aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/cvs/src/login.c
blob: 58b2c7a2d836dac1b36c70c22aca2ea2d7b31241 (plain) (blame)
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
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
/*
 * Copyright (c) 1995, Cyclic Software, Bloomington, IN, USA
 * 
 * You may distribute under the terms of the GNU General Public License as
 * specified in the README file that comes with CVS.
 * 
 * Allow user to log in for an authenticating server.
 *
 * $FreeBSD$
 */

#include "cvs.h"
#include "getline.h"

#ifdef AUTH_CLIENT_SUPPORT   /* This covers the rest of the file. */

#ifdef HAVE_GETPASSPHRASE
#define GETPASS getpassphrase
#else
#define GETPASS getpass
#endif

/* There seems to be very little agreement on which system header
   getpass is declared in.  With a lot of fancy autoconfiscation,
   we could perhaps detect this, but for now we'll just rely on
   _CRAY, since Cray is perhaps the only system on which our own
   declaration won't work (some Crays declare the 2#$@% thing as
   varadic, believe it or not).  On Cray, getpass will be declared
   in either stdlib.h or unistd.h.  */
#ifndef _CRAY
extern char *GETPASS ();
#endif

#ifndef CVS_PASSWORD_FILE 
#define CVS_PASSWORD_FILE ".cvspass"
#endif

/* If non-NULL, get_cvs_password() will just return this. */
static char *cvs_password = NULL;

static char *construct_cvspass_filename PROTO ((void));

/* The return value will need to be freed. */
static char *
construct_cvspass_filename ()
{
    char *homedir;
    char *passfile;

    /* Environment should override file. */
    if ((passfile = getenv ("CVS_PASSFILE")) != NULL)
	return xstrdup (passfile);

    /* Construct absolute pathname to user's password file. */
    /* todo: does this work under OS/2 ? */
    homedir = get_homedir ();
    if (! homedir)
    {
	/* FIXME?  This message confuses a lot of users, at least
	   on Win95 (which doesn't set HOMEDRIVE and HOMEPATH like
	   NT does).  I suppose the answer for Win95 is to store the
	   passwords in the registry or something (??).  And .cvsrc
	   and such too?  Wonder what WinCVS does (about .cvsrc, the
	   right thing for a GUI is to just store the password in
	   memory only)...  */
	error (1, 0, "could not find out home directory");
	return (char *) NULL;
    }

    passfile = strcat_filename_onto_homedir (homedir, CVS_PASSWORD_FILE);

    /* Safety first and last, Scouts. */
    if (isfile (passfile))
	/* xchmod() is too polite. */
	chmod (passfile, 0600);

    return passfile;
}



/*
 * static char *
 * password_entry_parseline (
 *			      const char *cvsroot_canonical,
 *			      const unsigned char warn,
 *			      const int linenumber,
 *			      char *linebuf
 *			     );
 *
 * Internal function used by password_entry_operation.  Parse a single line
 * from a ~/.cvsroot password file and return a pointer to the password if the
 * line refers to the same cvsroot as cvsroot_canonical
 *
 * INPUTS
 *	cvsroot_canonical	the root we are looking for
 *	warn			Boolean: print warnings for invalid lines?
 *	linenumber		the line number for error messages
 *	linebuf			the current line
 *
 * RETURNS
 * 	NULL			if the line doesn't match
 * 	char *password		as a pointer into linebuf
 *
 * NOTES
 *	This function temporarily alters linebuf, so it isn't thread safe when
 *	called on the same linebuf
 */
static char *
password_entry_parseline (cvsroot_canonical, warn, linenumber, linebuf)
    const char *cvsroot_canonical;
    const unsigned char warn;
    const int linenumber;
    char *linebuf;
{
    char *password = NULL;
    char *p;

    /* look for '^/' */
    if (*linebuf == '/')
    {
	/* Yes: slurp '^/\d+\D' and parse the rest of the line according to version number */
	char *q;
	unsigned long int entry_version;

	if (isspace(*(linebuf + 1)))
	    /* special case since strtoul ignores leading white space */
	    entry_version = 0;
	else
	    entry_version = strtoul (linebuf + 1, &q, 10);

	if (q == linebuf + 1)
	    /* no valid digits found by strtoul */
	    entry_version = 0;
	else
	    /* assume a delimiting seperator */
	    q++;

	switch (entry_version)
	{
	    case 1:
		/* this means the same normalize_cvsroot we are using was
		 * used to create this entry.  strcmp is good enough for
		 * us.
		 */
		p = strchr (q, ' ');
		if (p == NULL)
		{
		    if (warn && !really_quiet)
			error (0, 0, "warning: skipping invalid entry in password file at line %d",
				linenumber);
		}
		else
		{
		    *p = '\0';
		    if (strcmp (cvsroot_canonical, q) == 0)
			password = p + 1;
		    *p = ' ';
		}
		break;
	    case ULONG_MAX:
		if (warn && !really_quiet)
		{
		    error (0, errno, "warning: unable to convert version number in password file at line %d",
			    linenumber);
		    error (0, 0, "skipping entry");
		}
		break;
	    case 0:
		if (warn && !really_quiet)
		    error (0, 0, "warning: skipping entry with invalid version string in password file at line %d",
			    linenumber);
		break;
	    default:
		if (warn && !really_quiet)
		    error (0, 0, "warning: skipping entry with unknown version (%lu) in password file at line %d",
			    entry_version, linenumber);
		break;
	}
    }
    else
    {
	/* No: assume:
	 *
	 *	^cvsroot Aencoded_password$
	 *
	 * as header comment specifies and parse accordingly
	 */
	cvsroot_t *tmp_root;
	char *tmp_root_canonical;

	p = strchr (linebuf, ' ');
	if (p == NULL)
	{
	    if (warn && !really_quiet)
		error (0, 0, "warning: skipping invalid entry in password file at line %d", linenumber);
	    return NULL;;
	}

	*p = '\0';
	if ((tmp_root = parse_cvsroot (linebuf)) == NULL)
	{
	    if (warn && !really_quiet)
		error (0, 0, "warning: skipping invalid entry in password file at line %d", linenumber);
	    *p = ' ';
	    return NULL;
	}
	*p = ' ';
	tmp_root_canonical = normalize_cvsroot (tmp_root);
	if (strcmp (cvsroot_canonical, tmp_root_canonical) == 0)
	    password = p + 1;

	free (tmp_root_canonical);
	free_cvsroot_t (tmp_root);
    }

    return password;
}



/*
 * static char *
 * password_entry_operation (
 * 			     password_entry_operation_t operation,
 * 			     cvsroot_t *root,
 * 			     char *newpassword
 * 			    );
 *
 * Search the password file and depending on the value of operation:
 *
 *	Mode				Action
 *	password_entry_lookup		Return the password
 *	password_entry_delete		Delete the entry from the file, if it exists
 *	password_entry_add		Replace the line with the new one, else append it
 *
 * Because the user might be accessing multiple repositories, with
 * different passwords for each one, the format of ~/.cvspass is:
 *
 * [user@]host:[port]/path Aencoded_password
 * [user@]host:[port]/path Aencoded_password
 * ...
 *
 * New entries are always of the form:
 *
 * /1 user@host:port/path Aencoded_password
 *
 * but the old format is supported for backwards compatibility.
 * The entry version string wasn't strictly necessary, but it avoids the
 * overhead of parsing some entries since we know it is already in canonical
 * form and allows room for expansion later, say, if we want to allow spaces
 * and/or other characters to be escaped in the string.  Also, the new entries
 * would have been ignored by old versions of CVS anyhow since those versions
 * didn't know how to parse a port number.
 *
 * The "A" before "encoded_password" is a literal capital A.  It's a
 * version number indicating which form of scrambling we're doing on
 * the password -- someday we might provide something more secure than
 * the trivial encoding we do now, and when that day comes, it would
 * be nice to remain backward-compatible.
 *
 * Like .netrc, the file's permissions are the only thing preventing
 * it from being read by others.  Unlike .netrc, we will not be
 * fascist about it, at most issuing a warning, and never refusing to
 * work.
 *
 * INPUTS
 * 	operation	operation to perform
 * 	root		cvsroot_t to look up
 * 	newpassword	prescrambled new password, for password_entry_add_mode
 *
 * RETURNS
 * 	-1	if password_entry_lookup_mode not specified
 * 	NULL	on failed lookup
 * 	pointer to a copy of the password string otherwise, which the caller is
 * 		responsible for disposing of
 */

typedef enum password_entry_operation_e {
    password_entry_lookup,
    password_entry_delete,
    password_entry_add
} password_entry_operation_t;

static char *
password_entry_operation (operation, root, newpassword)
    password_entry_operation_t operation;
    cvsroot_t *root;
    char *newpassword;
{
    char *passfile;
    FILE *fp;
    char *cvsroot_canonical = NULL;
    char *password = NULL;
    int line_length;
    long line;
    char *linebuf = NULL;
    size_t linebuf_len;
    char *p;
    int save_errno = 0;

    if (root->method != pserver_method)
    {
	error (0, 0, "internal error: can only call password_entry_operation with pserver method");
	error (1, 0, "CVSROOT: %s", root->original);
    }

    cvsroot_canonical = normalize_cvsroot (root);

    /* Yes, the method below reads the user's password file twice when we have
     * to delete an entry.  It's inefficient, but we're not talking about a gig of
     * data here.
     */

    passfile = construct_cvspass_filename ();
    fp = CVS_FOPEN (passfile, "r");
    if (fp == NULL)
    {
	error (0, errno, "warning: failed to open %s for reading", passfile);
	goto process;
    }

    /* Check each line to see if we have this entry already. */
    line = 0;
    while ((line_length = getline (&linebuf, &linebuf_len, fp)) >= 0)
    {
	line++;
	password = password_entry_parseline(cvsroot_canonical, 1, line, linebuf);
	if (password != NULL)
	    /* this is it!  break out and deal with linebuf */
	    break;
    }
    if (line_length < 0 && !feof (fp))
    {
	error (0, errno, "cannot read %s", passfile);
	goto error_exit;
    }
    if (fclose (fp) < 0)
	/* not fatal, unless it cascades */
	error (0, errno, "cannot close %s", passfile);
    fp = NULL;

    /* Utter, total, raving paranoia, I know. */
    chmod (passfile, 0600);

    /* a copy to return or keep around so we can reuse linebuf */
    if (password != NULL)
    {
	/* chomp the EOL */
	p = strchr (password, '\n');
	if (p != NULL)
	    *p = '\0';
	password = xstrdup (password);
    }

process:

    /* might as well return now */
    if (operation == password_entry_lookup)
	goto out;

    /* same here */
    if (operation == password_entry_delete && password == NULL)
    {
	error (0, 0, "Entry not found.");
	goto out;
    }

    /* okay, file errors can simply be fatal from now on since we don't do
     * anything else if we're in lookup mode
     */

    /* copy the file with the entry deleted unless we're in add
     * mode and the line we found contains the same password we're supposed to
     * add
     */
    if (!noexec && password != NULL && (operation == password_entry_delete
	    || (operation == password_entry_add && strcmp (password, newpassword))))
    {
	long found_at = line;
	char *tmp_name;
	FILE *tmp_fp;

	/* open the original file again */
	fp = CVS_FOPEN (passfile, "r");
	if (fp == NULL)
	    error (1, errno, "failed to open %s for reading", passfile);

	/* create and open a temp file */
	if ((tmp_fp = cvs_temp_file (&tmp_name)) == NULL)
	    error (1, errno, "unable to open temp file %s", tmp_name);

	line = 0;
	while ((line_length = getline (&linebuf, &linebuf_len, fp)) >= 0)
	{
	    line++;
	    if (line < found_at
		|| (line != found_at
		    && !password_entry_parseline(cvsroot_canonical, 0, line, linebuf)))
	    {
		if (fprintf (tmp_fp, "%s", linebuf) == EOF)
		{
		    /* try and clean up anyhow */
		    error (0, errno, "fatal error: cannot write %s", tmp_name);
		    if (fclose (tmp_fp) == EOF)
			error (0, errno, "cannot close %s", tmp_name);
		    /* call CVS_UNLINK instead of unlink_file since the file
		     * got created in noexec mode
		     */
		    if (CVS_UNLINK (tmp_name) < 0)
			error (0, errno, "cannot remove %s", tmp_name);
		    /* but quit so we don't remove all the entries from a
		     * user's password file accidentally
		     */
		    error (1, 0, "exiting");
		}
	    }
	}
	if (line_length < 0 && !feof (fp))
	{
	    error (0, errno, "cannot read %s", passfile);
	    goto error_exit;
	}
	if (fclose (fp) < 0)
	    /* not fatal, unless it cascades */
	    error (0, errno, "cannot close %s", passfile);
	if (fclose (tmp_fp) < 0)
	    /* not fatal, unless it cascades */
	    /* FIXME - does copy_file return correct results if the file wasn't
	     * closed? should this be fatal?
	     */
	    error (0, errno, "cannot close %s", tmp_name);

	/* FIXME: rename_file would make more sense (e.g. almost
	 * always faster).
	 *
	 * I don't think so, unless we change the way rename_file works to
	 * attempt a cp/rm sequence when rename fails since rename doesn't
	 * work across file systems and it isn't uncommon to have /tmp
	 * on its own partition.
	 *
	 * For that matter, it's probably not uncommon to have a home
	 * directory on an NFS mount.
	 */
	copy_file (tmp_name, passfile);
	if (CVS_UNLINK (tmp_name) < 0)
	    error (0, errno, "cannot remove %s", tmp_name);
	free (tmp_name);
    }

    /* in add mode, if we didn't find an entry or found an entry with a
     * different password, append the new line
     */
    if (!noexec && operation == password_entry_add
	    && (password == NULL || strcmp (password, newpassword)))
    {
	if ((fp = CVS_FOPEN (passfile, "a")) == NULL)
	    error (1, errno, "could not open %s for writing", passfile);

	if (fprintf (fp, "/1 %s %s\n", cvsroot_canonical, newpassword) == EOF)
	    error (1, errno, "cannot write %s", passfile);
	if (fclose (fp) < 0)
	    error (0, errno, "cannot close %s", passfile);
    }

    /* Utter, total, raving paranoia, I know. */
    chmod (passfile, 0600);

    if (password)
    {
	free (password);
	password = NULL;
    }
    if (linebuf)
	free (linebuf);

out:
    free (cvsroot_canonical);
    free (passfile);
    return password;

error_exit:
    /* just exit when we're not in lookup mode */
    if (operation != password_entry_lookup)
	error (1, 0, "fatal error: exiting");
    /* clean up and exit in lookup mode so we can try a login with a NULL
     * password anyhow in case that's what we would have found
     */
    save_errno = errno;
    if (fp != NULL)
    {
	/* Utter, total, raving paranoia, I know. */
	chmod (passfile, 0600);
	if(fclose (fp) < 0)
	    error (0, errno, "cannot close %s", passfile);
    }
    if (linebuf)
	free (linebuf);
    if (cvsroot_canonical)
	free (cvsroot_canonical);
    free (passfile);
    errno = save_errno;
    return NULL;
}



/* Prompt for a password, and store it in the file "CVS/.cvspass".
 */

static const char *const login_usage[] =
{
    "Usage: %s %s\n",
    "(Specify the --help global option for a list of other help options)\n",
    NULL
};

int
login (argc, argv)
    int argc;
    char **argv;
{
    char *typed_password;
    char *cvsroot_canonical;

    if (argc < 0)
	usage (login_usage);

    if (current_parsed_root->method != pserver_method)
    {
	error (0, 0, "can only use `login' command with the 'pserver' method");
	error (1, 0, "CVSROOT: %s", current_parsed_root->original);
    }

    cvsroot_canonical = normalize_cvsroot(current_parsed_root);
    printf ("Logging in to %s\n", cvsroot_canonical);
    fflush (stdout);

    if (current_parsed_root->password)
    {
	typed_password = scramble (current_parsed_root->password);
    }
    else
    {
	char *tmp;
	tmp = GETPASS ("CVS password: ");
	/* Must deal with a NULL return value here.  I haven't managed to
	 * disconnect the CVS process from the tty and force a NULL return
	 * in sanity.sh, but the Linux version of getpass is documented
	 * to return NULL when it can't open /dev/tty...
	 */
	if (!tmp) error (1, errno, "login: Failed to read password.");
	typed_password = scramble (tmp);
	memset (tmp, 0, strlen (tmp));
    }

    /* Force get_cvs_password() to use this one (when the client
     * confirms the new password with the server), instead of
     * consulting the file.  We make a new copy because cvs_password
     * will get zeroed by connect_to_server().  */
    cvs_password = xstrdup (typed_password);

    connect_to_pserver (current_parsed_root, NULL, NULL, 1, 0);

    password_entry_operation (password_entry_add, current_parsed_root, typed_password);

    memset (typed_password, 0, strlen (typed_password));
    free (typed_password);

    free (cvs_password);
    free (cvsroot_canonical);
    cvs_password = NULL;

    return 0;
}

/* Returns the _scrambled_ password.  The server must descramble
   before hashing and comparing.  If password file not found, or
   password not found in the file, just return NULL. */
char *
get_cvs_password ()
{
    if (current_parsed_root->password)
	return (scramble(current_parsed_root->password));
 
    /* If someone (i.e., login()) is calling connect_to_pserver() out of
       context, then assume they have supplied the correct, scrambled
       password. */
    if (cvs_password)
	return cvs_password;

    if (getenv ("CVS_PASSWORD") != NULL)
    {
	/* In previous versions of CVS one could specify a password in
	 * CVS_PASSWORD.  This is a bad idea, because in BSD variants
	 * of unix anyone can see the environment variable with 'ps'.
	 * But for users who were using that feature we want to at
	 * least let them know what is going on.  After printing this
	 * warning, we should fall through to the regular error where
	 * we tell them to run "cvs login" (unless they already ran
	 * it, of course).
	 */
	 error (0, 0, "CVS_PASSWORD is no longer supported; ignored");
    }

    if (current_parsed_root->method != pserver_method)
    {
	error (0, 0, "can only call get_cvs_password with pserver method");
	error (1, 0, "CVSROOT: %s", current_parsed_root->original);
    }

    return password_entry_operation (password_entry_lookup, current_parsed_root, NULL);
}

static const char *const logout_usage[] =
{
    "Usage: %s %s\n",
    "(Specify the --help global option for a list of other help options)\n",
    NULL
};

/* Remove any entry for the CVSRoot repository found in .cvspass. */
int
logout (argc, argv)
    int argc;
    char **argv;
{
    char *cvsroot_canonical;

    if (argc < 0)
	usage (logout_usage);

    if (current_parsed_root->method != pserver_method)
    {
	error (0, 0, "can only use pserver method with `logout' command");
	error (1, 0, "CVSROOT: %s", current_parsed_root->original);
    }

    /* Hmm.  Do we want a variant of this command which deletes _all_
       the entries from the current .cvspass?  Might be easier to
       remember than "rm ~/.cvspass" but then again if people are
       mucking with HOME (common in Win95 as the system doesn't set
       it), then this variant of "cvs logout" might give a false sense
       of security, in that it wouldn't delete entries from any
       .cvspass files but the current one.  */

    if (!quiet)
    {
	cvsroot_canonical = normalize_cvsroot(current_parsed_root);
	printf ("Logging out of %s\n", cvsroot_canonical);
	fflush (stdout);
	free (cvsroot_canonical);
    }

    password_entry_operation (password_entry_delete, current_parsed_root, NULL);

    return 0;
}

#endif /* AUTH_CLIENT_SUPPORT from beginning of file. */