+/* $OpenBSD: hostfile.c,v 1.46 2009/10/11 23:03:15 djm Exp $ */
/*
- *
- * hostfile.c
- *
* Author: Tatu Ylonen <ylo@cs.hut.fi>
- *
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
- *
- * Created: Thu Jun 29 07:10:56 1995 ylo
- *
* 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 1.11 2000/01/04 00:07:59 markus Exp $");
-#include "packet.h"
-#include "ssh.h"
+#include <sys/types.h>
-/*
- * Reads a multiple-precision integer in hex from the buffer, and advances
- * the pointer. The integer must already be initialized. This function is
- * permitted to modify the buffer. This leaves *cpp to point just beyond the
- * last processed (and maybe modified) character. Note that this may modify
- * the buffer containing the number.
- */
+#include <netinet/in.h>
-int
-auth_rsa_read_bignum(char **cpp, BIGNUM * value)
-{
- char *cp = *cpp;
- int len, old;
+#include <openssl/hmac.h>
+#include <openssl/sha.h>
- /* Skip any leading whitespace. */
- for (; *cp == ' ' || *cp == '\t'; cp++)
- ;
+#include <resolv.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
- /* Check that it begins with a hex digit. */
- if (*cp < '0' || *cp > '9')
- return 0;
+#include "xmalloc.h"
+#include "match.h"
+#include "key.h"
+#include "hostfile.h"
+#include "log.h"
- /* Save starting position. */
- *cpp = cp;
+static int
+extract_salt(const char *s, u_int l, char *salt, size_t salt_len)
+{
+ char *p, *b64salt;
+ u_int b64len;
+ int ret;
- /* Move forward until all hex digits skipped. */
- for (; *cp >= '0' && *cp <= '9'; cp++)
- ;
+ 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);
+ }
- /* Compute the length of the hex number. */
- len = cp - *cpp;
+ 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);
+ }
- /* Save the old terminating character, and replace it by \0. */
- old = *cp;
- *cp = 0;
+ return (0);
+}
- /* Parse the number. */
- if (BN_dec2bn(&value, *cpp) == 0)
- 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);
+ }
- /* Restore old terminating character. */
- *cp = old;
+ HMAC_Init(&mac_ctx, salt, len, md);
+ HMAC_Update(&mac_ctx, host, strlen(host));
+ HMAC_Final(&mac_ctx, result, NULL);
+ HMAC_cleanup(&mac_ctx);
- /* Move beyond the number and return success. */
- *cpp = cp;
- return 1;
+ 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 key (number of bits, e, n) from a string. Moves the pointer
- * over the key. Skips any whitespace at the beginning and at end.
+ * 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
-auth_rsa_read_key(char **cpp, unsigned int *bitsp, BIGNUM * e, BIGNUM * n)
+hostfile_read_key(char **cpp, u_int *bitsp, Key *ret)
{
- unsigned int bits;
char *cp;
/* Skip leading whitespace. */
for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++)
;
- /* Get number of bits. */
- if (*cp < '0' || *cp > '9')
- return 0; /* Bad bit count... */
- for (bits = 0; *cp >= '0' && *cp <= '9'; cp++)
- bits = 10 * bits + *cp - '0';
-
- /* Get public exponent. */
- if (!auth_rsa_read_bignum(&cp, e))
- return 0;
-
- /* Get public modulus. */
- if (!auth_rsa_read_bignum(&cp, n))
+ if (key_read(ret, &cp) != 1)
return 0;
/* Skip trailing whitespace. */
/* Return results. */
*cpp = cp;
- *bitsp = bits;
+ *bitsp = key_size(ret);
return 1;
}
-/*
- * Tries to match the host name (which must be in all lowercase) against the
- * comma-separated sequence of subpatterns (each possibly preceded by ! to
- * indicate negation). Returns true if there is a positive match; zero
- * otherwise.
- */
-
-int
-match_hostname(const char *host, const char *pattern, unsigned int len)
+static int
+hostfile_check_key(int bits, const Key *key, const char *host, const char *filename, int linenum)
{
- char sub[1024];
- int negated;
- int got_positive;
- unsigned int i, subi;
-
- got_positive = 0;
- for (i = 0; i < len;) {
- /* Check if the subpattern is negated. */
- if (pattern[i] == '!') {
- negated = 1;
- i++;
- } else
- negated = 0;
-
- /*
- * Extract the subpattern up to a comma or end. Convert the
- * subpattern to lowercase.
- */
- for (subi = 0;
- i < len && subi < sizeof(sub) - 1 && pattern[i] != ',';
- subi++, i++)
- sub[subi] = isupper(pattern[i]) ? tolower(pattern[i]) : pattern[i];
- /* If subpattern too long, return failure (no match). */
- if (subi >= sizeof(sub) - 1)
- return 0;
-
- /* If the subpattern was terminated by a comma, skip the comma. */
- if (i < len && pattern[i] == ',')
- i++;
-
- /* Null-terminate the subpattern. */
- sub[subi] = '\0';
-
- /* Try to match the subpattern against the host name. */
- if (match_pattern(host, sub)) {
- if (negated)
- return 0; /* Fail */
- else
- got_positive = 1;
- }
+ 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 success if got a positive match. If there was a negative
- * match, we have already returned zero and never get here.
- */
- return got_positive;
+ 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,
- BIGNUM * e, BIGNUM * n, BIGNUM * ke, BIGNUM * kn)
+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;
- unsigned int bits, kbits, hostlen;
- char *cp, *cp2;
+ u_int kbits;
+ char *cp, *cp2, *hashed_host;
HostStatus end_return;
+ 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)
return HOST_NEW;
- /* Cache the length of the host name. */
- hostlen = strlen(host);
-
/*
* Return value when the loop terminates. This is set to
* HOST_CHANGED if we have seen a different key for the host and have
*/
end_return = HOST_NEW;
- /* size of modulus 'n' */
- bits = BN_num_bits(n);
-
- /* Go trough the file. */
+ /* Go through the file. */
while (fgets(line, sizeof(line), f)) {
cp = line;
linenum++;
;
/* Check if the host name matches. */
- if (!match_hostname(host, cp, (unsigned int) (cp2 - cp)))
- 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;
* Extract the key from the line. This will skip any leading
* whitespace. Ignore badly formatted lines.
*/
- if (!auth_rsa_read_key(&cp, &kbits, ke, kn))
+ if (!hostfile_read_key(&cp, &kbits, found))
continue;
- if (kbits != BN_num_bits(kn)) {
- error("Warning: %s, line %d: keysize mismatch for host %s: "
- "actual %d vs. announced %d.",
- filename, linenum, host, BN_num_bits(kn), kbits);
- error("Warning: replace %d with %d in %s, line %d.",
- kbits, BN_num_bits(kn), filename, linenum);
+ 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 (BN_cmp(ke, e) == 0 && BN_cmp(kn, n) == 0) {
+ 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,
- BIGNUM * e, BIGNUM * n)
+add_host_to_hostfile(const char *filename, const char *host, const Key *key,
+ int store_hash)
{
FILE *f;
- char *buf;
- unsigned int bits;
+ int success = 0;
+ char *hashed_host = NULL;
- /* Open the file for appending. */
+ if (key == NULL)
+ return 1; /* XXX ? */
f = fopen(filename, "a");
if (!f)
return 0;
- /* size of modulus 'n' */
- bits = BN_num_bits(n);
-
- /* Print the host name and key to the file. */
- fprintf(f, "%s %u ", host, bits);
- buf = BN_bn2dec(e);
- if (buf == NULL) {
- error("add_host_to_hostfile: BN_bn2dec(e) failed");
- fclose(f);
- return 0;
- }
- fprintf(f, "%s ", buf);
- free(buf);
- buf = BN_bn2dec(n);
- if (buf == NULL) {
- error("add_host_to_hostfile: BN_bn2dec(n) failed");
- fclose(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\n", buf);
- free(buf);
+ fprintf(f, "%s ", store_hash ? hashed_host : host);
- /* Close the file. */
+ 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 1;
+ return success;
}
andersk / openssh.git / blobdiff