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openssh-portable/hostfile.c

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/* $OpenBSD: hostfile.c,v 1.65 2015/03/31 22:57:06 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* Functions for manipulating the known hosts files.
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*
*
* Copyright (c) 1999, 2000 Markus Friedl. All rights reserved.
* Copyright (c) 1999 Niels Provos. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "includes.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <errno.h>
#include <resolv.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <unistd.h>
#include "xmalloc.h"
#include "match.h"
#include "sshkey.h"
#include "hostfile.h"
#include "log.h"
#include "misc.h"
#include "ssherr.h"
#include "digest.h"
#include "hmac.h"
struct hostkeys {
struct hostkey_entry *entries;
u_int num_entries;
};
/* XXX hmac is too easy to dictionary attack; use bcrypt? */
static int
extract_salt(const char *s, u_int l, u_char *salt, size_t salt_len)
{
char *p, *b64salt;
u_int b64len;
int ret;
if (l < sizeof(HASH_MAGIC) - 1) {
debug2("extract_salt: string too short");
return (-1);
}
if (strncmp(s, HASH_MAGIC, sizeof(HASH_MAGIC) - 1) != 0) {
debug2("extract_salt: invalid magic identifier");
return (-1);
}
s += sizeof(HASH_MAGIC) - 1;
l -= sizeof(HASH_MAGIC) - 1;
if ((p = memchr(s, HASH_DELIM, l)) == NULL) {
debug2("extract_salt: missing salt termination character");
return (-1);
}
b64len = p - s;
/* Sanity check */
if (b64len == 0 || b64len > 1024) {
debug2("extract_salt: bad encoded salt length %u", b64len);
return (-1);
}
b64salt = xmalloc(1 + b64len);
memcpy(b64salt, s, b64len);
b64salt[b64len] = '\0';
ret = __b64_pton(b64salt, salt, salt_len);
free(b64salt);
if (ret == -1) {
debug2("extract_salt: salt decode error");
return (-1);
}
if (ret != (int)ssh_hmac_bytes(SSH_DIGEST_SHA1)) {
debug2("extract_salt: expected salt len %zd, got %d",
ssh_hmac_bytes(SSH_DIGEST_SHA1), ret);
return (-1);
}
return (0);
}
char *
host_hash(const char *host, const char *name_from_hostfile, u_int src_len)
{
struct ssh_hmac_ctx *ctx;
u_char salt[256], result[256];
char uu_salt[512], uu_result[512];
static char encoded[1024];
u_int i, len;
len = ssh_digest_bytes(SSH_DIGEST_SHA1);
if (name_from_hostfile == NULL) {
/* Create new salt */
for (i = 0; i < len; i++)
salt[i] = arc4random();
} else {
/* Extract salt from known host entry */
if (extract_salt(name_from_hostfile, src_len, salt,
sizeof(salt)) == -1)
return (NULL);
}
if ((ctx = ssh_hmac_start(SSH_DIGEST_SHA1)) == NULL ||
ssh_hmac_init(ctx, salt, len) < 0 ||
ssh_hmac_update(ctx, host, strlen(host)) < 0 ||
ssh_hmac_final(ctx, result, sizeof(result)))
fatal("%s: ssh_hmac failed", __func__);
ssh_hmac_free(ctx);
if (__b64_ntop(salt, len, uu_salt, sizeof(uu_salt)) == -1 ||
__b64_ntop(result, len, uu_result, sizeof(uu_result)) == -1)
fatal("%s: __b64_ntop failed", __func__);
snprintf(encoded, sizeof(encoded), "%s%s%c%s", HASH_MAGIC, uu_salt,
HASH_DELIM, uu_result);
return (encoded);
}
/*
* Parses an RSA (number of bits, e, n) or DSA key from a string. Moves the
* pointer over the key. Skips any whitespace at the beginning and at end.
*/
int
hostfile_read_key(char **cpp, u_int *bitsp, struct sshkey *ret)
{
char *cp;
int r;
/* Skip leading whitespace. */
for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++)
;
if ((r = sshkey_read(ret, &cp)) != 0)
return 0;
/* Skip trailing whitespace. */
for (; *cp == ' ' || *cp == '\t'; cp++)
;
/* Return results. */
*cpp = cp;
if (bitsp != NULL)
*bitsp = sshkey_size(ret);
return 1;
}
static HostkeyMarker
check_markers(char **cpp)
{
char marker[32], *sp, *cp = *cpp;
int ret = MRK_NONE;
while (*cp == '@') {
/* Only one marker is allowed */
if (ret != MRK_NONE)
return MRK_ERROR;
/* Markers are terminated by whitespace */
if ((sp = strchr(cp, ' ')) == NULL &&
(sp = strchr(cp, '\t')) == NULL)
return MRK_ERROR;
/* Extract marker for comparison */
if (sp <= cp + 1 || sp >= cp + sizeof(marker))
return MRK_ERROR;
memcpy(marker, cp, sp - cp);
marker[sp - cp] = '\0';
if (strcmp(marker, CA_MARKER) == 0)
ret = MRK_CA;
else if (strcmp(marker, REVOKE_MARKER) == 0)
ret = MRK_REVOKE;
else
return MRK_ERROR;
/* Skip past marker and any whitespace that follows it */
cp = sp;
for (; *cp == ' ' || *cp == '\t'; cp++)
;
}
*cpp = cp;
return ret;
}
struct hostkeys *
init_hostkeys(void)
{
struct hostkeys *ret = xcalloc(1, sizeof(*ret));
ret->entries = NULL;
return ret;
}
struct load_callback_ctx {
const char *host;
u_long num_loaded;
struct hostkeys *hostkeys;
};
static int
record_hostkey(struct hostkey_foreach_line *l, void *_ctx)
{
struct load_callback_ctx *ctx = (struct load_callback_ctx *)_ctx;
struct hostkeys *hostkeys = ctx->hostkeys;
struct hostkey_entry *tmp;
if (l->status == HKF_STATUS_INVALID) {
/* XXX make this verbose() in the future */
debug("%s:%ld: parse error in hostkeys file",
l->path, l->linenum);
return 0;
}
debug3("%s: found %skey type %s in file %s:%lu", __func__,
l->marker == MRK_NONE ? "" :
(l->marker == MRK_CA ? "ca " : "revoked "),
sshkey_type(l->key), l->path, l->linenum);
if ((tmp = reallocarray(hostkeys->entries,
hostkeys->num_entries + 1, sizeof(*hostkeys->entries))) == NULL)
return SSH_ERR_ALLOC_FAIL;
hostkeys->entries = tmp;
hostkeys->entries[hostkeys->num_entries].host = xstrdup(ctx->host);
hostkeys->entries[hostkeys->num_entries].file = xstrdup(l->path);
hostkeys->entries[hostkeys->num_entries].line = l->linenum;
hostkeys->entries[hostkeys->num_entries].key = l->key;
l->key = NULL; /* steal it */
hostkeys->entries[hostkeys->num_entries].marker = l->marker;
hostkeys->num_entries++;
ctx->num_loaded++;
return 0;
}
void
load_hostkeys(struct hostkeys *hostkeys, const char *host, const char *path)
{
int r;
struct load_callback_ctx ctx;
ctx.host = host;
ctx.num_loaded = 0;
ctx.hostkeys = hostkeys;
if ((r = hostkeys_foreach(path, record_hostkey, &ctx, host, NULL,
HKF_WANT_MATCH|HKF_WANT_PARSE_KEY)) != 0) {
if (r != SSH_ERR_SYSTEM_ERROR && errno != ENOENT)
debug("%s: hostkeys_foreach failed for %s: %s",
__func__, path, ssh_err(r));
}
if (ctx.num_loaded != 0)
debug3("%s: loaded %lu keys from %s", __func__,
ctx.num_loaded, host);
}
void
free_hostkeys(struct hostkeys *hostkeys)
{
u_int i;
for (i = 0; i < hostkeys->num_entries; i++) {
free(hostkeys->entries[i].host);
free(hostkeys->entries[i].file);
sshkey_free(hostkeys->entries[i].key);
explicit_bzero(hostkeys->entries + i, sizeof(*hostkeys->entries));
}
free(hostkeys->entries);
explicit_bzero(hostkeys, sizeof(*hostkeys));
free(hostkeys);
}
static int
check_key_not_revoked(struct hostkeys *hostkeys, struct sshkey *k)
{
int is_cert = sshkey_is_cert(k);
u_int i;
for (i = 0; i < hostkeys->num_entries; i++) {
if (hostkeys->entries[i].marker != MRK_REVOKE)
continue;
if (sshkey_equal_public(k, hostkeys->entries[i].key))
return -1;
if (is_cert &&
sshkey_equal_public(k->cert->signature_key,
hostkeys->entries[i].key))
return -1;
}
return 0;
}
/*
* Match keys against a specified key, or look one up by key type.
*
* If looking for a keytype (key == NULL) and one is found then return
* HOST_FOUND, otherwise HOST_NEW.
*
* If looking for a key (key != NULL):
* 1. If the key is a cert and a matching CA is found, return HOST_OK
* 2. If the key is not a cert and a matching key is found, return HOST_OK
* 3. If no key matches but a key with a different type is found, then
* return HOST_CHANGED
* 4. If no matching keys are found, then return HOST_NEW.
*
* Finally, check any found key is not revoked.
*/
static HostStatus
check_hostkeys_by_key_or_type(struct hostkeys *hostkeys,
struct sshkey *k, int keytype, const struct hostkey_entry **found)
{
u_int i;
HostStatus end_return = HOST_NEW;
int want_cert = sshkey_is_cert(k);
HostkeyMarker want_marker = want_cert ? MRK_CA : MRK_NONE;
int proto = (k ? k->type : keytype) == KEY_RSA1 ? 1 : 2;
if (found != NULL)
*found = NULL;
for (i = 0; i < hostkeys->num_entries; i++) {
if (proto == 1 && hostkeys->entries[i].key->type != KEY_RSA1)
continue;
if (proto == 2 && hostkeys->entries[i].key->type == KEY_RSA1)
continue;
if (hostkeys->entries[i].marker != want_marker)
continue;
if (k == NULL) {
if (hostkeys->entries[i].key->type != keytype)
continue;
end_return = HOST_FOUND;
if (found != NULL)
*found = hostkeys->entries + i;
k = hostkeys->entries[i].key;
break;
}
if (want_cert) {
if (sshkey_equal_public(k->cert->signature_key,
hostkeys->entries[i].key)) {
/* A matching CA exists */
end_return = HOST_OK;
if (found != NULL)
*found = hostkeys->entries + i;
break;
}
} else {
if (sshkey_equal(k, hostkeys->entries[i].key)) {
end_return = HOST_OK;
if (found != NULL)
*found = hostkeys->entries + i;
break;
}
/* A non-maching key exists */
end_return = HOST_CHANGED;
if (found != NULL)
*found = hostkeys->entries + i;
}
}
if (check_key_not_revoked(hostkeys, k) != 0) {
end_return = HOST_REVOKED;
if (found != NULL)
*found = NULL;
}
return end_return;
}
HostStatus
check_key_in_hostkeys(struct hostkeys *hostkeys, struct sshkey *key,
const struct hostkey_entry **found)
{
if (key == NULL)
fatal("no key to look up");
return check_hostkeys_by_key_or_type(hostkeys, key, 0, found);
}
int
lookup_key_in_hostkeys_by_type(struct hostkeys *hostkeys, int keytype,
const struct hostkey_entry **found)
{
return (check_hostkeys_by_key_or_type(hostkeys, NULL, keytype,
found) == HOST_FOUND);
}
static int
write_host_entry(FILE *f, const char *host, const char *ip,
const struct sshkey *key, int store_hash)
{
int r, success = 0;
char *hashed_host = NULL;
if (store_hash) {
if ((hashed_host = host_hash(host, NULL, 0)) == NULL) {
error("%s: host_hash failed", __func__);
return 0;
}
fprintf(f, "%s ", hashed_host);
} else if (ip != NULL)
fprintf(f, "%s,%s ", host, ip);
else
fprintf(f, "%s ", host);
if ((r = sshkey_write(key, f)) == 0)
success = 1;
else
error("%s: sshkey_write failed: %s", __func__, ssh_err(r));
fputc('\n', f);
return success;
}
/*
* Appends an entry to the host file. Returns false if the entry could not
* be appended.
*/
int
add_host_to_hostfile(const char *filename, const char *host,
const struct sshkey *key, int store_hash)
{
FILE *f;
int success;
if (key == NULL)
return 1; /* XXX ? */
f = fopen(filename, "a");
if (!f)
return 0;
success = write_host_entry(f, host, NULL, key, store_hash);
fclose(f);
return success;
}
struct host_delete_ctx {
FILE *out;
int quiet;
const char *host;
int *skip_keys; /* XXX split for host/ip? might want to ensure both */
struct sshkey * const *keys;
size_t nkeys;
int modified;
};
static int
host_delete(struct hostkey_foreach_line *l, void *_ctx)
{
struct host_delete_ctx *ctx = (struct host_delete_ctx *)_ctx;
int loglevel = ctx->quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_VERBOSE;
size_t i;
if (l->status == HKF_STATUS_MATCHED) {
if (l->marker != MRK_NONE) {
/* Don't remove CA and revocation lines */
fprintf(ctx->out, "%s\n", l->line);
return 0;
}
/* XXX might need a knob for this later */
/* Don't remove RSA1 keys */
if (l->key->type == KEY_RSA1) {
fprintf(ctx->out, "%s\n", l->line);
return 0;
}
/*
* If this line contains one of the keys that we will be
* adding later, then don't change it and mark the key for
* skipping.
*/
for (i = 0; i < ctx->nkeys; i++) {
if (sshkey_equal(ctx->keys[i], l->key)) {
ctx->skip_keys[i] = 1;
fprintf(ctx->out, "%s\n", l->line);
debug3("%s: %s key already at %s:%ld", __func__,
sshkey_type(l->key), l->path, l->linenum);
return 0;
}
}
/*
* Hostname matches and has no CA/revoke marker, delete it
* by *not* writing the line to ctx->out.
*/
do_log2(loglevel, "%s%s%s:%ld: Removed %s key for host %s",
ctx->quiet ? __func__ : "", ctx->quiet ? ": " : "",
l->path, l->linenum, sshkey_type(l->key), ctx->host);
ctx->modified = 1;
return 0;
}
/* Retain non-matching hosts and invalid lines when deleting */
if (l->status == HKF_STATUS_INVALID) {
do_log2(loglevel, "%s%s%s:%ld: invalid known_hosts entry",
ctx->quiet ? __func__ : "", ctx->quiet ? ": " : "",
l->path, l->linenum);
}
fprintf(ctx->out, "%s\n", l->line);
return 0;
}
int
hostfile_replace_entries(const char *filename, const char *host, const char *ip,
struct sshkey **keys, size_t nkeys, int store_hash, int quiet, int hash_alg)
{
int r, fd, oerrno = 0;
int loglevel = quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_VERBOSE;
struct host_delete_ctx ctx;
char *fp, *temp = NULL, *back = NULL;
mode_t omask;
size_t i;
omask = umask(077);
memset(&ctx, 0, sizeof(ctx));
ctx.host = host;
ctx.quiet = quiet;
if ((ctx.skip_keys = calloc(nkeys, sizeof(*ctx.skip_keys))) == NULL)
return SSH_ERR_ALLOC_FAIL;
ctx.keys = keys;
ctx.nkeys = nkeys;
ctx.modified = 0;
/*
* Prepare temporary file for in-place deletion.
*/
if ((r = asprintf(&temp, "%s.XXXXXXXXXXX", filename)) < 0 ||
(r = asprintf(&back, "%s.old", filename)) < 0) {
r = SSH_ERR_ALLOC_FAIL;
goto fail;
}
if ((fd = mkstemp(temp)) == -1) {
oerrno = errno;
error("%s: mkstemp: %s", __func__, strerror(oerrno));
r = SSH_ERR_SYSTEM_ERROR;
goto fail;
}
if ((ctx.out = fdopen(fd, "w")) == NULL) {
oerrno = errno;
close(fd);
error("%s: fdopen: %s", __func__, strerror(oerrno));
r = SSH_ERR_SYSTEM_ERROR;
goto fail;
}
/* Remove all entries for the specified host from the file */
if ((r = hostkeys_foreach(filename, host_delete, &ctx, host, ip,
HKF_WANT_PARSE_KEY)) != 0) {
error("%s: hostkeys_foreach failed: %s", __func__, ssh_err(r));
goto fail;
}
/* Add the requested keys */
for (i = 0; i < nkeys; i++) {
if (ctx.skip_keys[i])
continue;
if ((fp = sshkey_fingerprint(keys[i], hash_alg,
SSH_FP_DEFAULT)) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto fail;
}
do_log2(loglevel, "%s%sAdding new key for %s to %s: %s %s",
quiet ? __func__ : "", quiet ? ": " : "", host, filename,
sshkey_ssh_name(keys[i]), fp);
free(fp);
if (!write_host_entry(ctx.out, host, ip, keys[i], store_hash)) {
r = SSH_ERR_INTERNAL_ERROR;
goto fail;
}
ctx.modified = 1;
}
fclose(ctx.out);
ctx.out = NULL;
if (ctx.modified) {
/* Backup the original file and replace it with the temporary */
if (unlink(back) == -1 && errno != ENOENT) {
oerrno = errno;
error("%s: unlink %.100s: %s", __func__,
back, strerror(errno));
r = SSH_ERR_SYSTEM_ERROR;
goto fail;
}
if (link(filename, back) == -1) {
oerrno = errno;
error("%s: link %.100s to %.100s: %s", __func__,
filename, back, strerror(errno));
r = SSH_ERR_SYSTEM_ERROR;
goto fail;
}
if (rename(temp, filename) == -1) {
oerrno = errno;
error("%s: rename \"%s\" to \"%s\": %s", __func__,
temp, filename, strerror(errno));
r = SSH_ERR_SYSTEM_ERROR;
goto fail;
}
} else {
/* No changes made; just delete the temporary file */
if (unlink(temp) != 0)
error("%s: unlink \"%s\": %s", __func__,
temp, strerror(errno));
}
/* success */
r = 0;
fail:
if (temp != NULL && r != 0)
unlink(temp);
free(temp);
free(back);
if (ctx.out != NULL)
fclose(ctx.out);
free(ctx.skip_keys);
umask(omask);
if (r == SSH_ERR_SYSTEM_ERROR)
errno = oerrno;
return r;
}
static int
match_maybe_hashed(const char *host, const char *names, int *was_hashed)
{
int hashed = *names == HASH_DELIM;
const char *hashed_host;
size_t nlen = strlen(names);
if (was_hashed != NULL)
*was_hashed = hashed;
if (hashed) {
if ((hashed_host = host_hash(host, names, nlen)) == NULL)
return -1;
return nlen == strlen(hashed_host) &&
strncmp(hashed_host, names, nlen) == 0;
}
return match_hostname(host, names, nlen) == 1;
}
int
hostkeys_foreach(const char *path, hostkeys_foreach_fn *callback, void *ctx,
const char *host, const char *ip, u_int options)
{
FILE *f;
char line[8192], oline[8192], ktype[128];
u_long linenum = 0;
char *cp, *cp2;
u_int kbits;
int hashed;
int s, r = 0;
struct hostkey_foreach_line lineinfo;
size_t l;
memset(&lineinfo, 0, sizeof(lineinfo));
if (host == NULL && (options & HKF_WANT_MATCH) != 0)
return SSH_ERR_INVALID_ARGUMENT;
if ((f = fopen(path, "r")) == NULL)
return SSH_ERR_SYSTEM_ERROR;
debug3("%s: reading file \"%s\"", __func__, path);
while (read_keyfile_line(f, path, line, sizeof(line), &linenum) == 0) {
line[strcspn(line, "\n")] = '\0';
strlcpy(oline, line, sizeof(oline));
sshkey_free(lineinfo.key);
memset(&lineinfo, 0, sizeof(lineinfo));
lineinfo.path = path;
lineinfo.linenum = linenum;
lineinfo.line = oline;
lineinfo.marker = MRK_NONE;
lineinfo.status = HKF_STATUS_OK;
lineinfo.keytype = KEY_UNSPEC;
/* Skip any leading whitespace, comments and empty lines. */
for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
;
if (!*cp || *cp == '#' || *cp == '\n') {
if ((options & HKF_WANT_MATCH) == 0) {
lineinfo.status = HKF_STATUS_COMMENT;
if ((r = callback(&lineinfo, ctx)) != 0)
break;
}
continue;
}
if ((lineinfo.marker = check_markers(&cp)) == MRK_ERROR) {
verbose("%s: invalid marker at %s:%lu",
__func__, path, linenum);
if ((options & HKF_WANT_MATCH) == 0)
goto bad;
continue;
}
/* Find the end of the host name portion. */
for (cp2 = cp; *cp2 && *cp2 != ' ' && *cp2 != '\t'; cp2++)
;
lineinfo.hosts = cp;
*cp2++ = '\0';
/* Check if the host name matches. */
if (host != NULL) {
if ((s = match_maybe_hashed(host, lineinfo.hosts,
&hashed)) == -1) {
debug2("%s: %s:%ld: bad host hash \"%.32s\"",
__func__, path, linenum, lineinfo.hosts);
goto bad;
}
if (s == 1) {
lineinfo.status = HKF_STATUS_MATCHED;
lineinfo.match |= HKF_MATCH_HOST |
(hashed ? HKF_MATCH_HOST_HASHED : 0);
}
/* Try matching IP address if supplied */
if (ip != NULL) {
if ((s = match_maybe_hashed(ip, lineinfo.hosts,
&hashed)) == -1) {
debug2("%s: %s:%ld: bad ip hash "
"\"%.32s\"", __func__, path,
linenum, lineinfo.hosts);
goto bad;
}
if (s == 1) {
lineinfo.status = HKF_STATUS_MATCHED;
lineinfo.match |= HKF_MATCH_IP |
(hashed ? HKF_MATCH_IP_HASHED : 0);
}
}
/*
* Skip this line if host matching requested and
* neither host nor address matched.
*/
if ((options & HKF_WANT_MATCH) != 0 &&
lineinfo.status != HKF_STATUS_MATCHED)
continue;
}
/* Got a match. Skip host name and any following whitespace */
for (; *cp2 == ' ' || *cp2 == '\t'; cp2++)
;
if (*cp2 == '\0' || *cp2 == '#') {
debug2("%s:%ld: truncated before key type",
path, linenum);
goto bad;
}
lineinfo.rawkey = cp = cp2;
if ((options & HKF_WANT_PARSE_KEY) != 0) {
/*
* Extract the key from the line. This will skip
* any leading whitespace. Ignore badly formatted
* lines.
*/
if ((lineinfo.key = sshkey_new(KEY_UNSPEC)) == NULL) {
error("%s: sshkey_new failed", __func__);
r = SSH_ERR_ALLOC_FAIL;
break;
}
if (!hostfile_read_key(&cp, &kbits, lineinfo.key)) {
#ifdef WITH_SSH1
sshkey_free(lineinfo.key);
lineinfo.key = sshkey_new(KEY_RSA1);
if (lineinfo.key == NULL) {
error("%s: sshkey_new fail", __func__);
r = SSH_ERR_ALLOC_FAIL;
break;
}
if (!hostfile_read_key(&cp, &kbits,
lineinfo.key))
goto bad;
#else
goto bad;
#endif
}
lineinfo.keytype = lineinfo.key->type;
lineinfo.comment = cp;
} else {
/* Extract and parse key type */
l = strcspn(lineinfo.rawkey, " \t");
if (l <= 1 || l >= sizeof(ktype) ||
lineinfo.rawkey[l] == '\0')
goto bad;
memcpy(ktype, lineinfo.rawkey, l);
ktype[l] = '\0';
lineinfo.keytype = sshkey_type_from_name(ktype);
/*
* Assume RSA1 if the first component is a short
* decimal number.
*/
if (lineinfo.keytype == KEY_UNSPEC && l < 8 &&
strspn(ktype, "0123456789") == l)
lineinfo.keytype = KEY_RSA1;
/*
* Check that something other than whitespace follows
* the key type. This won't catch all corruption, but
* it does catch trivial truncation.
*/
cp2 += l; /* Skip past key type */
for (; *cp2 == ' ' || *cp2 == '\t'; cp2++)
;
if (*cp2 == '\0' || *cp2 == '#') {
debug2("%s:%ld: truncated after key type",
path, linenum);
lineinfo.keytype = KEY_UNSPEC;
}
if (lineinfo.keytype == KEY_UNSPEC) {
bad:
sshkey_free(lineinfo.key);
lineinfo.key = NULL;
lineinfo.status = HKF_STATUS_INVALID;
if ((r = callback(&lineinfo, ctx)) != 0)
break;
continue;
}
}
if ((r = callback(&lineinfo, ctx)) != 0)
break;
}
sshkey_free(lineinfo.key);
fclose(f);
return r;
}
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