summaryrefslogtreecommitdiffstats
path: root/plugins/sudoers/cvtsudoers_pwutil.c
blob: a7b163e914f3c58436e52547597abea4814ea3bc (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
/*
 * SPDX-License-Identifier: ISC
 *
 * Copyright (c) 1996, 1998-2005, 2007-2019
 *	Todd C. Miller <Todd.Miller@sudo.ws>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * Sponsored in part by the Defense Advanced Research Projects
 * Agency (DARPA) and Air Force Research Laboratory, Air Force
 * Materiel Command, USAF, under agreement number F39502-99-1-0512.
 */

/*
 * This is an open source non-commercial project. Dear PVS-Studio, please check it.
 * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
 */

#include <config.h>

#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif /* HAVE_STRINGS_H */
#include <unistd.h>
#include <errno.h>
#include <limits.h>
#include <pwd.h>
#include <grp.h>

#include "sudoers.h"
#include "cvtsudoers.h"
#include "pwutil.h"

#ifndef LOGIN_NAME_MAX
# ifdef _POSIX_LOGIN_NAME_MAX
#  define LOGIN_NAME_MAX _POSIX_LOGIN_NAME_MAX
# else
#  define LOGIN_NAME_MAX 9
# endif
#endif /* LOGIN_NAME_MAX */

#define FIELD_SIZE(src, name, size)			\
do {							\
	if ((src)->name) {				\
		size = strlen((src)->name) + 1;		\
		total += size;				\
	} else {                                        \
		size = 0;				\
	}                                               \
} while (0)

#define FIELD_COPY(src, dst, name, size)		\
do {							\
	if ((src)->name) {				\
		memcpy(cp, (src)->name, size);		\
		(dst)->name = cp;			\
		cp += size;				\
	}						\
} while (0)

/*
 * Dynamically allocate space for a struct item plus the key and data
 * elements.  If name is non-NULL it is used as the key, else the
 * uid is the key.  Fills in datum from the users filter.
 * Returns NULL on calloc error or unknown name/id, setting errno
 * to ENOMEM or ENOENT respectively.
 */
struct cache_item *
cvtsudoers_make_pwitem(uid_t uid, const char *name)
{
    char *cp, uidstr[MAX_UID_T_LEN + 2];
    size_t nsize, psize, gsize, dsize, ssize, total;
#ifdef HAVE_LOGIN_CAP_H
    size_t csize;
#endif
    struct cache_item_pw *pwitem;
    struct passwd pw, *newpw;
    struct sudoers_string *s = NULL;
    debug_decl(cvtsudoers_make_pwitem, SUDOERS_DEBUG_NSS);

    /* Look up name or uid in filter list. */
    if (name != NULL) {
	STAILQ_FOREACH(s, &filters->users, entries) {
	    if (strcasecmp(name, s->str) == 0) {
		uid = (uid_t)-1;
		break;
	    }
	}
    } else {
	STAILQ_FOREACH(s, &filters->users, entries) {
	    const char *errstr;
	    uid_t filter_uid;

	    if (s->str[0] != '#')
		continue;

	    filter_uid = sudo_strtoid(s->str + 1, &errstr);
	    if (errstr == NULL) {
		if (uid != filter_uid)
		    continue;
		(void)snprintf(uidstr, sizeof(uidstr), "#%u",
		    (unsigned int)uid);
		break;
	    }
	}
    }
    if (s == NULL) {
	errno = ENOENT;
	debug_return_ptr(NULL);
    }

    /* Fake up a passwd struct. */
    memset(&pw, 0, sizeof(pw));
    pw.pw_name = name ? s->str : uidstr;
    pw.pw_passwd = "*";
    pw.pw_uid = uid;
    pw.pw_gid = (gid_t)-1;
    pw.pw_shell = _PATH_BSHELL;
    pw.pw_dir = "/";

    /* Allocate in one big chunk for easy freeing. */
    total = sizeof(*pwitem);
    FIELD_SIZE(&pw, pw_name, nsize);
    FIELD_SIZE(&pw, pw_passwd, psize);
#ifdef HAVE_LOGIN_CAP_H
    FIELD_SIZE(&pw, pw_class, csize);
#endif
    FIELD_SIZE(&pw, pw_gecos, gsize);
    FIELD_SIZE(&pw, pw_dir, dsize);
    FIELD_SIZE(&pw, pw_shell, ssize);
    if (name != NULL)
	total += strlen(name) + 1;

    /* Allocate space for struct item, struct passwd and the strings. */
    if ((pwitem = calloc(1, total)) == NULL) {
	sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
	    "unable to allocate memory");
	debug_return_ptr(NULL);
    }
    newpw = &pwitem->pw;

    /*
     * Copy in passwd contents and make strings relative to space
     * at the end of the struct.
     */
    memcpy(newpw, &pw, sizeof(pw));
    cp = (char *)(pwitem + 1);
    FIELD_COPY(&pw, newpw, pw_name, nsize);
    FIELD_COPY(&pw, newpw, pw_passwd, psize);
#ifdef HAVE_LOGIN_CAP_H
    FIELD_COPY(&pw, newpw, pw_class, csize);
#endif
    FIELD_COPY(&pw, newpw, pw_gecos, gsize);
    FIELD_COPY(&pw, newpw, pw_dir, dsize);
    FIELD_COPY(&pw, newpw, pw_shell, ssize);

    /* Set key and datum. */
    if (name != NULL) {
	memcpy(cp, name, strlen(name) + 1);
	pwitem->cache.k.name = cp;
    } else {
	pwitem->cache.k.uid = pw.pw_uid;
    }
    pwitem->cache.d.pw = newpw;
    pwitem->cache.refcnt = 1;

    debug_return_ptr(&pwitem->cache);
}

/*
 * Dynamically allocate space for a struct item plus the key and data
 * elements.  If name is non-NULL it is used as the key, else the
 * gid is the key.  Fills in datum from the groups filter.
 * Returns NULL on calloc error or unknown name/id, setting errno
 * to ENOMEM or ENOENT respectively.
 */
struct cache_item *
cvtsudoers_make_gritem(gid_t gid, const char *name)
{
    char *cp, gidstr[MAX_UID_T_LEN + 2];
    size_t nsize, psize, total, len, nmem = 0;
    struct cache_item_gr *gritem;
    struct group gr, *newgr;
    struct sudoers_string *s = NULL;
    debug_decl(cvtsudoers_make_gritem, SUDOERS_DEBUG_NSS);

    /* Look up name or gid in filter list. */
    if (name != NULL) {
	STAILQ_FOREACH(s, &filters->groups, entries) {
	    if (strcasecmp(name, s->str) == 0) {
		gid = (gid_t)-1;
		break;
	    }
	}
    } else {
	STAILQ_FOREACH(s, &filters->groups, entries) {
	    const char *errstr;
	    gid_t filter_gid;

	    if (s->str[0] != '#')
		continue;

	    filter_gid = sudo_strtoid(s->str + 1, &errstr);
	    if (errstr == NULL) {
		if (gid != filter_gid)
		    continue;
		(void)snprintf(gidstr, sizeof(gidstr), "#%u",
		    (unsigned int)gid);
		break;
	    }
	}
    }
    if (s == NULL) {
	errno = ENOENT;
	debug_return_ptr(NULL);
    }

    /* Fake up a group struct with all filter users as members. */
    memset(&gr, 0, sizeof(gr));
    gr.gr_name = name ? s->str : gidstr;
    gr.gr_gid = gid;

    /* Allocate in one big chunk for easy freeing. */
    total = sizeof(*gritem);
    FIELD_SIZE(&gr, gr_name, nsize);
    FIELD_SIZE(&gr, gr_passwd, psize);
    if (!STAILQ_EMPTY(&filters->users)) {
	STAILQ_FOREACH(s, &filters->users, entries) {
	    total += strlen(s->str) + 1;
	    nmem++;
	}
	total += sizeof(char *) * nmem;
    }
    if (name != NULL)
	total += strlen(name) + 1;

    if ((gritem = calloc(1, total)) == NULL) {
	sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
	    "unable to allocate memory");
	debug_return_ptr(NULL);
    }

    /*
     * Copy in group contents and make strings relative to space
     * at the end of the buffer.  Note that gr_mem must come
     * immediately after struct group to guarantee proper alignment.
     */
    newgr = &gritem->gr;
    memcpy(newgr, &gr, sizeof(gr));
    cp = (char *)(gritem + 1);
    if (nmem != 0) {
	newgr->gr_mem = (char **)cp;
	cp += sizeof(char *) * nmem;
	nmem = 0;
	STAILQ_FOREACH(s, &filters->users, entries) {
	    len = strlen(s->str) + 1;
	    memcpy(cp, s->str, len);
	    newgr->gr_mem[nmem++] = cp;
	    cp += len;
	}
	newgr->gr_mem[nmem] = NULL;
    }
    FIELD_COPY(&gr, newgr, gr_passwd, psize);
    FIELD_COPY(&gr, newgr, gr_name, nsize);

    /* Set key and datum. */
    if (name != NULL) {
	memcpy(cp, name, strlen(name) + 1);
	gritem->cache.k.name = cp;
    } else {
	gritem->cache.k.gid = gr.gr_gid;
    }
    gritem->cache.d.gr = newgr;
    gritem->cache.refcnt = 1;

    debug_return_ptr(&gritem->cache);
}

static struct cache_item_gidlist *gidlist_item;

/*
 * Dynamically allocate space for a struct item plus the key and data
 * elements.  Fills in datum from the groups filter.
 */
struct cache_item *
cvtsudoers_make_gidlist_item(const struct passwd *pw, char * const *unused1,
    unsigned int type)
{
    char *cp;
    size_t nsize, total;
    struct cache_item_gidlist *glitem;
    struct sudoers_string *s;
    struct gid_list *gidlist;
    GETGROUPS_T *gids = NULL;
    int i, ngids = 0;
    debug_decl(cvtsudoers_make_gidlist_item, SUDOERS_DEBUG_NSS);

    /*
     * There's only a single gid list.
     */
    if (gidlist_item != NULL) {
	gidlist_item->cache.refcnt++;
	debug_return_ptr(&gidlist_item->cache);
    }

    /* Count number of possible gids in the filter. */
    STAILQ_FOREACH(s, &filters->groups, entries) {
	if (s->str[0] == '#')
		ngids++;
    }

    /* Allocate gids[] array and fill it with parsed gids. */
    if (ngids != 0) {
	gids = reallocarray(NULL, ngids, sizeof(GETGROUPS_T));
	if (gids == NULL) {
	    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
		"unable to allocate memory");
	    debug_return_ptr(NULL);
	}
	ngids = 0;
	STAILQ_FOREACH(s, &filters->groups, entries) {
	    if (s->str[0] == '#') {
		const char *errstr;
		gid_t gid = sudo_strtoid(s->str + 1, &errstr);
		if (errstr == NULL) {
		    /* Valid gid. */
		    gids[ngids++] = gid;
		}
	    }
	}
    }
    if (ngids == 0) {
	free(gids);
	errno = ENOENT;
	debug_return_ptr(NULL);
    }

    /* Allocate in one big chunk for easy freeing. */
    nsize = strlen(pw->pw_name) + 1;
    total = sizeof(*glitem) + nsize;
    total += sizeof(gid_t *) * ngids;

    if ((glitem = calloc(1, total)) == NULL) {
	sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
	    "unable to allocate memory");
	free(gids);
	debug_return_ptr(NULL);
    }

    /*
     * Copy in group list and make pointers relative to space
     * at the end of the buffer.  Note that the groups array must come
     * immediately after struct group to guarantee proper alignment.
     */
    gidlist = &glitem->gidlist;
    cp = (char *)(glitem + 1);
    gidlist->gids = (gid_t *)cp;
    cp += sizeof(gid_t) * ngids;

    /* Set key and datum. */
    memcpy(cp, pw->pw_name, nsize);
    glitem->cache.k.name = cp;
    glitem->cache.d.gidlist = gidlist;
    glitem->cache.refcnt = 1;
    glitem->cache.type = type;

    /*
     * Store group IDs.
     */
    for (i = 0; i < ngids; i++)
	gidlist->gids[i] = gids[i];
    gidlist->ngids = ngids;
    free(gids);

    debug_return_ptr(&glitem->cache);
}

static struct cache_item_gidlist *grlist_item;

/*
 * Dynamically allocate space for a struct item plus the key and data
 * elements.  Fills in group names from the groups filter.
 */
struct cache_item *
cvtsudoers_make_grlist_item(const struct passwd *pw, char * const *unused1)
{
    char *cp;
    size_t nsize, ngroups, total, len;
    struct cache_item_grlist *grlitem;
    struct sudoers_string *s;
    struct group_list *grlist;
    int groupname_len;
    debug_decl(cvtsudoers_make_grlist_item, SUDOERS_DEBUG_NSS);

    /*
     * There's only a single group list.
     */
    if (grlist_item != NULL) {
	grlist_item->cache.refcnt++;
	debug_return_ptr(&grlist_item->cache);
    }

    /* Count number of groups in the filter. */
    ngroups = 0;
    STAILQ_FOREACH(s, &filters->groups, entries) {
	ngroups++;
    }

#ifdef _SC_LOGIN_NAME_MAX
    groupname_len = MAX((int)sysconf(_SC_LOGIN_NAME_MAX), 32);
#else
    groupname_len = MAX(LOGIN_NAME_MAX, 32);
#endif

    /* Allocate in one big chunk for easy freeing. */
    nsize = strlen(pw->pw_name) + 1;
    total = sizeof(*grlitem) + nsize;
    total += groupname_len * ngroups;

again:
    if ((grlitem = calloc(1, total)) == NULL) {
	sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
	    "unable to allocate memory");
	debug_return_ptr(NULL);
    }

    /*
     * Copy in group list and make pointers relative to space
     * at the end of the buffer.  Note that the groups array must come
     * immediately after struct group to guarantee proper alignment.
     */
    grlist = &grlitem->grlist;
    cp = (char *)(grlitem + 1);
    grlist->groups = (char **)cp;
    cp += sizeof(char *) * ngroups;

    /* Set key and datum. */
    memcpy(cp, pw->pw_name, nsize);
    grlitem->cache.k.name = cp;
    grlitem->cache.d.grlist = grlist;
    grlitem->cache.refcnt = 1;
    cp += nsize;

    /*
     * Copy groups from filter.
     */
    ngroups = 0;
    STAILQ_FOREACH(s, &filters->groups, entries) {
	if (s->str[0] == '#') {
	    const char *errstr;
	    sudo_strtoid(s->str + 1, &errstr);
	    if (errstr == NULL) {
		/* Group ID not name, ignore it. */
		continue;
	    }
	}
	len = strlen(s->str) + 1;
	if (cp - (char *)grlitem + len > total) {
	    total += len + groupname_len;
	    free(grlitem);
	    goto again;
	}
	memcpy(cp, s->str, len);
	grlist->groups[ngroups++] = cp;
	cp += len;
    }
    grlist->ngroups = ngroups;

    debug_return_ptr(&grlitem->cache);
}