summaryrefslogtreecommitdiff
path: root/source/utils/smbpasswd.c
blob: 167eb2ed5f3695458f584caa5a51cae545454c4c (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
#ifdef SMB_PASSWD

/*
 * Unix SMB/Netbios implementation. Version 1.9. smbpasswd module. Copyright
 * (C) Jeremy Allison 1995.
 * 
 * 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"
#include "des.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(p,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(p, "NO PASSWORD", 11)) {
			pw_buf.smb_passwd = NULL;	/* No password */
		} else {
			if(!gethexpwd(p,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(p,smbntpwd))
					pw_buf.smb_nt_passwd = smbntpwd;
			}
		}
		return &pw_buf;
	}
	return NULL;
}

/*
 * Print command usage on stderr and die.
 */
void 
usage(char *name)
{
	fprintf(stderr, "Usage is : %s [username]\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;
  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];
  
  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. */
    if (argc != 1 && argc != 2)
      usage(argv[0]);
  } else if (argc != 1)
    usage(argv[0]);
  
  
  if (real_uid == 0 && argc == 2) {
    /* If we are root we can change anothers password. */
    strncpy(user_name, argv[1], sizeof(user_name) - 1);
    user_name[sizeof(user_name) - 1] = '\0';
    pwd = getpwnam(user_name);
  } else {
    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) {
    p = getpass("Old SMB password:");
    strncpy(old_passwd, p, sizeof(fstring));
    old_passwd[sizeof(fstring)-1] = '\0';
  }
  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 (strcmp(p, new_passwd)) {
    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
   */
  if ((fp = fopen(pfile, "r+")) == NULL) {
    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) {
    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);
  }
  /* If we are root we don't need to check the old password. */
  if (real_uid != 0) {
    if ((valid_old_pwd == False) || (smb_pwent->smb_passwd == NULL)) {
      fprintf(stderr, "%s: User %s is disabled, plase contact your administrator to enable it.\n", argv[0], pwd->pw_name);
      fclose(fp);
      pw_file_unlock(lockfd);
      exit(1);
    }
    /* Check the old Lanman password */
    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;
}

#else

#include "includes.h"

int 
main(int argc, char **argv)
{
  printf("smb password encryption not selected in Makefile\n");
  return 0;
}
#endif