blob: d9fdcb8728b99057498cfc739bfe7b73edcab118 [file] [log] [blame]
djm@openbsd.org398f9ef2015-03-31 22:57:06 +00001/* $OpenBSD: hostfile.c,v 1.65 2015/03/31 22:57:06 djm Exp $ */
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002/*
Damien Miller95def091999-11-25 00:26:21 +11003 * Author: Tatu Ylonen <ylo@cs.hut.fi>
Damien Miller95def091999-11-25 00:26:21 +11004 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * All rights reserved
Damien Miller95def091999-11-25 00:26:21 +11006 * Functions for manipulating the known hosts files.
Damien Miller4af51302000-04-16 11:18:38 +10007 *
Damien Millere4340be2000-09-16 13:29:08 +11008 * 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 *
Ben Lindstrom44697232001-07-04 03:32:30 +000015 * Copyright (c) 1999, 2000 Markus Friedl. All rights reserved.
Damien Millere4340be2000-09-16 13:29:08 +110016 * 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.
Damien Miller95def091999-11-25 00:26:21 +110037 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100038
39#include "includes.h"
Damien Millere1776152005-03-01 21:47:37 +110040
Damien Miller8ec8c3e2006-07-10 20:35:38 +100041#include <sys/types.h>
djm@openbsd.org8d4f8722015-01-26 03:04:45 +000042#include <sys/stat.h>
Damien Miller8ec8c3e2006-07-10 20:35:38 +100043
44#include <netinet/in.h>
45
djm@openbsd.orgc29811c2015-01-18 21:40:23 +000046#include <errno.h>
Damien Millere7a1e5c2006-08-05 11:34:19 +100047#include <resolv.h>
Damien Millerded319c2006-09-01 15:38:36 +100048#include <stdarg.h>
Damien Millera7a73ee2006-08-05 11:37:59 +100049#include <stdio.h>
Damien Millere7a1e5c2006-08-05 11:34:19 +100050#include <stdlib.h>
51#include <string.h>
Damien Miller86687062014-07-02 15:28:02 +100052#include <stdarg.h>
djm@openbsd.org8d4f8722015-01-26 03:04:45 +000053#include <unistd.h>
Damien Millere7a1e5c2006-08-05 11:34:19 +100054
Damien Millerd7834352006-08-05 12:39:39 +100055#include "xmalloc.h"
Damien Miller450a7a12000-03-26 13:04:51 +100056#include "match.h"
djm@openbsd.org1129dcf2015-01-15 09:40:00 +000057#include "sshkey.h"
Damien Miller450a7a12000-03-26 13:04:51 +100058#include "hostfile.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000059#include "log.h"
Damien Millerd925dcd2010-12-01 12:21:51 +110060#include "misc.h"
djm@openbsd.org1129dcf2015-01-15 09:40:00 +000061#include "ssherr.h"
Damien Millerb3051d02014-01-10 10:58:53 +110062#include "digest.h"
Damien Miller4e8d9372014-02-04 11:02:42 +110063#include "hmac.h"
Damien Millerd925dcd2010-12-01 12:21:51 +110064
65struct hostkeys {
66 struct hostkey_entry *entries;
67 u_int num_entries;
68};
Damien Millere1776152005-03-01 21:47:37 +110069
djm@openbsd.orgc29811c2015-01-18 21:40:23 +000070/* XXX hmac is too easy to dictionary attack; use bcrypt? */
71
Damien Millere1776152005-03-01 21:47:37 +110072static int
Damien Millerce986542013-07-18 16:12:44 +100073extract_salt(const char *s, u_int l, u_char *salt, size_t salt_len)
Damien Millere1776152005-03-01 21:47:37 +110074{
75 char *p, *b64salt;
76 u_int b64len;
77 int ret;
78
79 if (l < sizeof(HASH_MAGIC) - 1) {
80 debug2("extract_salt: string too short");
81 return (-1);
82 }
83 if (strncmp(s, HASH_MAGIC, sizeof(HASH_MAGIC) - 1) != 0) {
84 debug2("extract_salt: invalid magic identifier");
85 return (-1);
86 }
87 s += sizeof(HASH_MAGIC) - 1;
88 l -= sizeof(HASH_MAGIC) - 1;
89 if ((p = memchr(s, HASH_DELIM, l)) == NULL) {
90 debug2("extract_salt: missing salt termination character");
91 return (-1);
92 }
93
94 b64len = p - s;
95 /* Sanity check */
96 if (b64len == 0 || b64len > 1024) {
97 debug2("extract_salt: bad encoded salt length %u", b64len);
98 return (-1);
99 }
100 b64salt = xmalloc(1 + b64len);
101 memcpy(b64salt, s, b64len);
102 b64salt[b64len] = '\0';
103
104 ret = __b64_pton(b64salt, salt, salt_len);
Darren Tuckera627d422013-06-02 07:31:17 +1000105 free(b64salt);
Damien Millere1776152005-03-01 21:47:37 +1100106 if (ret == -1) {
107 debug2("extract_salt: salt decode error");
108 return (-1);
109 }
Damien Miller4e8d9372014-02-04 11:02:42 +1100110 if (ret != (int)ssh_hmac_bytes(SSH_DIGEST_SHA1)) {
111 debug2("extract_salt: expected salt len %zd, got %d",
112 ssh_hmac_bytes(SSH_DIGEST_SHA1), ret);
Damien Millere1776152005-03-01 21:47:37 +1100113 return (-1);
114 }
Darren Tucker47eede72005-03-14 23:08:12 +1100115
Damien Millere1776152005-03-01 21:47:37 +1100116 return (0);
117}
118
119char *
120host_hash(const char *host, const char *name_from_hostfile, u_int src_len)
121{
Damien Miller4e8d9372014-02-04 11:02:42 +1100122 struct ssh_hmac_ctx *ctx;
Damien Millerce986542013-07-18 16:12:44 +1000123 u_char salt[256], result[256];
124 char uu_salt[512], uu_result[512];
Damien Millere1776152005-03-01 21:47:37 +1100125 static char encoded[1024];
126 u_int i, len;
127
Damien Miller4e8d9372014-02-04 11:02:42 +1100128 len = ssh_digest_bytes(SSH_DIGEST_SHA1);
Damien Millere1776152005-03-01 21:47:37 +1100129
130 if (name_from_hostfile == NULL) {
131 /* Create new salt */
132 for (i = 0; i < len; i++)
133 salt[i] = arc4random();
134 } else {
135 /* Extract salt from known host entry */
136 if (extract_salt(name_from_hostfile, src_len, salt,
137 sizeof(salt)) == -1)
138 return (NULL);
139 }
140
Damien Miller4e8d9372014-02-04 11:02:42 +1100141 if ((ctx = ssh_hmac_start(SSH_DIGEST_SHA1)) == NULL ||
142 ssh_hmac_init(ctx, salt, len) < 0 ||
143 ssh_hmac_update(ctx, host, strlen(host)) < 0 ||
144 ssh_hmac_final(ctx, result, sizeof(result)))
145 fatal("%s: ssh_hmac failed", __func__);
146 ssh_hmac_free(ctx);
Damien Millere1776152005-03-01 21:47:37 +1100147
Darren Tucker47eede72005-03-14 23:08:12 +1100148 if (__b64_ntop(salt, len, uu_salt, sizeof(uu_salt)) == -1 ||
Damien Millere1776152005-03-01 21:47:37 +1100149 __b64_ntop(result, len, uu_result, sizeof(uu_result)) == -1)
Damien Miller4e8d9372014-02-04 11:02:42 +1100150 fatal("%s: __b64_ntop failed", __func__);
Damien Millere1776152005-03-01 21:47:37 +1100151
152 snprintf(encoded, sizeof(encoded), "%s%s%c%s", HASH_MAGIC, uu_salt,
153 HASH_DELIM, uu_result);
154
155 return (encoded);
156}
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000157
Damien Miller5428f641999-11-25 11:54:57 +1100158/*
Damien Miller450a7a12000-03-26 13:04:51 +1000159 * Parses an RSA (number of bits, e, n) or DSA key from a string. Moves the
160 * pointer over the key. Skips any whitespace at the beginning and at end.
Damien Miller5428f641999-11-25 11:54:57 +1100161 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000162
Damien Miller5b2aea92001-12-21 12:47:09 +1100163int
djm@openbsd.org1129dcf2015-01-15 09:40:00 +0000164hostfile_read_key(char **cpp, u_int *bitsp, struct sshkey *ret)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000165{
Damien Miller95def091999-11-25 00:26:21 +1100166 char *cp;
djm@openbsd.org1129dcf2015-01-15 09:40:00 +0000167 int r;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000168
Damien Miller95def091999-11-25 00:26:21 +1100169 /* Skip leading whitespace. */
Damien Miller5428f641999-11-25 11:54:57 +1100170 for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++)
171 ;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000172
djm@openbsd.org1129dcf2015-01-15 09:40:00 +0000173 if ((r = sshkey_read(ret, &cp)) != 0)
Damien Miller95def091999-11-25 00:26:21 +1100174 return 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000175
Damien Miller95def091999-11-25 00:26:21 +1100176 /* Skip trailing whitespace. */
Damien Miller5428f641999-11-25 11:54:57 +1100177 for (; *cp == ' ' || *cp == '\t'; cp++)
178 ;
Damien Miller95def091999-11-25 00:26:21 +1100179
180 /* Return results. */
181 *cpp = cp;
djm@openbsd.org1129dcf2015-01-15 09:40:00 +0000182 if (bitsp != NULL)
183 *bitsp = sshkey_size(ret);
Damien Miller95def091999-11-25 00:26:21 +1100184 return 1;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000185}
186
Damien Millerd925dcd2010-12-01 12:21:51 +1100187static HostkeyMarker
Damien Miller1aed65e2010-03-04 21:53:35 +1100188check_markers(char **cpp)
189{
190 char marker[32], *sp, *cp = *cpp;
191 int ret = MRK_NONE;
192
193 while (*cp == '@') {
194 /* Only one marker is allowed */
195 if (ret != MRK_NONE)
196 return MRK_ERROR;
197 /* Markers are terminated by whitespace */
198 if ((sp = strchr(cp, ' ')) == NULL &&
199 (sp = strchr(cp, '\t')) == NULL)
200 return MRK_ERROR;
201 /* Extract marker for comparison */
202 if (sp <= cp + 1 || sp >= cp + sizeof(marker))
203 return MRK_ERROR;
204 memcpy(marker, cp, sp - cp);
205 marker[sp - cp] = '\0';
206 if (strcmp(marker, CA_MARKER) == 0)
207 ret = MRK_CA;
208 else if (strcmp(marker, REVOKE_MARKER) == 0)
209 ret = MRK_REVOKE;
210 else
211 return MRK_ERROR;
212
213 /* Skip past marker and any whitespace that follows it */
214 cp = sp;
215 for (; *cp == ' ' || *cp == '\t'; cp++)
216 ;
217 }
218 *cpp = cp;
219 return ret;
220}
221
Damien Millerd925dcd2010-12-01 12:21:51 +1100222struct hostkeys *
223init_hostkeys(void)
224{
225 struct hostkeys *ret = xcalloc(1, sizeof(*ret));
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000226
Damien Millerd925dcd2010-12-01 12:21:51 +1100227 ret->entries = NULL;
228 return ret;
229}
230
djm@openbsd.orgec3d0652015-01-18 21:48:09 +0000231struct load_callback_ctx {
232 const char *host;
233 u_long num_loaded;
234 struct hostkeys *hostkeys;
235};
236
237static int
238record_hostkey(struct hostkey_foreach_line *l, void *_ctx)
239{
240 struct load_callback_ctx *ctx = (struct load_callback_ctx *)_ctx;
241 struct hostkeys *hostkeys = ctx->hostkeys;
242 struct hostkey_entry *tmp;
243
244 if (l->status == HKF_STATUS_INVALID) {
djm@openbsd.org398f9ef2015-03-31 22:57:06 +0000245 /* XXX make this verbose() in the future */
246 debug("%s:%ld: parse error in hostkeys file",
djm@openbsd.orgec3d0652015-01-18 21:48:09 +0000247 l->path, l->linenum);
248 return 0;
249 }
250
251 debug3("%s: found %skey type %s in file %s:%lu", __func__,
252 l->marker == MRK_NONE ? "" :
253 (l->marker == MRK_CA ? "ca " : "revoked "),
254 sshkey_type(l->key), l->path, l->linenum);
255 if ((tmp = reallocarray(hostkeys->entries,
256 hostkeys->num_entries + 1, sizeof(*hostkeys->entries))) == NULL)
257 return SSH_ERR_ALLOC_FAIL;
258 hostkeys->entries = tmp;
259 hostkeys->entries[hostkeys->num_entries].host = xstrdup(ctx->host);
260 hostkeys->entries[hostkeys->num_entries].file = xstrdup(l->path);
261 hostkeys->entries[hostkeys->num_entries].line = l->linenum;
262 hostkeys->entries[hostkeys->num_entries].key = l->key;
263 l->key = NULL; /* steal it */
264 hostkeys->entries[hostkeys->num_entries].marker = l->marker;
265 hostkeys->num_entries++;
266 ctx->num_loaded++;
267
268 return 0;
269}
270
Damien Millerd925dcd2010-12-01 12:21:51 +1100271void
272load_hostkeys(struct hostkeys *hostkeys, const char *host, const char *path)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000273{
djm@openbsd.orgec3d0652015-01-18 21:48:09 +0000274 int r;
275 struct load_callback_ctx ctx;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000276
djm@openbsd.orgec3d0652015-01-18 21:48:09 +0000277 ctx.host = host;
278 ctx.num_loaded = 0;
279 ctx.hostkeys = hostkeys;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000280
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000281 if ((r = hostkeys_foreach(path, record_hostkey, &ctx, host, NULL,
282 HKF_WANT_MATCH|HKF_WANT_PARSE_KEY)) != 0) {
djm@openbsd.orgec3d0652015-01-18 21:48:09 +0000283 if (r != SSH_ERR_SYSTEM_ERROR && errno != ENOENT)
284 debug("%s: hostkeys_foreach failed for %s: %s",
285 __func__, path, ssh_err(r));
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000286 }
djm@openbsd.orgec3d0652015-01-18 21:48:09 +0000287 if (ctx.num_loaded != 0)
288 debug3("%s: loaded %lu keys from %s", __func__,
289 ctx.num_loaded, host);
djm@openbsd.org6fdcaeb2014-10-20 03:43:01 +0000290}
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000291
Damien Millerd925dcd2010-12-01 12:21:51 +1100292void
293free_hostkeys(struct hostkeys *hostkeys)
294{
295 u_int i;
296
297 for (i = 0; i < hostkeys->num_entries; i++) {
Darren Tuckera627d422013-06-02 07:31:17 +1000298 free(hostkeys->entries[i].host);
299 free(hostkeys->entries[i].file);
djm@openbsd.org1129dcf2015-01-15 09:40:00 +0000300 sshkey_free(hostkeys->entries[i].key);
Damien Miller1d2c4562014-02-04 11:18:20 +1100301 explicit_bzero(hostkeys->entries + i, sizeof(*hostkeys->entries));
Damien Millerd925dcd2010-12-01 12:21:51 +1100302 }
Darren Tuckera627d422013-06-02 07:31:17 +1000303 free(hostkeys->entries);
Damien Miller1d2c4562014-02-04 11:18:20 +1100304 explicit_bzero(hostkeys, sizeof(*hostkeys));
Darren Tuckera627d422013-06-02 07:31:17 +1000305 free(hostkeys);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000306}
307
Damien Millerd925dcd2010-12-01 12:21:51 +1100308static int
djm@openbsd.org1129dcf2015-01-15 09:40:00 +0000309check_key_not_revoked(struct hostkeys *hostkeys, struct sshkey *k)
Damien Millerd925dcd2010-12-01 12:21:51 +1100310{
djm@openbsd.org1129dcf2015-01-15 09:40:00 +0000311 int is_cert = sshkey_is_cert(k);
Damien Millerd925dcd2010-12-01 12:21:51 +1100312 u_int i;
313
314 for (i = 0; i < hostkeys->num_entries; i++) {
315 if (hostkeys->entries[i].marker != MRK_REVOKE)
316 continue;
djm@openbsd.org1129dcf2015-01-15 09:40:00 +0000317 if (sshkey_equal_public(k, hostkeys->entries[i].key))
Damien Millerd925dcd2010-12-01 12:21:51 +1100318 return -1;
319 if (is_cert &&
djm@openbsd.org1129dcf2015-01-15 09:40:00 +0000320 sshkey_equal_public(k->cert->signature_key,
Damien Millerd925dcd2010-12-01 12:21:51 +1100321 hostkeys->entries[i].key))
322 return -1;
323 }
324 return 0;
325}
326
327/*
328 * Match keys against a specified key, or look one up by key type.
329 *
330 * If looking for a keytype (key == NULL) and one is found then return
331 * HOST_FOUND, otherwise HOST_NEW.
332 *
333 * If looking for a key (key != NULL):
334 * 1. If the key is a cert and a matching CA is found, return HOST_OK
335 * 2. If the key is not a cert and a matching key is found, return HOST_OK
336 * 3. If no key matches but a key with a different type is found, then
337 * return HOST_CHANGED
338 * 4. If no matching keys are found, then return HOST_NEW.
339 *
340 * Finally, check any found key is not revoked.
341 */
342static HostStatus
343check_hostkeys_by_key_or_type(struct hostkeys *hostkeys,
djm@openbsd.org1129dcf2015-01-15 09:40:00 +0000344 struct sshkey *k, int keytype, const struct hostkey_entry **found)
Damien Millerd925dcd2010-12-01 12:21:51 +1100345{
346 u_int i;
347 HostStatus end_return = HOST_NEW;
djm@openbsd.org1129dcf2015-01-15 09:40:00 +0000348 int want_cert = sshkey_is_cert(k);
Damien Millerd925dcd2010-12-01 12:21:51 +1100349 HostkeyMarker want_marker = want_cert ? MRK_CA : MRK_NONE;
350 int proto = (k ? k->type : keytype) == KEY_RSA1 ? 1 : 2;
351
352 if (found != NULL)
353 *found = NULL;
354
355 for (i = 0; i < hostkeys->num_entries; i++) {
356 if (proto == 1 && hostkeys->entries[i].key->type != KEY_RSA1)
357 continue;
358 if (proto == 2 && hostkeys->entries[i].key->type == KEY_RSA1)
359 continue;
360 if (hostkeys->entries[i].marker != want_marker)
361 continue;
362 if (k == NULL) {
363 if (hostkeys->entries[i].key->type != keytype)
364 continue;
365 end_return = HOST_FOUND;
366 if (found != NULL)
367 *found = hostkeys->entries + i;
368 k = hostkeys->entries[i].key;
369 break;
370 }
371 if (want_cert) {
djm@openbsd.org1129dcf2015-01-15 09:40:00 +0000372 if (sshkey_equal_public(k->cert->signature_key,
Damien Millerd925dcd2010-12-01 12:21:51 +1100373 hostkeys->entries[i].key)) {
374 /* A matching CA exists */
375 end_return = HOST_OK;
376 if (found != NULL)
377 *found = hostkeys->entries + i;
378 break;
379 }
380 } else {
djm@openbsd.org1129dcf2015-01-15 09:40:00 +0000381 if (sshkey_equal(k, hostkeys->entries[i].key)) {
Damien Millerd925dcd2010-12-01 12:21:51 +1100382 end_return = HOST_OK;
383 if (found != NULL)
384 *found = hostkeys->entries + i;
385 break;
386 }
387 /* A non-maching key exists */
388 end_return = HOST_CHANGED;
389 if (found != NULL)
390 *found = hostkeys->entries + i;
391 }
392 }
393 if (check_key_not_revoked(hostkeys, k) != 0) {
394 end_return = HOST_REVOKED;
395 if (found != NULL)
396 *found = NULL;
397 }
398 return end_return;
399}
djm@openbsd.org6fdcaeb2014-10-20 03:43:01 +0000400
Ben Lindstrom3ed66402002-08-01 01:21:56 +0000401HostStatus
djm@openbsd.org1129dcf2015-01-15 09:40:00 +0000402check_key_in_hostkeys(struct hostkeys *hostkeys, struct sshkey *key,
Damien Millerd925dcd2010-12-01 12:21:51 +1100403 const struct hostkey_entry **found)
Ben Lindstrom3ed66402002-08-01 01:21:56 +0000404{
405 if (key == NULL)
406 fatal("no key to look up");
Damien Millerd925dcd2010-12-01 12:21:51 +1100407 return check_hostkeys_by_key_or_type(hostkeys, key, 0, found);
Ben Lindstrom3ed66402002-08-01 01:21:56 +0000408}
409
410int
Damien Millerd925dcd2010-12-01 12:21:51 +1100411lookup_key_in_hostkeys_by_type(struct hostkeys *hostkeys, int keytype,
412 const struct hostkey_entry **found)
Ben Lindstrom3ed66402002-08-01 01:21:56 +0000413{
Damien Millerd925dcd2010-12-01 12:21:51 +1100414 return (check_hostkeys_by_key_or_type(hostkeys, NULL, keytype,
415 found) == HOST_FOUND);
Ben Lindstrom3ed66402002-08-01 01:21:56 +0000416}
417
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000418static int
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000419write_host_entry(FILE *f, const char *host, const char *ip,
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000420 const struct sshkey *key, int store_hash)
421{
422 int r, success = 0;
423 char *hashed_host = NULL;
424
425 if (store_hash) {
426 if ((hashed_host = host_hash(host, NULL, 0)) == NULL) {
427 error("%s: host_hash failed", __func__);
428 return 0;
429 }
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000430 fprintf(f, "%s ", hashed_host);
431 } else if (ip != NULL)
432 fprintf(f, "%s,%s ", host, ip);
433 else
434 fprintf(f, "%s ", host);
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000435
436 if ((r = sshkey_write(key, f)) == 0)
437 success = 1;
438 else
439 error("%s: sshkey_write failed: %s", __func__, ssh_err(r));
440 fputc('\n', f);
441 return success;
442}
443
Damien Miller5428f641999-11-25 11:54:57 +1100444/*
445 * Appends an entry to the host file. Returns false if the entry could not
446 * be appended.
447 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000448int
djm@openbsd.org1129dcf2015-01-15 09:40:00 +0000449add_host_to_hostfile(const char *filename, const char *host,
450 const struct sshkey *key, int store_hash)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000451{
Damien Miller95def091999-11-25 00:26:21 +1100452 FILE *f;
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000453 int success;
Damien Millere1776152005-03-01 21:47:37 +1100454
Damien Miller450a7a12000-03-26 13:04:51 +1000455 if (key == NULL)
Damien Millereba71ba2000-04-29 23:57:08 +1000456 return 1; /* XXX ? */
Damien Miller95def091999-11-25 00:26:21 +1100457 f = fopen(filename, "a");
458 if (!f)
459 return 0;
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000460 success = write_host_entry(f, host, NULL, key, store_hash);
Damien Miller95def091999-11-25 00:26:21 +1100461 fclose(f);
Damien Miller450a7a12000-03-26 13:04:51 +1000462 return success;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000463}
djm@openbsd.orgc29811c2015-01-18 21:40:23 +0000464
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000465struct host_delete_ctx {
466 FILE *out;
467 int quiet;
468 const char *host;
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000469 int *skip_keys; /* XXX split for host/ip? might want to ensure both */
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000470 struct sshkey * const *keys;
471 size_t nkeys;
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000472 int modified;
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000473};
474
475static int
476host_delete(struct hostkey_foreach_line *l, void *_ctx)
477{
478 struct host_delete_ctx *ctx = (struct host_delete_ctx *)_ctx;
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000479 int loglevel = ctx->quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_VERBOSE;
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000480 size_t i;
481
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000482 if (l->status == HKF_STATUS_MATCHED) {
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000483 if (l->marker != MRK_NONE) {
484 /* Don't remove CA and revocation lines */
485 fprintf(ctx->out, "%s\n", l->line);
486 return 0;
487 }
488
489 /* XXX might need a knob for this later */
490 /* Don't remove RSA1 keys */
491 if (l->key->type == KEY_RSA1) {
492 fprintf(ctx->out, "%s\n", l->line);
493 return 0;
494 }
495
496 /*
497 * If this line contains one of the keys that we will be
498 * adding later, then don't change it and mark the key for
499 * skipping.
500 */
501 for (i = 0; i < ctx->nkeys; i++) {
502 if (sshkey_equal(ctx->keys[i], l->key)) {
503 ctx->skip_keys[i] = 1;
504 fprintf(ctx->out, "%s\n", l->line);
505 debug3("%s: %s key already at %s:%ld", __func__,
506 sshkey_type(l->key), l->path, l->linenum);
507 return 0;
508 }
509 }
510
511 /*
512 * Hostname matches and has no CA/revoke marker, delete it
513 * by *not* writing the line to ctx->out.
514 */
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000515 do_log2(loglevel, "%s%s%s:%ld: Removed %s key for host %s",
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000516 ctx->quiet ? __func__ : "", ctx->quiet ? ": " : "",
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000517 l->path, l->linenum, sshkey_type(l->key), ctx->host);
518 ctx->modified = 1;
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000519 return 0;
520 }
521 /* Retain non-matching hosts and invalid lines when deleting */
522 if (l->status == HKF_STATUS_INVALID) {
523 do_log2(loglevel, "%s%s%s:%ld: invalid known_hosts entry",
524 ctx->quiet ? __func__ : "", ctx->quiet ? ": " : "",
525 l->path, l->linenum);
526 }
527 fprintf(ctx->out, "%s\n", l->line);
528 return 0;
529}
530
531int
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000532hostfile_replace_entries(const char *filename, const char *host, const char *ip,
533 struct sshkey **keys, size_t nkeys, int store_hash, int quiet, int hash_alg)
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000534{
535 int r, fd, oerrno = 0;
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000536 int loglevel = quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_VERBOSE;
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000537 struct host_delete_ctx ctx;
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000538 char *fp, *temp = NULL, *back = NULL;
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000539 mode_t omask;
540 size_t i;
541
djm@openbsd.org3076ee72015-01-26 13:36:53 +0000542 omask = umask(077);
543
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000544 memset(&ctx, 0, sizeof(ctx));
545 ctx.host = host;
546 ctx.quiet = quiet;
547 if ((ctx.skip_keys = calloc(nkeys, sizeof(*ctx.skip_keys))) == NULL)
548 return SSH_ERR_ALLOC_FAIL;
549 ctx.keys = keys;
550 ctx.nkeys = nkeys;
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000551 ctx.modified = 0;
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000552
553 /*
554 * Prepare temporary file for in-place deletion.
555 */
556 if ((r = asprintf(&temp, "%s.XXXXXXXXXXX", filename)) < 0 ||
557 (r = asprintf(&back, "%s.old", filename)) < 0) {
558 r = SSH_ERR_ALLOC_FAIL;
559 goto fail;
560 }
561
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000562 if ((fd = mkstemp(temp)) == -1) {
563 oerrno = errno;
564 error("%s: mkstemp: %s", __func__, strerror(oerrno));
565 r = SSH_ERR_SYSTEM_ERROR;
566 goto fail;
567 }
568 if ((ctx.out = fdopen(fd, "w")) == NULL) {
569 oerrno = errno;
570 close(fd);
571 error("%s: fdopen: %s", __func__, strerror(oerrno));
572 r = SSH_ERR_SYSTEM_ERROR;
573 goto fail;
574 }
575
576 /* Remove all entries for the specified host from the file */
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000577 if ((r = hostkeys_foreach(filename, host_delete, &ctx, host, ip,
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000578 HKF_WANT_PARSE_KEY)) != 0) {
579 error("%s: hostkeys_foreach failed: %s", __func__, ssh_err(r));
580 goto fail;
581 }
582
583 /* Add the requested keys */
584 for (i = 0; i < nkeys; i++) {
585 if (ctx.skip_keys[i])
586 continue;
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000587 if ((fp = sshkey_fingerprint(keys[i], hash_alg,
588 SSH_FP_DEFAULT)) == NULL) {
589 r = SSH_ERR_ALLOC_FAIL;
590 goto fail;
591 }
592 do_log2(loglevel, "%s%sAdding new key for %s to %s: %s %s",
593 quiet ? __func__ : "", quiet ? ": " : "", host, filename,
594 sshkey_ssh_name(keys[i]), fp);
595 free(fp);
596 if (!write_host_entry(ctx.out, host, ip, keys[i], store_hash)) {
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000597 r = SSH_ERR_INTERNAL_ERROR;
598 goto fail;
599 }
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000600 ctx.modified = 1;
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000601 }
602 fclose(ctx.out);
603 ctx.out = NULL;
604
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000605 if (ctx.modified) {
606 /* Backup the original file and replace it with the temporary */
607 if (unlink(back) == -1 && errno != ENOENT) {
608 oerrno = errno;
609 error("%s: unlink %.100s: %s", __func__,
610 back, strerror(errno));
611 r = SSH_ERR_SYSTEM_ERROR;
612 goto fail;
613 }
614 if (link(filename, back) == -1) {
615 oerrno = errno;
616 error("%s: link %.100s to %.100s: %s", __func__,
617 filename, back, strerror(errno));
618 r = SSH_ERR_SYSTEM_ERROR;
619 goto fail;
620 }
621 if (rename(temp, filename) == -1) {
622 oerrno = errno;
623 error("%s: rename \"%s\" to \"%s\": %s", __func__,
624 temp, filename, strerror(errno));
625 r = SSH_ERR_SYSTEM_ERROR;
626 goto fail;
627 }
628 } else {
629 /* No changes made; just delete the temporary file */
630 if (unlink(temp) != 0)
631 error("%s: unlink \"%s\": %s", __func__,
632 temp, strerror(errno));
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000633 }
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000634
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000635 /* success */
636 r = 0;
637 fail:
638 if (temp != NULL && r != 0)
639 unlink(temp);
640 free(temp);
641 free(back);
642 if (ctx.out != NULL)
643 fclose(ctx.out);
644 free(ctx.skip_keys);
djm@openbsd.org3076ee72015-01-26 13:36:53 +0000645 umask(omask);
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000646 if (r == SSH_ERR_SYSTEM_ERROR)
647 errno = oerrno;
648 return r;
649}
650
djm@openbsd.orgc29811c2015-01-18 21:40:23 +0000651static int
652match_maybe_hashed(const char *host, const char *names, int *was_hashed)
653{
654 int hashed = *names == HASH_DELIM;
655 const char *hashed_host;
656 size_t nlen = strlen(names);
657
658 if (was_hashed != NULL)
659 *was_hashed = hashed;
660 if (hashed) {
661 if ((hashed_host = host_hash(host, names, nlen)) == NULL)
662 return -1;
663 return nlen == strlen(hashed_host) &&
664 strncmp(hashed_host, names, nlen) == 0;
665 }
666 return match_hostname(host, names, nlen) == 1;
667}
668
669int
670hostkeys_foreach(const char *path, hostkeys_foreach_fn *callback, void *ctx,
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000671 const char *host, const char *ip, u_int options)
djm@openbsd.orgc29811c2015-01-18 21:40:23 +0000672{
673 FILE *f;
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000674 char line[8192], oline[8192], ktype[128];
djm@openbsd.orgc29811c2015-01-18 21:40:23 +0000675 u_long linenum = 0;
676 char *cp, *cp2;
677 u_int kbits;
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000678 int hashed;
djm@openbsd.orgc29811c2015-01-18 21:40:23 +0000679 int s, r = 0;
680 struct hostkey_foreach_line lineinfo;
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000681 size_t l;
djm@openbsd.orgc29811c2015-01-18 21:40:23 +0000682
683 memset(&lineinfo, 0, sizeof(lineinfo));
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000684 if (host == NULL && (options & HKF_WANT_MATCH) != 0)
djm@openbsd.orgc29811c2015-01-18 21:40:23 +0000685 return SSH_ERR_INVALID_ARGUMENT;
686 if ((f = fopen(path, "r")) == NULL)
687 return SSH_ERR_SYSTEM_ERROR;
688
689 debug3("%s: reading file \"%s\"", __func__, path);
690 while (read_keyfile_line(f, path, line, sizeof(line), &linenum) == 0) {
691 line[strcspn(line, "\n")] = '\0';
692 strlcpy(oline, line, sizeof(oline));
693
694 sshkey_free(lineinfo.key);
695 memset(&lineinfo, 0, sizeof(lineinfo));
696 lineinfo.path = path;
697 lineinfo.linenum = linenum;
698 lineinfo.line = oline;
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000699 lineinfo.marker = MRK_NONE;
djm@openbsd.orgc29811c2015-01-18 21:40:23 +0000700 lineinfo.status = HKF_STATUS_OK;
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000701 lineinfo.keytype = KEY_UNSPEC;
djm@openbsd.orgc29811c2015-01-18 21:40:23 +0000702
703 /* Skip any leading whitespace, comments and empty lines. */
704 for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
705 ;
706 if (!*cp || *cp == '#' || *cp == '\n') {
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000707 if ((options & HKF_WANT_MATCH) == 0) {
djm@openbsd.orgc29811c2015-01-18 21:40:23 +0000708 lineinfo.status = HKF_STATUS_COMMENT;
709 if ((r = callback(&lineinfo, ctx)) != 0)
710 break;
711 }
712 continue;
713 }
714
715 if ((lineinfo.marker = check_markers(&cp)) == MRK_ERROR) {
716 verbose("%s: invalid marker at %s:%lu",
717 __func__, path, linenum);
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000718 if ((options & HKF_WANT_MATCH) == 0)
djm@openbsd.orgc29811c2015-01-18 21:40:23 +0000719 goto bad;
720 continue;
721 }
722
723 /* Find the end of the host name portion. */
724 for (cp2 = cp; *cp2 && *cp2 != ' ' && *cp2 != '\t'; cp2++)
725 ;
726 lineinfo.hosts = cp;
727 *cp2++ = '\0';
728
729 /* Check if the host name matches. */
730 if (host != NULL) {
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000731 if ((s = match_maybe_hashed(host, lineinfo.hosts,
732 &hashed)) == -1) {
djm@openbsd.orgc29811c2015-01-18 21:40:23 +0000733 debug2("%s: %s:%ld: bad host hash \"%.32s\"",
734 __func__, path, linenum, lineinfo.hosts);
735 goto bad;
736 }
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000737 if (s == 1) {
738 lineinfo.status = HKF_STATUS_MATCHED;
739 lineinfo.match |= HKF_MATCH_HOST |
740 (hashed ? HKF_MATCH_HOST_HASHED : 0);
741 }
742 /* Try matching IP address if supplied */
743 if (ip != NULL) {
744 if ((s = match_maybe_hashed(ip, lineinfo.hosts,
745 &hashed)) == -1) {
746 debug2("%s: %s:%ld: bad ip hash "
747 "\"%.32s\"", __func__, path,
748 linenum, lineinfo.hosts);
749 goto bad;
750 }
751 if (s == 1) {
752 lineinfo.status = HKF_STATUS_MATCHED;
753 lineinfo.match |= HKF_MATCH_IP |
754 (hashed ? HKF_MATCH_IP_HASHED : 0);
755 }
756 }
757 /*
758 * Skip this line if host matching requested and
759 * neither host nor address matched.
760 */
761 if ((options & HKF_WANT_MATCH) != 0 &&
762 lineinfo.status != HKF_STATUS_MATCHED)
763 continue;
djm@openbsd.orgc29811c2015-01-18 21:40:23 +0000764 }
765
766 /* Got a match. Skip host name and any following whitespace */
767 for (; *cp2 == ' ' || *cp2 == '\t'; cp2++)
768 ;
769 if (*cp2 == '\0' || *cp2 == '#') {
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000770 debug2("%s:%ld: truncated before key type",
771 path, linenum);
djm@openbsd.orgc29811c2015-01-18 21:40:23 +0000772 goto bad;
773 }
774 lineinfo.rawkey = cp = cp2;
775
776 if ((options & HKF_WANT_PARSE_KEY) != 0) {
777 /*
778 * Extract the key from the line. This will skip
779 * any leading whitespace. Ignore badly formatted
780 * lines.
781 */
782 if ((lineinfo.key = sshkey_new(KEY_UNSPEC)) == NULL) {
783 error("%s: sshkey_new failed", __func__);
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000784 r = SSH_ERR_ALLOC_FAIL;
785 break;
djm@openbsd.orgc29811c2015-01-18 21:40:23 +0000786 }
787 if (!hostfile_read_key(&cp, &kbits, lineinfo.key)) {
788#ifdef WITH_SSH1
789 sshkey_free(lineinfo.key);
790 lineinfo.key = sshkey_new(KEY_RSA1);
791 if (lineinfo.key == NULL) {
792 error("%s: sshkey_new fail", __func__);
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000793 r = SSH_ERR_ALLOC_FAIL;
794 break;
djm@openbsd.orgc29811c2015-01-18 21:40:23 +0000795 }
796 if (!hostfile_read_key(&cp, &kbits,
797 lineinfo.key))
798 goto bad;
799#else
800 goto bad;
801#endif
802 }
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000803 lineinfo.keytype = lineinfo.key->type;
804 lineinfo.comment = cp;
805 } else {
806 /* Extract and parse key type */
807 l = strcspn(lineinfo.rawkey, " \t");
808 if (l <= 1 || l >= sizeof(ktype) ||
809 lineinfo.rawkey[l] == '\0')
810 goto bad;
811 memcpy(ktype, lineinfo.rawkey, l);
812 ktype[l] = '\0';
813 lineinfo.keytype = sshkey_type_from_name(ktype);
djm@openbsd.org398f9ef2015-03-31 22:57:06 +0000814
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000815 /*
816 * Assume RSA1 if the first component is a short
817 * decimal number.
818 */
819 if (lineinfo.keytype == KEY_UNSPEC && l < 8 &&
820 strspn(ktype, "0123456789") == l)
821 lineinfo.keytype = KEY_RSA1;
djm@openbsd.org398f9ef2015-03-31 22:57:06 +0000822
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000823 /*
824 * Check that something other than whitespace follows
825 * the key type. This won't catch all corruption, but
826 * it does catch trivial truncation.
827 */
828 cp2 += l; /* Skip past key type */
829 for (; *cp2 == ' ' || *cp2 == '\t'; cp2++)
830 ;
831 if (*cp2 == '\0' || *cp2 == '#') {
832 debug2("%s:%ld: truncated after key type",
833 path, linenum);
834 lineinfo.keytype = KEY_UNSPEC;
835 }
836 if (lineinfo.keytype == KEY_UNSPEC) {
djm@openbsd.orgc29811c2015-01-18 21:40:23 +0000837 bad:
djm@openbsd.org6c5c9492015-02-16 22:08:57 +0000838 sshkey_free(lineinfo.key);
839 lineinfo.key = NULL;
djm@openbsd.orgc29811c2015-01-18 21:40:23 +0000840 lineinfo.status = HKF_STATUS_INVALID;
841 if ((r = callback(&lineinfo, ctx)) != 0)
842 break;
843 continue;
844 }
845 }
846 if ((r = callback(&lineinfo, ctx)) != 0)
847 break;
848 }
849 sshkey_free(lineinfo.key);
850 fclose(f);
851 return r;
852}