GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: usr.bin/ssh/lib/../hostfile.c Lines: 0 391 0.0 %
Date: 2017-11-13 Branches: 0 266 0.0 %

Line Branch Exec Source
1
/* $OpenBSD: hostfile.c,v 1.71 2017/05/31 09:15:42 deraadt Exp $ */
2
/*
3
 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4
 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5
 *                    All rights reserved
6
 * Functions for manipulating the known hosts files.
7
 *
8
 * As far as I am concerned, the code I have written for this software
9
 * can be used freely for any purpose.  Any derived versions of this
10
 * software must be clearly marked as such, and if the derived work is
11
 * incompatible with the protocol description in the RFC file, it must be
12
 * called by a name other than "ssh" or "Secure Shell".
13
 *
14
 *
15
 * Copyright (c) 1999, 2000 Markus Friedl.  All rights reserved.
16
 * Copyright (c) 1999 Niels Provos.  All rights reserved.
17
 *
18
 * Redistribution and use in source and binary forms, with or without
19
 * modification, are permitted provided that the following conditions
20
 * are met:
21
 * 1. Redistributions of source code must retain the above copyright
22
 *    notice, this list of conditions and the following disclaimer.
23
 * 2. Redistributions in binary form must reproduce the above copyright
24
 *    notice, this list of conditions and the following disclaimer in the
25
 *    documentation and/or other materials provided with the distribution.
26
 *
27
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
28
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
29
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
30
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
31
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
32
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
33
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
34
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
35
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
36
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37
 */
38
39
#include <sys/types.h>
40
#include <sys/stat.h>
41
42
#include <netinet/in.h>
43
44
#include <errno.h>
45
#include <resolv.h>
46
#include <stdio.h>
47
#include <stdlib.h>
48
#include <string.h>
49
#include <stdarg.h>
50
#include <unistd.h>
51
52
#include "xmalloc.h"
53
#include "match.h"
54
#include "sshkey.h"
55
#include "hostfile.h"
56
#include "log.h"
57
#include "misc.h"
58
#include "ssherr.h"
59
#include "digest.h"
60
#include "hmac.h"
61
62
struct hostkeys {
63
	struct hostkey_entry *entries;
64
	u_int num_entries;
65
};
66
67
/* XXX hmac is too easy to dictionary attack; use bcrypt? */
68
69
static int
70
extract_salt(const char *s, u_int l, u_char *salt, size_t salt_len)
71
{
72
	char *p, *b64salt;
73
	u_int b64len;
74
	int ret;
75
76
	if (l < sizeof(HASH_MAGIC) - 1) {
77
		debug2("extract_salt: string too short");
78
		return (-1);
79
	}
80
	if (strncmp(s, HASH_MAGIC, sizeof(HASH_MAGIC) - 1) != 0) {
81
		debug2("extract_salt: invalid magic identifier");
82
		return (-1);
83
	}
84
	s += sizeof(HASH_MAGIC) - 1;
85
	l -= sizeof(HASH_MAGIC) - 1;
86
	if ((p = memchr(s, HASH_DELIM, l)) == NULL) {
87
		debug2("extract_salt: missing salt termination character");
88
		return (-1);
89
	}
90
91
	b64len = p - s;
92
	/* Sanity check */
93
	if (b64len == 0 || b64len > 1024) {
94
		debug2("extract_salt: bad encoded salt length %u", b64len);
95
		return (-1);
96
	}
97
	b64salt = xmalloc(1 + b64len);
98
	memcpy(b64salt, s, b64len);
99
	b64salt[b64len] = '\0';
100
101
	ret = __b64_pton(b64salt, salt, salt_len);
102
	free(b64salt);
103
	if (ret == -1) {
104
		debug2("extract_salt: salt decode error");
105
		return (-1);
106
	}
107
	if (ret != (int)ssh_hmac_bytes(SSH_DIGEST_SHA1)) {
108
		debug2("extract_salt: expected salt len %zd, got %d",
109
		    ssh_hmac_bytes(SSH_DIGEST_SHA1), ret);
110
		return (-1);
111
	}
112
113
	return (0);
114
}
115
116
char *
117
host_hash(const char *host, const char *name_from_hostfile, u_int src_len)
118
{
119
	struct ssh_hmac_ctx *ctx;
120
	u_char salt[256], result[256];
121
	char uu_salt[512], uu_result[512];
122
	static char encoded[1024];
123
	u_int len;
124
125
	len = ssh_digest_bytes(SSH_DIGEST_SHA1);
126
127
	if (name_from_hostfile == NULL) {
128
		/* Create new salt */
129
		arc4random_buf(salt, len);
130
	} else {
131
		/* Extract salt from known host entry */
132
		if (extract_salt(name_from_hostfile, src_len, salt,
133
		    sizeof(salt)) == -1)
134
			return (NULL);
135
	}
136
137
	if ((ctx = ssh_hmac_start(SSH_DIGEST_SHA1)) == NULL ||
138
	    ssh_hmac_init(ctx, salt, len) < 0 ||
139
	    ssh_hmac_update(ctx, host, strlen(host)) < 0 ||
140
	    ssh_hmac_final(ctx, result, sizeof(result)))
141
		fatal("%s: ssh_hmac failed", __func__);
142
	ssh_hmac_free(ctx);
143
144
	if (__b64_ntop(salt, len, uu_salt, sizeof(uu_salt)) == -1 ||
145
	    __b64_ntop(result, len, uu_result, sizeof(uu_result)) == -1)
146
		fatal("%s: __b64_ntop failed", __func__);
147
148
	snprintf(encoded, sizeof(encoded), "%s%s%c%s", HASH_MAGIC, uu_salt,
149
	    HASH_DELIM, uu_result);
150
151
	return (encoded);
152
}
153
154
/*
155
 * Parses an RSA (number of bits, e, n) or DSA key from a string.  Moves the
156
 * pointer over the key.  Skips any whitespace at the beginning and at end.
157
 */
158
159
int
160
hostfile_read_key(char **cpp, u_int *bitsp, struct sshkey *ret)
161
{
162
	char *cp;
163
	int r;
164
165
	/* Skip leading whitespace. */
166
	for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++)
167
		;
168
169
	if ((r = sshkey_read(ret, &cp)) != 0)
170
		return 0;
171
172
	/* Skip trailing whitespace. */
173
	for (; *cp == ' ' || *cp == '\t'; cp++)
174
		;
175
176
	/* Return results. */
177
	*cpp = cp;
178
	if (bitsp != NULL)
179
		*bitsp = sshkey_size(ret);
180
	return 1;
181
}
182
183
static HostkeyMarker
184
check_markers(char **cpp)
185
{
186
	char marker[32], *sp, *cp = *cpp;
187
	int ret = MRK_NONE;
188
189
	while (*cp == '@') {
190
		/* Only one marker is allowed */
191
		if (ret != MRK_NONE)
192
			return MRK_ERROR;
193
		/* Markers are terminated by whitespace */
194
		if ((sp = strchr(cp, ' ')) == NULL &&
195
		    (sp = strchr(cp, '\t')) == NULL)
196
			return MRK_ERROR;
197
		/* Extract marker for comparison */
198
		if (sp <= cp + 1 || sp >= cp + sizeof(marker))
199
			return MRK_ERROR;
200
		memcpy(marker, cp, sp - cp);
201
		marker[sp - cp] = '\0';
202
		if (strcmp(marker, CA_MARKER) == 0)
203
			ret = MRK_CA;
204
		else if (strcmp(marker, REVOKE_MARKER) == 0)
205
			ret = MRK_REVOKE;
206
		else
207
			return MRK_ERROR;
208
209
		/* Skip past marker and any whitespace that follows it */
210
		cp = sp;
211
		for (; *cp == ' ' || *cp == '\t'; cp++)
212
			;
213
	}
214
	*cpp = cp;
215
	return ret;
216
}
217
218
struct hostkeys *
219
init_hostkeys(void)
220
{
221
	struct hostkeys *ret = xcalloc(1, sizeof(*ret));
222
223
	ret->entries = NULL;
224
	return ret;
225
}
226
227
struct load_callback_ctx {
228
	const char *host;
229
	u_long num_loaded;
230
	struct hostkeys *hostkeys;
231
};
232
233
static int
234
record_hostkey(struct hostkey_foreach_line *l, void *_ctx)
235
{
236
	struct load_callback_ctx *ctx = (struct load_callback_ctx *)_ctx;
237
	struct hostkeys *hostkeys = ctx->hostkeys;
238
	struct hostkey_entry *tmp;
239
240
	if (l->status == HKF_STATUS_INVALID) {
241
		/* XXX make this verbose() in the future */
242
		debug("%s:%ld: parse error in hostkeys file",
243
		    l->path, l->linenum);
244
		return 0;
245
	}
246
247
	debug3("%s: found %skey type %s in file %s:%lu", __func__,
248
	    l->marker == MRK_NONE ? "" :
249
	    (l->marker == MRK_CA ? "ca " : "revoked "),
250
	    sshkey_type(l->key), l->path, l->linenum);
251
	if ((tmp = recallocarray(hostkeys->entries, hostkeys->num_entries,
252
	    hostkeys->num_entries + 1, sizeof(*hostkeys->entries))) == NULL)
253
		return SSH_ERR_ALLOC_FAIL;
254
	hostkeys->entries = tmp;
255
	hostkeys->entries[hostkeys->num_entries].host = xstrdup(ctx->host);
256
	hostkeys->entries[hostkeys->num_entries].file = xstrdup(l->path);
257
	hostkeys->entries[hostkeys->num_entries].line = l->linenum;
258
	hostkeys->entries[hostkeys->num_entries].key = l->key;
259
	l->key = NULL; /* steal it */
260
	hostkeys->entries[hostkeys->num_entries].marker = l->marker;
261
	hostkeys->num_entries++;
262
	ctx->num_loaded++;
263
264
	return 0;
265
}
266
267
void
268
load_hostkeys(struct hostkeys *hostkeys, const char *host, const char *path)
269
{
270
	int r;
271
	struct load_callback_ctx ctx;
272
273
	ctx.host = host;
274
	ctx.num_loaded = 0;
275
	ctx.hostkeys = hostkeys;
276
277
	if ((r = hostkeys_foreach(path, record_hostkey, &ctx, host, NULL,
278
	    HKF_WANT_MATCH|HKF_WANT_PARSE_KEY)) != 0) {
279
		if (r != SSH_ERR_SYSTEM_ERROR && errno != ENOENT)
280
			debug("%s: hostkeys_foreach failed for %s: %s",
281
			    __func__, path, ssh_err(r));
282
	}
283
	if (ctx.num_loaded != 0)
284
		debug3("%s: loaded %lu keys from %s", __func__,
285
		    ctx.num_loaded, host);
286
}
287
288
void
289
free_hostkeys(struct hostkeys *hostkeys)
290
{
291
	u_int i;
292
293
	for (i = 0; i < hostkeys->num_entries; i++) {
294
		free(hostkeys->entries[i].host);
295
		free(hostkeys->entries[i].file);
296
		sshkey_free(hostkeys->entries[i].key);
297
		explicit_bzero(hostkeys->entries + i, sizeof(*hostkeys->entries));
298
	}
299
	free(hostkeys->entries);
300
	explicit_bzero(hostkeys, sizeof(*hostkeys));
301
	free(hostkeys);
302
}
303
304
static int
305
check_key_not_revoked(struct hostkeys *hostkeys, struct sshkey *k)
306
{
307
	int is_cert = sshkey_is_cert(k);
308
	u_int i;
309
310
	for (i = 0; i < hostkeys->num_entries; i++) {
311
		if (hostkeys->entries[i].marker != MRK_REVOKE)
312
			continue;
313
		if (sshkey_equal_public(k, hostkeys->entries[i].key))
314
			return -1;
315
		if (is_cert &&
316
		    sshkey_equal_public(k->cert->signature_key,
317
		    hostkeys->entries[i].key))
318
			return -1;
319
	}
320
	return 0;
321
}
322
323
/*
324
 * Match keys against a specified key, or look one up by key type.
325
 *
326
 * If looking for a keytype (key == NULL) and one is found then return
327
 * HOST_FOUND, otherwise HOST_NEW.
328
 *
329
 * If looking for a key (key != NULL):
330
 *  1. If the key is a cert and a matching CA is found, return HOST_OK
331
 *  2. If the key is not a cert and a matching key is found, return HOST_OK
332
 *  3. If no key matches but a key with a different type is found, then
333
 *     return HOST_CHANGED
334
 *  4. If no matching keys are found, then return HOST_NEW.
335
 *
336
 * Finally, check any found key is not revoked.
337
 */
338
static HostStatus
339
check_hostkeys_by_key_or_type(struct hostkeys *hostkeys,
340
    struct sshkey *k, int keytype, const struct hostkey_entry **found)
341
{
342
	u_int i;
343
	HostStatus end_return = HOST_NEW;
344
	int want_cert = sshkey_is_cert(k);
345
	HostkeyMarker want_marker = want_cert ? MRK_CA : MRK_NONE;
346
347
	if (found != NULL)
348
		*found = NULL;
349
350
	for (i = 0; i < hostkeys->num_entries; i++) {
351
		if (hostkeys->entries[i].marker != want_marker)
352
			continue;
353
		if (k == NULL) {
354
			if (hostkeys->entries[i].key->type != keytype)
355
				continue;
356
			end_return = HOST_FOUND;
357
			if (found != NULL)
358
				*found = hostkeys->entries + i;
359
			k = hostkeys->entries[i].key;
360
			break;
361
		}
362
		if (want_cert) {
363
			if (sshkey_equal_public(k->cert->signature_key,
364
			    hostkeys->entries[i].key)) {
365
				/* A matching CA exists */
366
				end_return = HOST_OK;
367
				if (found != NULL)
368
					*found = hostkeys->entries + i;
369
				break;
370
			}
371
		} else {
372
			if (sshkey_equal(k, hostkeys->entries[i].key)) {
373
				end_return = HOST_OK;
374
				if (found != NULL)
375
					*found = hostkeys->entries + i;
376
				break;
377
			}
378
			/* A non-maching key exists */
379
			end_return = HOST_CHANGED;
380
			if (found != NULL)
381
				*found = hostkeys->entries + i;
382
		}
383
	}
384
	if (check_key_not_revoked(hostkeys, k) != 0) {
385
		end_return = HOST_REVOKED;
386
		if (found != NULL)
387
			*found = NULL;
388
	}
389
	return end_return;
390
}
391
392
HostStatus
393
check_key_in_hostkeys(struct hostkeys *hostkeys, struct sshkey *key,
394
    const struct hostkey_entry **found)
395
{
396
	if (key == NULL)
397
		fatal("no key to look up");
398
	return check_hostkeys_by_key_or_type(hostkeys, key, 0, found);
399
}
400
401
int
402
lookup_key_in_hostkeys_by_type(struct hostkeys *hostkeys, int keytype,
403
    const struct hostkey_entry **found)
404
{
405
	return (check_hostkeys_by_key_or_type(hostkeys, NULL, keytype,
406
	    found) == HOST_FOUND);
407
}
408
409
static int
410
write_host_entry(FILE *f, const char *host, const char *ip,
411
    const struct sshkey *key, int store_hash)
412
{
413
	int r, success = 0;
414
	char *hashed_host = NULL, *lhost;
415
416
	lhost = xstrdup(host);
417
	lowercase(lhost);
418
419
	if (store_hash) {
420
		if ((hashed_host = host_hash(lhost, NULL, 0)) == NULL) {
421
			error("%s: host_hash failed", __func__);
422
			free(lhost);
423
			return 0;
424
		}
425
		fprintf(f, "%s ", hashed_host);
426
	} else if (ip != NULL)
427
		fprintf(f, "%s,%s ", lhost, ip);
428
	else {
429
		fprintf(f, "%s ", lhost);
430
	}
431
	free(lhost);
432
	if ((r = sshkey_write(key, f)) == 0)
433
		success = 1;
434
	else
435
		error("%s: sshkey_write failed: %s", __func__, ssh_err(r));
436
	fputc('\n', f);
437
	return success;
438
}
439
440
/*
441
 * Appends an entry to the host file.  Returns false if the entry could not
442
 * be appended.
443
 */
444
int
445
add_host_to_hostfile(const char *filename, const char *host,
446
    const struct sshkey *key, int store_hash)
447
{
448
	FILE *f;
449
	int success;
450
451
	if (key == NULL)
452
		return 1;	/* XXX ? */
453
	f = fopen(filename, "a");
454
	if (!f)
455
		return 0;
456
	success = write_host_entry(f, host, NULL, key, store_hash);
457
	fclose(f);
458
	return success;
459
}
460
461
struct host_delete_ctx {
462
	FILE *out;
463
	int quiet;
464
	const char *host;
465
	int *skip_keys; /* XXX split for host/ip? might want to ensure both */
466
	struct sshkey * const *keys;
467
	size_t nkeys;
468
	int modified;
469
};
470
471
static int
472
host_delete(struct hostkey_foreach_line *l, void *_ctx)
473
{
474
	struct host_delete_ctx *ctx = (struct host_delete_ctx *)_ctx;
475
	int loglevel = ctx->quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_VERBOSE;
476
	size_t i;
477
478
	if (l->status == HKF_STATUS_MATCHED) {
479
		if (l->marker != MRK_NONE) {
480
			/* Don't remove CA and revocation lines */
481
			fprintf(ctx->out, "%s\n", l->line);
482
			return 0;
483
		}
484
485
		/*
486
		 * If this line contains one of the keys that we will be
487
		 * adding later, then don't change it and mark the key for
488
		 * skipping.
489
		 */
490
		for (i = 0; i < ctx->nkeys; i++) {
491
			if (sshkey_equal(ctx->keys[i], l->key)) {
492
				ctx->skip_keys[i] = 1;
493
				fprintf(ctx->out, "%s\n", l->line);
494
				debug3("%s: %s key already at %s:%ld", __func__,
495
				    sshkey_type(l->key), l->path, l->linenum);
496
				return 0;
497
			}
498
		}
499
500
		/*
501
		 * Hostname matches and has no CA/revoke marker, delete it
502
		 * by *not* writing the line to ctx->out.
503
		 */
504
		do_log2(loglevel, "%s%s%s:%ld: Removed %s key for host %s",
505
		    ctx->quiet ? __func__ : "", ctx->quiet ? ": " : "",
506
		    l->path, l->linenum, sshkey_type(l->key), ctx->host);
507
		ctx->modified = 1;
508
		return 0;
509
	}
510
	/* Retain non-matching hosts and invalid lines when deleting */
511
	if (l->status == HKF_STATUS_INVALID) {
512
		do_log2(loglevel, "%s%s%s:%ld: invalid known_hosts entry",
513
		    ctx->quiet ? __func__ : "", ctx->quiet ? ": " : "",
514
		    l->path, l->linenum);
515
	}
516
	fprintf(ctx->out, "%s\n", l->line);
517
	return 0;
518
}
519
520
int
521
hostfile_replace_entries(const char *filename, const char *host, const char *ip,
522
    struct sshkey **keys, size_t nkeys, int store_hash, int quiet, int hash_alg)
523
{
524
	int r, fd, oerrno = 0;
525
	int loglevel = quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_VERBOSE;
526
	struct host_delete_ctx ctx;
527
	char *fp, *temp = NULL, *back = NULL;
528
	mode_t omask;
529
	size_t i;
530
531
	omask = umask(077);
532
533
	memset(&ctx, 0, sizeof(ctx));
534
	ctx.host = host;
535
	ctx.quiet = quiet;
536
	if ((ctx.skip_keys = calloc(nkeys, sizeof(*ctx.skip_keys))) == NULL)
537
		return SSH_ERR_ALLOC_FAIL;
538
	ctx.keys = keys;
539
	ctx.nkeys = nkeys;
540
	ctx.modified = 0;
541
542
	/*
543
	 * Prepare temporary file for in-place deletion.
544
	 */
545
	if ((r = asprintf(&temp, "%s.XXXXXXXXXXX", filename)) < 0 ||
546
	    (r = asprintf(&back, "%s.old", filename)) < 0) {
547
		r = SSH_ERR_ALLOC_FAIL;
548
		goto fail;
549
	}
550
551
	if ((fd = mkstemp(temp)) == -1) {
552
		oerrno = errno;
553
		error("%s: mkstemp: %s", __func__, strerror(oerrno));
554
		r = SSH_ERR_SYSTEM_ERROR;
555
		goto fail;
556
	}
557
	if ((ctx.out = fdopen(fd, "w")) == NULL) {
558
		oerrno = errno;
559
		close(fd);
560
		error("%s: fdopen: %s", __func__, strerror(oerrno));
561
		r = SSH_ERR_SYSTEM_ERROR;
562
		goto fail;
563
	}
564
565
	/* Remove all entries for the specified host from the file */
566
	if ((r = hostkeys_foreach(filename, host_delete, &ctx, host, ip,
567
	    HKF_WANT_PARSE_KEY)) != 0) {
568
		error("%s: hostkeys_foreach failed: %s", __func__, ssh_err(r));
569
		goto fail;
570
	}
571
572
	/* Add the requested keys */
573
	for (i = 0; i < nkeys; i++) {
574
		if (ctx.skip_keys[i])
575
			continue;
576
		if ((fp = sshkey_fingerprint(keys[i], hash_alg,
577
		    SSH_FP_DEFAULT)) == NULL) {
578
			r = SSH_ERR_ALLOC_FAIL;
579
			goto fail;
580
		}
581
		do_log2(loglevel, "%s%sAdding new key for %s to %s: %s %s",
582
		    quiet ? __func__ : "", quiet ? ": " : "", host, filename,
583
		    sshkey_ssh_name(keys[i]), fp);
584
		free(fp);
585
		if (!write_host_entry(ctx.out, host, ip, keys[i], store_hash)) {
586
			r = SSH_ERR_INTERNAL_ERROR;
587
			goto fail;
588
		}
589
		ctx.modified = 1;
590
	}
591
	fclose(ctx.out);
592
	ctx.out = NULL;
593
594
	if (ctx.modified) {
595
		/* Backup the original file and replace it with the temporary */
596
		if (unlink(back) == -1 && errno != ENOENT) {
597
			oerrno = errno;
598
			error("%s: unlink %.100s: %s", __func__,
599
			    back, strerror(errno));
600
			r = SSH_ERR_SYSTEM_ERROR;
601
			goto fail;
602
		}
603
		if (link(filename, back) == -1) {
604
			oerrno = errno;
605
			error("%s: link %.100s to %.100s: %s", __func__,
606
			    filename, back, strerror(errno));
607
			r = SSH_ERR_SYSTEM_ERROR;
608
			goto fail;
609
		}
610
		if (rename(temp, filename) == -1) {
611
			oerrno = errno;
612
			error("%s: rename \"%s\" to \"%s\": %s", __func__,
613
			    temp, filename, strerror(errno));
614
			r = SSH_ERR_SYSTEM_ERROR;
615
			goto fail;
616
		}
617
	} else {
618
		/* No changes made; just delete the temporary file */
619
		if (unlink(temp) != 0)
620
			error("%s: unlink \"%s\": %s", __func__,
621
			    temp, strerror(errno));
622
	}
623
624
	/* success */
625
	r = 0;
626
 fail:
627
	if (temp != NULL && r != 0)
628
		unlink(temp);
629
	free(temp);
630
	free(back);
631
	if (ctx.out != NULL)
632
		fclose(ctx.out);
633
	free(ctx.skip_keys);
634
	umask(omask);
635
	if (r == SSH_ERR_SYSTEM_ERROR)
636
		errno = oerrno;
637
	return r;
638
}
639
640
static int
641
match_maybe_hashed(const char *host, const char *names, int *was_hashed)
642
{
643
	int hashed = *names == HASH_DELIM;
644
	const char *hashed_host;
645
	size_t nlen = strlen(names);
646
647
	if (was_hashed != NULL)
648
		*was_hashed = hashed;
649
	if (hashed) {
650
		if ((hashed_host = host_hash(host, names, nlen)) == NULL)
651
			return -1;
652
		return nlen == strlen(hashed_host) &&
653
		    strncmp(hashed_host, names, nlen) == 0;
654
	}
655
	return match_hostname(host, names) == 1;
656
}
657
658
int
659
hostkeys_foreach(const char *path, hostkeys_foreach_fn *callback, void *ctx,
660
    const char *host, const char *ip, u_int options)
661
{
662
	FILE *f;
663
	char line[8192], oline[8192], ktype[128];
664
	u_long linenum = 0;
665
	char *cp, *cp2;
666
	u_int kbits;
667
	int hashed;
668
	int s, r = 0;
669
	struct hostkey_foreach_line lineinfo;
670
	size_t l;
671
672
	memset(&lineinfo, 0, sizeof(lineinfo));
673
	if (host == NULL && (options & HKF_WANT_MATCH) != 0)
674
		return SSH_ERR_INVALID_ARGUMENT;
675
	if ((f = fopen(path, "r")) == NULL)
676
		return SSH_ERR_SYSTEM_ERROR;
677
678
	debug3("%s: reading file \"%s\"", __func__, path);
679
	while (read_keyfile_line(f, path, line, sizeof(line), &linenum) == 0) {
680
		line[strcspn(line, "\n")] = '\0';
681
		strlcpy(oline, line, sizeof(oline));
682
683
		sshkey_free(lineinfo.key);
684
		memset(&lineinfo, 0, sizeof(lineinfo));
685
		lineinfo.path = path;
686
		lineinfo.linenum = linenum;
687
		lineinfo.line = oline;
688
		lineinfo.marker = MRK_NONE;
689
		lineinfo.status = HKF_STATUS_OK;
690
		lineinfo.keytype = KEY_UNSPEC;
691
692
		/* Skip any leading whitespace, comments and empty lines. */
693
		for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
694
			;
695
		if (!*cp || *cp == '#' || *cp == '\n') {
696
			if ((options & HKF_WANT_MATCH) == 0) {
697
				lineinfo.status = HKF_STATUS_COMMENT;
698
				if ((r = callback(&lineinfo, ctx)) != 0)
699
					break;
700
			}
701
			continue;
702
		}
703
704
		if ((lineinfo.marker = check_markers(&cp)) == MRK_ERROR) {
705
			verbose("%s: invalid marker at %s:%lu",
706
			    __func__, path, linenum);
707
			if ((options & HKF_WANT_MATCH) == 0)
708
				goto bad;
709
			continue;
710
		}
711
712
		/* Find the end of the host name portion. */
713
		for (cp2 = cp; *cp2 && *cp2 != ' ' && *cp2 != '\t'; cp2++)
714
			;
715
		lineinfo.hosts = cp;
716
		*cp2++ = '\0';
717
718
		/* Check if the host name matches. */
719
		if (host != NULL) {
720
			if ((s = match_maybe_hashed(host, lineinfo.hosts,
721
			    &hashed)) == -1) {
722
				debug2("%s: %s:%ld: bad host hash \"%.32s\"",
723
				    __func__, path, linenum, lineinfo.hosts);
724
				goto bad;
725
			}
726
			if (s == 1) {
727
				lineinfo.status = HKF_STATUS_MATCHED;
728
				lineinfo.match |= HKF_MATCH_HOST |
729
				    (hashed ? HKF_MATCH_HOST_HASHED : 0);
730
			}
731
			/* Try matching IP address if supplied */
732
			if (ip != NULL) {
733
				if ((s = match_maybe_hashed(ip, lineinfo.hosts,
734
				    &hashed)) == -1) {
735
					debug2("%s: %s:%ld: bad ip hash "
736
					    "\"%.32s\"", __func__, path,
737
					    linenum, lineinfo.hosts);
738
					goto bad;
739
				}
740
				if (s == 1) {
741
					lineinfo.status = HKF_STATUS_MATCHED;
742
					lineinfo.match |= HKF_MATCH_IP |
743
					    (hashed ? HKF_MATCH_IP_HASHED : 0);
744
				}
745
			}
746
			/*
747
			 * Skip this line if host matching requested and
748
			 * neither host nor address matched.
749
			 */
750
			if ((options & HKF_WANT_MATCH) != 0 &&
751
			    lineinfo.status != HKF_STATUS_MATCHED)
752
				continue;
753
		}
754
755
		/* Got a match.  Skip host name and any following whitespace */
756
		for (; *cp2 == ' ' || *cp2 == '\t'; cp2++)
757
			;
758
		if (*cp2 == '\0' || *cp2 == '#') {
759
			debug2("%s:%ld: truncated before key type",
760
			    path, linenum);
761
			goto bad;
762
		}
763
		lineinfo.rawkey = cp = cp2;
764
765
		if ((options & HKF_WANT_PARSE_KEY) != 0) {
766
			/*
767
			 * Extract the key from the line.  This will skip
768
			 * any leading whitespace.  Ignore badly formatted
769
			 * lines.
770
			 */
771
			if ((lineinfo.key = sshkey_new(KEY_UNSPEC)) == NULL) {
772
				error("%s: sshkey_new failed", __func__);
773
				r = SSH_ERR_ALLOC_FAIL;
774
				break;
775
			}
776
			if (!hostfile_read_key(&cp, &kbits, lineinfo.key)) {
777
				goto bad;
778
			}
779
			lineinfo.keytype = lineinfo.key->type;
780
			lineinfo.comment = cp;
781
		} else {
782
			/* Extract and parse key type */
783
			l = strcspn(lineinfo.rawkey, " \t");
784
			if (l <= 1 || l >= sizeof(ktype) ||
785
			    lineinfo.rawkey[l] == '\0')
786
				goto bad;
787
			memcpy(ktype, lineinfo.rawkey, l);
788
			ktype[l] = '\0';
789
			lineinfo.keytype = sshkey_type_from_name(ktype);
790
791
			/*
792
			 * Assume legacy RSA1 if the first component is a short
793
			 * decimal number.
794
			 */
795
			if (lineinfo.keytype == KEY_UNSPEC && l < 8 &&
796
			    strspn(ktype, "0123456789") == l)
797
				goto bad;
798
799
			/*
800
			 * Check that something other than whitespace follows
801
			 * the key type. This won't catch all corruption, but
802
			 * it does catch trivial truncation.
803
			 */
804
			cp2 += l; /* Skip past key type */
805
			for (; *cp2 == ' ' || *cp2 == '\t'; cp2++)
806
				;
807
			if (*cp2 == '\0' || *cp2 == '#') {
808
				debug2("%s:%ld: truncated after key type",
809
				    path, linenum);
810
				lineinfo.keytype = KEY_UNSPEC;
811
			}
812
			if (lineinfo.keytype == KEY_UNSPEC) {
813
 bad:
814
				sshkey_free(lineinfo.key);
815
				lineinfo.key = NULL;
816
				lineinfo.status = HKF_STATUS_INVALID;
817
				if ((r = callback(&lineinfo, ctx)) != 0)
818
					break;
819
				continue;
820
			}
821
		}
822
		if ((r = callback(&lineinfo, ctx)) != 0)
823
			break;
824
	}
825
	sshkey_free(lineinfo.key);
826
	fclose(f);
827
	return r;
828
}