name is selected to match/replace /etc/pam.d
 862          * We start from a random alphanum trying letters until
 863          * an available directory is found.
 864          */
 865         letter = 48 + (getpid() % 70);
 866         for (i = 0; i < 127; i++) {
 867                 if (isalpha(letter) || isdigit(letter)) {
 868                         tmp_config_dir[len - 1] = letter;
 869
 870                         rc = lstat(tmp_config_dir, &sb);
 871                         if (rc == 0) {
 872                                 PWRAP_LOG(PWRAP_LOG_TRACE,
 873                                           "Check if pam_wrapper dir %s is a "
 874                                           "stale directory",
 875                                           tmp_config_dir);
 876                                 pwrap_clean_stale_dirs(tmp_config_dir);
 877                         } else if (rc < 0) {
 878                                 if (errno != ENOENT) {
 879                                         continue;
 880                                 }
 881                                 break; /* found */
 882                         }
 883                 }
 884
 885                 letter++;
 886                 letter %= 127;
 887         }
 888
 889         if (i == 127) {
 890                 PWRAP_LOG(PWRAP_LOG_ERROR,
 891                           "Failed to find a possible path to create "
 892                           "pam_wrapper config dir: %s",
 893                           tmp_config_dir);
 894                 exit(1);
 895         }
 896
 897         PWRAP_LOG(PWRAP_LOG_DEBUG, "Initialize pam_wrapper");
 898
 899         pwrap_clean_stale_dirs(tmp_config_dir);
 900
 901         pwrap.config_dir = strdup(tmp_config_dir);
 902         if (pwrap.config_dir == NULL) {
 903                 PWRAP_LOG(PWRAP_LOG_ERROR,
 904                           "No memory");
 905                 exit(1);
 906         }
 907         PWRAP_LOG(PWRAP_LOG_TRACE,
 908                   "pam_wrapper config dir: %s",
 909                   tmp_config_dir);
 910
 911         rc = mkdir(pwrap.config_dir, 0755);
 912         if (rc != 0) {
 913                 PWRAP_LOG(PWRAP_LOG_ERROR,
 914                           "Failed to create pam_wrapper config dir: %s - %s",
 915                           tmp_config_dir, strerror(errno));
 916         }
 917
 918         /* Create file with the PID of the the process */
 919         ret = snprintf(pidfile_path, sizeof(pidfile_path),
 920                        "%s/pid", pwrap.config_dir);
 921         if (ret < 0) {
 922                 p_rmdirs(pwrap.config_dir);
 923                 exit(1);
 924         }
 925
 926         pidfile = fopen(pidfile_path, "w");
 927         if (pidfile == NULL) {
 928                 p_rmdirs(pwrap.config_dir);
 929                 exit(1);
 930         }
 931
 932         rc = fprintf(pidfile, "%d", getpid());
 933         fclose(pidfile);
 934         if (rc <= 0) {
 935                 p_rmdirs(pwrap.config_dir);
 936                 exit(1);
 937         }
 938
 939         /* create lib subdirectory */
 940         snprintf(libpam_path,
 941                  sizeof(libpam_path),
 942                  "%s/lib",
 943                  pwrap.config_dir);
 944
 945         rc = mkdir(libpam_path, 0755);
 946         if (rc != 0) {
 947                 PWRAP_LOG(PWRAP_LOG_ERROR,
 948                           "Failed to create pam_wrapper config dir: %s - %s",
 949                           tmp_config_dir, strerror(errno));
 950                 p_rmdirs(pwrap.config_dir);
 951                 exit(1);
 952         }
 953
 954         snprintf(libpam_path,
 955                  sizeof(libpam_path),
 956                  "%s/lib/%s",
 957                  pwrap.config_dir,
 958                  LIBPAM_NAME);
 959
 960         pwrap.libpam_so = strdup(libpam_path);
 961         if (pwrap.libpam_so == NULL) {
 962                 PWRAP_LOG(PWRAP_LOG_ERROR, "No memory");
 963                 p_rmdirs(pwrap.config_dir);
 964                 exit(1);
 965         }
 966
 967         /* copy libpam.so.0 */
 968         snprintf(libpam_path, sizeof(libpam_path), "%s", PAM_LIBRARY);
 969         PWRAP_LOG(PWRAP_LOG_TRACE,
 970                   "PAM path: %s",
 971                   libpam_path);
 972
 973         ret = readlink(libpam_path, pam_library, sizeof(pam_library) - 1);
 974         PWRAP_LOG(PWRAP_LOG_TRACE,
 975                   "PAM library: %s",
 976                   pam_library);
 977         if (ret <= 0) {
 978                 PWRAP_LOG(PWRAP_LOG_ERROR, "Failed to read %s link", LIBPAM_NAME);
 979                 p_rmdirs(pwrap.config_dir);
 980                 exit(1);
 981         }
 982
 983         if (pam_library[0] == '/') {
 984                 snprintf(libpam_path,
 985                          sizeof(libpam_path),
 986                          "%s",
 987                          pam_library);
 988         } else {
 989                 char libpam_path_cp[1024] = {0};
 990                 char *dname = NULL;
 991
 992                 snprintf(libpam_path_cp,
 993                          sizeof(libpam_path_cp),
 994                          "%s",
 995                          libpam_path);
 996
 997                 dname = dirname(libpam_path_cp);
 998                 if (dname == NULL) {
 999                         PWRAP_LOG(PWRAP_LOG_ERROR,
1000                                   "No directory component in %s", libpam_path);
1001                         p_rmdirs(pwrap.config_dir);
1002                         exit(1);
1003                 }
1004
1005                 snprintf(libpam_path,
1006                          sizeof(libpam_path),
1007                          "%s/%s",
1008                          dname,
1009                          pam_library);
1010         }
1011         PWRAP_LOG(PWRAP_LOG_TRACE, "Reconstructed PAM path: %s", libpam_path);
1012
1013         PWRAP_LOG(PWRAP_LOG_DEBUG, "Copy %s to %s", libpam_path, pwrap.libpam_so);
1014         rc = pso_copy(libpam_path, pwrap.libpam_so, pwrap.config_dir, 0644);
1015         if (rc != 0) {
1016                 PWRAP_LOG(PWRAP_LOG_ERROR,
1017                           "Failed to copy %s - error: %s",
1018                           LIBPAM_NAME,
1019                           strerror(errno));
1020                 p_rmdirs(pwrap.config_dir);
1021                 exit(1);
1022         }
1023
1024         pwrap.initialised = true;
1025
1026         env = getenv("PAM_WRAPPER_SERVICE_DIR");
1027         if (env == NULL) {
1028                 PWRAP_LOG(PWRAP_LOG_ERROR, "No config file");
1029                 p_rmdirs(pwrap.config_dir);
1030                 exit(1);
1031         }
1032
1033         rc = copy_confdir(env);
1034         if (rc != 0) {
1035                 PWRAP_LOG(PWRAP_LOG_ERROR, "Failed to copy config files");
1036                 p_rmdirs(pwrap.config_dir);
1037                 exit(1);
1038         }
1039
1040         setenv("PAM_WRAPPER_RUNTIME_DIR", pwrap.config_dir, 1);
1041
1042         PWRAP_LOG(PWRAP_LOG_DEBUG, "Successfully initialized pam_wrapper");
1043 }
1044
1045 bool pam_wrapper_enabled(void)
1046 {
1047         const char *env;
1048
1049         pwrap.enabled = false;
1050
1051         env = getenv("PAM_WRAPPER");
1052         if (env != NULL && env[0] == '1') {
1053                 pwrap.enabled = true;
1054         }
1055
1056         if (pwrap.enabled) {
1057                 pwrap.enabled = false;
1058
1059                 env = getenv("PAM_WRAPPER_SERVICE_DIR");
1060                 if (env != NULL && env[0] != '\0') {
1061                         pwrap.enabled = true;
1062                 }
1063         }
1064
1065         return pwrap.enabled;
1066 }
1067
1068 /****************************
1069  * CONSTRUCTOR
1070  ***************************/
1071 void pwrap_constructor(void)
1072 {
1073         /*
1074          * Here is safe place to call pwrap_init() and initialize data
1075          * for main process.
1076          */
1077         pwrap_init();
1078 }
1079
1080
1081 #ifdef HAVE_OPENPAM
1082 static int pwrap_openpam_start(const char *service_name,
1083                                const char *user,
1084                                const struct pam_conv *pam_conversation,
1085                                pam_handle_t **pamh)
1086 {
1087         int rv;
1088         char fullpath[1024];
1089
1090         rv = openpam_set_feature(OPENPAM_RESTRICT_SERVICE_NAME, 0);
1091         if (rv != PAM_SUCCESS) {
1092                 PWRAP_LOG(PWRAP_LOG_ERROR,
1093                           "Cannot disable OPENPAM_RESTRICT_SERVICE_NAME");
1094                 return rv;
1095         }
1096
1097         rv = openpam_set_feature(OPENPAM_RESTRICT_MODULE_NAME, 0);
1098         if (rv != PAM_SUCCESS) {
1099                 PWRAP_LOG(PWRAP_LOG_ERROR,
1100                           "Cannot disable OPENPAM_RESTRICT_MODULE_NAME");
1101                 return rv;
1102         }
1103
1104         rv = openpam_set_feature(OPENPAM_VERIFY_MODULE_FILE, 0);
1105         if (rv != PAM_SUCCESS) {
1106                 PWRAP_LOG(PWRAP_LOG_ERROR,
1107                           "Cannot disable OPENPAM_VERIFY_MODULE_FILE");
1108                 return rv;
1109         }
1110
1111         rv = openpam_set_feature(OPENPAM_VERIFY_POLICY_FILE, 0);
1112         if (rv != PAM_SUCCESS) {
1113                 PWRAP_LOG(PWRAP_LOG_ERROR,
1114                           "Cannot disable OPENPAM_VERIFY_POLICY_FILE");
1115                 return rv;
1116         }
1117
1118         snprintf(fullpath,
1119                  sizeof(fullpath),
1120                  "%s/%s",
1121                  pwrap.config_dir,
1122                  service_name);
1123
1124         return libpam_pam_start(fullpath,
1125                                 user,
1126                                 pam_conversation,
1127                                 pamh);
1128 }
1129 #endif
1130
1131 static int pwrap_pam_start(const char *service_name,
1132                            const char *user,
1133                            const struct pam_conv *pam_conversation,
1134                            pam_handle_t **pamh)
1135 {
1136         PWRAP_LOG(PWRAP_LOG_TRACE,
1137                   "pam_start service=%s, user=%s",
1138                   service_name,
1139                   user);
1140
1141 #ifdef HAVE_OPENPAM
1142         return pwrap_openpam_start(service_name,
1143                                    user,
1144                                    pam_conversation,
1145                                    pamh);
1146 #else
1147         return libpam_pam_start(service_name,
1148                                 user,
1149                                 pam_conversation,
1150                                 pamh);
1151 #endif
1152 }
1153
1154
1155 int pam_start(const char *service_name,
1156               const char *user,
1157               const struct pam_conv *pam_conversation,
1158               pam_handle_t **pamh)
1159 {
1160         return pwrap_pam_start(service_name, user, pam_conversation, pamh);
1161 }
1162
1163 static int pwrap_pam_end(pam_handle_t *pamh, int pam_status)
1164 {
1165         PWRAP_LOG(PWRAP_LOG_TRACE, "pam_end status=%d", pam_status);
1166         return libpam_pam_end(pamh, pam_status);
1167 }
1168
1169
1170 int pam_end(pam_handle_t *pamh, int pam_status)
1171 {
1172         return pwrap_pam_end(pamh, pam_status);
1173 }
1174
1175 static int pwrap_pam_authenticate(pam_handle_t *pamh, int flags)
1176 {
1177         PWRAP_LOG(PWRAP_LOG_TRACE, "pwrap_pam_authenticate flags=%d", flags);
1178         return libpam_pam_authenticate(pamh, flags);
1179 }
1180
1181 int pam_authenticate(pam_handle_t *pamh, int flags)
1182 {
1183         return pwrap_pam_authenticate(pamh, flags);
1184 }
1185
1186 static int pwrap_pam_chauthtok(pam_handle_t *pamh, int flags)
1187 {
1188         PWRAP_LOG(PWRAP_LOG_TRACE, "pwrap_pam_chauthtok flags=%d", flags);
1189         return libpam_pam_chauthtok(pamh, flags);
1190 }
1191
1192 int pam_chauthtok(pam_handle_t *pamh, int flags)
1193 {
1194         return pwrap_pam_chauthtok(pamh, flags);
1195 }
1196
1197 static int pwrap_pam_acct_mgmt(pam_handle_t *pamh, int flags)
1198 {
1199         PWRAP_LOG(PWRAP_LOG_TRACE, "pwrap_pam_acct_mgmt flags=%d", flags);
1200         return libpam_pam_acct_mgmt(pamh, flags);
1201 }
1202
1203 int pam_acct_mgmt(pam_handle_t *pamh, int flags)
1204 {
1205         return pwrap_pam_acct_mgmt(pamh, flags);
1206 }
1207
1208 static int pwrap_pam_putenv(pam_handle_t *pamh, const char *name_value)
1209 {
1210         PWRAP_LOG(PWRAP_LOG_TRACE, "pwrap_putenv name_value=%s", name_value);
1211         return libpam_pam_putenv(pamh, name_value);
1212 }
1213
1214 int pam_putenv(pam_handle_t *pamh, const char *name_value)
1215 {
1216         return pwrap_pam_putenv(pamh, name_value);
1217 }
1218
1219 static const char *pwrap_pam_getenv(pam_handle_t *pamh, const char *name)
1220 {
1221         PWRAP_LOG(PWRAP_LOG_TRACE, "pwrap_getenv name=%s", name);
1222         return libpam_pam_getenv(pamh, name);
1223 }
1224
1225 const char *pam_getenv(pam_handle_t *pamh, const char *name)
1226 {
1227         return pwrap_pam_getenv(pamh, name);
1228 }
1229
1230 static char **pwrap_pam_getenvlist(pam_handle_t *pamh)
1231 {
1232         PWRAP_LOG(PWRAP_LOG_TRACE, "pwrap_getenvlist called");
1233         return libpam_pam_getenvlist(pamh);
1234 }
1235
1236 char **pam_getenvlist(pam_handle_t *pamh)
1237 {
1238         return pwrap_pam_getenvlist(pamh);
1239 }
1240
1241 static int pwrap_pam_open_session(pam_handle_t *pamh, int flags)
1242 {
1243         PWRAP_LOG(PWRAP_LOG_TRACE, "pwrap_pam_open_session flags=%d", flags);
1244         return libpam_pam_open_session(pamh, flags);
1245 }
1246
1247 int pam_open_session(pam_handle_t *pamh, int flags)
1248 {
1249         return pwrap_pam_open_session(pamh, flags);
1250 }
1251
1252 static int pwrap_pam_close_session(pam_handle_t *pamh, int flags)
1253 {
1254         PWRAP_LOG(PWRAP_LOG_TRACE, "pwrap_pam_close_session flags=%d", flags);
1255         return libpam_pam_close_session(pamh, flags);
1256 }
1257
1258 int pam_close_session(pam_handle_t *pamh, int flags)
1259 {
1260         return pwrap_pam_close_session(pamh, flags);
1261 }
1262
1263 static int pwrap_pam_setcred(pam_handle_t *pamh, int flags)
1264 {
1265         PWRAP_LOG(PWRAP_LOG_TRACE, "pwrap_pam_setcred flags=%d", flags);
1266         return libpam_pam_setcred(pamh, flags);
1267 }
1268
1269 int pam_setcred(pam_handle_t *pamh, int flags)
1270 {
1271         return pwrap_pam_setcred(pamh, flags);
1272 }
1273
1274 static const char *pwrap_get_service(const char *libpam_service)
1275 {
1276 #ifdef HAVE_OPENPAM
1277         const char *service_name;
1278
1279         PWRAP_LOG(PWRAP_LOG_TRACE,
1280                   "internal PAM_SERVICE=%s", libpam_service);
1281         service_name = strrchr(libpam_service, '/');
1282         if (service_name != NULL && service_name[0] == '/') {
1283                 service_name++;
1284         }
1285         PWRAP_LOG(PWRAP_LOG_TRACE,
1286                   "PAM_SERVICE=%s", service_name);
1287         return service_name;
1288 #else
1289         return libpam_service;
1290 #endif
1291 }
1292
1293 static int pwrap_pam_get_item(const pam_handle_t *pamh,
1294                               int item_type,
1295                               const void **item)
1296 {
1297         int rc;
1298         const char *svc;
1299
1300         PWRAP_LOG(PWRAP_LOG_TRACE, "pwrap_get_item called");
1301
1302         rc = libpam_pam_get_item(pamh, item_type, item);
1303
1304         if (rc == PAM_SUCCESS) {
1305                 switch(item_type) {
1306                 case PAM_USER:
1307                         PWRAP_LOG(PWRAP_LOG_TRACE,
1308                                   "pwrap_get_item PAM_USER=%s",
1309                                   (const char *)*item);
1310                         break;
1311                 case PAM_SERVICE:
1312                         svc = pwrap_get_service((const char *) *item);
1313
1314                         PWRAP_LOG(PWRAP_LOG_TRACE,
1315                                   "pwrap_get_item PAM_SERVICE=%s",
1316                                   svc);
1317                         *item = svc;
1318                         break;
1319                 case PAM_USER_PROMPT:
1320                         PWRAP_LOG(PWRAP_LOG_TRACE,
1321                                   "pwrap_get_item PAM_USER_PROMPT=%s",
1322                                   (const char *)*item);
1323                         break;
1324                 case PAM_TTY:
1325                         PWRAP_LOG(PWRAP_LOG_TRACE,
1326                                   "pwrap_get_item PAM_TTY=%s",
1327                                   (const char *)*item);
1328                         break;
1329                 case PAM_RUSER:
1330                         PWRAP_LOG(PWRAP_LOG_TRACE,
1331                                   "pwrap_get_item PAM_RUSER=%s",
1332                                   (const char *)*item);
1333                         break;
1334                 case PAM_RHOST:
1335                         PWRAP_LOG(PWRAP_LOG_TRACE,
1336                                   "pwrap_get_item PAM_RHOST=%s",
1337                                   (const char *)*item);
1338                         break;
1339                 case PAM_AUTHTOK:
1340                         PWRAP_LOG(PWRAP_LOG_TRACE,
1341                                   "pwrap_get_item PAM_AUTHTOK=%s",
1342                                   (const char *)*item);
1343                         break;
1344                 case PAM_OLDAUTHTOK:
1345                         PWRAP_LOG(PWRAP_LOG_TRACE,
1346                                   "pwrap_get_item PAM_OLDAUTHTOK=%s",
1347                                   (const char *)*item);
1348                         break;
1349                 case PAM_CONV:
1350                         PWRAP_LOG(PWRAP_LOG_TRACE,
1351                                   "pwrap_get_item PAM_CONV=%p",
1352                                   (const void *)*item);
1353                         break;
1354                 default:
1355                         PWRAP_LOG(PWRAP_LOG_TRACE,
1356                                   "pwrap_get_item item_type=%d item=%p",
1357                                   item_type, (const void *)*item);
1358                         break;
1359                 }
1360         } else {
1361                 PWRAP_LOG(PWRAP_LOG_TRACE, "pwrap_get_item failed rc=%d", rc);
1362         }
1363
1364         return rc;
1365 }
1366
1367 int pam_get_item(const pam_handle_t *pamh, int item_type, const void **item)
1368 {
1369         return pwrap_pam_get_item(pamh, item_type, item);
1370 }
1371
1372 static int pwrap_pam_set_item(pam_handle_t *pamh,
1373                               int item_type,
1374                               const void *item)
1375 {
1376         int rc;
1377
1378         PWRAP_LOG(PWRAP_LOG_TRACE, "pwrap_set_item called");
1379
1380         rc = libpam_pam_set_item(pamh, item_type, item);
1381         if (rc == PAM_SUCCESS) {
1382                 switch(item_type) {
1383                 case PAM_USER:
1384                         PWRAP_LOG(PWRAP_LOG_TRACE,
1385                                   "pwrap_set_item PAM_USER=%s",
1386                                   (const char *)item);
1387                         break;
1388                 case PAM_SERVICE:
1389                         PWRAP_LOG(PWRAP_LOG_TRACE,
1390                                   "pwrap_set_item PAM_SERVICE=%s",
1391                                   (const char *)item);
1392                         break;
1393                 case PAM_USER_PROMPT:
1394                         PWRAP_LOG(PWRAP_LOG_TRACE,
1395                                   "pwrap_set_item PAM_USER_PROMPT=%s",
1396                                   (const char *)item);
1397                         break;
1398                 case PAM_TTY:
1399                         PWRAP_LOG(PWRAP_LOG_TRACE,
1400                                   "pwrap_set_item PAM_TTY=%s",
1401                                   (const char *)item);
1402                         break;
1403                 case PAM_RUSER:
1404                         PWRAP_LOG(PWRAP_LOG_TRACE,
1405                                   "pwrap_set_item PAM_RUSER=%s",
1406                                   (const char *)item);
1407                         break;
1408                 case PAM_RHOST:
1409                         PWRAP_LOG(PWRAP_LOG_TRACE,
1410                                   "pwrap_set_item PAM_RHOST=%s",
1411                                   (const char *)item);
1412                         break;
1413                 case PAM_AUTHTOK:
1414                         PWRAP_LOG(PWRAP_LOG_TRACE,
1415                                   "pwrap_set_item PAM_AUTHTOK=%s",
1416                                   (const char *)item);
1417                         break;
1418                 case PAM_OLDAUTHTOK:
1419                         PWRAP_LOG(PWRAP_LOG_TRACE,
1420                                   "pwrap_set_item PAM_OLDAUTHTOK=%s",
1421                                   (const char *)item);
1422                         break;
1423                 case PAM_CONV:
1424                         PWRAP_LOG(PWRAP_LOG_TRACE,
1425                                   "pwrap_set_item PAM_CONV=%p",
1426                                   item);
1427                         break;
1428                 default:
1429                         PWRAP_LOG(PWRAP_LOG_TRACE,
1430                                   "pwrap_set_item item_type=%d item=%p",
1431                                   item_type, item);
1432                         break;
1433                 }
1434         } else {
1435                 PWRAP_LOG(PWRAP_LOG_TRACE, "pwrap_set_item failed rc=%d", rc);
1436         }
1437
1438         return rc;
1439 }
1440
1441 int pam_set_item(pam_handle_t *pamh, int item_type, const void *item)
1442 {
1443         return pwrap_pam_set_item(pamh, item_type, item);
1444 }
1445
1446 static int pwrap_pam_get_data(const pam_handle_t *pamh,
1447                               const char *module_data_name,
1448                               const void **data)
1449 {
1450         PWRAP_LOG(PWRAP_LOG_TRACE,
1451                   "pwrap_get_data module_data_name=%s", module_data_name);
1452         return libpam_pam_get_data(pamh, module_data_name, data);
1453 }
1454
1455 int pam_get_data(const pam_handle_t *pamh,
1456                  const char *module_data_name,
1457                  const void **data)
1458 {
1459         return pwrap_pam_get_data(pamh, module_data_name, data);
1460 }
1461
1462 static int pwrap_pam_set_data(pam_handle_t *pamh,
1463                               const char *module_data_name,
1464                               void *data,
1465                               void (*cleanup)(pam_handle_t *pamh,
1466                                               void *data,
1467                                               int error_status))
1468 {
1469         PWRAP_LOG(PWRAP_LOG_TRACE,
1470                   "pwrap_set_data module_data_name=%s data=%p",
1471                   module_data_name, data);
1472         return libpam_pam_set_data(pamh, module_data_name, data, cleanup);
1473 }
1474
1475 int pam_set_data(pam_handle_t *pamh,
1476                  const char *module_data_name,
1477                  void *data,
1478                  void (*cleanup)(pam_handle_t *pamh,
1479                                  void *data,
1480                                  int error_status))
1481 {
1482         return pwrap_pam_set_data(pamh, module_data_name, data, cleanup);
1483 }
1484
1485 #ifdef HAVE_PAM_VPROMPT_CONST
1486 static int pwrap_pam_vprompt(const pam_handle_t *pamh,
1487 #else
1488 static int pwrap_pam_vprompt(pam_handle_t *pamh,
1489 #endif
1490                              int style,
1491                              char **response,
1492                              const char *fmt,
1493                              va_list args)
1494 {
1495         PWRAP_LOG(PWRAP_LOG_TRACE, "pwrap_pam_vprompt style=%d", style);
1496         return libpam_pam_vprompt(discard_const_p(pam_handle_t, pamh),
1497                                   style,
1498                                   response,
1499                                   fmt,
1500                                   args);
1501 }
1502
1503 #ifdef HAVE_PAM_VPROMPT_CONST
1504 int pam_vprompt(const pam_handle_t *pamh,
1505                 int style,
1506                 char **response,
1507                 const char *fmt,
1508                 va_list args)
1509 #else
1510 int pam_vprompt(pam_handle_t *pamh,
1511                 int style,
1512                 char **response,
1513                 const char *fmt,
1514                 va_list args)
1515 #endif
1516 {
1517         return pwrap_pam_vprompt(discard_const_p(pam_handle_t, pamh),
1518                                  style,
1519                                  response,
1520                                  fmt,
1521                                  args);
1522 }
1523
1524 #ifdef HAVE_PAM_PROMPT_CONST
1525 int pam_prompt(const pam_handle_t *pamh,
1526                int style,
1527                char **response,
1528                const char *fmt, ...)
1529 #else
1530 int pam_prompt(pam_handle_t *pamh,
1531                int style,
1532                char **response,
1533                const char *fmt, ...)
1534 #endif
1535 {
1536         va_list args;
1537         int rv;
1538
1539         va_start(args, fmt);
1540         rv = pwrap_pam_vprompt(discard_const_p(pam_handle_t, pamh),
1541                                style,
1542                                response,
1543                                fmt,
1544                                args);
1545         va_end(args);
1546
1547         return rv;
1548 }
1549
1550 #ifdef HAVE_PAM_STRERROR_CONST
1551 static const char *pwrap_pam_strerror(const pam_handle_t *pamh, int errnum)
1552 #else
1553 static const char *pwrap_pam_strerror(pam_handle_t *pamh, int errnum)
1554 #endif
1555 {
1556         const char *str;
1557
1558         pwrap_init();
1559
1560         PWRAP_LOG(PWRAP_LOG_TRACE, "pam_strerror errnum=%d", errnum);
1561
1562         str = libpam_pam_strerror(discard_const_p(pam_handle_t, pamh),
1563                                   errnum);
1564
1565         PWRAP_LOG(PWRAP_LOG_TRACE, "pam_strerror error=%s", str);
1566
1567         return str;
1568 }
1569
1570 #ifdef HAVE_PAM_STRERROR_CONST
1571 const char *pam_strerror(const pam_handle_t *pamh, int errnum)
1572 #else
1573 const char *pam_strerror(pam_handle_t *pamh, int errnum)
1574 #endif
1575 {
1576         return pwrap_pam_strerror(discard_const_p(pam_handle_t, pamh),
1577                                   errnum);
1578 }
1579
1580 #if defined(HAVE_PAM_VSYSLOG) || defined(HAVE_PAM_SYSLOG)
1581 static void pwrap_pam_vsyslog(const pam_handle_t *pamh,
1582                               int priority,
1583                               const char *fmt,
1584                               va_list args) PRINTF_ATTRIBUTE(3, 0);
1585
1586 static void pwrap_pam_vsyslog(const pam_handle_t *pamh,
1587                               int priority,
1588                               const char *fmt,
1589                               va_list args)
1590 {
1591         const char *d;
1592         char syslog_str[32] = {0};
1593         enum pwrap_dbglvl_e dbglvl = PWRAP_LOG_TRACE;
1594
1595         PWRAP_LOG(PWRAP_LOG_TRACE, "pwrap_pam_vsyslog called");
1596
1597 #ifdef HAVE_PAM_VSYSLOG
1598         d = getenv("PAM_WRAPPER_USE_SYSLOG");
1599         if (d != NULL && d[0] == '1') {
1600                 libpam_pam_vsyslog(pamh, priority, fmt, args);
1601                 return;
1602         }
1603 #endif /* HAVE_PAM_VSYSLOG */
1604
1605         switch(priority) {
1606         case 0: /* LOG_EMERG */
1607         case 1: /* LOG_ALERT */
1608         case 2: /* LOG_CRIT */
1609         case 3: /* LOG_ERR */
1610                 dbglvl = PWRAP_LOG_ERROR;
1611                 break;
1612         case 4: /* LOG_WARN */
1613                 dbglvl = PWRAP_LOG_WARN;
1614                 break;
1615         case 5: /* LOG_NOTICE */
1616         case 6: /* LOG_INFO */
1617         case 7: /* LOG_DEBUG */
1618                 dbglvl = PWRAP_LOG_DEBUG;
1619                 break;
1620         default:
1621                 dbglvl = PWRAP_LOG_TRACE;
1622                 break;
1623         }
1624
1625         snprintf(syslog_str, sizeof(syslog_str), "SYSLOG(%d)", priority);
1626
1627         pwrap_vlog(dbglvl, syslog_str, fmt, args);
1628 }
1629 #endif /* defined(HAVE_PAM_VSYSLOG) || defined(HAVE_PAM_SYSLOG) */
1630
1631 #ifdef HAVE_PAM_VSYSLOG
1632 void pam_vsyslog(const pam_handle_t *pamh,
1633                  int priority,
1634                  const char *fmt,
1635                  va_list args)
1636 {
1637         pwrap_pam_vsyslog(pamh, priority, fmt, args);
1638 }
1639 #endif
1640
1641 #ifdef HAVE_PAM_SYSLOG
1642 void pam_syslog(const pam_handle_t *pamh,
1643                 int priority,
1644                 const char *fmt, ...)
1645 {
1646         va_list args;
1647
1648         va_start(args, fmt);
1649         pwrap_pam_vsyslog(pamh, priority, fmt, args);
1650         va_end(args);
1651 }
1652 #endif
1653
1654 /* This might be called by pam_end() running with sshd */
1655 int audit_open(void);
1656 int audit_open(void)
1657 {
1658         /*
1659          * Tell the application that the kernel doesn't
1660          * have audit compiled in.
1661          */
1662         errno = EPROTONOSUPPORT;
1663         return -1;
1664 }
1665
1666 /* Disable BSD auditing */
1667 int cannot_audit(int x);
1668 int cannot_audit(int x)
1669 {
1670         (void) x;
1671
1672         return 1;
1673 }
1674
1675 /****************************
1676  * DESTRUCTOR
1677  ***************************/
1678
1679 static int p_rmdirs_at(const char *path, int parent_fd)
1680 {
1681         DIR *d;
1682         struct dirent *dp;
1683         struct stat sb;
1684         int path_fd;
1685         int rc;
1686
1687         /* If path is absolute, parent_fd is ignored. */
1688         PWRAP_LOG(PWRAP_LOG_TRACE,
1689                   "p_rmdirs_at removing %s at %d\n", path, parent_fd);
1690
1691         path_fd = openat(parent_fd,
1692                          path, O_RDONLY | O_DIRECTORY | O_NOFOLLOW);
1693         if (path_fd == -1) {
1694                 return -1;
1695         }
1696
1697         d = fdopendir(path_fd);
1698         if (d == NULL) {
1699                 close(path_fd);
1700                 return -1;
1701         }
1702
1703         while ((dp = readdir(d)) != NULL) {
1704                 /* skip '.' and '..' */
1705                 if (dp->d_name[0] == '.' &&
1706                         (dp->d_name[1] == '\0' ||
1707                         (dp->d_name[1] == '.' && dp->d_name[2] == '\0'))) {
1708                         continue;
1709                 }
1710
1711                 rc = fstatat(path_fd, dp->d_name,
1712                              &sb, AT_SYMLINK_NOFOLLOW);
1713                 if (rc != 0) {
1714                         continue;
1715                 }
1716
1717                 if (S_ISDIR(sb.st_mode)) {
1718                         rc = p_rmdirs_at(dp->d_name, path_fd);
1719                 } else {
1720                         rc = unlinkat(path_fd, dp->d_name, 0);
1721                 }
1722                 if (rc != 0) {
1723                         continue;
1724                 }
1725         }
1726         closedir(d);
1727
1728         rc = unlinkat(parent_fd, path, AT_REMOVEDIR);
1729         if (rc != 0) {
1730                 rc = errno;
1731                 PWRAP_LOG(PWRAP_LOG_TRACE,
1732                           "cannot unlink %s error %d\n", path, rc);
1733                 return -1;
1734         }
1735
1736         return 0;
1737 }
1738
1739 static int p_rmdirs(const char *path)
1740 {
1741         /*
1742          * If path is absolute, p_rmdirs_at ignores parent_fd.
1743          * If it's relative, start from cwd.
1744          */
1745         return p_rmdirs_at(path, AT_FDCWD);
1746 }
1747
1748 /*
1749  * This function is called when the library is unloaded and makes sure that
1750  * resources are freed.
1751  */
1752 void pwrap_destructor(void)
1753 {
1754         const char *env;
1755
1756         PWRAP_LOG(PWRAP_LOG_TRACE, "entering pwrap_destructor");
1757
1758         if (pwrap.libpam.handle != NULL) {
1759                 dlclose(pwrap.libpam.handle);
1760         }
1761
1762         if (pwrap.libpam_so != NULL) {
1763                 free(pwrap.libpam_so);
1764                 pwrap.libpam_so = NULL;
1765         }
1766
1767         if (!pwrap.initialised) {
1768                 return;
1769         }
1770
1771         PWRAP_LOG(PWRAP_LOG_TRACE,
1772                   "destructor called for pam_wrapper dir %s",
1773                   pwrap.config_dir);
1774         env = getenv("PAM_WRAPPER_KEEP_DIR");
1775         if (env == NULL || env[0] != '1') {
1776                 p_rmdirs(pwrap.config_dir);
1777         }
1778
1779         if (pwrap.config_dir != NULL) {
1780                 free(pwrap.config_dir);
1781                 pwrap.config_dir = NULL;
1782         }
1783 }