* New upstream release (closes: #395507, #397961, #420035). Important

  changes not previously backported to 4.3p2:
  - 4.4/4.4p1 (http://www.openssh.org/txt/release-4.4):
    + On portable OpenSSH, fix a GSSAPI authentication abort that could be
      used to determine the validity of usernames on some platforms.
    + Implemented conditional configuration in sshd_config(5) using the
      "Match" directive. This allows some configuration options to be
      selectively overridden if specific criteria (based on user, group,
      hostname and/or address) are met. So far a useful subset of
      post-authentication options are supported and more are expected to
      be added in future releases.
    + Add support for Diffie-Hellman group exchange key agreement with a
      final hash of SHA256.
    + Added a "ForceCommand" directive to sshd_config(5). Similar to the
      command="..." option accepted in ~/.ssh/authorized_keys, this forces
      the execution of the specified command regardless of what the user
      requested. This is very useful in conjunction with the new "Match"
      option.
    + Add a "PermitOpen" directive to sshd_config(5). This mirrors the
      permitopen="..." authorized_keys option, allowing fine-grained
      control over the port-forwardings that a user is allowed to
      establish.
    + Add optional logging of transactions to sftp-server(8).
    + ssh(1) will now record port numbers for hosts stored in
      ~/.ssh/known_hosts when a non-standard port has been requested
      (closes: #50612).
    + Add an "ExitOnForwardFailure" option to cause ssh(1) to exit (with a
      non-zero exit code) when requested port forwardings could not be
      established.
    + Extend sshd_config(5) "SubSystem" declarations to allow the
      specification of command-line arguments.
    + Replacement of all integer overflow susceptible invocations of
      malloc(3) and realloc(3) with overflow-checking equivalents.
    + Many manpage fixes and improvements.
    + Add optional support for OpenSSL hardware accelerators (engines),
      enabled using the --with-ssl-engine configure option.
    + Tokens in configuration files may be double-quoted in order to
      contain spaces (closes: #319639).
    + Move a debug() call out of a SIGCHLD handler, fixing a hang when the
      session exits very quickly (closes: #307890).
    + Fix some incorrect buffer allocation calculations (closes: #410599).
    + ssh-add doesn't ask for a passphrase if key file permissions are too
      liberal (closes: #103677).
    + Likewise, ssh doesn't ask either (closes: #99675).
  - 4.6/4.6p1 (http://www.openssh.org/txt/release-4.6):
    + sshd now allows the enabling and disabling of authentication methods
      on a per user, group, host and network basis via the Match directive
      in sshd_config.
    + Fixed an inconsistent check for a terminal when displaying scp
      progress meter (closes: #257524).
    + Fix "hang on exit" when background processes are running at the time
      of exit on a ttyful/login session (closes: #88337).
* Update to current GSSAPI patch from
  http://www.sxw.org.uk/computing/patches/openssh-4.6p1-gsskex-20070312.patch;
  install ChangeLog.gssapi.

1 files changed, 30 insertions, 9 deletions

diff --git a/dh.c b/dh.c
index 044d869fb..78e230b9f 100644
--- a/dh.c
+++ b/dh.c
@@ -1,3 +1,4 @@
+/* $OpenBSD: dh.c,v 1.44 2006/11/07 13:02:07 markus Exp $ */
 /*
  * Copyright (c) 2000 Niels Provos.  All rights reserved.
  *
@@ -23,17 +24,17 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: dh.c,v 1.31 2004/08/04 10:37:52 djm Exp $");
 
-#include "xmalloc.h"
+#include <sys/param.h>
 
 #include <openssl/bn.h>
 #include <openssl/dh.h>
-#include <openssl/evp.h>
 
-#include "buffer.h"
-#include "cipher.h"
-#include "kex.h"
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
 #include "dh.h"
 #include "pathnames.h"
 #include "log.h"
@@ -44,9 +45,11 @@ parse_prime(int linenum, char *line, struct dhgroup *dhg)
 {
         char *cp, *arg;
         char *strsize, *gen, *prime;
+        const char *errstr = NULL;
 
         cp = line;
-        arg = strdelim(&cp);
+        if ((arg = strdelim(&cp)) == NULL)
+                return 0;
         /* Ignore leading whitespace */
         if (*arg == '\0')
                 arg = strdelim(&cp);
@@ -67,7 +70,8 @@ parse_prime(int linenum, char *line, struct dhgroup *dhg)
                 goto fail;
         strsize = strsep(&cp, " "); /* size */
         if (cp == NULL || *strsize == '\0' ||
-            (dhg->size = atoi(strsize)) == 0)
+            (dhg->size = (u_int)strtonum(strsize, 0, 64*1024, &errstr)) == 0 ||
+            errstr)
                 goto fail;
         /* The whole group is one bit larger */
         dhg->size++;
@@ -178,19 +182,36 @@ dh_pub_is_valid(DH *dh, BIGNUM *dh_pub)
         int i;
         int n = BN_num_bits(dh_pub);
         int bits_set = 0;
+        BIGNUM *tmp;
 
         if (dh_pub->neg) {
                 logit("invalid public DH value: negativ");
                 return 0;
         }
+        if (BN_cmp(dh_pub, BN_value_one()) != 1) {      /* pub_exp <= 1 */
+                logit("invalid public DH value: <= 1");
+                return 0;
+        }
+
+        if ((tmp = BN_new()) == NULL)
+                return (-1);
+        if (!BN_sub(tmp, dh->p, BN_value_one()) ||
+            BN_cmp(dh_pub, tmp) != -1) {                /* pub_exp > p-2 */
+                BN_clear_free(tmp);
+                logit("invalid public DH value: >= p-1");
+                return 0;
+        }
+        BN_clear_free(tmp);
+
         for (i = 0; i <= n; i++)
                 if (BN_is_bit_set(dh_pub, i))
                         bits_set++;
         debug2("bits set: %d/%d", bits_set, BN_num_bits(dh->p));
 
         /* if g==2 and bits_set==1 then computing log_g(dh_pub) is trivial */
-        if (bits_set > 1 && (BN_cmp(dh_pub, dh->p) == -1))
+        if (bits_set > 1)
                 return 1;
+
         logit("invalid public DH value (%d/%d)", bits_set, BN_num_bits(dh->p));
         return 0;
 }