X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/4d19544715ea43252fa1dc6ddfbfd8979506968f..556f1c050904b36aa3c83a423d9c50f5ceeff685:/hostfile.c

diff --git a/hostfile.c b/hostfile.c
index 04e9a355..dcee0344 100644
--- a/hostfile.c
+++ b/hostfile.c
@@ -1,294 +1,232 @@
 /*
-
-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.
-
-*/
+ * 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("$Id$");
+RCSID("$OpenBSD: hostfile.c,v 1.30 2002/07/24 16:11:18 markus Exp $");
 
 #include "packet.h"
-#include "ssh.h"
+#include "match.h"
+#include "key.h"
+#include "hostfile.h"
+#include "log.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. */
+/*
+ * 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_bignum(char **cpp, BIGNUM *value)
+hostfile_read_key(char **cpp, u_int *bitsp, Key *ret)
 {
-  char *cp = *cpp;
-  int len, old;
-
-  /* Skip any leading whitespace. */
-  for (; *cp == ' ' || *cp == '\t'; cp++)
-    ;
-
-  /* Check that it begins with a hex digit. */
-  if (*cp < '0' || *cp > '9')
-    return 0;
-
-  /* Save starting position. */
-  *cpp = cp;
-
-  /* Move forward until all hex digits skipped. */
-  for (; *cp >= '0' && *cp <= '9'; cp++)
-    ;
-
-  /* Compute the length of the hex number. */
-  len = cp - *cpp;
+	char *cp;
 
-  /* Save the old terminating character, and replace it by \0. */
-  old = *cp;
-  *cp = 0;
+	/* Skip leading whitespace. */
+	for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++)
+		;
 
-  
-  /* Parse the number. */
-  if (BN_dec2bn(&value, *cpp) == 0)
-    return 0;
+	if (key_read(ret, &cp) != 1)
+		return 0;
 
-  /* Restore old terminating character. */
-  *cp = old;
+	/* Skip trailing whitespace. */
+	for (; *cp == ' ' || *cp == '\t'; cp++)
+		;
 
-  /* Move beyond the number and return success. */
-  *cpp = cp;
-  return 1;
+	/* Return results. */
+	*cpp = cp;
+	*bitsp = key_size(ret);
+	return 1;
 }
 
-/* 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. */
-
-int
-auth_rsa_read_key(char **cpp, unsigned int *bitsp, BIGNUM *e, BIGNUM *n)
+static int
+hostfile_check_key(int bits, Key *key, const char *host, const char *filename, int linenum)
 {
-  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))
-    return 0;
-
-  /* Skip trailing whitespace. */
-  for (; *cp == ' ' || *cp == '\t'; cp++)
-    ;
-  
-  /* Return results. */
-  *cpp = cp;
-  *bitsp = bits;
-  return 1;
+	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;
 }
 
-/* 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)
+/*
+ * 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, Key *key, int keytype, Key *found, int *numret)
 {
-  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++;
+	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);
+
+	/* 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 (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;
 	}
-      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 if host matches any negated subpattern. */
-        else
-	  got_positive = 1;
-      }
-    }
-
-  /* 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;
+	/* 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;
 }
 
-/* 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,
-		       BIGNUM *e, BIGNUM *n, BIGNUM *ke, BIGNUM *kn)
+check_host_in_hostfile(const char *filename, const char *host, Key *key,
+    Key *found, int *numret)
 {
-  FILE *f;
-  char line[8192];
-  int linenum = 0;
-  unsigned int bits, kbits, hostlen;
-  char *cp, *cp2;
-  HostStatus end_return;
-
-  /* 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 not found the proper
-     one. */
-  end_return = HOST_NEW;
-
-  /* size of modulus 'n' */
-  bits = BN_num_bits(n);
-
-  /* Go trough the file. */
-  while (fgets(line, sizeof(line), f))
-    {
-      cp = line;
-      linenum++;
-
-      /* Skip any leading whitespace. */
-      for (; *cp == ' ' || *cp == '\t'; cp++)
-	;
-
-      /* Ignore comment lines and empty lines. */
-      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, (unsigned int)(cp2 - cp)))
-	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))
-	continue;
-
-      if (kbits != BN_num_bits(kn)) {
-        error("Warning: error in %s, line %d: keysize mismatch for host %s: "
-	      "actual size %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);
-      }
-
-      /* Check if the current key is the same as the given key. */
-      if (kbits == bits && BN_cmp(ke, e) == 0 && BN_cmp(kn, n) == 0)
-	{
-	  /* Ok, they match. */
-	  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;
+	if (key == NULL)
+		fatal("no key to look up");
+	return (check_host_in_hostfile_by_key_or_type(filename, host, key, 0,
+	    found, numret));
 }
 
-/* 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)
+lookup_key_in_hostfile_by_type(const char *filename, const char *host,
+    int keytype, Key *found, int *numret)
 {
-  FILE *f;
-  char *buf;
-  unsigned int bits;
- 
-  /* Open the file for appending. */
-  f = fopen(filename, "a");
-  if (!f)
-    return 0;
-
-  /* size of modulus 'n' */
-  bits = BN_num_bits(n);
+	return (check_host_in_hostfile_by_key_or_type(filename, host, NULL,
+	    keytype, found, numret) == HOST_FOUND);
+}
 
-  /* 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;
-  }
-  fprintf(f, "%s\n", buf);
-  free (buf);
+/*
+ * Appends an entry to the host file.  Returns false if the entry could not
+ * be appended.
+ */
 
-  /* Close the file. */
-  fclose(f);
-  return 1;
+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;
 }