* New upstream release (closes: #536182). Yes, I know 5.3p1 has been out

  for a while, but there's no GSSAPI patch available for it yet.
  - Change the default cipher order to prefer the AES CTR modes and the
    revised "arcfour256" mode to CBC mode ciphers that are susceptible to
    CPNI-957037 "Plaintext Recovery Attack Against SSH".
  - Add countermeasures to mitigate CPNI-957037-style attacks against the
    SSH protocol's use of CBC-mode ciphers. Upon detection of an invalid
    packet length or Message Authentication Code, ssh/sshd will continue
    reading up to the maximum supported packet length rather than
    immediately terminating the connection. This eliminates most of the
    known differences in behaviour that leaked information about the
    plaintext of injected data which formed the basis of this attack
    (closes: #506115, LP: #379329).
  - ForceCommand directive now accepts commandline arguments for the
    internal-sftp server (closes: #524423, LP: #362511).
  - Add AllowAgentForwarding to available Match keywords list (closes:
    #540623).
  - Make ssh(1) send the correct channel number for
    SSH2_MSG_CHANNEL_SUCCESS and SSH2_MSG_CHANNEL_FAILURE messages to
    avoid triggering 'Non-public channel' error messages on sshd(8) in
    openssh-5.1.
  - Avoid printing 'Non-public channel' warnings in sshd(8), since the
    ssh(1) has sent incorrect channel numbers since ~2004 (this reverts a
    behaviour introduced in openssh-5.1; closes: #496017).
* Update to GSSAPI patch from
  http://www.sxw.org.uk/computing/patches/openssh-5.2p1-gsskex-all-20090726.patch,
  including cascading credentials support (LP: #416958).

1 files changed, 68 insertions, 2 deletions

diff --git a/gss-serv-krb5.c b/gss-serv-krb5.c
index b400081f6..e7170ee41 100644
--- a/gss-serv-krb5.c
+++ b/gss-serv-krb5.c
@@ -1,7 +1,7 @@
 /* $OpenBSD: gss-serv-krb5.c,v 1.7 2006/08/03 03:34:42 deraadt Exp $ */
 
 /*
- * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
+ * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -190,6 +190,71 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client)
         return;
 }
 
+int
+ssh_gssapi_krb5_updatecreds(ssh_gssapi_ccache *store, 
+    ssh_gssapi_client *client)
+{
+        krb5_ccache ccache = NULL;
+        krb5_principal principal = NULL;
+        char *name = NULL;
+        krb5_error_code problem;
+        OM_uint32 maj_status, min_status;
+
+        if ((problem = krb5_cc_resolve(krb_context, store->envval, &ccache))) {
+                logit("krb5_cc_resolve(): %.100s",
+                    krb5_get_err_text(krb_context, problem));
+                return 0;
+        }
+        
+        /* Find out who the principal in this cache is */
+        if ((problem = krb5_cc_get_principal(krb_context, ccache, 
+            &principal))) {
+                logit("krb5_cc_get_principal(): %.100s",
+                    krb5_get_err_text(krb_context, problem));
+                krb5_cc_close(krb_context, ccache);
+                return 0;
+        }
+
+        if ((problem = krb5_unparse_name(krb_context, principal, &name))) {
+                logit("krb5_unparse_name(): %.100s",
+                    krb5_get_err_text(krb_context, problem));
+                krb5_free_principal(krb_context, principal);
+                krb5_cc_close(krb_context, ccache);
+                return 0;
+        }
+
+
+        if (strcmp(name,client->exportedname.value)!=0) {
+                debug("Name in local credentials cache differs. Not storing");
+                krb5_free_principal(krb_context, principal);
+                krb5_cc_close(krb_context, ccache);
+                krb5_free_unparsed_name(krb_context, name);
+                return 0;
+        }
+        krb5_free_unparsed_name(krb_context, name);
+
+        /* Name matches, so lets get on with it! */
+
+        if ((problem = krb5_cc_initialize(krb_context, ccache, principal))) {
+                logit("krb5_cc_initialize(): %.100s",
+                    krb5_get_err_text(krb_context, problem));
+                krb5_free_principal(krb_context, principal);
+                krb5_cc_close(krb_context, ccache);
+                return 0;
+        }
+
+        krb5_free_principal(krb_context, principal);
+
+        if ((maj_status = gss_krb5_copy_ccache(&min_status, client->creds,
+            ccache))) {
+                logit("gss_krb5_copy_ccache() failed. Sorry!");
+                krb5_cc_close(krb_context, ccache);
+                return 0;
+        }
+
+        return 1;
+}
+
 ssh_gssapi_mech gssapi_kerberos_mech = {
         "toWM5Slw5Ew8Mqkay+al2g==",
         "Kerberos",
@@ -197,7 +262,8 @@ ssh_gssapi_mech gssapi_kerberos_mech = {
         NULL,
         &ssh_gssapi_krb5_userok,
         NULL,
-        &ssh_gssapi_krb5_storecreds
+        &ssh_gssapi_krb5_storecreds,
+        &ssh_gssapi_krb5_updatecreds
 };
 
 #endif /* KRB5 */