Index: openssh-5.3p1/gss-serv.c
===================================================================
--- openssh-5.3p1.orig/gss-serv.c	2008-05-19 06:05:07.000000000 +0100
+++ openssh-5.3p1/gss-serv.c	2010-01-24 10:27:01.000000000 +0000
@@ -45,9 +45,12 @@
 #include "channels.h"
 #include "session.h"
 #include "misc.h"
+#include "servconf.h"
 
 #include "ssh-gss.h"
 
+extern ServerOptions options;
+
 static ssh_gssapi_client gssapi_client =
     { GSS_C_EMPTY_BUFFER, GSS_C_EMPTY_BUFFER,
     GSS_C_NO_CREDENTIAL, NULL, {NULL, NULL, NULL}};
@@ -81,25 +84,32 @@
 	char lname[MAXHOSTNAMELEN];
 	gss_OID_set oidset;
 
-	gss_create_empty_oid_set(&status, &oidset);
-	gss_add_oid_set_member(&status, ctx->oid, &oidset);
+	if (options.gss_strict_acceptor) {
+		gss_create_empty_oid_set(&status, &oidset);
+		gss_add_oid_set_member(&status, ctx->oid, &oidset);
+
+		if (gethostname(lname, MAXHOSTNAMELEN)) {
+			gss_release_oid_set(&status, &oidset);
+			return (-1);
+		}
 
-	if (gethostname(lname, MAXHOSTNAMELEN)) {
-		gss_release_oid_set(&status, &oidset);
-		return (-1);
-	}
+		if (GSS_ERROR(ssh_gssapi_import_name(ctx, lname))) {
+			gss_release_oid_set(&status, &oidset);
+			return (ctx->major);
+		}
+
+		if ((ctx->major = gss_acquire_cred(&ctx->minor,
+		    ctx->name, 0, oidset, GSS_C_ACCEPT, &ctx->creds, 
+		    NULL, NULL)))
+			ssh_gssapi_error(ctx);
 
-	if (GSS_ERROR(ssh_gssapi_import_name(ctx, lname))) {
 		gss_release_oid_set(&status, &oidset);
 		return (ctx->major);
+	} else {
+		ctx->name = GSS_C_NO_NAME;
+		ctx->creds = GSS_C_NO_CREDENTIAL;
 	}
-
-	if ((ctx->major = gss_acquire_cred(&ctx->minor,
-	    ctx->name, 0, oidset, GSS_C_ACCEPT, &ctx->creds, NULL, NULL)))
-		ssh_gssapi_error(ctx);
-
-	gss_release_oid_set(&status, &oidset);
-	return (ctx->major);
+	return GSS_S_COMPLETE;
 }
 
 /* Privileged */
Index: openssh-5.3p1/servconf.c
===================================================================
--- openssh-5.3p1.orig/servconf.c	2009-06-21 11:26:17.000000000 +0100
+++ openssh-5.3p1/servconf.c	2010-01-24 10:27:01.000000000 +0000
@@ -93,6 +93,7 @@
 	options->kerberos_get_afs_token = -1;
 	options->gss_authentication=-1;
 	options->gss_cleanup_creds = -1;
+	options->gss_strict_acceptor = -1;
 	options->password_authentication = -1;
 	options->kbd_interactive_authentication = -1;
 	options->challenge_response_authentication = -1;
@@ -212,6 +213,8 @@
 		options->gss_authentication = 0;
 	if (options->gss_cleanup_creds == -1)
 		options->gss_cleanup_creds = 1;
+	if (options->gss_strict_acceptor == -1)
+		options->gss_strict_acceptor = 0;
 	if (options->password_authentication == -1)
 		options->password_authentication = 1;
 	if (options->kbd_interactive_authentication == -1)
@@ -302,7 +305,8 @@
 	sBanner, sUseDNS, sHostbasedAuthentication,
 	sHostbasedUsesNameFromPacketOnly, sClientAliveInterval,
 	sClientAliveCountMax, sAuthorizedKeysFile, sAuthorizedKeysFile2,
-	sGssAuthentication, sGssCleanupCreds, sAcceptEnv, sPermitTunnel,
+	sGssAuthentication, sGssCleanupCreds, sGssStrictAcceptor,
+	sAcceptEnv, sPermitTunnel,
 	sMatch, sPermitOpen, sForceCommand, sChrootDirectory,
 	sUsePrivilegeSeparation, sAllowAgentForwarding,
 	sZeroKnowledgePasswordAuthentication,
@@ -364,9 +368,11 @@
 #ifdef GSSAPI
 	{ "gssapiauthentication", sGssAuthentication, SSHCFG_ALL },
 	{ "gssapicleanupcredentials", sGssCleanupCreds, SSHCFG_GLOBAL },
+	{ "gssapistrictacceptorcheck", sGssStrictAcceptor, SSHCFG_GLOBAL },
 #else
 	{ "gssapiauthentication", sUnsupported, SSHCFG_ALL },
 	{ "gssapicleanupcredentials", sUnsupported, SSHCFG_GLOBAL },
+	{ "gssapistrictacceptorcheck", sUnsupported, SSHCFG_GLOBAL },
 #endif
 	{ "passwordauthentication", sPasswordAuthentication, SSHCFG_ALL },
 	{ "kbdinteractiveauthentication", sKbdInteractiveAuthentication, SSHCFG_ALL },
@@ -895,6 +901,10 @@
 		intptr = &options->gss_cleanup_creds;
 		goto parse_flag;
 
+	case sGssStrictAcceptor:
+		intptr = &options->gss_strict_acceptor;
+		goto parse_flag;
+
 	case sPasswordAuthentication:
 		intptr = &options->password_authentication;
 		goto parse_flag;
Index: openssh-5.3p1/servconf.h
===================================================================
--- openssh-5.3p1.orig/servconf.h	2009-01-28 05:31:23.000000000 +0000
+++ openssh-5.3p1/servconf.h	2010-01-24 10:27:01.000000000 +0000
@@ -92,6 +92,7 @@
 						 * authenticated with Kerberos. */
 	int     gss_authentication;	/* If true, permit GSSAPI authentication */
 	int     gss_cleanup_creds;	/* If true, destroy cred cache on logout */
+	int 	gss_strict_acceptor;	/* If true, restrict the GSSAPI acceptor name */
 	int     password_authentication;	/* If true, permit password
 						 * authentication. */
 	int     kbd_interactive_authentication;	/* If true, permit */
Index: openssh-5.3p1/sshd_config
===================================================================
--- openssh-5.3p1.orig/sshd_config	2008-07-02 13:35:43.000000000 +0100
+++ openssh-5.3p1/sshd_config	2010-01-24 10:27:01.000000000 +0000
@@ -73,6 +73,7 @@
 # GSSAPI options
 #GSSAPIAuthentication no
 #GSSAPICleanupCredentials yes
+#GSSAPIStrictAcceptorCheck yes
 
 # Set this to 'yes' to enable PAM authentication, account processing, 
 # and session processing. If this is enabled, PAM authentication will 
Index: openssh-5.3p1/sshd_config.5
===================================================================
--- openssh-5.3p1.orig/sshd_config.5	2009-08-28 01:27:08.000000000 +0100
+++ openssh-5.3p1/sshd_config.5	2010-01-24 10:27:01.000000000 +0000
@@ -385,6 +385,23 @@
 The default is
 .Dq yes .
 Note that this option applies to protocol version 2 only.
+.It Cm GSSAPIStrictAcceptorCheck
+Determines whether to be strict about the identity of the GSSAPI acceptor 
+a client authenticates against. If
+.Dq yes
+then the client must authenticate against the
+.Pa host
+service on the current hostname. If 
+.Dq no
+then the client may authenticate against any service key stored in the 
+machine's default store. This facility is provided to assist with operation 
+on multi homed machines. 
+The default is
+.Dq yes .
+Note that this option applies only to protocol version 2 GSSAPI connections,
+and setting it to 
+.Dq no
+may only work with recent Kerberos GSSAPI libraries.
 .It Cm HostbasedAuthentication
 Specifies whether rhosts or /etc/hosts.equiv authentication together
 with successful public key client host authentication is allowed