Annotation of src/usr.bin/ssh/hostfile.c, Revision 1.64
1.64 ! djm 1: /* $OpenBSD: hostfile.c,v 1.63 2015/01/26 13:36:53 djm 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];
123: u_int i, len;
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 */
129: for (i = 0; i < len; i++)
130: salt[i] = arc4random();
131: } else {
132: /* Extract salt from known host entry */
133: if (extract_salt(name_from_hostfile, src_len, salt,
134: sizeof(salt)) == -1)
135: return (NULL);
136: }
137:
1.54 markus 138: if ((ctx = ssh_hmac_start(SSH_DIGEST_SHA1)) == NULL ||
139: ssh_hmac_init(ctx, salt, len) < 0 ||
140: ssh_hmac_update(ctx, host, strlen(host)) < 0 ||
141: ssh_hmac_final(ctx, result, sizeof(result)))
142: fatal("%s: ssh_hmac failed", __func__);
143: ssh_hmac_free(ctx);
1.33 djm 144:
1.34 deraadt 145: if (__b64_ntop(salt, len, uu_salt, sizeof(uu_salt)) == -1 ||
1.33 djm 146: __b64_ntop(result, len, uu_result, sizeof(uu_result)) == -1)
1.54 markus 147: fatal("%s: __b64_ntop failed", __func__);
1.33 djm 148:
149: snprintf(encoded, sizeof(encoded), "%s%s%c%s", HASH_MAGIC, uu_salt,
150: HASH_DELIM, uu_result);
151:
152: return (encoded);
153: }
1.1 deraadt 154:
1.9 markus 155: /*
1.14 markus 156: * Parses an RSA (number of bits, e, n) or DSA key from a string. Moves the
157: * pointer over the key. Skips any whitespace at the beginning and at end.
1.9 markus 158: */
1.1 deraadt 159:
1.29 jakob 160: int
1.59 djm 161: hostfile_read_key(char **cpp, u_int *bitsp, struct sshkey *ret)
1.1 deraadt 162: {
1.7 markus 163: char *cp;
1.59 djm 164: int r;
1.7 markus 165:
166: /* Skip leading whitespace. */
1.9 markus 167: for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++)
168: ;
1.1 deraadt 169:
1.59 djm 170: if ((r = sshkey_read(ret, &cp)) != 0)
1.7 markus 171: return 0;
172:
173: /* Skip trailing whitespace. */
1.9 markus 174: for (; *cp == ' ' || *cp == '\t'; cp++)
175: ;
1.7 markus 176:
177: /* Return results. */
178: *cpp = cp;
1.59 djm 179: if (bitsp != NULL)
180: *bitsp = sshkey_size(ret);
1.7 markus 181: return 1;
1.14 markus 182: }
1.1 deraadt 183:
1.49 djm 184: static HostkeyMarker
1.48 djm 185: check_markers(char **cpp)
186: {
187: char marker[32], *sp, *cp = *cpp;
188: int ret = MRK_NONE;
189:
190: while (*cp == '@') {
191: /* Only one marker is allowed */
192: if (ret != MRK_NONE)
193: return MRK_ERROR;
194: /* Markers are terminated by whitespace */
195: if ((sp = strchr(cp, ' ')) == NULL &&
196: (sp = strchr(cp, '\t')) == NULL)
197: return MRK_ERROR;
198: /* Extract marker for comparison */
199: if (sp <= cp + 1 || sp >= cp + sizeof(marker))
200: return MRK_ERROR;
201: memcpy(marker, cp, sp - cp);
202: marker[sp - cp] = '\0';
203: if (strcmp(marker, CA_MARKER) == 0)
204: ret = MRK_CA;
205: else if (strcmp(marker, REVOKE_MARKER) == 0)
206: ret = MRK_REVOKE;
207: else
208: return MRK_ERROR;
209:
210: /* Skip past marker and any whitespace that follows it */
211: cp = sp;
212: for (; *cp == ' ' || *cp == '\t'; cp++)
213: ;
214: }
215: *cpp = cp;
216: return ret;
217: }
218:
1.49 djm 219: struct hostkeys *
220: init_hostkeys(void)
221: {
222: struct hostkeys *ret = xcalloc(1, sizeof(*ret));
223:
224: ret->entries = NULL;
225: return ret;
226: }
1.1 deraadt 227:
1.61 djm 228: struct load_callback_ctx {
229: const char *host;
230: u_long num_loaded;
231: struct hostkeys *hostkeys;
232: };
233:
234: static int
235: record_hostkey(struct hostkey_foreach_line *l, void *_ctx)
1.1 deraadt 236: {
1.61 djm 237: struct load_callback_ctx *ctx = (struct load_callback_ctx *)_ctx;
238: struct hostkeys *hostkeys = ctx->hostkeys;
239: struct hostkey_entry *tmp;
240:
241: if (l->status == HKF_STATUS_INVALID) {
242: error("%s:%ld: parse error in hostkeys file",
243: l->path, l->linenum);
244: return 0;
245: }
1.7 markus 246:
1.61 djm 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 = reallocarray(hostkeys->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++;
1.7 markus 263:
1.61 djm 264: return 0;
265: }
1.47 djm 266:
1.61 djm 267: void
268: load_hostkeys(struct hostkeys *hostkeys, const char *host, const char *path)
269: {
270: int r;
271: struct load_callback_ctx ctx;
1.7 markus 272:
1.61 djm 273: ctx.host = host;
274: ctx.num_loaded = 0;
275: ctx.hostkeys = hostkeys;
276:
1.64 ! djm 277: if ((r = hostkeys_foreach(path, record_hostkey, &ctx, host, NULL,
! 278: HKF_WANT_MATCH|HKF_WANT_PARSE_KEY)) != 0) {
1.61 djm 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);
1.58 djm 286: }
1.49 djm 287:
288: void
289: free_hostkeys(struct hostkeys *hostkeys)
290: {
291: u_int i;
292:
293: for (i = 0; i < hostkeys->num_entries; i++) {
1.51 djm 294: free(hostkeys->entries[i].host);
295: free(hostkeys->entries[i].file);
1.59 djm 296: sshkey_free(hostkeys->entries[i].key);
1.55 tedu 297: explicit_bzero(hostkeys->entries + i, sizeof(*hostkeys->entries));
1.49 djm 298: }
1.51 djm 299: free(hostkeys->entries);
1.55 tedu 300: explicit_bzero(hostkeys, sizeof(*hostkeys));
1.51 djm 301: free(hostkeys);
1.49 djm 302: }
303:
304: static int
1.59 djm 305: check_key_not_revoked(struct hostkeys *hostkeys, struct sshkey *k)
1.49 djm 306: {
1.59 djm 307: int is_cert = sshkey_is_cert(k);
1.49 djm 308: u_int i;
1.7 markus 309:
1.49 djm 310: for (i = 0; i < hostkeys->num_entries; i++) {
311: if (hostkeys->entries[i].marker != MRK_REVOKE)
1.30 markus 312: continue;
1.59 djm 313: if (sshkey_equal_public(k, hostkeys->entries[i].key))
1.49 djm 314: return -1;
315: if (is_cert &&
1.59 djm 316: sshkey_equal_public(k->cert->signature_key,
1.49 djm 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,
1.59 djm 340: struct sshkey *k, int keytype, const struct hostkey_entry **found)
1.49 djm 341: {
342: u_int i;
343: HostStatus end_return = HOST_NEW;
1.59 djm 344: int want_cert = sshkey_is_cert(k);
1.49 djm 345: HostkeyMarker want_marker = want_cert ? MRK_CA : MRK_NONE;
346: int proto = (k ? k->type : keytype) == KEY_RSA1 ? 1 : 2;
347:
348: if (found != NULL)
349: *found = NULL;
1.30 markus 350:
1.49 djm 351: for (i = 0; i < hostkeys->num_entries; i++) {
352: if (proto == 1 && hostkeys->entries[i].key->type != KEY_RSA1)
353: continue;
354: if (proto == 2 && hostkeys->entries[i].key->type == KEY_RSA1)
1.30 markus 355: continue;
1.49 djm 356: if (hostkeys->entries[i].marker != want_marker)
357: continue;
358: if (k == NULL) {
359: if (hostkeys->entries[i].key->type != keytype)
360: continue;
361: end_return = HOST_FOUND;
362: if (found != NULL)
363: *found = hostkeys->entries + i;
364: k = hostkeys->entries[i].key;
365: break;
366: }
367: if (want_cert) {
1.59 djm 368: if (sshkey_equal_public(k->cert->signature_key,
1.49 djm 369: hostkeys->entries[i].key)) {
370: /* A matching CA exists */
371: end_return = HOST_OK;
372: if (found != NULL)
373: *found = hostkeys->entries + i;
374: break;
1.48 djm 375: }
1.49 djm 376: } else {
1.59 djm 377: if (sshkey_equal(k, hostkeys->entries[i].key)) {
1.49 djm 378: end_return = HOST_OK;
379: if (found != NULL)
380: *found = hostkeys->entries + i;
381: break;
1.48 djm 382: }
1.49 djm 383: /* A non-maching key exists */
384: end_return = HOST_CHANGED;
385: if (found != NULL)
386: *found = hostkeys->entries + i;
1.48 djm 387: }
1.1 deraadt 388: }
1.49 djm 389: if (check_key_not_revoked(hostkeys, k) != 0) {
390: end_return = HOST_REVOKED;
391: if (found != NULL)
392: *found = NULL;
393: }
1.7 markus 394: return end_return;
1.30 markus 395: }
1.58 djm 396:
1.30 markus 397: HostStatus
1.59 djm 398: check_key_in_hostkeys(struct hostkeys *hostkeys, struct sshkey *key,
1.49 djm 399: const struct hostkey_entry **found)
1.30 markus 400: {
401: if (key == NULL)
402: fatal("no key to look up");
1.49 djm 403: return check_hostkeys_by_key_or_type(hostkeys, key, 0, found);
1.30 markus 404: }
405:
406: int
1.49 djm 407: lookup_key_in_hostkeys_by_type(struct hostkeys *hostkeys, int keytype,
408: const struct hostkey_entry **found)
1.30 markus 409: {
1.49 djm 410: return (check_hostkeys_by_key_or_type(hostkeys, NULL, keytype,
411: found) == HOST_FOUND);
1.1 deraadt 412: }
413:
1.62 djm 414: static int
1.64 ! djm 415: write_host_entry(FILE *f, const char *host, const char *ip,
1.62 djm 416: const struct sshkey *key, int store_hash)
417: {
418: int r, success = 0;
419: char *hashed_host = NULL;
420:
421: if (store_hash) {
422: if ((hashed_host = host_hash(host, NULL, 0)) == NULL) {
423: error("%s: host_hash failed", __func__);
424: return 0;
425: }
1.64 ! djm 426: fprintf(f, "%s ", hashed_host);
! 427: } else if (ip != NULL)
! 428: fprintf(f, "%s,%s ", host, ip);
! 429: else
! 430: fprintf(f, "%s ", host);
1.62 djm 431:
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:
1.9 markus 440: /*
441: * Appends an entry to the host file. Returns false if the entry could not
442: * be appended.
443: */
1.2 provos 444: int
1.59 djm 445: add_host_to_hostfile(const char *filename, const char *host,
446: const struct sshkey *key, int store_hash)
1.1 deraadt 447: {
1.7 markus 448: FILE *f;
1.62 djm 449: int success;
1.33 djm 450:
1.14 markus 451: if (key == NULL)
1.17 markus 452: return 1; /* XXX ? */
1.7 markus 453: f = fopen(filename, "a");
454: if (!f)
455: return 0;
1.64 ! djm 456: success = write_host_entry(f, host, NULL, key, store_hash);
1.62 djm 457: fclose(f);
458: return success;
459: }
460:
461: struct host_delete_ctx {
462: FILE *out;
463: int quiet;
464: const char *host;
1.64 ! djm 465: int *skip_keys; /* XXX split for host/ip? might want to ensure both */
1.62 djm 466: struct sshkey * const *keys;
467: size_t nkeys;
1.64 ! djm 468: int modified;
1.62 djm 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;
1.64 ! djm 475: int loglevel = ctx->quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_VERBOSE;
1.62 djm 476: size_t i;
477:
1.64 ! djm 478: if (l->status == HKF_STATUS_MATCHED) {
1.62 djm 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: }
1.33 djm 484:
1.62 djm 485: /* XXX might need a knob for this later */
486: /* Don't remove RSA1 keys */
487: if (l->key->type == KEY_RSA1) {
488: fprintf(ctx->out, "%s\n", l->line);
1.33 djm 489: return 0;
490: }
1.62 djm 491:
492: /*
493: * If this line contains one of the keys that we will be
494: * adding later, then don't change it and mark the key for
495: * skipping.
496: */
497: for (i = 0; i < ctx->nkeys; i++) {
498: if (sshkey_equal(ctx->keys[i], l->key)) {
499: ctx->skip_keys[i] = 1;
500: fprintf(ctx->out, "%s\n", l->line);
501: debug3("%s: %s key already at %s:%ld", __func__,
502: sshkey_type(l->key), l->path, l->linenum);
503: return 0;
504: }
505: }
506:
507: /*
508: * Hostname matches and has no CA/revoke marker, delete it
509: * by *not* writing the line to ctx->out.
510: */
1.64 ! djm 511: do_log2(loglevel, "%s%s%s:%ld: Removed %s key for host %s",
1.62 djm 512: ctx->quiet ? __func__ : "", ctx->quiet ? ": " : "",
1.64 ! djm 513: l->path, l->linenum, sshkey_type(l->key), ctx->host);
! 514: ctx->modified = 1;
1.62 djm 515: return 0;
516: }
517: /* Retain non-matching hosts and invalid lines when deleting */
518: if (l->status == HKF_STATUS_INVALID) {
519: do_log2(loglevel, "%s%s%s:%ld: invalid known_hosts entry",
520: ctx->quiet ? __func__ : "", ctx->quiet ? ": " : "",
521: l->path, l->linenum);
522: }
523: fprintf(ctx->out, "%s\n", l->line);
524: return 0;
525: }
526:
527: int
1.64 ! djm 528: hostfile_replace_entries(const char *filename, const char *host, const char *ip,
! 529: struct sshkey **keys, size_t nkeys, int store_hash, int quiet, int hash_alg)
1.62 djm 530: {
531: int r, fd, oerrno = 0;
1.64 ! djm 532: int loglevel = quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_VERBOSE;
1.62 djm 533: struct host_delete_ctx ctx;
1.64 ! djm 534: char *fp, *temp = NULL, *back = NULL;
1.62 djm 535: mode_t omask;
536: size_t i;
537:
1.63 djm 538: omask = umask(077);
539:
1.62 djm 540: memset(&ctx, 0, sizeof(ctx));
541: ctx.host = host;
542: ctx.quiet = quiet;
543: if ((ctx.skip_keys = calloc(nkeys, sizeof(*ctx.skip_keys))) == NULL)
544: return SSH_ERR_ALLOC_FAIL;
545: ctx.keys = keys;
546: ctx.nkeys = nkeys;
1.64 ! djm 547: ctx.modified = 0;
1.62 djm 548:
549: /*
550: * Prepare temporary file for in-place deletion.
551: */
552: if ((r = asprintf(&temp, "%s.XXXXXXXXXXX", filename)) < 0 ||
553: (r = asprintf(&back, "%s.old", filename)) < 0) {
554: r = SSH_ERR_ALLOC_FAIL;
555: goto fail;
556: }
557:
558: if ((fd = mkstemp(temp)) == -1) {
559: oerrno = errno;
560: error("%s: mkstemp: %s", __func__, strerror(oerrno));
561: r = SSH_ERR_SYSTEM_ERROR;
562: goto fail;
563: }
564: if ((ctx.out = fdopen(fd, "w")) == NULL) {
565: oerrno = errno;
566: close(fd);
567: error("%s: fdopen: %s", __func__, strerror(oerrno));
568: r = SSH_ERR_SYSTEM_ERROR;
569: goto fail;
570: }
571:
572: /* Remove all entries for the specified host from the file */
1.64 ! djm 573: if ((r = hostkeys_foreach(filename, host_delete, &ctx, host, ip,
1.62 djm 574: HKF_WANT_PARSE_KEY)) != 0) {
575: error("%s: hostkeys_foreach failed: %s", __func__, ssh_err(r));
576: goto fail;
577: }
578:
579: /* Add the requested keys */
580: for (i = 0; i < nkeys; i++) {
581: if (ctx.skip_keys[i])
582: continue;
1.64 ! djm 583: if ((fp = sshkey_fingerprint(keys[i], hash_alg,
! 584: SSH_FP_DEFAULT)) == NULL) {
! 585: r = SSH_ERR_ALLOC_FAIL;
! 586: goto fail;
! 587: }
! 588: do_log2(loglevel, "%s%sAdding new key for %s to %s: %s %s",
! 589: quiet ? __func__ : "", quiet ? ": " : "", host, filename,
! 590: sshkey_ssh_name(keys[i]), fp);
! 591: free(fp);
! 592: if (!write_host_entry(ctx.out, host, ip, keys[i], store_hash)) {
1.62 djm 593: r = SSH_ERR_INTERNAL_ERROR;
594: goto fail;
595: }
1.64 ! djm 596: ctx.modified = 1;
1.33 djm 597: }
1.62 djm 598: fclose(ctx.out);
599: ctx.out = NULL;
1.33 djm 600:
1.64 ! djm 601: if (ctx.modified) {
! 602: /* Backup the original file and replace it with the temporary */
! 603: if (unlink(back) == -1 && errno != ENOENT) {
! 604: oerrno = errno;
! 605: error("%s: unlink %.100s: %s", __func__,
! 606: back, strerror(errno));
! 607: r = SSH_ERR_SYSTEM_ERROR;
! 608: goto fail;
! 609: }
! 610: if (link(filename, back) == -1) {
! 611: oerrno = errno;
! 612: error("%s: link %.100s to %.100s: %s", __func__,
! 613: filename, back, strerror(errno));
! 614: r = SSH_ERR_SYSTEM_ERROR;
! 615: goto fail;
! 616: }
! 617: if (rename(temp, filename) == -1) {
! 618: oerrno = errno;
! 619: error("%s: rename \"%s\" to \"%s\": %s", __func__,
! 620: temp, filename, strerror(errno));
! 621: r = SSH_ERR_SYSTEM_ERROR;
! 622: goto fail;
! 623: }
! 624: } else {
! 625: /* No changes made; just delete the temporary file */
! 626: if (unlink(temp) != 0)
! 627: error("%s: unlink \"%s\": %s", __func__,
! 628: temp, strerror(errno));
1.62 djm 629: }
1.64 ! djm 630:
1.62 djm 631: /* success */
632: r = 0;
633: fail:
634: if (temp != NULL && r != 0)
635: unlink(temp);
636: free(temp);
637: free(back);
638: if (ctx.out != NULL)
639: fclose(ctx.out);
640: free(ctx.skip_keys);
1.63 djm 641: umask(omask);
1.62 djm 642: if (r == SSH_ERR_SYSTEM_ERROR)
643: errno = oerrno;
644: return r;
1.60 djm 645: }
646:
647: static int
648: match_maybe_hashed(const char *host, const char *names, int *was_hashed)
649: {
650: int hashed = *names == HASH_DELIM;
651: const char *hashed_host;
652: size_t nlen = strlen(names);
653:
654: if (was_hashed != NULL)
655: *was_hashed = hashed;
656: if (hashed) {
657: if ((hashed_host = host_hash(host, names, nlen)) == NULL)
658: return -1;
659: return nlen == strlen(hashed_host) &&
660: strncmp(hashed_host, names, nlen) == 0;
661: }
662: return match_hostname(host, names, nlen) == 1;
663: }
664:
665: int
666: hostkeys_foreach(const char *path, hostkeys_foreach_fn *callback, void *ctx,
1.64 ! djm 667: const char *host, const char *ip, u_int options)
1.60 djm 668: {
669: FILE *f;
1.64 ! djm 670: char line[8192], oline[8192], ktype[128];
1.60 djm 671: u_long linenum = 0;
672: char *cp, *cp2;
673: u_int kbits;
1.64 ! djm 674: int hashed;
1.60 djm 675: int s, r = 0;
676: struct hostkey_foreach_line lineinfo;
1.64 ! djm 677: size_t l;
1.60 djm 678:
679: memset(&lineinfo, 0, sizeof(lineinfo));
1.64 ! djm 680: if (host == NULL && (options & HKF_WANT_MATCH) != 0)
1.60 djm 681: return SSH_ERR_INVALID_ARGUMENT;
682: if ((f = fopen(path, "r")) == NULL)
683: return SSH_ERR_SYSTEM_ERROR;
684:
685: debug3("%s: reading file \"%s\"", __func__, path);
686: while (read_keyfile_line(f, path, line, sizeof(line), &linenum) == 0) {
687: line[strcspn(line, "\n")] = '\0';
688: strlcpy(oline, line, sizeof(oline));
689:
690: sshkey_free(lineinfo.key);
691: memset(&lineinfo, 0, sizeof(lineinfo));
692: lineinfo.path = path;
693: lineinfo.linenum = linenum;
694: lineinfo.line = oline;
1.64 ! djm 695: lineinfo.marker = MRK_NONE;
1.60 djm 696: lineinfo.status = HKF_STATUS_OK;
1.64 ! djm 697: lineinfo.keytype = KEY_UNSPEC;
1.60 djm 698:
699: /* Skip any leading whitespace, comments and empty lines. */
700: for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
701: ;
702: if (!*cp || *cp == '#' || *cp == '\n') {
1.64 ! djm 703: if ((options & HKF_WANT_MATCH) == 0) {
1.60 djm 704: lineinfo.status = HKF_STATUS_COMMENT;
705: if ((r = callback(&lineinfo, ctx)) != 0)
706: break;
707: }
708: continue;
709: }
710:
711: if ((lineinfo.marker = check_markers(&cp)) == MRK_ERROR) {
712: verbose("%s: invalid marker at %s:%lu",
713: __func__, path, linenum);
1.64 ! djm 714: if ((options & HKF_WANT_MATCH) == 0)
1.60 djm 715: goto bad;
716: continue;
717: }
718:
719: /* Find the end of the host name portion. */
720: for (cp2 = cp; *cp2 && *cp2 != ' ' && *cp2 != '\t'; cp2++)
721: ;
722: lineinfo.hosts = cp;
723: *cp2++ = '\0';
724:
725: /* Check if the host name matches. */
726: if (host != NULL) {
1.64 ! djm 727: if ((s = match_maybe_hashed(host, lineinfo.hosts,
! 728: &hashed)) == -1) {
1.60 djm 729: debug2("%s: %s:%ld: bad host hash \"%.32s\"",
730: __func__, path, linenum, lineinfo.hosts);
731: goto bad;
732: }
1.64 ! djm 733: if (s == 1) {
! 734: lineinfo.status = HKF_STATUS_MATCHED;
! 735: lineinfo.match |= HKF_MATCH_HOST |
! 736: (hashed ? HKF_MATCH_HOST_HASHED : 0);
! 737: }
! 738: /* Try matching IP address if supplied */
! 739: if (ip != NULL) {
! 740: if ((s = match_maybe_hashed(ip, lineinfo.hosts,
! 741: &hashed)) == -1) {
! 742: debug2("%s: %s:%ld: bad ip hash "
! 743: "\"%.32s\"", __func__, path,
! 744: linenum, lineinfo.hosts);
! 745: goto bad;
! 746: }
! 747: if (s == 1) {
! 748: lineinfo.status = HKF_STATUS_MATCHED;
! 749: lineinfo.match |= HKF_MATCH_IP |
! 750: (hashed ? HKF_MATCH_IP_HASHED : 0);
! 751: }
! 752: }
! 753: /*
! 754: * Skip this line if host matching requested and
! 755: * neither host nor address matched.
! 756: */
! 757: if ((options & HKF_WANT_MATCH) != 0 &&
! 758: lineinfo.status != HKF_STATUS_MATCHED)
! 759: continue;
1.60 djm 760: }
761:
762: /* Got a match. Skip host name and any following whitespace */
763: for (; *cp2 == ' ' || *cp2 == '\t'; cp2++)
764: ;
765: if (*cp2 == '\0' || *cp2 == '#') {
1.64 ! djm 766: debug2("%s:%ld: truncated before key type",
! 767: path, linenum);
1.60 djm 768: goto bad;
769: }
770: lineinfo.rawkey = cp = cp2;
771:
772: if ((options & HKF_WANT_PARSE_KEY) != 0) {
773: /*
774: * Extract the key from the line. This will skip
775: * any leading whitespace. Ignore badly formatted
776: * lines.
777: */
778: if ((lineinfo.key = sshkey_new(KEY_UNSPEC)) == NULL) {
779: error("%s: sshkey_new failed", __func__);
1.64 ! djm 780: r = SSH_ERR_ALLOC_FAIL;
! 781: break;
1.60 djm 782: }
783: if (!hostfile_read_key(&cp, &kbits, lineinfo.key)) {
784: #ifdef WITH_SSH1
785: sshkey_free(lineinfo.key);
786: lineinfo.key = sshkey_new(KEY_RSA1);
787: if (lineinfo.key == NULL) {
788: error("%s: sshkey_new fail", __func__);
1.64 ! djm 789: r = SSH_ERR_ALLOC_FAIL;
! 790: break;
1.60 djm 791: }
792: if (!hostfile_read_key(&cp, &kbits,
793: lineinfo.key))
794: goto bad;
795: #else
796: goto bad;
797: #endif
798: }
1.64 ! djm 799: lineinfo.keytype = lineinfo.key->type;
! 800: lineinfo.comment = cp;
! 801: } else {
! 802: /* Extract and parse key type */
! 803: l = strcspn(lineinfo.rawkey, " \t");
! 804: if (l <= 1 || l >= sizeof(ktype) ||
! 805: lineinfo.rawkey[l] == '\0')
! 806: goto bad;
! 807: memcpy(ktype, lineinfo.rawkey, l);
! 808: ktype[l] = '\0';
! 809: lineinfo.keytype = sshkey_type_from_name(ktype);
! 810: #ifdef WITH_SSH1
! 811: /*
! 812: * Assume RSA1 if the first component is a short
! 813: * decimal number.
! 814: */
! 815: if (lineinfo.keytype == KEY_UNSPEC && l < 8 &&
! 816: strspn(ktype, "0123456789") == l)
! 817: lineinfo.keytype = KEY_RSA1;
! 818: #endif
! 819: /*
! 820: * Check that something other than whitespace follows
! 821: * the key type. This won't catch all corruption, but
! 822: * it does catch trivial truncation.
! 823: */
! 824: cp2 += l; /* Skip past key type */
! 825: for (; *cp2 == ' ' || *cp2 == '\t'; cp2++)
! 826: ;
! 827: if (*cp2 == '\0' || *cp2 == '#') {
! 828: debug2("%s:%ld: truncated after key type",
! 829: path, linenum);
! 830: lineinfo.keytype = KEY_UNSPEC;
! 831: }
! 832: if (lineinfo.keytype == KEY_UNSPEC) {
1.60 djm 833: bad:
1.64 ! djm 834: sshkey_free(lineinfo.key);
! 835: lineinfo.key = NULL;
1.60 djm 836: lineinfo.status = HKF_STATUS_INVALID;
837: if ((r = callback(&lineinfo, ctx)) != 0)
838: break;
839: continue;
840: }
841: }
842: if ((r = callback(&lineinfo, ctx)) != 0)
843: break;
844: }
845: sshkey_free(lineinfo.key);
846: fclose(f);
847: return r;
1.1 deraadt 848: }
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