Annotation of src/usr.bin/ssh/hostfile.c, Revision 1.73
1.73 ! djm 1: /* $OpenBSD: hostfile.c,v 1.72 2018/06/06 18:29:18 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;
1.59 djm 163: int r;
1.7 markus 164:
165: /* Skip leading whitespace. */
1.9 markus 166: for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++)
167: ;
1.1 deraadt 168:
1.59 djm 169: if ((r = sshkey_read(ret, &cp)) != 0)
1.7 markus 170: return 0;
171:
172: /* Skip trailing whitespace. */
1.9 markus 173: for (; *cp == ' ' || *cp == '\t'; cp++)
174: ;
1.7 markus 175:
176: /* Return results. */
177: *cpp = cp;
1.59 djm 178: if (bitsp != NULL)
179: *bitsp = sshkey_size(ret);
1.7 markus 180: return 1;
1.14 markus 181: }
1.1 deraadt 182:
1.49 djm 183: static HostkeyMarker
1.48 djm 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:
1.49 djm 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: }
1.1 deraadt 226:
1.61 djm 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)
1.1 deraadt 235: {
1.61 djm 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) {
1.65 djm 241: /* XXX make this verbose() in the future */
242: debug("%s:%ld: parse error in hostkeys file",
1.61 djm 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);
1.71 deraadt 251: if ((tmp = recallocarray(hostkeys->entries, hostkeys->num_entries,
1.61 djm 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:
347: if (found != NULL)
348: *found = NULL;
1.30 markus 349:
1.49 djm 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) {
1.59 djm 363: if (sshkey_equal_public(k->cert->signature_key,
1.49 djm 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;
1.48 djm 370: }
1.49 djm 371: } else {
1.59 djm 372: if (sshkey_equal(k, hostkeys->entries[i].key)) {
1.49 djm 373: end_return = HOST_OK;
374: if (found != NULL)
375: *found = hostkeys->entries + i;
376: break;
1.48 djm 377: }
1.49 djm 378: /* A non-maching key exists */
379: end_return = HOST_CHANGED;
380: if (found != NULL)
381: *found = hostkeys->entries + i;
1.48 djm 382: }
1.1 deraadt 383: }
1.49 djm 384: if (check_key_not_revoked(hostkeys, k) != 0) {
385: end_return = HOST_REVOKED;
386: if (found != NULL)
387: *found = NULL;
388: }
1.7 markus 389: return end_return;
1.30 markus 390: }
1.58 djm 391:
1.30 markus 392: HostStatus
1.59 djm 393: check_key_in_hostkeys(struct hostkeys *hostkeys, struct sshkey *key,
1.49 djm 394: const struct hostkey_entry **found)
1.30 markus 395: {
396: if (key == NULL)
397: fatal("no key to look up");
1.49 djm 398: return check_hostkeys_by_key_or_type(hostkeys, key, 0, found);
1.30 markus 399: }
400:
401: int
1.49 djm 402: lookup_key_in_hostkeys_by_type(struct hostkeys *hostkeys, int keytype,
403: const struct hostkey_entry **found)
1.30 markus 404: {
1.49 djm 405: return (check_hostkeys_by_key_or_type(hostkeys, NULL, keytype,
406: found) == HOST_FOUND);
1.1 deraadt 407: }
408:
1.62 djm 409: static int
1.64 djm 410: write_host_entry(FILE *f, const char *host, const char *ip,
1.62 djm 411: const struct sshkey *key, int store_hash)
412: {
413: int r, success = 0;
1.68 djm 414: char *hashed_host = NULL, *lhost;
415:
416: lhost = xstrdup(host);
417: lowercase(lhost);
1.62 djm 418:
419: if (store_hash) {
1.68 djm 420: if ((hashed_host = host_hash(lhost, NULL, 0)) == NULL) {
1.62 djm 421: error("%s: host_hash failed", __func__);
1.68 djm 422: free(lhost);
1.62 djm 423: return 0;
424: }
1.64 djm 425: fprintf(f, "%s ", hashed_host);
426: } else if (ip != NULL)
1.68 djm 427: fprintf(f, "%s,%s ", lhost, ip);
428: else {
429: fprintf(f, "%s ", lhost);
430: }
431: free(lhost);
1.62 djm 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: /*
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: */
1.64 djm 504: do_log2(loglevel, "%s%s%s:%ld: Removed %s key for host %s",
1.62 djm 505: ctx->quiet ? __func__ : "", ctx->quiet ? ": " : "",
1.64 djm 506: l->path, l->linenum, sshkey_type(l->key), ctx->host);
507: ctx->modified = 1;
1.62 djm 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
1.64 djm 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)
1.62 djm 523: {
524: int r, fd, oerrno = 0;
1.64 djm 525: int loglevel = quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_VERBOSE;
1.62 djm 526: struct host_delete_ctx ctx;
1.64 djm 527: char *fp, *temp = NULL, *back = NULL;
1.62 djm 528: mode_t omask;
529: size_t i;
530:
1.63 djm 531: omask = umask(077);
532:
1.62 djm 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;
1.64 djm 540: ctx.modified = 0;
1.62 djm 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 */
1.64 djm 566: if ((r = hostkeys_foreach(filename, host_delete, &ctx, host, ip,
1.62 djm 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;
1.64 djm 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)) {
1.62 djm 586: r = SSH_ERR_INTERNAL_ERROR;
587: goto fail;
588: }
1.64 djm 589: ctx.modified = 1;
1.33 djm 590: }
1.62 djm 591: fclose(ctx.out);
592: ctx.out = NULL;
1.33 djm 593:
1.64 djm 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));
1.62 djm 622: }
1.64 djm 623:
1.62 djm 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);
1.63 djm 634: umask(omask);
1.62 djm 635: if (r == SSH_ERR_SYSTEM_ERROR)
636: errno = oerrno;
637: return r;
1.60 djm 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: }
1.66 djm 655: return match_hostname(host, names) == 1;
1.60 djm 656: }
657:
658: int
659: hostkeys_foreach(const char *path, hostkeys_foreach_fn *callback, void *ctx,
1.64 djm 660: const char *host, const char *ip, u_int options)
1.60 djm 661: {
662: FILE *f;
1.72 markus 663: char *line = NULL, ktype[128];
1.60 djm 664: u_long linenum = 0;
665: char *cp, *cp2;
666: u_int kbits;
1.64 djm 667: int hashed;
1.60 djm 668: int s, r = 0;
669: struct hostkey_foreach_line lineinfo;
1.72 markus 670: size_t linesize = 0, l;
1.60 djm 671:
672: memset(&lineinfo, 0, sizeof(lineinfo));
1.64 djm 673: if (host == NULL && (options & HKF_WANT_MATCH) != 0)
1.60 djm 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);
1.72 markus 679: while (getline(&line, &linesize, f) != -1) {
680: linenum++;
1.60 djm 681: line[strcspn(line, "\n")] = '\0';
682:
1.73 ! djm 683: free(lineinfo.line);
1.60 djm 684: sshkey_free(lineinfo.key);
685: memset(&lineinfo, 0, sizeof(lineinfo));
686: lineinfo.path = path;
687: lineinfo.linenum = linenum;
1.72 markus 688: lineinfo.line = xstrdup(line);
1.64 djm 689: lineinfo.marker = MRK_NONE;
1.60 djm 690: lineinfo.status = HKF_STATUS_OK;
1.64 djm 691: lineinfo.keytype = KEY_UNSPEC;
1.60 djm 692:
693: /* Skip any leading whitespace, comments and empty lines. */
694: for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
695: ;
696: if (!*cp || *cp == '#' || *cp == '\n') {
1.64 djm 697: if ((options & HKF_WANT_MATCH) == 0) {
1.60 djm 698: lineinfo.status = HKF_STATUS_COMMENT;
699: if ((r = callback(&lineinfo, ctx)) != 0)
700: break;
701: }
702: continue;
703: }
704:
705: if ((lineinfo.marker = check_markers(&cp)) == MRK_ERROR) {
706: verbose("%s: invalid marker at %s:%lu",
707: __func__, path, linenum);
1.64 djm 708: if ((options & HKF_WANT_MATCH) == 0)
1.60 djm 709: goto bad;
710: continue;
711: }
712:
713: /* Find the end of the host name portion. */
714: for (cp2 = cp; *cp2 && *cp2 != ' ' && *cp2 != '\t'; cp2++)
715: ;
716: lineinfo.hosts = cp;
717: *cp2++ = '\0';
718:
719: /* Check if the host name matches. */
720: if (host != NULL) {
1.64 djm 721: if ((s = match_maybe_hashed(host, lineinfo.hosts,
722: &hashed)) == -1) {
1.60 djm 723: debug2("%s: %s:%ld: bad host hash \"%.32s\"",
724: __func__, path, linenum, lineinfo.hosts);
725: goto bad;
726: }
1.64 djm 727: if (s == 1) {
728: lineinfo.status = HKF_STATUS_MATCHED;
729: lineinfo.match |= HKF_MATCH_HOST |
730: (hashed ? HKF_MATCH_HOST_HASHED : 0);
731: }
732: /* Try matching IP address if supplied */
733: if (ip != NULL) {
734: if ((s = match_maybe_hashed(ip, lineinfo.hosts,
735: &hashed)) == -1) {
736: debug2("%s: %s:%ld: bad ip hash "
737: "\"%.32s\"", __func__, path,
738: linenum, lineinfo.hosts);
739: goto bad;
740: }
741: if (s == 1) {
742: lineinfo.status = HKF_STATUS_MATCHED;
743: lineinfo.match |= HKF_MATCH_IP |
744: (hashed ? HKF_MATCH_IP_HASHED : 0);
745: }
746: }
747: /*
748: * Skip this line if host matching requested and
749: * neither host nor address matched.
750: */
751: if ((options & HKF_WANT_MATCH) != 0 &&
752: lineinfo.status != HKF_STATUS_MATCHED)
753: continue;
1.60 djm 754: }
755:
756: /* Got a match. Skip host name and any following whitespace */
757: for (; *cp2 == ' ' || *cp2 == '\t'; cp2++)
758: ;
759: if (*cp2 == '\0' || *cp2 == '#') {
1.64 djm 760: debug2("%s:%ld: truncated before key type",
761: path, linenum);
1.60 djm 762: goto bad;
763: }
764: lineinfo.rawkey = cp = cp2;
765:
766: if ((options & HKF_WANT_PARSE_KEY) != 0) {
767: /*
768: * Extract the key from the line. This will skip
769: * any leading whitespace. Ignore badly formatted
770: * lines.
771: */
772: if ((lineinfo.key = sshkey_new(KEY_UNSPEC)) == NULL) {
773: error("%s: sshkey_new failed", __func__);
1.64 djm 774: r = SSH_ERR_ALLOC_FAIL;
775: break;
1.60 djm 776: }
777: if (!hostfile_read_key(&cp, &kbits, lineinfo.key)) {
778: goto bad;
779: }
1.64 djm 780: lineinfo.keytype = lineinfo.key->type;
781: lineinfo.comment = cp;
782: } else {
783: /* Extract and parse key type */
784: l = strcspn(lineinfo.rawkey, " \t");
785: if (l <= 1 || l >= sizeof(ktype) ||
786: lineinfo.rawkey[l] == '\0')
787: goto bad;
788: memcpy(ktype, lineinfo.rawkey, l);
789: ktype[l] = '\0';
790: lineinfo.keytype = sshkey_type_from_name(ktype);
1.65 djm 791:
1.64 djm 792: /*
1.70 djm 793: * Assume legacy RSA1 if the first component is a short
1.64 djm 794: * decimal number.
795: */
796: if (lineinfo.keytype == KEY_UNSPEC && l < 8 &&
797: strspn(ktype, "0123456789") == l)
1.70 djm 798: goto bad;
1.65 djm 799:
1.64 djm 800: /*
801: * Check that something other than whitespace follows
802: * the key type. This won't catch all corruption, but
803: * it does catch trivial truncation.
804: */
805: cp2 += l; /* Skip past key type */
806: for (; *cp2 == ' ' || *cp2 == '\t'; cp2++)
807: ;
808: if (*cp2 == '\0' || *cp2 == '#') {
809: debug2("%s:%ld: truncated after key type",
810: path, linenum);
811: lineinfo.keytype = KEY_UNSPEC;
812: }
813: if (lineinfo.keytype == KEY_UNSPEC) {
1.60 djm 814: bad:
1.64 djm 815: sshkey_free(lineinfo.key);
816: lineinfo.key = NULL;
1.60 djm 817: lineinfo.status = HKF_STATUS_INVALID;
818: if ((r = callback(&lineinfo, ctx)) != 0)
819: break;
820: continue;
821: }
822: }
823: if ((r = callback(&lineinfo, ctx)) != 0)
824: break;
825: }
826: sshkey_free(lineinfo.key);
1.72 markus 827: free(lineinfo.line);
828: free(line);
1.60 djm 829: fclose(f);
830: return r;
1.1 deraadt 831: }