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/* $OpenBSD: hostfile.c,v 1.71 2017/05/31 09:15:42 deraadt 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 <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 <stdio.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include <stdarg.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 "ssherr.h" |
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#include "digest.h" |
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#include "hmac.h" |
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struct hostkeys { |
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struct hostkey_entry *entries; |
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u_int num_entries; |
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}; |
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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("%s: ssh_hmac failed", __func__); |
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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("%s: __b64_ntop failed", __func__); |
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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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int r; |
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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 ((r = 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("%s: found %skey type %s in file %s:%lu", __func__, |
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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->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(struct hostkeys *hostkeys, const char *host, const char *path) |
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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(path, record_hostkey, &ctx, host, NULL, |
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HKF_WANT_MATCH|HKF_WANT_PARSE_KEY)) != 0) { |
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if (r != SSH_ERR_SYSTEM_ERROR && errno != ENOENT) |
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debug("%s: hostkeys_foreach failed for %s: %s", |
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__func__, path, ssh_err(r)); |
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} |
283 |
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if (ctx.num_loaded != 0) |
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debug3("%s: loaded %lu keys from %s", __func__, |
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ctx.num_loaded, host); |
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} |
287 |
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288 |
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void |
289 |
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free_hostkeys(struct hostkeys *hostkeys) |
290 |
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{ |
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u_int i; |
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293 |
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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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} |
299 |
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free(hostkeys->entries); |
300 |
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explicit_bzero(hostkeys, sizeof(*hostkeys)); |
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free(hostkeys); |
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} |
303 |
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304 |
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static int |
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check_key_not_revoked(struct hostkeys *hostkeys, struct sshkey *k) |
306 |
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{ |
307 |
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int is_cert = sshkey_is_cert(k); |
308 |
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u_int i; |
309 |
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310 |
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for (i = 0; i < hostkeys->num_entries; i++) { |
311 |
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if (hostkeys->entries[i].marker != MRK_REVOKE) |
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continue; |
313 |
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if (sshkey_equal_public(k, hostkeys->entries[i].key)) |
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return -1; |
315 |
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if (is_cert && |
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sshkey_equal_public(k->cert->signature_key, |
317 |
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hostkeys->entries[i].key)) |
318 |
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return -1; |
319 |
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} |
320 |
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return 0; |
321 |
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} |
322 |
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323 |
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/* |
324 |
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* Match keys against a specified key, or look one up by key type. |
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* |
326 |
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* If looking for a keytype (key == NULL) and one is found then return |
327 |
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* HOST_FOUND, otherwise HOST_NEW. |
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* |
329 |
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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 |
331 |
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* 2. If the key is not a cert and a matching key is found, return HOST_OK |
332 |
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* 3. If no key matches but a key with a different type is found, then |
333 |
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* return HOST_CHANGED |
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* 4. If no matching keys are found, then return HOST_NEW. |
335 |
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* |
336 |
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* Finally, check any found key is not revoked. |
337 |
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*/ |
338 |
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static HostStatus |
339 |
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check_hostkeys_by_key_or_type(struct hostkeys *hostkeys, |
340 |
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struct sshkey *k, int keytype, const struct hostkey_entry **found) |
341 |
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{ |
342 |
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u_int i; |
343 |
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HostStatus end_return = HOST_NEW; |
344 |
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int want_cert = sshkey_is_cert(k); |
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HostkeyMarker want_marker = want_cert ? MRK_CA : MRK_NONE; |
346 |
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347 |
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if (found != NULL) |
348 |
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*found = NULL; |
349 |
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350 |
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for (i = 0; i < hostkeys->num_entries; i++) { |
351 |
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if (hostkeys->entries[i].marker != want_marker) |
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continue; |
353 |
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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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end_return = HOST_FOUND; |
357 |
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if (found != NULL) |
358 |
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*found = hostkeys->entries + i; |
359 |
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k = hostkeys->entries[i].key; |
360 |
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break; |
361 |
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} |
362 |
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if (want_cert) { |
363 |
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if (sshkey_equal_public(k->cert->signature_key, |
364 |
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hostkeys->entries[i].key)) { |
365 |
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/* A matching CA exists */ |
366 |
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end_return = HOST_OK; |
367 |
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if (found != NULL) |
368 |
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*found = hostkeys->entries + i; |
369 |
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break; |
370 |
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} |
371 |
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} else { |
372 |
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if (sshkey_equal(k, hostkeys->entries[i].key)) { |
373 |
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end_return = HOST_OK; |
374 |
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if (found != NULL) |
375 |
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*found = hostkeys->entries + i; |
376 |
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break; |
377 |
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} |
378 |
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/* A non-maching key exists */ |
379 |
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end_return = HOST_CHANGED; |
380 |
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if (found != NULL) |
381 |
|
|
*found = hostkeys->entries + i; |
382 |
|
|
} |
383 |
|
|
} |
384 |
|
|
if (check_key_not_revoked(hostkeys, k) != 0) { |
385 |
|
|
end_return = HOST_REVOKED; |
386 |
|
|
if (found != NULL) |
387 |
|
|
*found = NULL; |
388 |
|
|
} |
389 |
|
|
return end_return; |
390 |
|
|
} |
391 |
|
|
|
392 |
|
|
HostStatus |
393 |
|
|
check_key_in_hostkeys(struct hostkeys *hostkeys, struct sshkey *key, |
394 |
|
|
const struct hostkey_entry **found) |
395 |
|
|
{ |
396 |
|
|
if (key == NULL) |
397 |
|
|
fatal("no key to look up"); |
398 |
|
|
return check_hostkeys_by_key_or_type(hostkeys, key, 0, found); |
399 |
|
|
} |
400 |
|
|
|
401 |
|
|
int |
402 |
|
|
lookup_key_in_hostkeys_by_type(struct hostkeys *hostkeys, int keytype, |
403 |
|
|
const struct hostkey_entry **found) |
404 |
|
|
{ |
405 |
|
|
return (check_hostkeys_by_key_or_type(hostkeys, NULL, keytype, |
406 |
|
|
found) == HOST_FOUND); |
407 |
|
|
} |
408 |
|
|
|
409 |
|
|
static int |
410 |
|
|
write_host_entry(FILE *f, const char *host, const char *ip, |
411 |
|
|
const struct sshkey *key, int store_hash) |
412 |
|
|
{ |
413 |
|
|
int r, success = 0; |
414 |
|
|
char *hashed_host = NULL, *lhost; |
415 |
|
|
|
416 |
|
|
lhost = xstrdup(host); |
417 |
|
|
lowercase(lhost); |
418 |
|
|
|
419 |
|
|
if (store_hash) { |
420 |
|
|
if ((hashed_host = host_hash(lhost, NULL, 0)) == NULL) { |
421 |
|
|
error("%s: host_hash failed", __func__); |
422 |
|
|
free(lhost); |
423 |
|
|
return 0; |
424 |
|
|
} |
425 |
|
|
fprintf(f, "%s ", hashed_host); |
426 |
|
|
} else if (ip != NULL) |
427 |
|
|
fprintf(f, "%s,%s ", lhost, ip); |
428 |
|
|
else { |
429 |
|
|
fprintf(f, "%s ", lhost); |
430 |
|
|
} |
431 |
|
|
free(lhost); |
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 |
|
|
|
440 |
|
|
/* |
441 |
|
|
* Appends an entry to the host file. Returns false if the entry could not |
442 |
|
|
* be appended. |
443 |
|
|
*/ |
444 |
|
|
int |
445 |
|
|
add_host_to_hostfile(const char *filename, const char *host, |
446 |
|
|
const struct sshkey *key, int store_hash) |
447 |
|
|
{ |
448 |
|
|
FILE *f; |
449 |
|
|
int success; |
450 |
|
|
|
451 |
|
|
if (key == NULL) |
452 |
|
|
return 1; /* XXX ? */ |
453 |
|
|
f = fopen(filename, "a"); |
454 |
|
|
if (!f) |
455 |
|
|
return 0; |
456 |
|
|
success = write_host_entry(f, host, NULL, key, store_hash); |
457 |
|
|
fclose(f); |
458 |
|
|
return success; |
459 |
|
|
} |
460 |
|
|
|
461 |
|
|
struct host_delete_ctx { |
462 |
|
|
FILE *out; |
463 |
|
|
int quiet; |
464 |
|
|
const char *host; |
465 |
|
|
int *skip_keys; /* XXX split for host/ip? might want to ensure both */ |
466 |
|
|
struct sshkey * const *keys; |
467 |
|
|
size_t nkeys; |
468 |
|
|
int modified; |
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; |
475 |
|
|
int loglevel = ctx->quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_VERBOSE; |
476 |
|
|
size_t i; |
477 |
|
|
|
478 |
|
|
if (l->status == HKF_STATUS_MATCHED) { |
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 |
|
|
} |
484 |
|
|
|
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 |
|
|
*/ |
504 |
|
|
do_log2(loglevel, "%s%s%s:%ld: Removed %s key for host %s", |
505 |
|
|
ctx->quiet ? __func__ : "", ctx->quiet ? ": " : "", |
506 |
|
|
l->path, l->linenum, sshkey_type(l->key), ctx->host); |
507 |
|
|
ctx->modified = 1; |
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 |
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) |
523 |
|
|
{ |
524 |
|
|
int r, fd, oerrno = 0; |
525 |
|
|
int loglevel = quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_VERBOSE; |
526 |
|
|
struct host_delete_ctx ctx; |
527 |
|
|
char *fp, *temp = NULL, *back = NULL; |
528 |
|
|
mode_t omask; |
529 |
|
|
size_t i; |
530 |
|
|
|
531 |
|
|
omask = umask(077); |
532 |
|
|
|
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; |
540 |
|
|
ctx.modified = 0; |
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 */ |
566 |
|
|
if ((r = hostkeys_foreach(filename, host_delete, &ctx, host, ip, |
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; |
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)) { |
586 |
|
|
r = SSH_ERR_INTERNAL_ERROR; |
587 |
|
|
goto fail; |
588 |
|
|
} |
589 |
|
|
ctx.modified = 1; |
590 |
|
|
} |
591 |
|
|
fclose(ctx.out); |
592 |
|
|
ctx.out = NULL; |
593 |
|
|
|
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)); |
622 |
|
|
} |
623 |
|
|
|
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); |
634 |
|
|
umask(omask); |
635 |
|
|
if (r == SSH_ERR_SYSTEM_ERROR) |
636 |
|
|
errno = oerrno; |
637 |
|
|
return r; |
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 |
|
|
} |
655 |
|
|
return match_hostname(host, names) == 1; |
656 |
|
|
} |
657 |
|
|
|
658 |
|
|
int |
659 |
|
|
hostkeys_foreach(const char *path, hostkeys_foreach_fn *callback, void *ctx, |
660 |
|
|
const char *host, const char *ip, u_int options) |
661 |
|
|
{ |
662 |
|
|
FILE *f; |
663 |
|
|
char line[8192], oline[8192], ktype[128]; |
664 |
|
|
u_long linenum = 0; |
665 |
|
|
char *cp, *cp2; |
666 |
|
|
u_int kbits; |
667 |
|
|
int hashed; |
668 |
|
|
int s, r = 0; |
669 |
|
|
struct hostkey_foreach_line lineinfo; |
670 |
|
|
size_t l; |
671 |
|
|
|
672 |
|
|
memset(&lineinfo, 0, sizeof(lineinfo)); |
673 |
|
|
if (host == NULL && (options & HKF_WANT_MATCH) != 0) |
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); |
679 |
|
|
while (read_keyfile_line(f, path, line, sizeof(line), &linenum) == 0) { |
680 |
|
|
line[strcspn(line, "\n")] = '\0'; |
681 |
|
|
strlcpy(oline, line, sizeof(oline)); |
682 |
|
|
|
683 |
|
|
sshkey_free(lineinfo.key); |
684 |
|
|
memset(&lineinfo, 0, sizeof(lineinfo)); |
685 |
|
|
lineinfo.path = path; |
686 |
|
|
lineinfo.linenum = linenum; |
687 |
|
|
lineinfo.line = oline; |
688 |
|
|
lineinfo.marker = MRK_NONE; |
689 |
|
|
lineinfo.status = HKF_STATUS_OK; |
690 |
|
|
lineinfo.keytype = KEY_UNSPEC; |
691 |
|
|
|
692 |
|
|
/* Skip any leading whitespace, comments and empty lines. */ |
693 |
|
|
for (cp = line; *cp == ' ' || *cp == '\t'; cp++) |
694 |
|
|
; |
695 |
|
|
if (!*cp || *cp == '#' || *cp == '\n') { |
696 |
|
|
if ((options & HKF_WANT_MATCH) == 0) { |
697 |
|
|
lineinfo.status = HKF_STATUS_COMMENT; |
698 |
|
|
if ((r = callback(&lineinfo, ctx)) != 0) |
699 |
|
|
break; |
700 |
|
|
} |
701 |
|
|
continue; |
702 |
|
|
} |
703 |
|
|
|
704 |
|
|
if ((lineinfo.marker = check_markers(&cp)) == MRK_ERROR) { |
705 |
|
|
verbose("%s: invalid marker at %s:%lu", |
706 |
|
|
__func__, path, linenum); |
707 |
|
|
if ((options & HKF_WANT_MATCH) == 0) |
708 |
|
|
goto bad; |
709 |
|
|
continue; |
710 |
|
|
} |
711 |
|
|
|
712 |
|
|
/* Find the end of the host name portion. */ |
713 |
|
|
for (cp2 = cp; *cp2 && *cp2 != ' ' && *cp2 != '\t'; cp2++) |
714 |
|
|
; |
715 |
|
|
lineinfo.hosts = cp; |
716 |
|
|
*cp2++ = '\0'; |
717 |
|
|
|
718 |
|
|
/* Check if the host name matches. */ |
719 |
|
|
if (host != NULL) { |
720 |
|
|
if ((s = match_maybe_hashed(host, lineinfo.hosts, |
721 |
|
|
&hashed)) == -1) { |
722 |
|
|
debug2("%s: %s:%ld: bad host hash \"%.32s\"", |
723 |
|
|
__func__, path, linenum, lineinfo.hosts); |
724 |
|
|
goto bad; |
725 |
|
|
} |
726 |
|
|
if (s == 1) { |
727 |
|
|
lineinfo.status = HKF_STATUS_MATCHED; |
728 |
|
|
lineinfo.match |= HKF_MATCH_HOST | |
729 |
|
|
(hashed ? HKF_MATCH_HOST_HASHED : 0); |
730 |
|
|
} |
731 |
|
|
/* Try matching IP address if supplied */ |
732 |
|
|
if (ip != NULL) { |
733 |
|
|
if ((s = match_maybe_hashed(ip, lineinfo.hosts, |
734 |
|
|
&hashed)) == -1) { |
735 |
|
|
debug2("%s: %s:%ld: bad ip hash " |
736 |
|
|
"\"%.32s\"", __func__, path, |
737 |
|
|
linenum, lineinfo.hosts); |
738 |
|
|
goto bad; |
739 |
|
|
} |
740 |
|
|
if (s == 1) { |
741 |
|
|
lineinfo.status = HKF_STATUS_MATCHED; |
742 |
|
|
lineinfo.match |= HKF_MATCH_IP | |
743 |
|
|
(hashed ? HKF_MATCH_IP_HASHED : 0); |
744 |
|
|
} |
745 |
|
|
} |
746 |
|
|
/* |
747 |
|
|
* Skip this line if host matching requested and |
748 |
|
|
* neither host nor address matched. |
749 |
|
|
*/ |
750 |
|
|
if ((options & HKF_WANT_MATCH) != 0 && |
751 |
|
|
lineinfo.status != HKF_STATUS_MATCHED) |
752 |
|
|
continue; |
753 |
|
|
} |
754 |
|
|
|
755 |
|
|
/* Got a match. Skip host name and any following whitespace */ |
756 |
|
|
for (; *cp2 == ' ' || *cp2 == '\t'; cp2++) |
757 |
|
|
; |
758 |
|
|
if (*cp2 == '\0' || *cp2 == '#') { |
759 |
|
|
debug2("%s:%ld: truncated before key type", |
760 |
|
|
path, linenum); |
761 |
|
|
goto bad; |
762 |
|
|
} |
763 |
|
|
lineinfo.rawkey = cp = cp2; |
764 |
|
|
|
765 |
|
|
if ((options & HKF_WANT_PARSE_KEY) != 0) { |
766 |
|
|
/* |
767 |
|
|
* Extract the key from the line. This will skip |
768 |
|
|
* any leading whitespace. Ignore badly formatted |
769 |
|
|
* lines. |
770 |
|
|
*/ |
771 |
|
|
if ((lineinfo.key = sshkey_new(KEY_UNSPEC)) == NULL) { |
772 |
|
|
error("%s: sshkey_new failed", __func__); |
773 |
|
|
r = SSH_ERR_ALLOC_FAIL; |
774 |
|
|
break; |
775 |
|
|
} |
776 |
|
|
if (!hostfile_read_key(&cp, &kbits, lineinfo.key)) { |
777 |
|
|
goto bad; |
778 |
|
|
} |
779 |
|
|
lineinfo.keytype = lineinfo.key->type; |
780 |
|
|
lineinfo.comment = cp; |
781 |
|
|
} else { |
782 |
|
|
/* Extract and parse key type */ |
783 |
|
|
l = strcspn(lineinfo.rawkey, " \t"); |
784 |
|
|
if (l <= 1 || l >= sizeof(ktype) || |
785 |
|
|
lineinfo.rawkey[l] == '\0') |
786 |
|
|
goto bad; |
787 |
|
|
memcpy(ktype, lineinfo.rawkey, l); |
788 |
|
|
ktype[l] = '\0'; |
789 |
|
|
lineinfo.keytype = sshkey_type_from_name(ktype); |
790 |
|
|
|
791 |
|
|
/* |
792 |
|
|
* Assume legacy RSA1 if the first component is a short |
793 |
|
|
* decimal number. |
794 |
|
|
*/ |
795 |
|
|
if (lineinfo.keytype == KEY_UNSPEC && l < 8 && |
796 |
|
|
strspn(ktype, "0123456789") == l) |
797 |
|
|
goto bad; |
798 |
|
|
|
799 |
|
|
/* |
800 |
|
|
* Check that something other than whitespace follows |
801 |
|
|
* the key type. This won't catch all corruption, but |
802 |
|
|
* it does catch trivial truncation. |
803 |
|
|
*/ |
804 |
|
|
cp2 += l; /* Skip past key type */ |
805 |
|
|
for (; *cp2 == ' ' || *cp2 == '\t'; cp2++) |
806 |
|
|
; |
807 |
|
|
if (*cp2 == '\0' || *cp2 == '#') { |
808 |
|
|
debug2("%s:%ld: truncated after key type", |
809 |
|
|
path, linenum); |
810 |
|
|
lineinfo.keytype = KEY_UNSPEC; |
811 |
|
|
} |
812 |
|
|
if (lineinfo.keytype == KEY_UNSPEC) { |
813 |
|
|
bad: |
814 |
|
|
sshkey_free(lineinfo.key); |
815 |
|
|
lineinfo.key = NULL; |
816 |
|
|
lineinfo.status = HKF_STATUS_INVALID; |
817 |
|
|
if ((r = callback(&lineinfo, ctx)) != 0) |
818 |
|
|
break; |
819 |
|
|
continue; |
820 |
|
|
} |
821 |
|
|
} |
822 |
|
|
if ((r = callback(&lineinfo, ctx)) != 0) |
823 |
|
|
break; |
824 |
|
|
} |
825 |
|
|
sshkey_free(lineinfo.key); |
826 |
|
|
fclose(f); |
827 |
|
|
return r; |
828 |
|
|
} |