Annotation of src/usr.bin/ssh/hostfile.c, Revision 1.80
1.80 ! djm 1: /* $OpenBSD: hostfile.c,v 1.79 2020/03/06 18:25:12 markus Exp $ */
1.1 deraadt 2: /*
1.8 deraadt 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.
1.16 markus 7: *
1.20 deraadt 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: *
1.28 markus 15: * Copyright (c) 1999, 2000 Markus Friedl. All rights reserved.
1.20 deraadt 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.
1.8 deraadt 37: */
1.1 deraadt 38:
1.41 stevesk 39: #include <sys/types.h>
1.62 djm 40: #include <sys/stat.h>
1.41 stevesk 41:
42: #include <netinet/in.h>
1.33 djm 43:
1.60 djm 44: #include <errno.h>
1.33 djm 45: #include <resolv.h>
1.44 stevesk 46: #include <stdio.h>
1.43 stevesk 47: #include <stdlib.h>
1.42 stevesk 48: #include <string.h>
1.57 djm 49: #include <stdarg.h>
1.62 djm 50: #include <unistd.h>
1.1 deraadt 51:
1.45 deraadt 52: #include "xmalloc.h"
1.14 markus 53: #include "match.h"
1.59 djm 54: #include "sshkey.h"
1.14 markus 55: #include "hostfile.h"
1.24 markus 56: #include "log.h"
1.49 djm 57: #include "misc.h"
1.59 djm 58: #include "ssherr.h"
1.53 djm 59: #include "digest.h"
1.54 markus 60: #include "hmac.h"
1.49 djm 61:
62: struct hostkeys {
63: struct hostkey_entry *entries;
64: u_int num_entries;
65: };
1.33 djm 66:
1.60 djm 67: /* XXX hmac is too easy to dictionary attack; use bcrypt? */
68:
1.33 djm 69: static int
1.52 djm 70: extract_salt(const char *s, u_int l, u_char *salt, size_t salt_len)
1.33 djm 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);
1.51 djm 102: free(b64salt);
1.33 djm 103: if (ret == -1) {
104: debug2("extract_salt: salt decode error");
105: return (-1);
106: }
1.54 markus 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);
1.33 djm 110: return (-1);
111: }
1.34 deraadt 112:
1.33 djm 113: return (0);
114: }
115:
116: char *
117: host_hash(const char *host, const char *name_from_hostfile, u_int src_len)
118: {
1.54 markus 119: struct ssh_hmac_ctx *ctx;
1.52 djm 120: u_char salt[256], result[256];
121: char uu_salt[512], uu_result[512];
1.33 djm 122: static char encoded[1024];
1.67 tedu 123: u_int len;
1.33 djm 124:
1.54 markus 125: len = ssh_digest_bytes(SSH_DIGEST_SHA1);
1.33 djm 126:
127: if (name_from_hostfile == NULL) {
128: /* Create new salt */
1.67 tedu 129: arc4random_buf(salt, len);
1.33 djm 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:
1.54 markus 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);
1.33 djm 143:
1.34 deraadt 144: if (__b64_ntop(salt, len, uu_salt, sizeof(uu_salt)) == -1 ||
1.33 djm 145: __b64_ntop(result, len, uu_result, sizeof(uu_result)) == -1)
1.54 markus 146: fatal("%s: __b64_ntop failed", __func__);
1.33 djm 147:
148: snprintf(encoded, sizeof(encoded), "%s%s%c%s", HASH_MAGIC, uu_salt,
149: HASH_DELIM, uu_result);
150:
151: return (encoded);
152: }
1.1 deraadt 153:
1.9 markus 154: /*
1.14 markus 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.
1.9 markus 157: */
1.1 deraadt 158:
1.29 jakob 159: int
1.59 djm 160: hostfile_read_key(char **cpp, u_int *bitsp, struct sshkey *ret)
1.1 deraadt 161: {
1.7 markus 162: char *cp;
163:
164: /* Skip leading whitespace. */
1.9 markus 165: for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++)
166: ;
1.1 deraadt 167:
1.76 dtucker 168: if (sshkey_read(ret, &cp) != 0)
1.7 markus 169: return 0;
170:
171: /* Skip trailing whitespace. */
1.9 markus 172: for (; *cp == ' ' || *cp == '\t'; cp++)
173: ;
1.7 markus 174:
175: /* Return results. */
176: *cpp = cp;
1.59 djm 177: if (bitsp != NULL)
178: *bitsp = sshkey_size(ret);
1.7 markus 179: return 1;
1.14 markus 180: }
1.1 deraadt 181:
1.49 djm 182: static HostkeyMarker
1.48 djm 183: check_markers(char **cpp)
184: {
185: char marker[32], *sp, *cp = *cpp;
186: int ret = MRK_NONE;
187:
188: while (*cp == '@') {
189: /* Only one marker is allowed */
190: if (ret != MRK_NONE)
191: return MRK_ERROR;
192: /* Markers are terminated by whitespace */
193: if ((sp = strchr(cp, ' ')) == NULL &&
194: (sp = strchr(cp, '\t')) == NULL)
195: return MRK_ERROR;
196: /* Extract marker for comparison */
197: if (sp <= cp + 1 || sp >= cp + sizeof(marker))
198: return MRK_ERROR;
199: memcpy(marker, cp, sp - cp);
200: marker[sp - cp] = '\0';
201: if (strcmp(marker, CA_MARKER) == 0)
202: ret = MRK_CA;
203: else if (strcmp(marker, REVOKE_MARKER) == 0)
204: ret = MRK_REVOKE;
205: else
206: return MRK_ERROR;
207:
208: /* Skip past marker and any whitespace that follows it */
209: cp = sp;
210: for (; *cp == ' ' || *cp == '\t'; cp++)
211: ;
212: }
213: *cpp = cp;
214: return ret;
215: }
216:
1.49 djm 217: struct hostkeys *
218: init_hostkeys(void)
219: {
220: struct hostkeys *ret = xcalloc(1, sizeof(*ret));
221:
222: ret->entries = NULL;
223: return ret;
224: }
1.1 deraadt 225:
1.61 djm 226: struct load_callback_ctx {
227: const char *host;
228: u_long num_loaded;
229: struct hostkeys *hostkeys;
230: };
231:
232: static int
233: record_hostkey(struct hostkey_foreach_line *l, void *_ctx)
1.1 deraadt 234: {
1.61 djm 235: struct load_callback_ctx *ctx = (struct load_callback_ctx *)_ctx;
236: struct hostkeys *hostkeys = ctx->hostkeys;
237: struct hostkey_entry *tmp;
238:
239: if (l->status == HKF_STATUS_INVALID) {
1.65 djm 240: /* XXX make this verbose() in the future */
241: debug("%s:%ld: parse error in hostkeys file",
1.61 djm 242: l->path, l->linenum);
243: return 0;
244: }
1.7 markus 245:
1.61 djm 246: debug3("%s: found %skey type %s in file %s:%lu", __func__,
247: l->marker == MRK_NONE ? "" :
248: (l->marker == MRK_CA ? "ca " : "revoked "),
249: sshkey_type(l->key), l->path, l->linenum);
1.71 deraadt 250: if ((tmp = recallocarray(hostkeys->entries, hostkeys->num_entries,
1.61 djm 251: hostkeys->num_entries + 1, sizeof(*hostkeys->entries))) == NULL)
252: return SSH_ERR_ALLOC_FAIL;
253: hostkeys->entries = tmp;
254: hostkeys->entries[hostkeys->num_entries].host = xstrdup(ctx->host);
255: hostkeys->entries[hostkeys->num_entries].file = xstrdup(l->path);
256: hostkeys->entries[hostkeys->num_entries].line = l->linenum;
257: hostkeys->entries[hostkeys->num_entries].key = l->key;
258: l->key = NULL; /* steal it */
259: hostkeys->entries[hostkeys->num_entries].marker = l->marker;
260: hostkeys->num_entries++;
261: ctx->num_loaded++;
1.7 markus 262:
1.61 djm 263: return 0;
264: }
1.47 djm 265:
1.61 djm 266: void
267: load_hostkeys(struct hostkeys *hostkeys, const char *host, const char *path)
268: {
269: int r;
270: struct load_callback_ctx ctx;
1.7 markus 271:
1.61 djm 272: ctx.host = host;
273: ctx.num_loaded = 0;
274: ctx.hostkeys = hostkeys;
275:
1.64 djm 276: if ((r = hostkeys_foreach(path, record_hostkey, &ctx, host, NULL,
277: HKF_WANT_MATCH|HKF_WANT_PARSE_KEY)) != 0) {
1.61 djm 278: if (r != SSH_ERR_SYSTEM_ERROR && errno != ENOENT)
279: debug("%s: hostkeys_foreach failed for %s: %s",
280: __func__, path, ssh_err(r));
281: }
282: if (ctx.num_loaded != 0)
283: debug3("%s: loaded %lu keys from %s", __func__,
284: ctx.num_loaded, host);
1.58 djm 285: }
1.49 djm 286:
287: void
288: free_hostkeys(struct hostkeys *hostkeys)
289: {
290: u_int i;
291:
292: for (i = 0; i < hostkeys->num_entries; i++) {
1.51 djm 293: free(hostkeys->entries[i].host);
294: free(hostkeys->entries[i].file);
1.59 djm 295: sshkey_free(hostkeys->entries[i].key);
1.55 tedu 296: explicit_bzero(hostkeys->entries + i, sizeof(*hostkeys->entries));
1.49 djm 297: }
1.51 djm 298: free(hostkeys->entries);
1.78 jsg 299: freezero(hostkeys, sizeof(*hostkeys));
1.49 djm 300: }
301:
302: static int
1.59 djm 303: check_key_not_revoked(struct hostkeys *hostkeys, struct sshkey *k)
1.49 djm 304: {
1.59 djm 305: int is_cert = sshkey_is_cert(k);
1.49 djm 306: u_int i;
1.7 markus 307:
1.49 djm 308: for (i = 0; i < hostkeys->num_entries; i++) {
309: if (hostkeys->entries[i].marker != MRK_REVOKE)
1.30 markus 310: continue;
1.59 djm 311: if (sshkey_equal_public(k, hostkeys->entries[i].key))
1.49 djm 312: return -1;
1.79 markus 313: if (is_cert && k != NULL &&
1.59 djm 314: sshkey_equal_public(k->cert->signature_key,
1.49 djm 315: hostkeys->entries[i].key))
316: return -1;
317: }
318: return 0;
319: }
320:
321: /*
322: * Match keys against a specified key, or look one up by key type.
323: *
324: * If looking for a keytype (key == NULL) and one is found then return
325: * HOST_FOUND, otherwise HOST_NEW.
326: *
327: * If looking for a key (key != NULL):
328: * 1. If the key is a cert and a matching CA is found, return HOST_OK
329: * 2. If the key is not a cert and a matching key is found, return HOST_OK
330: * 3. If no key matches but a key with a different type is found, then
331: * return HOST_CHANGED
332: * 4. If no matching keys are found, then return HOST_NEW.
333: *
334: * Finally, check any found key is not revoked.
335: */
336: static HostStatus
337: check_hostkeys_by_key_or_type(struct hostkeys *hostkeys,
1.59 djm 338: struct sshkey *k, int keytype, const struct hostkey_entry **found)
1.49 djm 339: {
340: u_int i;
341: HostStatus end_return = HOST_NEW;
1.59 djm 342: int want_cert = sshkey_is_cert(k);
1.49 djm 343: HostkeyMarker want_marker = want_cert ? MRK_CA : MRK_NONE;
344:
345: if (found != NULL)
346: *found = NULL;
1.30 markus 347:
1.49 djm 348: for (i = 0; i < hostkeys->num_entries; i++) {
349: if (hostkeys->entries[i].marker != want_marker)
350: continue;
351: if (k == NULL) {
352: if (hostkeys->entries[i].key->type != keytype)
353: continue;
354: end_return = HOST_FOUND;
355: if (found != NULL)
356: *found = hostkeys->entries + i;
357: k = hostkeys->entries[i].key;
358: break;
359: }
360: if (want_cert) {
1.59 djm 361: if (sshkey_equal_public(k->cert->signature_key,
1.49 djm 362: hostkeys->entries[i].key)) {
363: /* A matching CA exists */
364: end_return = HOST_OK;
365: if (found != NULL)
366: *found = hostkeys->entries + i;
367: break;
1.48 djm 368: }
1.49 djm 369: } else {
1.59 djm 370: if (sshkey_equal(k, hostkeys->entries[i].key)) {
1.49 djm 371: end_return = HOST_OK;
372: if (found != NULL)
373: *found = hostkeys->entries + i;
374: break;
1.48 djm 375: }
1.49 djm 376: /* A non-maching key exists */
377: end_return = HOST_CHANGED;
378: if (found != NULL)
379: *found = hostkeys->entries + i;
1.48 djm 380: }
1.1 deraadt 381: }
1.49 djm 382: if (check_key_not_revoked(hostkeys, k) != 0) {
383: end_return = HOST_REVOKED;
384: if (found != NULL)
385: *found = NULL;
386: }
1.7 markus 387: return end_return;
1.30 markus 388: }
1.58 djm 389:
1.30 markus 390: HostStatus
1.59 djm 391: check_key_in_hostkeys(struct hostkeys *hostkeys, struct sshkey *key,
1.49 djm 392: const struct hostkey_entry **found)
1.30 markus 393: {
394: if (key == NULL)
395: fatal("no key to look up");
1.49 djm 396: return check_hostkeys_by_key_or_type(hostkeys, key, 0, found);
1.30 markus 397: }
398:
399: int
1.49 djm 400: lookup_key_in_hostkeys_by_type(struct hostkeys *hostkeys, int keytype,
401: const struct hostkey_entry **found)
1.30 markus 402: {
1.49 djm 403: return (check_hostkeys_by_key_or_type(hostkeys, NULL, keytype,
404: found) == HOST_FOUND);
1.80 ! djm 405: }
! 406:
! 407: int
! 408: lookup_marker_in_hostkeys(struct hostkeys *hostkeys, int want_marker)
! 409: {
! 410: u_int i;
! 411:
! 412: for (i = 0; i < hostkeys->num_entries; i++) {
! 413: if (hostkeys->entries[i].marker == (HostkeyMarker)want_marker)
! 414: return 1;
! 415: }
! 416: return 0;
1.1 deraadt 417: }
418:
1.62 djm 419: static int
1.64 djm 420: write_host_entry(FILE *f, const char *host, const char *ip,
1.62 djm 421: const struct sshkey *key, int store_hash)
422: {
423: int r, success = 0;
1.68 djm 424: char *hashed_host = NULL, *lhost;
425:
426: lhost = xstrdup(host);
427: lowercase(lhost);
1.62 djm 428:
429: if (store_hash) {
1.68 djm 430: if ((hashed_host = host_hash(lhost, NULL, 0)) == NULL) {
1.62 djm 431: error("%s: host_hash failed", __func__);
1.68 djm 432: free(lhost);
1.62 djm 433: return 0;
434: }
1.64 djm 435: fprintf(f, "%s ", hashed_host);
436: } else if (ip != NULL)
1.68 djm 437: fprintf(f, "%s,%s ", lhost, ip);
438: else {
439: fprintf(f, "%s ", lhost);
440: }
441: free(lhost);
1.62 djm 442: if ((r = sshkey_write(key, f)) == 0)
443: success = 1;
444: else
445: error("%s: sshkey_write failed: %s", __func__, ssh_err(r));
446: fputc('\n', f);
447: return success;
448: }
449:
1.9 markus 450: /*
451: * Appends an entry to the host file. Returns false if the entry could not
452: * be appended.
453: */
1.2 provos 454: int
1.59 djm 455: add_host_to_hostfile(const char *filename, const char *host,
456: const struct sshkey *key, int store_hash)
1.1 deraadt 457: {
1.7 markus 458: FILE *f;
1.62 djm 459: int success;
1.33 djm 460:
1.14 markus 461: if (key == NULL)
1.17 markus 462: return 1; /* XXX ? */
1.7 markus 463: f = fopen(filename, "a");
464: if (!f)
465: return 0;
1.64 djm 466: success = write_host_entry(f, host, NULL, key, store_hash);
1.62 djm 467: fclose(f);
468: return success;
469: }
470:
471: struct host_delete_ctx {
472: FILE *out;
473: int quiet;
474: const char *host;
1.64 djm 475: int *skip_keys; /* XXX split for host/ip? might want to ensure both */
1.62 djm 476: struct sshkey * const *keys;
477: size_t nkeys;
1.64 djm 478: int modified;
1.62 djm 479: };
480:
481: static int
482: host_delete(struct hostkey_foreach_line *l, void *_ctx)
483: {
484: struct host_delete_ctx *ctx = (struct host_delete_ctx *)_ctx;
1.64 djm 485: int loglevel = ctx->quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_VERBOSE;
1.62 djm 486: size_t i;
487:
1.64 djm 488: if (l->status == HKF_STATUS_MATCHED) {
1.62 djm 489: if (l->marker != MRK_NONE) {
490: /* Don't remove CA and revocation lines */
491: fprintf(ctx->out, "%s\n", l->line);
492: return 0;
493: }
1.33 djm 494:
1.62 djm 495: /*
496: * If this line contains one of the keys that we will be
497: * adding later, then don't change it and mark the key for
498: * skipping.
499: */
500: for (i = 0; i < ctx->nkeys; i++) {
501: if (sshkey_equal(ctx->keys[i], l->key)) {
502: ctx->skip_keys[i] = 1;
503: fprintf(ctx->out, "%s\n", l->line);
504: debug3("%s: %s key already at %s:%ld", __func__,
505: sshkey_type(l->key), l->path, l->linenum);
506: return 0;
507: }
508: }
509:
510: /*
511: * Hostname matches and has no CA/revoke marker, delete it
512: * by *not* writing the line to ctx->out.
513: */
1.64 djm 514: do_log2(loglevel, "%s%s%s:%ld: Removed %s key for host %s",
1.62 djm 515: ctx->quiet ? __func__ : "", ctx->quiet ? ": " : "",
1.64 djm 516: l->path, l->linenum, sshkey_type(l->key), ctx->host);
517: ctx->modified = 1;
1.62 djm 518: return 0;
519: }
520: /* Retain non-matching hosts and invalid lines when deleting */
521: if (l->status == HKF_STATUS_INVALID) {
522: do_log2(loglevel, "%s%s%s:%ld: invalid known_hosts entry",
523: ctx->quiet ? __func__ : "", ctx->quiet ? ": " : "",
524: l->path, l->linenum);
525: }
526: fprintf(ctx->out, "%s\n", l->line);
527: return 0;
528: }
529:
530: int
1.64 djm 531: hostfile_replace_entries(const char *filename, const char *host, const char *ip,
532: struct sshkey **keys, size_t nkeys, int store_hash, int quiet, int hash_alg)
1.62 djm 533: {
534: int r, fd, oerrno = 0;
1.64 djm 535: int loglevel = quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_VERBOSE;
1.62 djm 536: struct host_delete_ctx ctx;
1.64 djm 537: char *fp, *temp = NULL, *back = NULL;
1.62 djm 538: mode_t omask;
539: size_t i;
540:
1.63 djm 541: omask = umask(077);
542:
1.62 djm 543: memset(&ctx, 0, sizeof(ctx));
544: ctx.host = host;
545: ctx.quiet = quiet;
546: if ((ctx.skip_keys = calloc(nkeys, sizeof(*ctx.skip_keys))) == NULL)
547: return SSH_ERR_ALLOC_FAIL;
548: ctx.keys = keys;
549: ctx.nkeys = nkeys;
1.64 djm 550: ctx.modified = 0;
1.62 djm 551:
552: /*
553: * Prepare temporary file for in-place deletion.
554: */
1.75 deraadt 555: if ((r = asprintf(&temp, "%s.XXXXXXXXXXX", filename)) == -1 ||
1.74 deraadt 556: (r = asprintf(&back, "%s.old", filename)) == -1) {
1.62 djm 557: r = SSH_ERR_ALLOC_FAIL;
558: goto fail;
559: }
560:
561: if ((fd = mkstemp(temp)) == -1) {
562: oerrno = errno;
563: error("%s: mkstemp: %s", __func__, strerror(oerrno));
564: r = SSH_ERR_SYSTEM_ERROR;
565: goto fail;
566: }
567: if ((ctx.out = fdopen(fd, "w")) == NULL) {
568: oerrno = errno;
569: close(fd);
570: error("%s: fdopen: %s", __func__, strerror(oerrno));
571: r = SSH_ERR_SYSTEM_ERROR;
572: goto fail;
573: }
574:
575: /* Remove all entries for the specified host from the file */
1.64 djm 576: if ((r = hostkeys_foreach(filename, host_delete, &ctx, host, ip,
1.62 djm 577: HKF_WANT_PARSE_KEY)) != 0) {
1.77 djm 578: oerrno = errno;
1.62 djm 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;
1.64 djm 587: 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)) {
1.62 djm 597: r = SSH_ERR_INTERNAL_ERROR;
598: goto fail;
599: }
1.64 djm 600: ctx.modified = 1;
1.33 djm 601: }
1.62 djm 602: fclose(ctx.out);
603: ctx.out = NULL;
1.33 djm 604:
1.64 djm 605: 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));
1.62 djm 633: }
1.64 djm 634:
1.62 djm 635: /* 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);
1.63 djm 645: umask(omask);
1.62 djm 646: if (r == SSH_ERR_SYSTEM_ERROR)
647: errno = oerrno;
648: return r;
1.60 djm 649: }
650:
651: static int
652: match_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: }
1.66 djm 666: return match_hostname(host, names) == 1;
1.60 djm 667: }
668:
669: int
670: hostkeys_foreach(const char *path, hostkeys_foreach_fn *callback, void *ctx,
1.64 djm 671: const char *host, const char *ip, u_int options)
1.60 djm 672: {
673: FILE *f;
1.72 markus 674: char *line = NULL, ktype[128];
1.60 djm 675: u_long linenum = 0;
676: char *cp, *cp2;
677: u_int kbits;
1.64 djm 678: int hashed;
1.60 djm 679: int s, r = 0;
680: struct hostkey_foreach_line lineinfo;
1.72 markus 681: size_t linesize = 0, l;
1.60 djm 682:
683: memset(&lineinfo, 0, sizeof(lineinfo));
1.64 djm 684: if (host == NULL && (options & HKF_WANT_MATCH) != 0)
1.60 djm 685: 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);
1.72 markus 690: while (getline(&line, &linesize, f) != -1) {
691: linenum++;
1.60 djm 692: line[strcspn(line, "\n")] = '\0';
693:
1.73 djm 694: free(lineinfo.line);
1.60 djm 695: sshkey_free(lineinfo.key);
696: memset(&lineinfo, 0, sizeof(lineinfo));
697: lineinfo.path = path;
698: lineinfo.linenum = linenum;
1.72 markus 699: lineinfo.line = xstrdup(line);
1.64 djm 700: lineinfo.marker = MRK_NONE;
1.60 djm 701: lineinfo.status = HKF_STATUS_OK;
1.64 djm 702: lineinfo.keytype = KEY_UNSPEC;
1.60 djm 703:
704: /* Skip any leading whitespace, comments and empty lines. */
705: for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
706: ;
707: if (!*cp || *cp == '#' || *cp == '\n') {
1.64 djm 708: if ((options & HKF_WANT_MATCH) == 0) {
1.60 djm 709: lineinfo.status = HKF_STATUS_COMMENT;
710: if ((r = callback(&lineinfo, ctx)) != 0)
711: break;
712: }
713: continue;
714: }
715:
716: if ((lineinfo.marker = check_markers(&cp)) == MRK_ERROR) {
717: verbose("%s: invalid marker at %s:%lu",
718: __func__, path, linenum);
1.64 djm 719: if ((options & HKF_WANT_MATCH) == 0)
1.60 djm 720: goto bad;
721: continue;
722: }
723:
724: /* Find the end of the host name portion. */
725: for (cp2 = cp; *cp2 && *cp2 != ' ' && *cp2 != '\t'; cp2++)
726: ;
727: lineinfo.hosts = cp;
728: *cp2++ = '\0';
729:
730: /* Check if the host name matches. */
731: if (host != NULL) {
1.64 djm 732: if ((s = match_maybe_hashed(host, lineinfo.hosts,
733: &hashed)) == -1) {
1.60 djm 734: debug2("%s: %s:%ld: bad host hash \"%.32s\"",
735: __func__, path, linenum, lineinfo.hosts);
736: goto bad;
737: }
1.64 djm 738: if (s == 1) {
739: lineinfo.status = HKF_STATUS_MATCHED;
740: lineinfo.match |= HKF_MATCH_HOST |
741: (hashed ? HKF_MATCH_HOST_HASHED : 0);
742: }
743: /* Try matching IP address if supplied */
744: if (ip != NULL) {
745: if ((s = match_maybe_hashed(ip, lineinfo.hosts,
746: &hashed)) == -1) {
747: debug2("%s: %s:%ld: bad ip hash "
748: "\"%.32s\"", __func__, path,
749: linenum, lineinfo.hosts);
750: goto bad;
751: }
752: if (s == 1) {
753: lineinfo.status = HKF_STATUS_MATCHED;
754: lineinfo.match |= HKF_MATCH_IP |
755: (hashed ? HKF_MATCH_IP_HASHED : 0);
756: }
757: }
758: /*
759: * Skip this line if host matching requested and
760: * neither host nor address matched.
761: */
762: if ((options & HKF_WANT_MATCH) != 0 &&
763: lineinfo.status != HKF_STATUS_MATCHED)
764: continue;
1.60 djm 765: }
766:
767: /* Got a match. Skip host name and any following whitespace */
768: for (; *cp2 == ' ' || *cp2 == '\t'; cp2++)
769: ;
770: if (*cp2 == '\0' || *cp2 == '#') {
1.64 djm 771: debug2("%s:%ld: truncated before key type",
772: path, linenum);
1.60 djm 773: goto bad;
774: }
775: lineinfo.rawkey = cp = cp2;
776:
777: if ((options & HKF_WANT_PARSE_KEY) != 0) {
778: /*
779: * Extract the key from the line. This will skip
780: * any leading whitespace. Ignore badly formatted
781: * lines.
782: */
783: if ((lineinfo.key = sshkey_new(KEY_UNSPEC)) == NULL) {
784: error("%s: sshkey_new failed", __func__);
1.64 djm 785: r = SSH_ERR_ALLOC_FAIL;
786: break;
1.60 djm 787: }
788: if (!hostfile_read_key(&cp, &kbits, lineinfo.key)) {
789: goto bad;
790: }
1.64 djm 791: lineinfo.keytype = lineinfo.key->type;
792: lineinfo.comment = cp;
793: } else {
794: /* Extract and parse key type */
795: l = strcspn(lineinfo.rawkey, " \t");
796: if (l <= 1 || l >= sizeof(ktype) ||
797: lineinfo.rawkey[l] == '\0')
798: goto bad;
799: memcpy(ktype, lineinfo.rawkey, l);
800: ktype[l] = '\0';
801: lineinfo.keytype = sshkey_type_from_name(ktype);
1.65 djm 802:
1.64 djm 803: /*
1.70 djm 804: * Assume legacy RSA1 if the first component is a short
1.64 djm 805: * decimal number.
806: */
807: if (lineinfo.keytype == KEY_UNSPEC && l < 8 &&
808: strspn(ktype, "0123456789") == l)
1.70 djm 809: goto bad;
1.65 djm 810:
1.64 djm 811: /*
812: * Check that something other than whitespace follows
813: * the key type. This won't catch all corruption, but
814: * it does catch trivial truncation.
815: */
816: cp2 += l; /* Skip past key type */
817: for (; *cp2 == ' ' || *cp2 == '\t'; cp2++)
818: ;
819: if (*cp2 == '\0' || *cp2 == '#') {
820: debug2("%s:%ld: truncated after key type",
821: path, linenum);
822: lineinfo.keytype = KEY_UNSPEC;
823: }
824: if (lineinfo.keytype == KEY_UNSPEC) {
1.60 djm 825: bad:
1.64 djm 826: sshkey_free(lineinfo.key);
827: lineinfo.key = NULL;
1.60 djm 828: lineinfo.status = HKF_STATUS_INVALID;
829: if ((r = callback(&lineinfo, ctx)) != 0)
830: break;
831: continue;
832: }
833: }
834: if ((r = callback(&lineinfo, ctx)) != 0)
835: break;
836: }
837: sshkey_free(lineinfo.key);
1.72 markus 838: free(lineinfo.line);
839: free(line);
1.60 djm 840: fclose(f);
841: return r;
1.1 deraadt 842: }
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