--- /dev/null
+/*
+ * 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 1.28 2001/06/25 08:25:37 markus Exp $");
+
+#include "packet.h"
+#include "match.h"
+#include "key.h"
+#include "hostfile.h"
+#include "log.h"
+
+/*
+ * 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.
+ */
+
+static 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;
+}
+
+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;
+}
+
+static int
+hostfile_check_key(int bits, 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: "
+ "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.",
+ 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.
+ */
+
+HostStatus
+check_host_in_hostfile(const char *filename, const char *host, Key *key,
+ Key *found, int *numret)
+{
+ FILE *f;
+ char line[8192];
+ int linenum = 0;
+ u_int kbits;
+ char *cp, *cp2;
+ HostStatus end_return;
+
+ debug3("check_host_in_hostfile: filename %s", filename);
+ if (key == NULL)
+ fatal("no key to look up");
+ /* 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)
+ 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 (!hostfile_check_key(kbits, found, host, filename, linenum))
+ continue;
+
+ if (numret != NULL)
+ *numret = linenum;
+
+ /* 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;
+}
+
+/*
+ * 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)
+{
+ FILE *f;
+ int success = 0;
+ if (key == NULL)
+ return 1; /* XXX ? */
+ f = fopen(filename, "a");
+ if (!f)
+ return 0;
+ fprintf(f, "%s ", 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;
+}
andersk / gssapi-openssh.git / blobdiff