source/utils/smbpasswd.c

   1 /*
   2  * Unix SMB/Netbios implementation. Version 1.9. smbpasswd module. Copyright
   3  * (C) Jeremy Allison 1995-1997.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it under
   6  * the terms of the GNU General Public License as published by the Free
   7  * Software Foundation; either version 2 of the License, or (at your option)
   8  * any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along with
  16  * this program; if not, write to the Free Software Foundation, Inc., 675
  17  * Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19
  20 #include "includes.h"
  21
  22 /* Static buffers we will return. */
  23 static struct smb_passwd pw_buf;
  24 static pstring  user_name;
  25 static unsigned char smbpwd[16];
  26 static unsigned char smbntpwd[16];
  27
  28 static int gethexpwd(char *p, char *pwd)
  29 {
  30         int i;
  31         unsigned char   lonybble, hinybble;
  32         char           *hexchars = "0123456789ABCDEF";
  33         char           *p1, *p2;
  34         for (i = 0; i < 32; i += 2) {
  35                 hinybble = toupper(p[i]);
  36                 lonybble = toupper(p[i + 1]);
  37
  38                 p1 = strchr(hexchars, hinybble);
  39                 p2 = strchr(hexchars, lonybble);
  40                 if (!p1 || !p2)
  41                         return (False);
  42
  43                 hinybble = PTR_DIFF(p1, hexchars);
  44                 lonybble = PTR_DIFF(p2, hexchars);
  45
  46                 pwd[i / 2] = (hinybble << 4) | lonybble;
  47         }
  48         return (True);
  49 }
  50
  51 struct smb_passwd *
  52 _my_get_smbpwnam(FILE * fp, char *name, BOOL * valid_old_pwd,
  53                 BOOL *got_valid_nt_entry, long *pwd_seekpos)
  54 {
  55         char            linebuf[256];
  56         unsigned char   c;
  57         unsigned char  *p;
  58         long            uidval;
  59         long            linebuf_len;
  60
  61         /*
  62          * Scan the file, a line at a time and check if the name matches.
  63          */
  64         while (!feof(fp)) {
  65                 linebuf[0] = '\0';
  66                 *pwd_seekpos = ftell(fp);
  67
  68                 fgets(linebuf, 256, fp);
  69                 if (ferror(fp))
  70                         return NULL;
  71
  72                 /*
  73                  * Check if the string is terminated with a newline - if not
  74                  * then we must keep reading and discard until we get one.
  75                  */
  76                 linebuf_len = strlen(linebuf);
  77                 if (linebuf[linebuf_len - 1] != '\n') {
  78                         c = '\0';
  79                         while (!ferror(fp) && !feof(fp)) {
  80                                 c = fgetc(fp);
  81                                 if (c == '\n')
  82                                         break;
  83                         }
  84                 } else
  85                         linebuf[linebuf_len - 1] = '\0';
  86
  87                 if ((linebuf[0] == 0) && feof(fp))
  88                         break;
  89                 /*
  90                  * The line we have should be of the form :-
  91                  *
  92                  * username:uid:[32hex bytes]:....other flags presently
  93                  * ignored....
  94                  *
  95                  * or,
  96                  *
  97                  * username:uid:[32hex bytes]:[32hex bytes]:....ignored....
  98                  *
  99                  * if Windows NT compatible passwords are also present.
 100                  */
 101
 102                 if (linebuf[0] == '#' || linebuf[0] == '\0')
 103                         continue;
 104                 p = (unsigned char *) strchr(linebuf, ':');
 105                 if (p == NULL)
 106                         continue;
 107                 /*
 108                  * As 256 is shorter than a pstring we don't need to check
 109                  * length here - if this ever changes....
 110                  */
 111                 strncpy(user_name, linebuf, PTR_DIFF(p, linebuf));
 112                 user_name[PTR_DIFF(p, linebuf)] = '\0';
 113                 if (!strequal(user_name, name))
 114                         continue;
 115
 116                 /* User name matches - get uid and password */
 117                 p++;            /* Go past ':' */
 118                 if (!isdigit(*p))
 119                         return (False);
 120
 121                 uidval = atoi((char *) p);
 122                 while (*p && isdigit(*p))
 123                         p++;
 124
 125                 if (*p != ':')
 126                         return (False);
 127
 128                 /*
 129                  * Now get the password value - this should be 32 hex digits
 130                  * which are the ascii representations of a 16 byte string.
 131                  * Get two at a time and put them into the password.
 132                  */
 133                 p++;
 134                 *pwd_seekpos += PTR_DIFF(p, linebuf);   /* Save exact position
 135                                                          * of passwd in file -
 136                                                          * this is used by
 137                                                          * smbpasswd.c */
 138                 if (*p == '*' || *p == 'X') {
 139                         /* Password deliberately invalid - end here. */
 140                         *valid_old_pwd = False;
 141                         *got_valid_nt_entry = False;
 142                         pw_buf.smb_nt_passwd = NULL;    /* No NT password (yet)*/
 143
 144                         /* Now check if the NT compatible password is
 145                            available. */
 146                         p += 33; /* Move to the first character of the line after
 147                                                 the lanman password. */
 148                         if ((linebuf_len >= (PTR_DIFF(p, linebuf) + 33)) && (p[32] == ':')) {
 149                                 /* NT Entry was valid - even if 'X' or '*', can be overwritten */
 150                                 *got_valid_nt_entry = True;
 151                                 if (*p != '*' && *p != 'X') {
 152                                   if (gethexpwd((char *)p,(char *)smbntpwd))
 153                                     pw_buf.smb_nt_passwd = smbntpwd;
 154                                 }
 155                         }
 156                         pw_buf.smb_name = user_name;
 157                         pw_buf.smb_userid = uidval;
 158                         pw_buf.smb_passwd = NULL;       /* No password */
 159                         return (&pw_buf);
 160                 }
 161                 if (linebuf_len < (PTR_DIFF(p, linebuf) + 33))
 162                         return (False);
 163
 164                 if (p[32] != ':')
 165                         return (False);
 166
 167                 if (!strncasecmp((char *)p, "NO PASSWORD", 11)) {
 168                   pw_buf.smb_passwd = NULL;     /* No password */
 169                 } else {
 170                   if(!gethexpwd((char *)p,(char *)smbpwd))
 171                     return False;
 172                   pw_buf.smb_passwd = smbpwd;
 173                 }
 174
 175                 pw_buf.smb_name = user_name;
 176                 pw_buf.smb_userid = uidval;
 177                 pw_buf.smb_nt_passwd = NULL;
 178                 *got_valid_nt_entry = False;
 179                 *valid_old_pwd = True;
 180
 181                 /* Now check if the NT compatible password is
 182                    available. */
 183                 p += 33; /* Move to the first character of the line after
 184                                         the lanman password. */
 185                 if ((linebuf_len >= (PTR_DIFF(p, linebuf) + 33)) && (p[32] == ':')) {
 186                         /* NT Entry was valid - even if 'X' or '*', can be overwritten */
 187                         *got_valid_nt_entry = True;
 188                         if (*p != '*' && *p != 'X') {
 189                           if (gethexpwd((char *)p,(char *)smbntpwd))
 190                             pw_buf.smb_nt_passwd = smbntpwd;
 191                         }
 192                 }
 193                 return &pw_buf;
 194         }
 195         return NULL;
 196 }
 197
 198 /*
 199  * Print command usage on stderr and die.
 200  */
 201 static void usage(char *name)
 202 {
 203         fprintf(stderr, "Usage is : %s [-add] [username] [password]\n", name);
 204         exit(1);
 205 }
 206
 207  int main(int argc, char **argv)
 208 {
 209   int             real_uid;
 210   struct passwd  *pwd;
 211   fstring         old_passwd;
 212   uchar           old_p16[16];
 213   uchar           old_nt_p16[16];
 214   fstring         new_passwd;
 215   uchar           new_p16[16];
 216   uchar           new_nt_p16[16];
 217   char           *p;
 218   struct smb_passwd *smb_pwent;
 219   FILE           *fp;
 220   BOOL            valid_old_pwd = False;
 221   BOOL                  got_valid_nt_entry = False;
 222   BOOL            add_user = False;
 223   int             add_pass = 0;
 224   long            seekpos;
 225   int             pwfd;
 226   char            ascii_p16[66];
 227   char            c;
 228   int             ret, i, err, writelen;
 229   int             lockfd = -1;
 230   char           *pfile = SMB_PASSWD_FILE;
 231   char            readbuf[16 * 1024];
 232
 233   TimeInit();
 234
 235   setup_logging(argv[0],True);
 236
 237   charset_initialise();
 238
 239 #ifndef DEBUG_PASSWORD
 240   /* Check the effective uid */
 241   if (geteuid() != 0) {
 242     fprintf(stderr, "%s: Must be setuid root.\n", argv[0]);
 243     exit(1);
 244   }
 245 #endif
 246
 247   /* Get the real uid */
 248   real_uid = getuid();
 249
 250   /* Deal with usage problems */
 251   if (real_uid == 0)
 252   {
 253     /* As root we can change anothers password and add a user. */
 254     if (argc > 4 )
 255       usage(argv[0]);
 256   }
 257   else if (argc == 2 || argc > 3)
 258   {
 259     fprintf(stderr, "%s: Only root can set anothers password.\n", argv[0]);
 260     usage(argv[0]);
 261   }
 262
 263   if (real_uid == 0 && (argc > 1))
 264   {
 265     /* We are root - check if we should add the user */
 266     if ((argv[1][0] == '-') && (argv[1][1] == 'a'))
 267       add_user = True;
 268
 269     if(add_user && (argc <= 2 || argc > 4))
 270       usage(argv[0]);
 271
 272     /* root can specify password on command-line */
 273     if (argc == (add_user ? 4 : 3))
 274     {
 275       /* -a argument (add_user): new password is 3rd argument. */
 276       /* no -a argument (add_user): new password is 2nd argument */
 277
 278       add_pass = add_user ? 3 : 2;
 279     }
 280
 281     /* If we are root we can change another's password. */
 282     strncpy(user_name, add_user ? argv[2] : argv[1], sizeof(user_name) - 1);
 283     user_name[sizeof(user_name) - 1] = '\0';
 284
 285     pwd = getpwnam(user_name);
 286   }
 287   else
 288   {
 289     /* non-root can specify old pass / new pass on command-line */
 290     if (argc == 3)
 291     {
 292        /* non-root specifies new password as 2nd argument */
 293        add_pass = 2;
 294     }
 295
 296     pwd = getpwuid(real_uid);
 297   }
 298
 299   if (pwd == 0) {
 300     fprintf(stderr, "%s: Unable to get UNIX password entry for user.\n", argv[0]);
 301     exit(1);
 302   }
 303
 304   /* If we are root we don't ask for the old password. */
 305   old_passwd[0] = '\0';
 306   if (real_uid != 0)
 307   {
 308     if (add_pass)
 309     {
 310       /* old password, as non-root, is 1st argument */
 311       strncpy(old_passwd, argv[1], sizeof(fstring));
 312     }
 313     else
 314     {
 315       p = getpass("Old SMB password:");
 316       strncpy(old_passwd, p, sizeof(fstring));
 317     }
 318     old_passwd[sizeof(fstring)-1] = '\0';
 319   }
 320
 321   if (add_pass)
 322   {
 323     /* new password is specified on the command line */
 324     strncpy(new_passwd, argv[add_user ? 3 : 2], sizeof(new_passwd) - 1);
 325     new_passwd[sizeof(new_passwd) - 1] = '\0';
 326   }
 327   else
 328   {
 329     new_passwd[0] = '\0';
 330
 331     p = getpass("New SMB password:");
 332
 333     strncpy(new_passwd, p, sizeof(fstring));
 334     new_passwd[sizeof(fstring)-1] = '\0';
 335
 336     p = getpass("Retype new SMB password:");
 337
 338     if (strncmp(p, new_passwd, sizeof(fstring)-1))
 339     {
 340       fprintf(stderr, "%s: Mismatch - password unchanged.\n", argv[0]);
 341       exit(1);
 342     }
 343   }
 344
 345   if (new_passwd[0] == '\0')
 346   {
 347     printf("Password not set\n");
 348     exit(0);
 349   }
 350
 351   /* Calculate the MD4 hash (NT compatible) of the old and new passwords */
 352   memset(old_nt_p16, '\0', 16);
 353   E_md4hash((uchar *)old_passwd, old_nt_p16);
 354
 355   memset(new_nt_p16, '\0', 16);
 356   E_md4hash((uchar *) new_passwd, new_nt_p16);
 357
 358   /* Mangle the passwords into Lanman format */
 359   old_passwd[14] = '\0';
 360   strupper(old_passwd);
 361   new_passwd[14] = '\0';
 362   strupper(new_passwd);
 363
 364   /*
 365    * Calculate the SMB (lanman) hash functions of both old and new passwords.
 366    */
 367
 368   memset(old_p16, '\0', 16);
 369   E_P16((uchar *) old_passwd, old_p16);
 370
 371   memset(new_p16, '\0', 16);
 372   E_P16((uchar *) new_passwd, new_p16);
 373
 374   /*
 375    * Open the smbpaswd file XXXX - we need to parse smb.conf to get the
 376    * filename
 377    */
 378   fp = fopen(pfile, "r+");
 379   if (!fp && errno == ENOENT) {
 380           fp = fopen(pfile, "w");
 381           if (fp) {
 382                   fprintf(fp, "# Samba SMB password file\n");
 383                   fclose(fp);
 384                   fp = fopen(pfile, "r+");
 385           }
 386   }
 387   if (!fp) {
 388           err = errno;
 389           fprintf(stderr, "%s: Failed to open password file %s.\n",
 390                   argv[0], pfile);
 391           errno = err;
 392           perror(argv[0]);
 393           exit(err);
 394   }
 395
 396   /* Set read buffer to 16k for effiecient reads */
 397   setvbuf(fp, readbuf, _IOFBF, sizeof(readbuf));
 398
 399   /* make sure it is only rw by the owner */
 400   chmod(pfile, 0600);
 401
 402   /* Lock the smbpasswd file for write. */
 403   if ((lockfd = pw_file_lock(pfile, F_WRLCK, 5)) < 0) {
 404     err = errno;
 405     fprintf(stderr, "%s: Failed to lock password file %s.\n",
 406             argv[0], pfile);
 407     fclose(fp);
 408     errno = err;
 409     perror(argv[0]);
 410     exit(err);
 411   }
 412   /* Get the smb passwd entry for this user */
 413   smb_pwent = _my_get_smbpwnam(fp, pwd->pw_name, &valid_old_pwd,
 414                                &got_valid_nt_entry, &seekpos);
 415   if (smb_pwent == NULL) {
 416     if(add_user == False) {
 417       fprintf(stderr, "%s: Failed to find entry for user %s in file %s.\n",
 418               argv[0], pwd->pw_name, pfile);
 419       fclose(fp);
 420       pw_file_unlock(lockfd);
 421       exit(1);
 422     }
 423
 424     /* Create a new smb passwd entry and set it to the given password. */
 425     {
 426       int fd;
 427       int new_entry_length;
 428       char *new_entry;
 429       long offpos;
 430
 431       /* The add user write needs to be atomic - so get the fd from
 432          the fp and do a raw write() call.
 433        */
 434       fd = fileno(fp);
 435
 436       if((offpos = lseek(fd, 0, SEEK_END)) == -1) {
 437         fprintf(stderr, "%s: Failed to add entry for user %s to file %s. \
 438 Error was %s\n", argv[0], pwd->pw_name, pfile, strerror(errno));
 439         fclose(fp);
 440         pw_file_unlock(lockfd);
 441         exit(1);
 442       }
 443
 444       new_entry_length = strlen(pwd->pw_name) + 1 + 15 + 1 +
 445                          32 + 1 + 32 + 1 + strlen(pwd->pw_gecos) +
 446                          1 + strlen(pwd->pw_dir) + 1 +
 447                          strlen(pwd->pw_shell) + 1;
 448       if((new_entry = (char *)malloc( new_entry_length )) == 0) {
 449         fprintf(stderr, "%s: Failed to add entry for user %s to file %s. \
 450 Error was %s\n", argv[0], pwd->pw_name, pfile, strerror(errno));
 451         fclose(fp);
 452         pw_file_unlock(lockfd);
 453         exit(1);
 454       }
 455
 456       sprintf(new_entry, "%s:%u:", pwd->pw_name, (unsigned)pwd->pw_uid);
 457       p = &new_entry[strlen(new_entry)];
 458       for( i = 0; i < 16; i++)
 459         sprintf(&p[i*2], "%02X", new_p16[i]);
 460       p += 32;
 461       *p++ = ':';
 462       for( i = 0; i < 16; i++)
 463         sprintf(&p[i*2], "%02X", new_nt_p16[i]);
 464       p += 32;
 465       *p++ = ':';
 466       sprintf(p, "%s:%s:%s\n", pwd->pw_gecos,
 467               pwd->pw_dir, pwd->pw_shell);
 468       if(write(fd, new_entry, strlen(new_entry)) != strlen(new_entry)) {
 469         fprintf(stderr, "%s: Failed to add entry for user %s to file %s. \
 470 Error was %s\n", argv[0], pwd->pw_name, pfile, strerror(errno));
 471         /* Remove the entry we just wrote. */
 472         if(ftruncate(fd, offpos) == -1) {
 473           fprintf(stderr, "%s: ERROR failed to ftruncate file %s. \
 474 Error was %s. Password file may be corrupt ! Please examine by hand !\n",
 475                    argv[0], pwd->pw_name, strerror(errno));
 476         }
 477         fclose(fp);
 478         pw_file_unlock(lockfd);
 479         exit(1);
 480       }
 481
 482       fclose(fp);
 483       pw_file_unlock(lockfd);
 484       exit(0);
 485     }
 486   } else {
 487           /* the entry already existed */
 488           add_user = False;
 489   }
 490
 491   /* If we are root or the password is 'NO PASSWORD' then
 492      we don't need to check the old password. */
 493   if (real_uid != 0) {
 494     if (valid_old_pwd == False) {
 495       fprintf(stderr, "%s: User %s has no old SMB password.\n", argv[0], pwd->pw_name);
 496     }
 497     /* Check the old Lanman password - NULL means 'NO PASSWORD' */
 498     if (smb_pwent->smb_passwd != NULL) {
 499       if (memcmp(old_p16, smb_pwent->smb_passwd, 16)) {
 500         fprintf(stderr, "%s: Couldn't change password.\n", argv[0]);
 501         fclose(fp);
 502         pw_file_unlock(lockfd);
 503         exit(1);
 504       }
 505     }
 506     /* Check the NT password if it exists */
 507     if (smb_pwent->smb_nt_passwd != NULL) {
 508       if (memcmp(old_nt_p16, smb_pwent->smb_nt_passwd, 16)) {
 509         fprintf(stderr, "%s: Couldn't change password.\n", argv[0]);
 510         fclose(fp);
 511         pw_file_unlock(lockfd);
 512         exit(1);
 513       }
 514     }
 515   }
 516   /*
 517    * If we get here either we were root or the old password checked out
 518    * ok.
 519    */
 520   /* Create the 32 byte representation of the new p16 */
 521   for (i = 0; i < 16; i++) {
 522     sprintf(&ascii_p16[i * 2], "%02X", (uchar) new_p16[i]);
 523   }
 524   if(got_valid_nt_entry) {
 525     /* Add on the NT md4 hash */
 526     ascii_p16[32] = ':';
 527     for (i = 0; i < 16; i++) {
 528       sprintf(&ascii_p16[(i * 2)+33], "%02X", (uchar) new_nt_p16[i]);
 529     }
 530   }
 531   /*
 532    * Do an atomic write into the file at the position defined by
 533    * seekpos.
 534    */
 535   pwfd = fileno(fp);
 536   ret = lseek(pwfd, seekpos - 1, SEEK_SET);
 537   if (ret != seekpos - 1) {
 538     err = errno;
 539     fprintf(stderr, "%s: seek fail on file %s.\n",
 540             argv[0], pfile);
 541     fclose(fp);
 542     errno = err;
 543     perror(argv[0]);
 544     pw_file_unlock(lockfd);
 545     exit(1);
 546   }
 547   /* Sanity check - ensure the character is a ':' */
 548   if (read(pwfd, &c, 1) != 1) {
 549     err = errno;
 550     fprintf(stderr, "%s: read fail on file %s.\n",
 551             argv[0], pfile);
 552     fclose(fp);
 553     errno = err;
 554     perror(argv[0]);
 555     pw_file_unlock(lockfd);
 556     exit(1);
 557   }
 558   if (c != ':') {
 559     fprintf(stderr, "%s: sanity check on passwd file %s failed.\n",
 560             argv[0], pfile);
 561     fclose(fp);
 562     pw_file_unlock(lockfd);
 563     exit(1);
 564   }
 565   writelen = (got_valid_nt_entry) ? 65 : 32;
 566   if (write(pwfd, ascii_p16, writelen) != writelen) {
 567     err = errno;
 568     fprintf(stderr, "%s: write fail in file %s.\n",
 569             argv[0], pfile);
 570     fclose(fp);
 571     errno = err;
 572     perror(argv[0]);
 573     pw_file_unlock(lockfd);
 574     exit(err);
 575   }
 576   fclose(fp);
 577   pw_file_unlock(lockfd);
 578   printf("Password changed\n");
 579   return 0;
 580 }
 581