source/utils/smbpasswd.c

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