summaryrefslogtreecommitdiff
path: root/source3/utils/smbpasswd.c
blob: a4c25417ca2685fdb502b03cc1cf83cff2d1f241 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
/*
 * Unix SMB/Netbios implementation. Version 1.9. smbpasswd module. Copyright
 * (C) Jeremy Allison 1995-1997.
 * 
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 * 
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 675
 * Mass Ave, Cambridge, MA 02139, USA.
 */

#include "includes.h"

/* Static buffers we will return. */
static struct smb_passwd pw_buf;
static pstring  user_name;
static unsigned char smbpwd[16];
static unsigned char smbntpwd[16];

static int gethexpwd(char *p, char *pwd)
{
	int i;
	unsigned char   lonybble, hinybble;
	char           *hexchars = "0123456789ABCDEF";
	char           *p1, *p2;
	for (i = 0; i < 32; i += 2) {
		hinybble = toupper(p[i]);
		lonybble = toupper(p[i + 1]);

		p1 = strchr(hexchars, hinybble);
		p2 = strchr(hexchars, lonybble);
		if (!p1 || !p2)
			return (False);

		hinybble = PTR_DIFF(p1, hexchars);
		lonybble = PTR_DIFF(p2, hexchars);

		pwd[i / 2] = (hinybble << 4) | lonybble;
	}
	return (True);
}

struct smb_passwd *
_my_get_smbpwnam(FILE * fp, char *name, BOOL * valid_old_pwd, 
		BOOL *got_valid_nt_entry, long *pwd_seekpos)
{
	char            linebuf[256];
	unsigned char   c;
	unsigned char  *p;
	long            uidval;
	long            linebuf_len;

	/*
	 * Scan the file, a line at a time and check if the name matches.
	 */
	while (!feof(fp)) {
		linebuf[0] = '\0';
		*pwd_seekpos = ftell(fp);

		fgets(linebuf, 256, fp);
		if (ferror(fp))
			return NULL;

		/*
		 * Check if the string is terminated with a newline - if not
		 * then we must keep reading and discard until we get one.
		 */
		linebuf_len = strlen(linebuf);
		if (linebuf[linebuf_len - 1] != '\n') {
			c = '\0';
			while (!ferror(fp) && !feof(fp)) {
				c = fgetc(fp);
				if (c == '\n')
					break;
			}
		} else
			linebuf[linebuf_len - 1] = '\0';

		if ((linebuf[0] == 0) && feof(fp))
			break;
		/*
		 * The line we have should be of the form :-
		 * 
		 * username:uid:[32hex bytes]:....other flags presently
		 * ignored....
		 * 
		 * or,
		 * 
		 * username:uid:[32hex bytes]:[32hex bytes]:....ignored....
		 * 
		 * if Windows NT compatible passwords are also present.
		 */

		if (linebuf[0] == '#' || linebuf[0] == '\0')
			continue;
		p = (unsigned char *) strchr(linebuf, ':');
		if (p == NULL)
			continue;
		/*
		 * As 256 is shorter than a pstring we don't need to check
		 * length here - if this ever changes....
		 */
		strncpy(user_name, linebuf, PTR_DIFF(p, linebuf));
		user_name[PTR_DIFF(p, linebuf)] = '\0';
		if (!strequal(user_name, name))
			continue;

		/* User name matches - get uid and password */
		p++;		/* Go past ':' */
		if (!isdigit(*p))
			return (False);

		uidval = atoi((char *) p);
		while (*p && isdigit(*p))
			p++;

		if (*p != ':')
			return (False);

		/*
		 * Now get the password value - this should be 32 hex digits
		 * which are the ascii representations of a 16 byte string.
		 * Get two at a time and put them into the password.
		 */
		p++;
		*pwd_seekpos += PTR_DIFF(p, linebuf);	/* Save exact position
							 * of passwd in file -
							 * this is used by
							 * smbpasswd.c */
		if (*p == '*' || *p == 'X') {
			/* Password deliberately invalid - end here. */
			*valid_old_pwd = False;
			*got_valid_nt_entry = False;
			pw_buf.smb_nt_passwd = NULL;	/* No NT password (yet)*/

			/* Now check if the NT compatible password is
			   available. */
			p += 33; /* Move to the first character of the line after 
						the lanman password. */
			if ((linebuf_len >= (PTR_DIFF(p, linebuf) + 33)) && (p[32] == ':')) {
				/* NT Entry was valid - even if 'X' or '*', can be overwritten */
				*got_valid_nt_entry = True;
				if (*p != '*' && *p != 'X') {
				  if (gethexpwd((char *)p,(char *)smbntpwd))
				    pw_buf.smb_nt_passwd = smbntpwd;
				}
			}
			pw_buf.smb_name = user_name;
			pw_buf.smb_userid = uidval;
			pw_buf.smb_passwd = NULL;	/* No password */
			return (&pw_buf);
		}
		if (linebuf_len < (PTR_DIFF(p, linebuf) + 33))
			return (False);

		if (p[32] != ':')
			return (False);

		if (!strncasecmp((char *)p, "NO PASSWORD", 11)) {
		  pw_buf.smb_passwd = NULL;	/* No password */
		} else {
		  if(!gethexpwd((char *)p,(char *)smbpwd))
		    return False;
		  pw_buf.smb_passwd = smbpwd;
		}

		pw_buf.smb_name = user_name;
		pw_buf.smb_userid = uidval;
		pw_buf.smb_nt_passwd = NULL;
		*got_valid_nt_entry = False;
		*valid_old_pwd = True;

		/* Now check if the NT compatible password is
		   available. */
		p += 33; /* Move to the first character of the line after 
					the lanman password. */
		if ((linebuf_len >= (PTR_DIFF(p, linebuf) + 33)) && (p[32] == ':')) {
			/* NT Entry was valid - even if 'X' or '*', can be overwritten */
			*got_valid_nt_entry = True;
			if (*p != '*' && *p != 'X') {
			  if (gethexpwd((char *)p,(char *)smbntpwd))
			    pw_buf.smb_nt_passwd = smbntpwd;
			}
		}
		return &pw_buf;
	}
	return NULL;
}

/*
 * Print command usage on stderr and die.
 */
static void usage(char *name)
{
	fprintf(stderr, "Usage is : %s [-add] [username] [password]\n", name);
	exit(1);
}

 int main(int argc, char **argv)
{
  int             real_uid;
  struct passwd  *pwd;
  fstring         old_passwd;
  uchar           old_p16[16];
  uchar           old_nt_p16[16];
  fstring         new_passwd;
  uchar           new_p16[16];
  uchar           new_nt_p16[16];
  char           *p;
  struct smb_passwd *smb_pwent;
  FILE           *fp;
  BOOL            valid_old_pwd = False;
  BOOL 			got_valid_nt_entry = False;
  BOOL            add_user = False;
  int             add_pass = 0;
  long            seekpos;
  int             pwfd;
  char            ascii_p16[66];
  char            c;
  int             ret, i, err, writelen;
  int             lockfd = -1;
  char           *pfile = SMB_PASSWD_FILE;
  char            readbuf[16 * 1024];
  
  TimeInit();

  setup_logging(argv[0],True);
  
  charset_initialise();
  
#ifndef DEBUG_PASSWORD
  /* Check the effective uid */
  if (geteuid() != 0) {
    fprintf(stderr, "%s: Must be setuid root.\n", argv[0]);
    exit(1);
  }
#endif
  
  /* Get the real uid */
  real_uid = getuid();
  
  /* Deal with usage problems */
  if (real_uid == 0)
  {
    /* As root we can change anothers password and add a user. */
    if (argc > 4 )
      usage(argv[0]);
  }
  else if (argc == 2 || argc > 3)
  {
    fprintf(stderr, "%s: Only root can set anothers password.\n", argv[0]);
    usage(argv[0]);
  }
  
  if (real_uid == 0 && (argc > 1))
  {
    /* We are root - check if we should add the user */
    if ((argv[1][0] == '-') && (argv[1][1] == 'a'))
      add_user = True;

    if(add_user && (argc <= 2 || argc > 4))
      usage(argv[0]);

    /* root can specify password on command-line */
    if (argc == (add_user ? 4 : 3))
    {
      /* -a argument (add_user): new password is 3rd argument. */
      /* no -a argument (add_user): new password is 2nd argument */

      add_pass = add_user ? 3 : 2;
    }

    /* If we are root we can change another's password. */
    strncpy(user_name, add_user ? argv[2] : argv[1], sizeof(user_name) - 1);
    user_name[sizeof(user_name) - 1] = '\0';

    pwd = getpwnam(user_name);
  }
  else
  {
    /* non-root can specify old pass / new pass on command-line */
    if (argc == 3)
    {
       /* non-root specifies new password as 2nd argument */
       add_pass = 2;
    }

    pwd = getpwuid(real_uid);
  }
  
  if (pwd == 0) {
    fprintf(stderr, "%s: Unable to get UNIX password entry for user.\n", argv[0]);
    exit(1);
  }

  /* If we are root we don't ask for the old password. */
  old_passwd[0] = '\0';
  if (real_uid != 0)
  {
    if (add_pass)
    {
      /* old password, as non-root, is 1st argument */
      strncpy(old_passwd, argv[1], sizeof(fstring));
    }
    else
    {
      p = getpass("Old SMB password:");
      strncpy(old_passwd, p, sizeof(fstring));
    }
    old_passwd[sizeof(fstring)-1] = '\0';
  }

  if (add_pass)
  {
    /* new password is specified on the command line */
    strncpy(new_passwd, argv[add_user ? 3 : 2], sizeof(new_passwd) - 1);
    new_passwd[sizeof(new_passwd) - 1] = '\0';
  }
  else
  {
    new_passwd[0] = '\0';

    p = getpass("New SMB password:");

    strncpy(new_passwd, p, sizeof(fstring));
    new_passwd[sizeof(fstring)-1] = '\0';

    p = getpass("Retype new SMB password:");

    if (strncmp(p, new_passwd, sizeof(fstring)-1))
    {
      fprintf(stderr, "%s: Mismatch - password unchanged.\n", argv[0]);
      exit(1);
    }
  }
  
  if (new_passwd[0] == '\0')
  {
    printf("Password not set\n");
    exit(0);
  }
  
  /* Calculate the MD4 hash (NT compatible) of the old and new passwords */
  memset(old_nt_p16, '\0', 16);
  E_md4hash((uchar *)old_passwd, old_nt_p16);
  
  memset(new_nt_p16, '\0', 16);
  E_md4hash((uchar *) new_passwd, new_nt_p16);
  
  /* Mangle the passwords into Lanman format */
  old_passwd[14] = '\0';
  strupper(old_passwd);
  new_passwd[14] = '\0';
  strupper(new_passwd);
  
  /*
   * Calculate the SMB (lanman) hash functions of both old and new passwords.
   */
  
  memset(old_p16, '\0', 16);
  E_P16((uchar *) old_passwd, old_p16);
  
  memset(new_p16, '\0', 16);
  E_P16((uchar *) new_passwd, new_p16);
  
  /*
   * Open the smbpaswd file XXXX - we need to parse smb.conf to get the
   * filename
   */
  fp = fopen(pfile, "r+");
  if (!fp && errno == ENOENT) {
	  fp = fopen(pfile, "w");
	  if (fp) {
		  fprintf(fp, "# Samba SMB password file\n");
		  fclose(fp);
		  fp = fopen(pfile, "r+");
	  }
  }
  if (!fp) {
	  err = errno;
	  fprintf(stderr, "%s: Failed to open password file %s.\n",
		  argv[0], pfile);
	  errno = err;
	  perror(argv[0]);
	  exit(err);
  }
  
  /* Set read buffer to 16k for effiecient reads */
  setvbuf(fp, readbuf, _IOFBF, sizeof(readbuf));
  
  /* make sure it is only rw by the owner */
  chmod(pfile, 0600);

  /* Lock the smbpasswd file for write. */
  if ((lockfd = pw_file_lock(pfile, F_WRLCK, 5)) < 0) {
    err = errno;
    fprintf(stderr, "%s: Failed to lock password file %s.\n",
	    argv[0], pfile);
    fclose(fp);
    errno = err;
    perror(argv[0]);
    exit(err);
  }
  /* Get the smb passwd entry for this user */
  smb_pwent = _my_get_smbpwnam(fp, pwd->pw_name, &valid_old_pwd, 
			       &got_valid_nt_entry, &seekpos);
  if (smb_pwent == NULL) {
    if(add_user == False) {
      fprintf(stderr, "%s: Failed to find entry for user %s in file %s.\n",
  	      argv[0], pwd->pw_name, pfile);
      fclose(fp);
      pw_file_unlock(lockfd);
      exit(1);
    }

    /* Create a new smb passwd entry and set it to the given password. */
    {
      int fd;
      int new_entry_length;
      char *new_entry;
      long offpos;

      /* The add user write needs to be atomic - so get the fd from 
         the fp and do a raw write() call.
       */
      fd = fileno(fp);

      if((offpos = lseek(fd, 0, SEEK_END)) == -1) {
        fprintf(stderr, "%s: Failed to add entry for user %s to file %s. \
Error was %s\n", argv[0], pwd->pw_name, pfile, strerror(errno));
        fclose(fp);
        pw_file_unlock(lockfd);
        exit(1);
      }

      new_entry_length = strlen(pwd->pw_name) + 1 + 15 + 1 + 
                         32 + 1 + 32 + 1 + strlen(pwd->pw_gecos) + 
                         1 + strlen(pwd->pw_dir) + 1 + 
                         strlen(pwd->pw_shell) + 1;
      if((new_entry = (char *)malloc( new_entry_length )) == 0) {
        fprintf(stderr, "%s: Failed to add entry for user %s to file %s. \
Error was %s\n", argv[0], pwd->pw_name, pfile, strerror(errno));
        fclose(fp);
        pw_file_unlock(lockfd);
        exit(1);
      }

      sprintf(new_entry, "%s:%u:", pwd->pw_name, pwd->pw_uid);
      p = &new_entry[strlen(new_entry)];
      for( i = 0; i < 16; i++)
        sprintf(&p[i*2], "%02X", new_p16[i]);
      p += 32;
      *p++ = ':';
      for( i = 0; i < 16; i++)
        sprintf(&p[i*2], "%02X", new_nt_p16[i]);
      p += 32;
      *p++ = ':';
      sprintf(p, "%s:%s:%s\n", pwd->pw_gecos, 
              pwd->pw_dir, pwd->pw_shell);
      if(write(fd, new_entry, strlen(new_entry)) != strlen(new_entry)) {
        fprintf(stderr, "%s: Failed to add entry for user %s to file %s. \
Error was %s\n", argv[0], pwd->pw_name, pfile, strerror(errno));
        /* Remove the entry we just wrote. */
        if(ftruncate(fd, offpos) == -1) {
          fprintf(stderr, "%s: ERROR failed to ftruncate file %s. \
Error was %s. Password file may be corrupt ! Please examine by hand !\n", 
                   argv[0], pwd->pw_name, strerror(errno));
        }
        fclose(fp);
        pw_file_unlock(lockfd);
        exit(1);
      }
      
      fclose(fp);  
      pw_file_unlock(lockfd);  
      exit(0);
    }
  } else {
	  /* the entry already existed */
	  add_user = False;
  }

  /* If we are root or the password is 'NO PASSWORD' then
     we don't need to check the old password. */
  if (real_uid != 0) {
    if (valid_old_pwd == False) {
      fprintf(stderr, "%s: User %s has no old SMB password.\n", argv[0], pwd->pw_name);
    }
    /* Check the old Lanman password - NULL means 'NO PASSWORD' */
    if (smb_pwent->smb_passwd != NULL) {
      if (memcmp(old_p16, smb_pwent->smb_passwd, 16)) {
        fprintf(stderr, "%s: Couldn't change password.\n", argv[0]);
        fclose(fp);
        pw_file_unlock(lockfd);
        exit(1);
      }
    }
    /* Check the NT password if it exists */
    if (smb_pwent->smb_nt_passwd != NULL) {
      if (memcmp(old_nt_p16, smb_pwent->smb_nt_passwd, 16)) {
	fprintf(stderr, "%s: Couldn't change password.\n", argv[0]);
	fclose(fp);
	pw_file_unlock(lockfd);
	exit(1);
      }
    }
  }
  /*
   * If we get here either we were root or the old password checked out
   * ok.
   */
  /* Create the 32 byte representation of the new p16 */
  for (i = 0; i < 16; i++) {
    sprintf(&ascii_p16[i * 2], "%02X", (uchar) new_p16[i]);
  }
  if(got_valid_nt_entry) {
    /* Add on the NT md4 hash */
    ascii_p16[32] = ':';
    for (i = 0; i < 16; i++) {
      sprintf(&ascii_p16[(i * 2)+33], "%02X", (uchar) new_nt_p16[i]);
    }
  }
  /*
   * Do an atomic write into the file at the position defined by
   * seekpos.
   */
  pwfd = fileno(fp);
  ret = lseek(pwfd, seekpos - 1, SEEK_SET);
  if (ret != seekpos - 1) {
    err = errno;
    fprintf(stderr, "%s: seek fail on file %s.\n",
	    argv[0], pfile);
    fclose(fp);
    errno = err;
    perror(argv[0]);
    pw_file_unlock(lockfd);
    exit(1);
  }
  /* Sanity check - ensure the character is a ':' */
  if (read(pwfd, &c, 1) != 1) {
    err = errno;
    fprintf(stderr, "%s: read fail on file %s.\n",
	    argv[0], pfile);
    fclose(fp);
    errno = err;
    perror(argv[0]);
    pw_file_unlock(lockfd);
    exit(1);
  }
  if (c != ':') {
    fprintf(stderr, "%s: sanity check on passwd file %s failed.\n",
	    argv[0], pfile);
    fclose(fp);
    pw_file_unlock(lockfd);
    exit(1);
  }
  writelen = (got_valid_nt_entry) ? 65 : 32;
  if (write(pwfd, ascii_p16, writelen) != writelen) {
    err = errno;
    fprintf(stderr, "%s: write fail in file %s.\n",
	    argv[0], pfile);
    fclose(fp);
    errno = err;
    perror(argv[0]);
    pw_file_unlock(lockfd);
    exit(err);
  }
  fclose(fp);
  pw_file_unlock(lockfd);
  printf("Password changed\n");
  return 0;
}