зеркало из https://github.com/Azure/sonic-openssh.git
936 строки
24 KiB
C
936 строки
24 KiB
C
/* $OpenBSD: hostfile.c,v 1.91 2021/07/05 01:16:46 dtucker Exp $ */
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/*
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* Author: Tatu Ylonen <ylo@cs.hut.fi>
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* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
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* All rights reserved
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* Functions for manipulating the known hosts files.
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*
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* As far as I am concerned, the code I have written for this software
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* can be used freely for any purpose. Any derived versions of this
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* software must be clearly marked as such, and if the derived work is
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* incompatible with the protocol description in the RFC file, it must be
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* called by a name other than "ssh" or "Secure Shell".
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*
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*
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* Copyright (c) 1999, 2000 Markus Friedl. All rights reserved.
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* Copyright (c) 1999 Niels Provos. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "includes.h"
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <netinet/in.h>
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#include <errno.h>
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#include <resolv.h>
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#include <stdarg.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include "xmalloc.h"
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#include "match.h"
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#include "sshkey.h"
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#include "hostfile.h"
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#include "log.h"
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#include "misc.h"
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#include "pathnames.h"
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#include "ssherr.h"
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#include "digest.h"
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#include "hmac.h"
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#include "sshbuf.h"
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/* XXX hmac is too easy to dictionary attack; use bcrypt? */
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static int
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extract_salt(const char *s, u_int l, u_char *salt, size_t salt_len)
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{
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char *p, *b64salt;
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u_int b64len;
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int ret;
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if (l < sizeof(HASH_MAGIC) - 1) {
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debug2("extract_salt: string too short");
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return (-1);
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}
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if (strncmp(s, HASH_MAGIC, sizeof(HASH_MAGIC) - 1) != 0) {
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debug2("extract_salt: invalid magic identifier");
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return (-1);
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}
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s += sizeof(HASH_MAGIC) - 1;
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l -= sizeof(HASH_MAGIC) - 1;
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if ((p = memchr(s, HASH_DELIM, l)) == NULL) {
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debug2("extract_salt: missing salt termination character");
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return (-1);
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}
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b64len = p - s;
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/* Sanity check */
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if (b64len == 0 || b64len > 1024) {
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debug2("extract_salt: bad encoded salt length %u", b64len);
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return (-1);
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}
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b64salt = xmalloc(1 + b64len);
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memcpy(b64salt, s, b64len);
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b64salt[b64len] = '\0';
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ret = __b64_pton(b64salt, salt, salt_len);
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free(b64salt);
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if (ret == -1) {
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debug2("extract_salt: salt decode error");
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return (-1);
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}
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if (ret != (int)ssh_hmac_bytes(SSH_DIGEST_SHA1)) {
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debug2("extract_salt: expected salt len %zd, got %d",
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ssh_hmac_bytes(SSH_DIGEST_SHA1), ret);
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return (-1);
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}
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return (0);
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}
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char *
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host_hash(const char *host, const char *name_from_hostfile, u_int src_len)
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{
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struct ssh_hmac_ctx *ctx;
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u_char salt[256], result[256];
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char uu_salt[512], uu_result[512];
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static char encoded[1024];
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u_int len;
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len = ssh_digest_bytes(SSH_DIGEST_SHA1);
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if (name_from_hostfile == NULL) {
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/* Create new salt */
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arc4random_buf(salt, len);
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} else {
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/* Extract salt from known host entry */
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if (extract_salt(name_from_hostfile, src_len, salt,
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sizeof(salt)) == -1)
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return (NULL);
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}
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if ((ctx = ssh_hmac_start(SSH_DIGEST_SHA1)) == NULL ||
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ssh_hmac_init(ctx, salt, len) < 0 ||
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ssh_hmac_update(ctx, host, strlen(host)) < 0 ||
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ssh_hmac_final(ctx, result, sizeof(result)))
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fatal_f("ssh_hmac failed");
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ssh_hmac_free(ctx);
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if (__b64_ntop(salt, len, uu_salt, sizeof(uu_salt)) == -1 ||
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__b64_ntop(result, len, uu_result, sizeof(uu_result)) == -1)
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fatal_f("__b64_ntop failed");
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snprintf(encoded, sizeof(encoded), "%s%s%c%s", HASH_MAGIC, uu_salt,
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HASH_DELIM, uu_result);
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return (encoded);
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}
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/*
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* Parses an RSA (number of bits, e, n) or DSA key from a string. Moves the
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* pointer over the key. Skips any whitespace at the beginning and at end.
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*/
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int
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hostfile_read_key(char **cpp, u_int *bitsp, struct sshkey *ret)
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{
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char *cp;
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/* Skip leading whitespace. */
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for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++)
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;
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if (sshkey_read(ret, &cp) != 0)
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return 0;
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/* Skip trailing whitespace. */
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for (; *cp == ' ' || *cp == '\t'; cp++)
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;
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/* Return results. */
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*cpp = cp;
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if (bitsp != NULL)
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*bitsp = sshkey_size(ret);
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return 1;
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}
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static HostkeyMarker
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check_markers(char **cpp)
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{
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char marker[32], *sp, *cp = *cpp;
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int ret = MRK_NONE;
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while (*cp == '@') {
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/* Only one marker is allowed */
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if (ret != MRK_NONE)
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return MRK_ERROR;
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/* Markers are terminated by whitespace */
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if ((sp = strchr(cp, ' ')) == NULL &&
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(sp = strchr(cp, '\t')) == NULL)
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return MRK_ERROR;
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/* Extract marker for comparison */
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if (sp <= cp + 1 || sp >= cp + sizeof(marker))
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return MRK_ERROR;
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memcpy(marker, cp, sp - cp);
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marker[sp - cp] = '\0';
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if (strcmp(marker, CA_MARKER) == 0)
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ret = MRK_CA;
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else if (strcmp(marker, REVOKE_MARKER) == 0)
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ret = MRK_REVOKE;
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else
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return MRK_ERROR;
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/* Skip past marker and any whitespace that follows it */
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cp = sp;
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for (; *cp == ' ' || *cp == '\t'; cp++)
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;
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}
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*cpp = cp;
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return ret;
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}
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struct hostkeys *
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init_hostkeys(void)
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{
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struct hostkeys *ret = xcalloc(1, sizeof(*ret));
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ret->entries = NULL;
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return ret;
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}
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struct load_callback_ctx {
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const char *host;
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u_long num_loaded;
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struct hostkeys *hostkeys;
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};
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static int
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record_hostkey(struct hostkey_foreach_line *l, void *_ctx)
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{
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struct load_callback_ctx *ctx = (struct load_callback_ctx *)_ctx;
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struct hostkeys *hostkeys = ctx->hostkeys;
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struct hostkey_entry *tmp;
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if (l->status == HKF_STATUS_INVALID) {
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/* XXX make this verbose() in the future */
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debug("%s:%ld: parse error in hostkeys file",
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l->path, l->linenum);
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return 0;
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}
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debug3_f("found %skey type %s in file %s:%lu",
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l->marker == MRK_NONE ? "" :
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(l->marker == MRK_CA ? "ca " : "revoked "),
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sshkey_type(l->key), l->path, l->linenum);
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if ((tmp = recallocarray(hostkeys->entries, hostkeys->num_entries,
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hostkeys->num_entries + 1, sizeof(*hostkeys->entries))) == NULL)
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return SSH_ERR_ALLOC_FAIL;
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hostkeys->entries = tmp;
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hostkeys->entries[hostkeys->num_entries].host = xstrdup(ctx->host);
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hostkeys->entries[hostkeys->num_entries].file = xstrdup(l->path);
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hostkeys->entries[hostkeys->num_entries].line = l->linenum;
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hostkeys->entries[hostkeys->num_entries].key = l->key;
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l->key = NULL; /* steal it */
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hostkeys->entries[hostkeys->num_entries].marker = l->marker;
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hostkeys->entries[hostkeys->num_entries].note = l->note;
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hostkeys->num_entries++;
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ctx->num_loaded++;
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return 0;
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}
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void
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load_hostkeys_file(struct hostkeys *hostkeys, const char *host,
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const char *path, FILE *f, u_int note)
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{
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int r;
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struct load_callback_ctx ctx;
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ctx.host = host;
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ctx.num_loaded = 0;
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ctx.hostkeys = hostkeys;
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if ((r = hostkeys_foreach_file(path, f, record_hostkey, &ctx, host,
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NULL, HKF_WANT_MATCH|HKF_WANT_PARSE_KEY, note)) != 0) {
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if (r != SSH_ERR_SYSTEM_ERROR && errno != ENOENT)
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debug_fr(r, "hostkeys_foreach failed for %s", path);
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}
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if (ctx.num_loaded != 0)
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debug3_f("loaded %lu keys from %s", ctx.num_loaded, host);
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}
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void
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load_hostkeys(struct hostkeys *hostkeys, const char *host, const char *path,
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u_int note)
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{
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FILE *f;
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if ((f = fopen(path, "r")) == NULL) {
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debug_f("fopen %s: %s", path, strerror(errno));
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return;
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}
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load_hostkeys_file(hostkeys, host, path, f, note);
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fclose(f);
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}
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void
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free_hostkeys(struct hostkeys *hostkeys)
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{
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u_int i;
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for (i = 0; i < hostkeys->num_entries; i++) {
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free(hostkeys->entries[i].host);
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free(hostkeys->entries[i].file);
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sshkey_free(hostkeys->entries[i].key);
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explicit_bzero(hostkeys->entries + i, sizeof(*hostkeys->entries));
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}
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free(hostkeys->entries);
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freezero(hostkeys, sizeof(*hostkeys));
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}
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static int
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check_key_not_revoked(struct hostkeys *hostkeys, struct sshkey *k)
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{
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int is_cert = sshkey_is_cert(k);
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u_int i;
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for (i = 0; i < hostkeys->num_entries; i++) {
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if (hostkeys->entries[i].marker != MRK_REVOKE)
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continue;
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if (sshkey_equal_public(k, hostkeys->entries[i].key))
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return -1;
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if (is_cert && k != NULL &&
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sshkey_equal_public(k->cert->signature_key,
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hostkeys->entries[i].key))
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return -1;
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}
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return 0;
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}
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/*
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* Match keys against a specified key, or look one up by key type.
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*
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* If looking for a keytype (key == NULL) and one is found then return
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* HOST_FOUND, otherwise HOST_NEW.
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*
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* If looking for a key (key != NULL):
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* 1. If the key is a cert and a matching CA is found, return HOST_OK
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* 2. If the key is not a cert and a matching key is found, return HOST_OK
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* 3. If no key matches but a key with a different type is found, then
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* return HOST_CHANGED
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* 4. If no matching keys are found, then return HOST_NEW.
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*
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* Finally, check any found key is not revoked.
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*/
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static HostStatus
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check_hostkeys_by_key_or_type(struct hostkeys *hostkeys,
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struct sshkey *k, int keytype, int nid, const struct hostkey_entry **found)
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{
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u_int i;
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HostStatus end_return = HOST_NEW;
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int want_cert = sshkey_is_cert(k);
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HostkeyMarker want_marker = want_cert ? MRK_CA : MRK_NONE;
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if (found != NULL)
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*found = NULL;
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for (i = 0; i < hostkeys->num_entries; i++) {
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if (hostkeys->entries[i].marker != want_marker)
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continue;
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if (k == NULL) {
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if (hostkeys->entries[i].key->type != keytype)
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continue;
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if (nid != -1 &&
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sshkey_type_plain(keytype) == KEY_ECDSA &&
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hostkeys->entries[i].key->ecdsa_nid != nid)
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continue;
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end_return = HOST_FOUND;
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if (found != NULL)
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*found = hostkeys->entries + i;
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k = hostkeys->entries[i].key;
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break;
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}
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if (want_cert) {
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if (sshkey_equal_public(k->cert->signature_key,
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hostkeys->entries[i].key)) {
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/* A matching CA exists */
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end_return = HOST_OK;
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if (found != NULL)
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*found = hostkeys->entries + i;
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break;
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}
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} else {
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if (sshkey_equal(k, hostkeys->entries[i].key)) {
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end_return = HOST_OK;
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if (found != NULL)
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*found = hostkeys->entries + i;
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break;
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}
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/* A non-matching key exists */
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end_return = HOST_CHANGED;
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if (found != NULL)
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*found = hostkeys->entries + i;
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}
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}
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if (check_key_not_revoked(hostkeys, k) != 0) {
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end_return = HOST_REVOKED;
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if (found != NULL)
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*found = NULL;
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}
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return end_return;
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}
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HostStatus
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check_key_in_hostkeys(struct hostkeys *hostkeys, struct sshkey *key,
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const struct hostkey_entry **found)
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{
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if (key == NULL)
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fatal("no key to look up");
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return check_hostkeys_by_key_or_type(hostkeys, key, 0, -1, found);
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}
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int
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lookup_key_in_hostkeys_by_type(struct hostkeys *hostkeys, int keytype, int nid,
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const struct hostkey_entry **found)
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{
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return (check_hostkeys_by_key_or_type(hostkeys, NULL, keytype, nid,
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found) == HOST_FOUND);
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}
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int
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lookup_marker_in_hostkeys(struct hostkeys *hostkeys, int want_marker)
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{
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u_int i;
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for (i = 0; i < hostkeys->num_entries; i++) {
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if (hostkeys->entries[i].marker == (HostkeyMarker)want_marker)
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return 1;
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}
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return 0;
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}
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static int
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write_host_entry(FILE *f, const char *host, const char *ip,
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const struct sshkey *key, int store_hash)
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{
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int r, success = 0;
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char *hashed_host = NULL, *lhost;
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lhost = xstrdup(host);
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lowercase(lhost);
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if (store_hash) {
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if ((hashed_host = host_hash(lhost, NULL, 0)) == NULL) {
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error_f("host_hash failed");
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free(lhost);
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return 0;
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}
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fprintf(f, "%s ", hashed_host);
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} else if (ip != NULL)
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fprintf(f, "%s,%s ", lhost, ip);
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else {
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fprintf(f, "%s ", lhost);
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}
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free(lhost);
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if ((r = sshkey_write(key, f)) == 0)
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success = 1;
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else
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error_fr(r, "sshkey_write");
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fputc('\n', f);
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/* If hashing is enabled, the IP address needs to go on its own line */
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if (success && store_hash && ip != NULL)
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success = write_host_entry(f, ip, NULL, key, 1);
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return success;
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}
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/*
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* Create user ~/.ssh directory if it doesn't exist and we want to write to it.
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* If notify is set, a message will be emitted if the directory is created.
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*/
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void
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hostfile_create_user_ssh_dir(const char *filename, int notify)
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{
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char *dotsshdir = NULL, *p;
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size_t len;
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struct stat st;
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if ((p = strrchr(filename, '/')) == NULL)
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return;
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len = p - filename;
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dotsshdir = tilde_expand_filename("~/" _PATH_SSH_USER_DIR, getuid());
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if (strlen(dotsshdir) > len || strncmp(filename, dotsshdir, len) != 0)
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goto out; /* not ~/.ssh prefixed */
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if (stat(dotsshdir, &st) == 0)
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goto out; /* dir already exists */
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else if (errno != ENOENT)
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error("Could not stat %s: %s", dotsshdir, strerror(errno));
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else {
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#ifdef WITH_SELINUX
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ssh_selinux_setfscreatecon(dotsshdir);
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#endif
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if (mkdir(dotsshdir, 0700) == -1)
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error("Could not create directory '%.200s' (%s).",
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dotsshdir, strerror(errno));
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else if (notify)
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logit("Created directory '%s'.", dotsshdir);
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#ifdef WITH_SELINUX
|
|
ssh_selinux_setfscreatecon(NULL);
|
|
#endif
|
|
}
|
|
out:
|
|
free(dotsshdir);
|
|
}
|
|
|
|
/*
|
|
* 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 ? */
|
|
hostfile_create_user_ssh_dir(filename, 0);
|
|
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, *ip;
|
|
u_int *match_keys; /* mask of HKF_MATCH_* for this key */
|
|
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;
|
|
|
|
/* Don't remove CA and revocation lines */
|
|
if (l->status == HKF_STATUS_MATCHED && l->marker == MRK_NONE) {
|
|
/*
|
|
* 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))
|
|
continue;
|
|
ctx->match_keys[i] |= l->match;
|
|
fprintf(ctx->out, "%s\n", l->line);
|
|
debug3_f("%s key already at %s:%ld",
|
|
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;
|
|
const char *what;
|
|
mode_t omask;
|
|
size_t i;
|
|
u_int want;
|
|
|
|
omask = umask(077);
|
|
|
|
memset(&ctx, 0, sizeof(ctx));
|
|
ctx.host = host;
|
|
ctx.ip = ip;
|
|
ctx.quiet = quiet;
|
|
|
|
if ((ctx.match_keys = calloc(nkeys, sizeof(*ctx.match_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)) == -1 ||
|
|
(r = asprintf(&back, "%s.old", filename)) == -1) {
|
|
r = SSH_ERR_ALLOC_FAIL;
|
|
goto fail;
|
|
}
|
|
|
|
if ((fd = mkstemp(temp)) == -1) {
|
|
oerrno = errno;
|
|
error_f("mkstemp: %s", strerror(oerrno));
|
|
r = SSH_ERR_SYSTEM_ERROR;
|
|
goto fail;
|
|
}
|
|
if ((ctx.out = fdopen(fd, "w")) == NULL) {
|
|
oerrno = errno;
|
|
close(fd);
|
|
error_f("fdopen: %s", strerror(oerrno));
|
|
r = SSH_ERR_SYSTEM_ERROR;
|
|
goto fail;
|
|
}
|
|
|
|
/* Remove stale/mismatching entries for the specified host */
|
|
if ((r = hostkeys_foreach(filename, host_delete, &ctx, host, ip,
|
|
HKF_WANT_PARSE_KEY, 0)) != 0) {
|
|
oerrno = errno;
|
|
error_fr(r, "hostkeys_foreach");
|
|
goto fail;
|
|
}
|
|
|
|
/* Re-add the requested keys */
|
|
want = HKF_MATCH_HOST | (ip == NULL ? 0 : HKF_MATCH_IP);
|
|
for (i = 0; i < nkeys; i++) {
|
|
if ((want & ctx.match_keys[i]) == want)
|
|
continue;
|
|
if ((fp = sshkey_fingerprint(keys[i], hash_alg,
|
|
SSH_FP_DEFAULT)) == NULL) {
|
|
r = SSH_ERR_ALLOC_FAIL;
|
|
goto fail;
|
|
}
|
|
/* write host/ip */
|
|
what = "";
|
|
if (ctx.match_keys[i] == 0) {
|
|
what = "Adding new key";
|
|
if (!write_host_entry(ctx.out, host, ip,
|
|
keys[i], store_hash)) {
|
|
r = SSH_ERR_INTERNAL_ERROR;
|
|
goto fail;
|
|
}
|
|
} else if ((want & ~ctx.match_keys[i]) == HKF_MATCH_HOST) {
|
|
what = "Fixing match (hostname)";
|
|
if (!write_host_entry(ctx.out, host, NULL,
|
|
keys[i], store_hash)) {
|
|
r = SSH_ERR_INTERNAL_ERROR;
|
|
goto fail;
|
|
}
|
|
} else if ((want & ~ctx.match_keys[i]) == HKF_MATCH_IP) {
|
|
what = "Fixing match (address)";
|
|
if (!write_host_entry(ctx.out, ip, NULL,
|
|
keys[i], store_hash)) {
|
|
r = SSH_ERR_INTERNAL_ERROR;
|
|
goto fail;
|
|
}
|
|
}
|
|
do_log2(loglevel, "%s%s%s for %s%s%s to %s: %s %s",
|
|
quiet ? __func__ : "", quiet ? ": " : "", what,
|
|
host, ip == NULL ? "" : ",", ip == NULL ? "" : ip, filename,
|
|
sshkey_ssh_name(keys[i]), fp);
|
|
free(fp);
|
|
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_f("unlink %.100s: %s", back, strerror(errno));
|
|
r = SSH_ERR_SYSTEM_ERROR;
|
|
goto fail;
|
|
}
|
|
if (link(filename, back) == -1) {
|
|
oerrno = errno;
|
|
error_f("link %.100s to %.100s: %s", filename,
|
|
back, strerror(errno));
|
|
r = SSH_ERR_SYSTEM_ERROR;
|
|
goto fail;
|
|
}
|
|
if (rename(temp, filename) == -1) {
|
|
oerrno = errno;
|
|
error_f("rename \"%s\" to \"%s\": %s", 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_f("unlink \"%s\": %s", 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.match_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) == 1;
|
|
}
|
|
|
|
int
|
|
hostkeys_foreach_file(const char *path, FILE *f, hostkeys_foreach_fn *callback,
|
|
void *ctx, const char *host, const char *ip, u_int options, u_int note)
|
|
{
|
|
char *line = NULL, 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 linesize = 0, l;
|
|
|
|
memset(&lineinfo, 0, sizeof(lineinfo));
|
|
if (host == NULL && (options & HKF_WANT_MATCH) != 0)
|
|
return SSH_ERR_INVALID_ARGUMENT;
|
|
|
|
while (getline(&line, &linesize, f) != -1) {
|
|
linenum++;
|
|
line[strcspn(line, "\n")] = '\0';
|
|
|
|
free(lineinfo.line);
|
|
sshkey_free(lineinfo.key);
|
|
memset(&lineinfo, 0, sizeof(lineinfo));
|
|
lineinfo.path = path;
|
|
lineinfo.linenum = linenum;
|
|
lineinfo.line = xstrdup(line);
|
|
lineinfo.marker = MRK_NONE;
|
|
lineinfo.status = HKF_STATUS_OK;
|
|
lineinfo.keytype = KEY_UNSPEC;
|
|
lineinfo.note = note;
|
|
|
|
/* 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_f("invalid marker at %s:%lu", 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_f("%s:%ld: bad host hash \"%.32s\"",
|
|
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_f("%s:%ld: bad ip hash "
|
|
"\"%.32s\"", 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_f("sshkey_new failed");
|
|
r = SSH_ERR_ALLOC_FAIL;
|
|
break;
|
|
}
|
|
if (!hostfile_read_key(&cp, &kbits, lineinfo.key)) {
|
|
goto bad;
|
|
}
|
|
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 legacy RSA1 if the first component is a short
|
|
* decimal number.
|
|
*/
|
|
if (lineinfo.keytype == KEY_UNSPEC && l < 8 &&
|
|
strspn(ktype, "0123456789") == l)
|
|
goto bad;
|
|
|
|
/*
|
|
* 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);
|
|
free(lineinfo.line);
|
|
free(line);
|
|
return r;
|
|
}
|
|
|
|
int
|
|
hostkeys_foreach(const char *path, hostkeys_foreach_fn *callback, void *ctx,
|
|
const char *host, const char *ip, u_int options, u_int note)
|
|
{
|
|
FILE *f;
|
|
int r, oerrno;
|
|
|
|
if ((f = fopen(path, "r")) == NULL)
|
|
return SSH_ERR_SYSTEM_ERROR;
|
|
|
|
debug3_f("reading file \"%s\"", path);
|
|
r = hostkeys_foreach_file(path, f, callback, ctx, host, ip,
|
|
options, note);
|
|
oerrno = errno;
|
|
fclose(f);
|
|
errno = oerrno;
|
|
return r;
|
|
}
|