+/* $OpenBSD: hostfile.c,v 1.46 2009/10/11 23:03:15 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* called by a name other than "ssh" or "Secure Shell".
*
*
- * Copyright (c) 1999,2000 Markus Friedl. All rights reserved.
+ * 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
*/
#include "includes.h"
-RCSID("$OpenBSD: hostfile.c,v 1.25 2001/04/06 22:12:47 stevesk Exp $");
-#include "packet.h"
+#include <sys/types.h>
+
+#include <netinet/in.h>
+
+#include <openssl/hmac.h>
+#include <openssl/sha.h>
+
+#include <resolv.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "xmalloc.h"
#include "match.h"
#include "key.h"
#include "hostfile.h"
#include "log.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 %d, got %d",
+ SHA_DIGEST_LENGTH, 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.
return 1;
}
-int
-auth_rsa_read_key(char **cpp, u_int *bitsp, BIGNUM * e, BIGNUM * n)
-{
- Key *k = key_new(KEY_RSA1);
- int ret = hostfile_read_key(cpp, bitsp, k);
- BN_copy(e, k->rsa->e);
- BN_copy(n, k->rsa->n);
- key_free(k);
- return ret;
-}
-
-int
-hostfile_check_key(int bits, Key *key, const char *host, const char *filename, int linenum)
+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)) {
- log("Warning: %s, line %d: keysize mismatch for host %s: "
+ 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);
- log("Warning: replace %d with %d in %s, line %d.",
+ logit("Warning: replace %d with %d in %s, line %d.",
bits, BN_num_bits(key->rsa->n), filename, linenum);
}
return 1;
* 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.
*/
-HostStatus
-check_host_in_hostfile(const char *filename, const char *host, Key *key,
- Key *found, int *numret)
+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;
+ char *cp, *cp2, *hashed_host;
HostStatus end_return;
- if (key == NULL)
- fatal("no key to look up");
+ debug3("check_host_in_hostfile: host %s filename %s", host, filename);
+
/* Open the file containing the list of known hosts. */
f = fopen(filename, "r");
if (!f)
;
/* Check if the host name matches. */
- if (match_hostname(host, cp, (u_int) (cp2 - cp)) != 1)
- continue;
+ 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;
*/
if (!hostfile_read_key(&cp, &kbits, found))
continue;
- if (!hostfile_check_key(kbits, found, host, filename, linenum))
- continue;
if (numret != NULL)
*numret = linenum;
+ if (key == NULL) {
+ /* we found a key of the requested type */
+ if (found->type == keytype) {
+ fclose(f);
+ 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;
}
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, Key *key)
+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;
- fprintf(f, "%s ", host);
+
+ 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 {
andersk / openssh.git / blobdiff