[openssh.git] / hostfile.c

/*
 * Author: Tatu Ylonen <ylo@cs.hut.fi>
 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
 *                    All rights reserved
 * Functions for manipulating the known hosts files.
 *
 * As far as I am concerned, the code I have written for this software
 * can be used freely for any purpose.  Any derived versions of this
 * software must be clearly marked as such, and if the derived work is
 * incompatible with the protocol description in the RFC file, it must be
 * called by a name other than "ssh" or "Secure Shell".
 *
 *
 * Copyright (c) 1999, 2000 Markus Friedl.  All rights reserved.
 * Copyright (c) 1999 Niels Provos.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "includes.h"
RCSID("$OpenBSD: hostfile.c,v 1.35 2005/07/27 10:39:03 dtucker Exp $");

#include <resolv.h>
#include <openssl/hmac.h>
#include <openssl/sha.h>

#include "packet.h"
#include "match.h"
#include "key.h"
#include "hostfile.h"
#include "log.h"
#include "xmalloc.h"

static int
extract_salt(const char *s, u_int l, char *salt, size_t salt_len)
{
	char *p, *b64salt;
	u_int b64len;
	int ret;

	if (l < sizeof(HASH_MAGIC) - 1) {
		debug2("extract_salt: string too short");
		return (-1);
	}
	if (strncmp(s, HASH_MAGIC, sizeof(HASH_MAGIC) - 1) != 0) {
		debug2("extract_salt: invalid magic identifier");
		return (-1);
	}
	s += sizeof(HASH_MAGIC) - 1;
	l -= sizeof(HASH_MAGIC) - 1;
	if ((p = memchr(s, HASH_DELIM, l)) == NULL) {
		debug2("extract_salt: missing salt termination character");
		return (-1);
	}

	b64len = p - s;
	/* Sanity check */
	if (b64len == 0 || b64len > 1024) {
		debug2("extract_salt: bad encoded salt length %u", b64len);
		return (-1);
	}
	b64salt = xmalloc(1 + b64len);
	memcpy(b64salt, s, b64len);
	b64salt[b64len] = '\0';

	ret = __b64_pton(b64salt, salt, salt_len);
	xfree(b64salt);
	if (ret == -1) {
		debug2("extract_salt: salt decode error");
		return (-1);
	}
	if (ret != SHA_DIGEST_LENGTH) {
		debug2("extract_salt: expected salt len %u, got %u",
		    salt_len, ret);
		return (-1);
	}

	return (0);
}

char *
host_hash(const char *host, const char *name_from_hostfile, u_int src_len)
{
	const EVP_MD *md = EVP_sha1();
	HMAC_CTX mac_ctx;
	char salt[256], result[256], uu_salt[512], uu_result[512];
	static char encoded[1024];
	u_int i, len;

	len = EVP_MD_size(md);

	if (name_from_hostfile == NULL) {
		/* Create new salt */
		for (i = 0; i < len; i++)
			salt[i] = arc4random();
	} else {
		/* Extract salt from known host entry */
		if (extract_salt(name_from_hostfile, src_len, salt,
		    sizeof(salt)) == -1)
			return (NULL);
	}

	HMAC_Init(&mac_ctx, salt, len, md);
	HMAC_Update(&mac_ctx, host, strlen(host));
	HMAC_Final(&mac_ctx, result, NULL);
	HMAC_cleanup(&mac_ctx);

	if (__b64_ntop(salt, len, uu_salt, sizeof(uu_salt)) == -1 ||
	    __b64_ntop(result, len, uu_result, sizeof(uu_result)) == -1)
		fatal("host_hash: __b64_ntop failed");

	snprintf(encoded, sizeof(encoded), "%s%s%c%s", HASH_MAGIC, uu_salt,
	    HASH_DELIM, uu_result);

	return (encoded);
}

/*
 * Parses an RSA (number of bits, e, n) or DSA key from a string.  Moves the
 * pointer over the key.  Skips any whitespace at the beginning and at end.
 */

int
hostfile_read_key(char **cpp, u_int *bitsp, Key *ret)
{
	char *cp;

	/* Skip leading whitespace. */
	for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++)
		;

	if (key_read(ret, &cp) != 1)
		return 0;

	/* Skip trailing whitespace. */
	for (; *cp == ' ' || *cp == '\t'; cp++)
		;

	/* Return results. */
	*cpp = cp;
	*bitsp = key_size(ret);
	return 1;
}

static int
hostfile_check_key(int bits, const Key *key, const char *host, const char *filename, int linenum)
{
	if (key == NULL || key->type != KEY_RSA1 || key->rsa == NULL)
		return 1;
	if (bits != BN_num_bits(key->rsa->n)) {
		logit("Warning: %s, line %d: keysize mismatch for host %s: "
		    "actual %d vs. announced %d.",
		    filename, linenum, host, BN_num_bits(key->rsa->n), bits);
		logit("Warning: replace %d with %d in %s, line %d.",
		    bits, BN_num_bits(key->rsa->n), filename, linenum);
	}
	return 1;
}

/*
 * Checks whether the given host (which must be in all lowercase) is already
 * in the list of our known hosts. Returns HOST_OK if the host is known and
 * has the specified key, HOST_NEW if the host is not known, and HOST_CHANGED
 * if the host is known but used to have a different host key.
 *
 * If no 'key' has been specified and a key of type 'keytype' is known
 * for the specified host, then HOST_FOUND is returned.
 */

static HostStatus
check_host_in_hostfile_by_key_or_type(const char *filename,
    const char *host, const Key *key, int keytype, Key *found, int *numret)
{
	FILE *f;
	char line[8192];
	int linenum = 0;
	u_int kbits;
	char *cp, *cp2, *hashed_host;
	HostStatus end_return;

	debug3("check_host_in_hostfile: filename %s", filename);

	/* Open the file containing the list of known hosts. */
	f = fopen(filename, "r");
	if (!f)
		return HOST_NEW;

	/*
	 * Return value when the loop terminates.  This is set to
	 * HOST_CHANGED if we have seen a different key for the host and have
	 * not found the proper one.
	 */
	end_return = HOST_NEW;

	/* Go through the file. */
	while (fgets(line, sizeof(line), f)) {
		cp = line;
		linenum++;

		/* Skip any leading whitespace, comments and empty lines. */
		for (; *cp == ' ' || *cp == '\t'; cp++)
			;
		if (!*cp || *cp == '#' || *cp == '\n')
			continue;

		/* Find the end of the host name portion. */
		for (cp2 = cp; *cp2 && *cp2 != ' ' && *cp2 != '\t'; cp2++)
			;

		/* Check if the host name matches. */
		if (match_hostname(host, cp, (u_int) (cp2 - cp)) != 1) {
			if (*cp != HASH_DELIM)
				continue;
			hashed_host = host_hash(host, cp, (u_int) (cp2 - cp));
			if (hashed_host == NULL) {
				debug("Invalid hashed host line %d of %s",
				    linenum, filename);
				continue;
			}
			if (strncmp(hashed_host, cp, (u_int) (cp2 - cp)) != 0)
				continue;
		}

		/* Got a match.  Skip host name. */
		cp = cp2;

		/*
		 * Extract the key from the line.  This will skip any leading
		 * whitespace.  Ignore badly formatted lines.
		 */
		if (!hostfile_read_key(&cp, &kbits, found))
			continue;

		if (numret != NULL)
			*numret = linenum;

		if (key == NULL) {
			/* we found a key of the requested type */
			if (found->type == keytype)
				return HOST_FOUND;
			continue;
		}

		if (!hostfile_check_key(kbits, found, host, filename, linenum))
			continue;

		/* Check if the current key is the same as the given key. */
		if (key_equal(key, found)) {
			/* Ok, they match. */
			debug3("check_host_in_hostfile: match line %d", linenum);
			fclose(f);
			return HOST_OK;
		}
		/*
		 * They do not match.  We will continue to go through the
		 * file; however, we note that we will not return that it is
		 * new.
		 */
		end_return = HOST_CHANGED;
	}
	/* Clear variables and close the file. */
	fclose(f);

	/*
	 * Return either HOST_NEW or HOST_CHANGED, depending on whether we
	 * saw a different key for the host.
	 */
	return end_return;
}

HostStatus
check_host_in_hostfile(const char *filename, const char *host, const Key *key,
    Key *found, int *numret)
{
	if (key == NULL)
		fatal("no key to look up");
	return (check_host_in_hostfile_by_key_or_type(filename, host, key, 0,
	    found, numret));
}

int
lookup_key_in_hostfile_by_type(const char *filename, const char *host,
    int keytype, Key *found, int *numret)
{
	return (check_host_in_hostfile_by_key_or_type(filename, host, NULL,
	    keytype, found, numret) == HOST_FOUND);
}

/*
 * 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 Key *key,
    int store_hash)
{
	FILE *f;
	int success = 0;
	char *hashed_host = NULL;

	if (key == NULL)
		return 1;	/* XXX ? */
	f = fopen(filename, "a");
	if (!f)
		return 0;

	if (store_hash) {
		if ((hashed_host = host_hash(host, NULL, 0)) == NULL) {
			error("add_host_to_hostfile: host_hash failed");
			fclose(f);
			return 0;
		}
	}
	fprintf(f, "%s ", store_hash ? hashed_host : host);

	if (key_write(key, f)) {
		success = 1;
	} else {
		error("add_host_to_hostfile: saving key in %s failed", filename);
	}
	fprintf(f, "\n");
	fclose(f);
	return success;
}
Commit	Line	Data
8efc0c15	1	/*
5260325f	2	* Author: Tatu Ylonen <ylo@cs.hut.fi>
5260325f	3	* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5260325f	4	* All rights reserved
bcbf86ec	5	* Functions for manipulating the known hosts files.
6ae2364d	6	*
bcbf86ec	7	* As far as I am concerned, the code I have written for this software
	8	* can be used freely for any purpose. Any derived versions of this
	9	* software must be clearly marked as such, and if the derived work is
	10	* incompatible with the protocol description in the RFC file, it must be
	11	* called by a name other than "ssh" or "Secure Shell".
6ae2364d	12	*
6ae2364d	13	*
a96070d4	14	* Copyright (c) 1999, 2000 Markus Friedl. All rights reserved.
bcbf86ec	15	* Copyright (c) 1999 Niels Provos. All rights reserved.
	16	*
	17	* Redistribution and use in source and binary forms, with or without
	18	* modification, are permitted provided that the following conditions
	19	* are met:
	20	* 1. Redistributions of source code must retain the above copyright
	21	* notice, this list of conditions and the following disclaimer.
	22	* 2. Redistributions in binary form must reproduce the above copyright
	23	* notice, this list of conditions and the following disclaimer in the
	24	* documentation and/or other materials provided with the distribution.
	25	*
	26	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	27	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	28	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	29	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	30	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	31	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	32	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	33	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	34	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	35	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
5260325f	36	*/
8efc0c15	37
8efc0c15	38	#include "includes.h"
a056dfa2	39	RCSID("$OpenBSD: hostfile.c,v 1.35 2005/07/27 10:39:03 dtucker Exp $");
5c63c2ab	40
	41	#include <resolv.h>
	42	#include <openssl/hmac.h>
	43	#include <openssl/sha.h>
4fe2af09	44
8efc0c15	45	#include "packet.h"
4fe2af09	46	#include "match.h"
4fe2af09	47	#include "key.h"
4fe2af09	48	#include "hostfile.h"
42f11eb2	49	#include "log.h"
5c63c2ab	50	#include "xmalloc.h"
	51
	52	static int
	53	extract_salt(const char s, u_int l, char salt, size_t salt_len)
	54	{
	55	char p, b64salt;
	56	u_int b64len;
	57	int ret;
	58
	59	if (l < sizeof(HASH_MAGIC) - 1) {
	60	debug2("extract_salt: string too short");
	61	return (-1);
	62	}
	63	if (strncmp(s, HASH_MAGIC, sizeof(HASH_MAGIC) - 1) != 0) {
	64	debug2("extract_salt: invalid magic identifier");
	65	return (-1);
	66	}
	67	s += sizeof(HASH_MAGIC) - 1;
	68	l -= sizeof(HASH_MAGIC) - 1;
	69	if ((p = memchr(s, HASH_DELIM, l)) == NULL) {
	70	debug2("extract_salt: missing salt termination character");
	71	return (-1);
	72	}
	73
	74	b64len = p - s;
	75	/* Sanity check */
	76	if (b64len == 0 \|\| b64len > 1024) {
	77	debug2("extract_salt: bad encoded salt length %u", b64len);
	78	return (-1);
	79	}
	80	b64salt = xmalloc(1 + b64len);
	81	memcpy(b64salt, s, b64len);
	82	b64salt[b64len] = '\0';
	83
	84	ret = __b64_pton(b64salt, salt, salt_len);
	85	xfree(b64salt);
	86	if (ret == -1) {
	87	debug2("extract_salt: salt decode error");
	88	return (-1);
	89	}
	90	if (ret != SHA_DIGEST_LENGTH) {
	91	debug2("extract_salt: expected salt len %u, got %u",
	92	salt_len, ret);
	93	return (-1);
	94	}
f8cc7664	95
5c63c2ab	96	return (0);
	97	}
	98
	99	char *
	100	host_hash(const char host, const char name_from_hostfile, u_int src_len)
	101	{
	102	const EVP_MD *md = EVP_sha1();
	103	HMAC_CTX mac_ctx;
	104	char salt[256], result[256], uu_salt[512], uu_result[512];
	105	static char encoded[1024];
	106	u_int i, len;
	107
	108	len = EVP_MD_size(md);
	109
	110	if (name_from_hostfile == NULL) {
	111	/* Create new salt */
	112	for (i = 0; i < len; i++)
	113	salt[i] = arc4random();
	114	} else {
	115	/* Extract salt from known host entry */
	116	if (extract_salt(name_from_hostfile, src_len, salt,
	117	sizeof(salt)) == -1)
	118	return (NULL);
	119	}
	120
	121	HMAC_Init(&mac_ctx, salt, len, md);
	122	HMAC_Update(&mac_ctx, host, strlen(host));
	123	HMAC_Final(&mac_ctx, result, NULL);
	124	HMAC_cleanup(&mac_ctx);
	125
f8cc7664	126	if (__b64_ntop(salt, len, uu_salt, sizeof(uu_salt)) == -1 \|\|
5c63c2ab	127	__b64_ntop(result, len, uu_result, sizeof(uu_result)) == -1)
	128	fatal("host_hash: __b64_ntop failed");
	129
	130	snprintf(encoded, sizeof(encoded), "%s%s%c%s", HASH_MAGIC, uu_salt,
	131	HASH_DELIM, uu_result);
	132
	133	return (encoded);
	134	}
8efc0c15	135
aa3378df	136	/*
4fe2af09	137	* Parses an RSA (number of bits, e, n) or DSA key from a string. Moves the
4fe2af09	138	* pointer over the key. Skips any whitespace at the beginning and at end.
aa3378df	139	*/
8efc0c15	140
fb396518	141	int
1e3b8b07	142	hostfile_read_key(char *cpp, u_int bitsp, Key *ret)
8efc0c15	143	{
5260325f	144	char *cp;
	145
	146	/* Skip leading whitespace. */
aa3378df	147	for (cp = cpp; cp == ' ' \|\| *cp == '\t'; cp++)
aa3378df	148	;
5260325f	149
fa08c86b	150	if (key_read(ret, &cp) != 1)
5260325f	151	return 0;
	152
	153	/* Skip trailing whitespace. */
aa3378df	154	for (; cp == ' ' \|\| cp == '\t'; cp++)
aa3378df	155	;
5260325f	156
	157	/* Return results. */
	158	*cpp = cp;
fa08c86b	159	*bitsp = key_size(ret);
5260325f	160	return 1;
8efc0c15	161	}
8efc0c15	162
396c147e	163	static int
b6c7b7b7	164	hostfile_check_key(int bits, const Key key, const char host, const char *filename, int linenum)
4fe2af09	165	{
fa08c86b	166	if (key == NULL \|\| key->type != KEY_RSA1 \|\| key->rsa == NULL)
4fe2af09	167	return 1;
4fe2af09	168	if (bits != BN_num_bits(key->rsa->n)) {
bbe88b6d	169	logit("Warning: %s, line %d: keysize mismatch for host %s: "
4fe2af09	170	"actual %d vs. announced %d.",
4fe2af09	171	filename, linenum, host, BN_num_bits(key->rsa->n), bits);
bbe88b6d	172	logit("Warning: replace %d with %d in %s, line %d.",
4fe2af09	173	bits, BN_num_bits(key->rsa->n), filename, linenum);
8efc0c15	174	}
4fe2af09	175	return 1;
8efc0c15	176	}
8efc0c15	177
aa3378df	178	/*
	179	* Checks whether the given host (which must be in all lowercase) is already
	180	* in the list of our known hosts. Returns HOST_OK if the host is known and
	181	* has the specified key, HOST_NEW if the host is not known, and HOST_CHANGED
	182	* if the host is known but used to have a different host key.
8a48a7ef	183	*
	184	* If no 'key' has been specified and a key of type 'keytype' is known
	185	* for the specified host, then HOST_FOUND is returned.
aa3378df	186	*/
8efc0c15	187
8a48a7ef	188	static HostStatus
8a48a7ef	189	check_host_in_hostfile_by_key_or_type(const char *filename,
b6c7b7b7	190	const char host, const Key key, int keytype, Key found, int numret)
8efc0c15	191	{
5260325f	192	FILE *f;
	193	char line[8192];
	194	int linenum = 0;
d9d49fdb	195	u_int kbits;
5c63c2ab	196	char cp, cp2, *hashed_host;
5260325f	197	HostStatus end_return;
5260325f	198
8002af61	199	debug3("check_host_in_hostfile: filename %s", filename);
8a48a7ef	200
5260325f	201	/* Open the file containing the list of known hosts. */
	202	f = fopen(filename, "r");
	203	if (!f)
	204	return HOST_NEW;
	205
aa3378df	206	/*
	207	* Return value when the loop terminates. This is set to
	208	* HOST_CHANGED if we have seen a different key for the host and have
	209	* not found the proper one.
	210	*/
5260325f	211	end_return = HOST_NEW;
5260325f	212
d9d49fdb	213	/* Go through the file. */
5260325f	214	while (fgets(line, sizeof(line), f)) {
	215	cp = line;
	216	linenum++;
	217
aa3378df	218	/* Skip any leading whitespace, comments and empty lines. */
	219	for (; cp == ' ' \|\| cp == '\t'; cp++)
	220	;
5260325f	221	if (!cp \|\| cp == '#' \|\| *cp == '\n')
	222	continue;
	223
	224	/* Find the end of the host name portion. */
aa3378df	225	for (cp2 = cp; cp2 && cp2 != ' ' && *cp2 != '\t'; cp2++)
aa3378df	226	;
5260325f	227
5260325f	228	/* Check if the host name matches. */
5c63c2ab	229	if (match_hostname(host, cp, (u_int) (cp2 - cp)) != 1) {
	230	if (*cp != HASH_DELIM)
	231	continue;
	232	hashed_host = host_hash(host, cp, (u_int) (cp2 - cp));
	233	if (hashed_host == NULL) {
	234	debug("Invalid hashed host line %d of %s",
	235	linenum, filename);
	236	continue;
	237	}
	238	if (strncmp(hashed_host, cp, (u_int) (cp2 - cp)) != 0)
	239	continue;
	240	}
5260325f	241
	242	/* Got a match. Skip host name. */
	243	cp = cp2;
	244
aa3378df	245	/*
	246	* Extract the key from the line. This will skip any leading
	247	* whitespace. Ignore badly formatted lines.
	248	*/
4fe2af09	249	if (!hostfile_read_key(&cp, &kbits, found))
4fe2af09	250	continue;
5260325f	251
1e3b8b07	252	if (numret != NULL)
	253	*numret = linenum;
	254
8a48a7ef	255	if (key == NULL) {
	256	/* we found a key of the requested type */
	257	if (found->type == keytype)
	258	return HOST_FOUND;
	259	continue;
	260	}
	261
	262	if (!hostfile_check_key(kbits, found, host, filename, linenum))
	263	continue;
	264
5260325f	265	/* Check if the current key is the same as the given key. */
4fe2af09	266	if (key_equal(key, found)) {
5260325f	267	/* Ok, they match. */
8002af61	268	debug3("check_host_in_hostfile: match line %d", linenum);
5260325f	269	fclose(f);
	270	return HOST_OK;
	271	}
aa3378df	272	/*
	273	* They do not match. We will continue to go through the
	274	* file; however, we note that we will not return that it is
	275	* new.
	276	*/
5260325f	277	end_return = HOST_CHANGED;
8efc0c15	278	}
5260325f	279	/* Clear variables and close the file. */
	280	fclose(f);
	281
aa3378df	282	/*
	283	* Return either HOST_NEW or HOST_CHANGED, depending on whether we
	284	* saw a different key for the host.
	285	*/
5260325f	286	return end_return;
8efc0c15	287	}
8efc0c15	288
8a48a7ef	289	HostStatus
b6c7b7b7	290	check_host_in_hostfile(const char filename, const char host, const Key *key,
8a48a7ef	291	Key found, int numret)
	292	{
	293	if (key == NULL)
	294	fatal("no key to look up");
	295	return (check_host_in_hostfile_by_key_or_type(filename, host, key, 0,
	296	found, numret));
	297	}
	298
	299	int
	300	lookup_key_in_hostfile_by_type(const char filename, const char host,
	301	int keytype, Key found, int numret)
	302	{
	303	return (check_host_in_hostfile_by_key_or_type(filename, host, NULL,
	304	keytype, found, numret) == HOST_FOUND);
	305	}
	306
aa3378df	307	/*
	308	* Appends an entry to the host file. Returns false if the entry could not
	309	* be appended.
	310	*/
8efc0c15	311
8efc0c15	312	int
f8cc7664	313	add_host_to_hostfile(const char filename, const char host, const Key *key,
5c63c2ab	314	int store_hash)
8efc0c15	315	{
5260325f	316	FILE *f;
4fe2af09	317	int success = 0;
a056dfa2	318	char *hashed_host = NULL;
5c63c2ab	319
4fe2af09	320	if (key == NULL)
a306f2dd	321	return 1; /* XXX ? */
5260325f	322	f = fopen(filename, "a");
	323	if (!f)
	324	return 0;
5c63c2ab	325
	326	if (store_hash) {
	327	if ((hashed_host = host_hash(host, NULL, 0)) == NULL) {
	328	error("add_host_to_hostfile: host_hash failed");
	329	fclose(f);
	330	return 0;
	331	}
	332	}
	333	fprintf(f, "%s ", store_hash ? hashed_host : host);
	334
4fe2af09	335	if (key_write(key, f)) {
4fe2af09	336	success = 1;
4fe2af09	337	} else {
a306f2dd	338	error("add_host_to_hostfile: saving key in %s failed", filename);
5260325f	339	}
a306f2dd	340	fprintf(f, "\n");
5260325f	341	fclose(f);
4fe2af09	342	return success;
8efc0c15	343	}