openssh/openssh-7.2p2-gssapi_key_exchange.patch

# HG changeset patch
# Parent  df12d82287e3434a52c21a994b901302bd0c8064
GSSAPI Key Exchange implementation

diff --git a/openssh-7.2p2/ChangeLog.gssapi b/openssh-7.2p2/ChangeLog.gssapi
new file mode 100644
--- /dev/null
+++ b/openssh-7.2p2/ChangeLog.gssapi
@@ -0,0 +1,113 @@
+20110101
+  - Finally update for OpenSSH 5.6p1
+  - Add GSSAPIServerIdentity option from Jim Basney
+ 
+20100308
+  - [ Makefile.in, key.c, key.h ]
+    Updates for OpenSSH 5.4p1
+  - [ servconf.c ]
+    Include GSSAPI options in the sshd -T configuration dump, and flag
+    some older configuration options as being unsupported. Thanks to Colin 
+    Watson.
+  -
+
+20100124
+  - [ sshconnect2.c ]
+    Adapt to deal with additional element in Authmethod structure. Thanks to
+    Colin Watson
+
+20090615
+  - [ gss-genr.c gss-serv.c kexgssc.c kexgsss.c monitor.c sshconnect2.c
+      sshd.c ]
+    Fix issues identified by Greg Hudson following a code review
+	Check return value of gss_indicate_mechs
+	Protect GSSAPI calls in monitor, so they can only be used if enabled
+	Check return values of bignum functions in key exchange
+	Use BN_clear_free to clear other side's DH value
+	Make ssh_gssapi_id_kex more robust
+	Only configure kex table pointers if GSSAPI is enabled
+	Don't leak mechanism list, or gss mechanism list
+	Cast data.length before printing
+	If serverkey isn't provided, use an empty string, rather than NULL
+
+20090201
+  - [ gss-genr.c gss-serv.c kex.h kexgssc.c readconf.c readconf.h ssh-gss.h
+      ssh_config.5 sshconnet2.c ]
+    Add support for the GSSAPIClientIdentity option, which allows the user
+    to specify which GSSAPI identity to use to contact a given server
+
+20080404
+  - [ gss-serv.c ]
+    Add code to actually implement GSSAPIStrictAcceptCheck, which had somehow
+    been omitted from a previous version of this patch. Reported by Borislav
+    Stoichkov
+
+20070317
+  - [ gss-serv-krb5.c ]
+    Remove C99ism, where new_ccname was being declared in the middle of a 
+    function
+
+20061220
+  - [ servconf.c ]
+    Make default for GSSAPIStrictAcceptorCheck be Yes, to match previous, and 
+    documented, behaviour. Reported by Dan Watson.
+
+20060910
+  - [ gss-genr.c kexgssc.c kexgsss.c kex.h monitor.c sshconnect2.c sshd.c
+      ssh-gss.h ]
+    add support for gss-group14-sha1 key exchange mechanisms
+  - [ gss-serv.c servconf.c servconf.h sshd_config sshd_config.5 ]
+    Add GSSAPIStrictAcceptorCheck option to allow the disabling of
+    acceptor principal checking on multi-homed machines.
+    <Bugzilla #928>
+  - [ sshd_config ssh_config ]
+    Add settings for GSSAPIKeyExchange and GSSAPITrustDNS to the sample
+    configuration files
+  - [ kexgss.c kegsss.c sshconnect2.c sshd.c ]
+    Code cleanup. Replace strlen/xmalloc/snprintf sequences with xasprintf()
+    Limit length of error messages displayed by client
+
+20060909
+  - [ gss-genr.c gss-serv.c ]
+    move ssh_gssapi_acquire_cred() and ssh_gssapi_server_ctx to be server
+    only, where they belong 
+    <Bugzilla #1225>
+
+20060829
+  - [ gss-serv-krb5.c ]
+    Fix CCAPI credentials cache name when creating KRB5CCNAME environment 
+    variable
+
+20060828
+  - [ gss-genr.c ]
+    Avoid Heimdal context freeing problem
+    <Fixed upstream 20060829>
+
+20060818
+  - [ gss-genr.c ssh-gss.h sshconnect2.c ]
+    Make sure that SPENGO is disabled 
+    <Bugzilla #1218 - Fixed upstream 20060818>
+
+20060421
+  - [ gssgenr.c, sshconnect2.c ]
+    a few type changes (signed versus unsigned, int versus size_t) to
+    fix compiler errors/warnings 
+    (from jbasney AT ncsa.uiuc.edu)
+  - [ kexgssc.c, sshconnect2.c ]
+    fix uninitialized variable warnings
+    (from jbasney AT ncsa.uiuc.edu)
+  - [ gssgenr.c ]
+    pass oid to gss_display_status (helpful when using GSSAPI mechglue)
+    (from jbasney AT ncsa.uiuc.edu)
+    <Bugzilla #1220 >
+  - [ gss-serv-krb5.c ]
+    #ifdef HAVE_GSSAPI_KRB5 should be #ifdef HAVE_GSSAPI_KRB5_H
+    (from jbasney AT ncsa.uiuc.edu)
+    <Fixed upstream 20060304>
+  - [ readconf.c, readconf.h, ssh_config.5, sshconnect2.c 
+    add client-side GssapiKeyExchange option
+    (from jbasney AT ncsa.uiuc.edu)
+  - [ sshconnect2.c ]
+    add support for GssapiTrustDns option for gssapi-with-mic
+    (from jbasney AT ncsa.uiuc.edu)
+    <gssapi-with-mic support is Bugzilla #1008>
diff --git a/openssh-7.2p2/Makefile.in b/openssh-7.2p2/Makefile.in
--- a/openssh-7.2p2/Makefile.in
+++ b/openssh-7.2p2/Makefile.in
@@ -89,18 +89,18 @@ LIBSSH_OBJS=${LIBOPENSSH_OBJS} \
 	atomicio.o key.o dispatch.o mac.o uidswap.o uuencode.o misc.o \
 	monitor_fdpass.o rijndael.o ssh-dss.o ssh-ecdsa.o ssh-rsa.o dh.o \
 	msg.o progressmeter.o dns.o entropy.o gss-genr.o umac.o umac128.o \
 	ssh-pkcs11.o smult_curve25519_ref.o \
 	poly1305.o chacha.o cipher-chachapoly.o \
 	ssh-ed25519.o digest-openssl.o digest-libc.o hmac.o \
 	sc25519.o ge25519.o fe25519.o ed25519.o verify.o hash.o blocks.o \
 	kex.o kexdh.o kexgex.o kexecdh.o kexc25519.o \
-	kexdhc.o kexgexc.o kexecdhc.o kexc25519c.o \
-	kexdhs.o kexgexs.o kexecdhs.o kexc25519s.o \
+	kexdhc.o kexgexc.o kexecdhc.o kexc25519c.o kexgssc.o \
+	kexdhs.o kexgexs.o kexecdhs.o kexc25519s.o kexgsss.o \
 	platform-pledge.o
 
 LIBSSH_OBJS += fips.o
 
 SSHOBJS= ssh.o readconf.o clientloop.o sshtty.o \
 	sshconnect.o sshconnect1.o sshconnect2.o mux.o
 
 SSHDOBJS=sshd.o auth-rhosts.o auth-passwd.o auth-rsa.o auth-rh-rsa.o \
diff --git a/openssh-7.2p2/auth-krb5.c b/openssh-7.2p2/auth-krb5.c
--- a/openssh-7.2p2/auth-krb5.c
+++ b/openssh-7.2p2/auth-krb5.c
@@ -178,18 +178,23 @@ auth_krb5_password(Authctxt *authctxt, c
 	if (problem)
 		goto out;
 #endif
 
 	authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
 
 	len = strlen(authctxt->krb5_ticket_file) + 6;
 	authctxt->krb5_ccname = xmalloc(len);
+#ifdef USE_CCAPI
+	snprintf(authctxt->krb5_ccname, len, "API:%s",
+	    authctxt->krb5_ticket_file);
+#else
 	snprintf(authctxt->krb5_ccname, len, "FILE:%s",
 	    authctxt->krb5_ticket_file);
+#endif
 
 #ifdef USE_PAM
 	if (options.use_pam)
 		do_pam_putenv("KRB5CCNAME", authctxt->krb5_ccname);
 #endif
 
  out:
 	restore_uid();
@@ -239,35 +244,42 @@ krb5_cleanup_proc(Authctxt *authctxt)
 }
 
 #ifndef HEIMDAL
 krb5_error_code
 ssh_krb5_cc_gen(krb5_context ctx, krb5_ccache *ccache) {
 	int tmpfd, ret, oerrno;
 	char ccname[40];
 	mode_t old_umask;
+#ifdef USE_CCAPI
+	char cctemplate[] = "API:krb5cc_%d";
+#else
+	char cctemplate[] = "FILE:/tmp/krb5cc_%d_XXXXXXXXXX";
+#endif
 
 	ret = snprintf(ccname, sizeof(ccname),
-	    "FILE:/tmp/krb5cc_%d_XXXXXXXXXX", geteuid());
+	    cctemplate, geteuid());
 	if (ret < 0 || (size_t)ret >= sizeof(ccname))
 		return ENOMEM;
 
+#ifndef USE_CCAPI
 	old_umask = umask(0177);
 	tmpfd = mkstemp(ccname + strlen("FILE:"));
 	oerrno = errno;
 	umask(old_umask);
 	if (tmpfd == -1) {
 		logit("mkstemp(): %.100s", strerror(oerrno));
 		return oerrno;
 	}
 
 	if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) {
 		oerrno = errno;
 		logit("fchmod(): %.100s", strerror(oerrno));
 		close(tmpfd);
 		return oerrno;
 	}
 	close(tmpfd);
+#endif
 
 	return (krb5_cc_resolve(ctx, ccname, ccache));
 }
 #endif /* !HEIMDAL */
 #endif /* KRB5 */
diff --git a/openssh-7.2p2/auth2-gss.c b/openssh-7.2p2/auth2-gss.c
--- a/openssh-7.2p2/auth2-gss.c
+++ b/openssh-7.2p2/auth2-gss.c
@@ -1,12 +1,12 @@
 /* $OpenBSD: auth2-gss.c,v 1.22 2015/01/19 20:07:45 markus 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
  * 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
@@ -48,16 +48,50 @@
 
 extern ServerOptions options;
 
 static int input_gssapi_token(int type, u_int32_t plen, void *ctxt);
 static int input_gssapi_mic(int type, u_int32_t plen, void *ctxt);
 static int input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt);
 static int input_gssapi_errtok(int, u_int32_t, void *);
 
+/* 
+ * The 'gssapi_keyex' userauth mechanism.
+ */
+static int
+userauth_gsskeyex(Authctxt *authctxt)
+{
+	int authenticated = 0;
+	Buffer b;
+	gss_buffer_desc mic, gssbuf;
+	u_int len;
+
+	mic.value = packet_get_string(&len);
+	mic.length = len;
+
+	packet_check_eom();
+
+	ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service,
+	    "gssapi-keyex");
+
+	gssbuf.value = buffer_ptr(&b);
+	gssbuf.length = buffer_len(&b);
+
+	/* gss_kex_context is NULL with privsep, so we can't check it here */
+	if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gss_kex_context, 
+	    &gssbuf, &mic))))
+		authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user,
+		    authctxt->pw));
+	
+	buffer_free(&b);
+	free(mic.value);
+
+	return (authenticated);
+}
+
 /*
  * We only support those mechanisms that we know about (ie ones that we know
  * how to check local user kuserok and the like)
  */
 static int
 userauth_gssapi(Authctxt *authctxt)
 {
 	gss_OID_desc goid = {0, NULL};
@@ -233,17 +267,18 @@ input_gssapi_exchange_complete(int type,
 
 	/*
 	 * We don't need to check the status, because we're only enabled in
 	 * the dispatcher once the exchange is complete
 	 */
 
 	packet_check_eom();
 
-	authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
+	authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user,
+	    authctxt->pw));
 
 	authctxt->postponed = 0;
 	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
 	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
 	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_MIC, NULL);
 	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
 	userauth_finish(authctxt, authenticated, "gssapi-with-mic", NULL);
 	return 0;
@@ -269,31 +304,38 @@ input_gssapi_mic(int type, u_int32_t ple
 
 	ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service,
 	    "gssapi-with-mic");
 
 	gssbuf.value = buffer_ptr(&b);
 	gssbuf.length = buffer_len(&b);
 
 	if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic))))
-		authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
+		authenticated = 
+		    PRIVSEP(ssh_gssapi_userok(authctxt->user, authctxt->pw));
 	else
 		logit("GSSAPI MIC check failed");
 
 	buffer_free(&b);
 	free(mic.value);
 
 	authctxt->postponed = 0;
 	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
 	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
 	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_MIC, NULL);
 	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
 	userauth_finish(authctxt, authenticated, "gssapi-with-mic", NULL);
 	return 0;
 }
 
+Authmethod method_gsskeyex = {
+	"gssapi-keyex",
+	userauth_gsskeyex,
+	&options.gss_authentication
+};
+
 Authmethod method_gssapi = {
 	"gssapi-with-mic",
 	userauth_gssapi,
 	&options.gss_authentication
 };
 
 #endif /* GSSAPI */
diff --git a/openssh-7.2p2/auth2.c b/openssh-7.2p2/auth2.c
--- a/openssh-7.2p2/auth2.c
+++ b/openssh-7.2p2/auth2.c
@@ -65,23 +65,25 @@ extern Buffer loginmsg;
 /* methods */
 
 extern Authmethod method_none;
 extern Authmethod method_pubkey;
 extern Authmethod method_passwd;
 extern Authmethod method_kbdint;
 extern Authmethod method_hostbased;
 #ifdef GSSAPI
+extern Authmethod method_gsskeyex;
 extern Authmethod method_gssapi;
 #endif
 
 Authmethod *authmethods[] = {
 	&method_none,
 	&method_pubkey,
 #ifdef GSSAPI
+	&method_gsskeyex,
 	&method_gssapi,
 #endif
 	&method_passwd,
 	&method_kbdint,
 	&method_hostbased,
 	NULL
 };
 
diff --git a/openssh-7.2p2/clientloop.c b/openssh-7.2p2/clientloop.c
--- a/openssh-7.2p2/clientloop.c
+++ b/openssh-7.2p2/clientloop.c
@@ -109,16 +109,20 @@
 #include "authfd.h"
 #include "atomicio.h"
 #include "sshpty.h"
 #include "match.h"
 #include "msg.h"
 #include "ssherr.h"
 #include "hostfile.h"
 
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
+
 /* import options */
 extern Options options;
 
 /* Flag indicating that stdin should be redirected from /dev/null. */
 extern int stdin_null_flag;
 
 /* Flag indicating that no shell has been requested */
 extern int no_shell_flag;
@@ -1657,19 +1661,28 @@ client_loop(int have_pty, int escape_cha
 		max_fd2 = max_fd;
 		client_wait_until_can_do_something(&readset, &writeset,
 		    &max_fd2, &nalloc, ssh_packet_is_rekeying(active_state));
 
 		if (quit_pending)
 			break;
 
 		/* Do channel operations unless rekeying in progress. */
-		if (!ssh_packet_is_rekeying(active_state))
+		if (!ssh_packet_is_rekeying(active_state)) {
 			channel_after_select(readset, writeset);
 
+#ifdef GSSAPI
+			if (options.gss_renewal_rekey &&
+			    ssh_gssapi_credentials_updated((Gssctxt *)NULL)) {
+				debug("credentials updated - forcing rekey");
+				need_rekeying = 1;
+			}
+#endif
+		}
+
 		/* Buffer input from the connection.  */
 		client_process_net_input(readset);
 
 		if (quit_pending)
 			break;
 
 		if (!compat20) {
 			/* Buffer data from stdin */
diff --git a/openssh-7.2p2/configure.ac b/openssh-7.2p2/configure.ac
--- a/openssh-7.2p2/configure.ac
+++ b/openssh-7.2p2/configure.ac
@@ -627,16 +627,40 @@ main() { if (NSVersionOfRunTimeLibrary("
 	AC_DEFINE([BROKEN_GLOB], [1], [OS X glob does not do what we expect])
 	AC_DEFINE_UNQUOTED([BIND_8_COMPAT], [1],
 		[Define if your resolver libs need this for getrrsetbyname])
 	AC_DEFINE([SSH_TUN_FREEBSD], [1], [Open tunnel devices the FreeBSD way])
 	AC_DEFINE([SSH_TUN_COMPAT_AF], [1],
 	    [Use tunnel device compatibility to OpenBSD])
 	AC_DEFINE([SSH_TUN_PREPEND_AF], [1],
 	    [Prepend the address family to IP tunnel traffic])
+	AC_MSG_CHECKING(if we have the Security Authorization Session API)
+	AC_TRY_COMPILE([#include <Security/AuthSession.h>],
+		[SessionCreate(0, 0);],
+		[ac_cv_use_security_session_api="yes"
+		 AC_DEFINE(USE_SECURITY_SESSION_API, 1, 
+			[platform has the Security Authorization Session API])
+		 LIBS="$LIBS -framework Security"
+		 AC_MSG_RESULT(yes)],
+		[ac_cv_use_security_session_api="no"
+		 AC_MSG_RESULT(no)])
+	AC_MSG_CHECKING(if we have an in-memory credentials cache)
+	AC_TRY_COMPILE(
+		[#include <Kerberos/Kerberos.h>],
+		[cc_context_t c;
+		 (void) cc_initialize (&c, 0, NULL, NULL);],
+		[AC_DEFINE(USE_CCAPI, 1, 
+			[platform uses an in-memory credentials cache])
+		 LIBS="$LIBS -framework Security"
+		 AC_MSG_RESULT(yes)
+		 if test "x$ac_cv_use_security_session_api" = "xno"; then
+			AC_MSG_ERROR(*** Need a security framework to use the credentials cache API ***)
+		fi],
+		[AC_MSG_RESULT(no)]
+	)
 	m4_pattern_allow([AU_IPv])
 	AC_CHECK_DECL([AU_IPv4], [], 
 	    AC_DEFINE([AU_IPv4], [0], [System only supports IPv4 audit records])
 	    [#include <bsm/audit.h>]
 	AC_DEFINE([LASTLOG_WRITE_PUTUTXLINE], [1],
 	    [Define if pututxline updates lastlog too])
 	)
 	AC_DEFINE([SPT_TYPE], [SPT_REUSEARGV],
diff --git a/openssh-7.2p2/gss-genr.c b/openssh-7.2p2/gss-genr.c
--- a/openssh-7.2p2/gss-genr.c
+++ b/openssh-7.2p2/gss-genr.c
@@ -1,12 +1,12 @@
 /* $OpenBSD: gss-genr.c,v 1.23 2015/01/20 23:14:00 deraadt Exp $ */
 
 /*
- * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved.
+ * Copyright (c) 2001-2009 Simon Wilkinson. 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
@@ -36,22 +36,177 @@
 #include <string.h>
 #include <signal.h>
 #include <unistd.h>
 
 #include "xmalloc.h"
 #include "buffer.h"
 #include "log.h"
 #include "ssh2.h"
+#include "cipher.h"
+#include "key.h"
+#include "kex.h"
+#include <openssl/evp.h>
 
 #include "ssh-gss.h"
 
 extern u_char *session_id2;
 extern u_int session_id2_len;
 
+typedef struct {
+	char *encoded;
+	gss_OID oid;
+} ssh_gss_kex_mapping;
+
+/*
+ * XXX - It would be nice to find a more elegant way of handling the
+ * XXX   passing of the key exchange context to the userauth routines
+ */
+
+Gssctxt *gss_kex_context = NULL;
+
+static ssh_gss_kex_mapping *gss_enc2oid = NULL;
+
+int 
+ssh_gssapi_oid_table_ok() {
+	return (gss_enc2oid != NULL);
+}
+
+/*
+ * Return a list of the gss-group1-sha1 mechanisms supported by this program
+ *
+ * We test mechanisms to ensure that we can use them, to avoid starting
+ * a key exchange with a bad mechanism
+ */
+
+char *
+ssh_gssapi_client_mechanisms(const char *host, const char *client) {
+	gss_OID_set gss_supported;
+	OM_uint32 min_status;
+
+	if (GSS_ERROR(gss_indicate_mechs(&min_status, &gss_supported)))
+		return NULL;
+
+	return(ssh_gssapi_kex_mechs(gss_supported, ssh_gssapi_check_mechanism,
+	    host, client));
+}
+
+char *
+ssh_gssapi_kex_mechs(gss_OID_set gss_supported, ssh_gssapi_check_fn *check,
+    const char *host, const char *client) {
+	Buffer buf;
+	size_t i;
+	int oidpos, enclen;
+	char *mechs, *encoded;
+	u_char digest[EVP_MAX_MD_SIZE];
+	char deroid[2];
+	const EVP_MD *evp_md = EVP_md5();
+	EVP_MD_CTX md;
+
+	if (gss_enc2oid != NULL) {
+		for (i = 0; gss_enc2oid[i].encoded != NULL; i++)
+			free(gss_enc2oid[i].encoded);
+		free(gss_enc2oid);
+	}
+
+	gss_enc2oid = xmalloc(sizeof(ssh_gss_kex_mapping) *
+	    (gss_supported->count + 1));
+
+	buffer_init(&buf);
+
+	oidpos = 0;
+	for (i = 0; i < gss_supported->count; i++) {
+		if (gss_supported->elements[i].length < 128 &&
+		    (*check)(NULL, &(gss_supported->elements[i]), host, client)) {
+
+			deroid[0] = SSH_GSS_OIDTYPE;
+			deroid[1] = gss_supported->elements[i].length;
+
+			EVP_DigestInit(&md, evp_md);
+			EVP_DigestUpdate(&md, deroid, 2);
+			EVP_DigestUpdate(&md,
+			    gss_supported->elements[i].elements,
+			    gss_supported->elements[i].length);
+			EVP_DigestFinal(&md, digest, NULL);
+
+			encoded = xmalloc(EVP_MD_size(evp_md) * 2);
+			enclen = __b64_ntop(digest, EVP_MD_size(evp_md),
+			    encoded, EVP_MD_size(evp_md) * 2);
+
+			if (oidpos != 0)
+				buffer_put_char(&buf, ',');
+
+			buffer_append(&buf, KEX_GSS_GEX_SHA1_ID,
+			    sizeof(KEX_GSS_GEX_SHA1_ID) - 1);
+			buffer_append(&buf, encoded, enclen);
+			buffer_put_char(&buf, ',');
+			buffer_append(&buf, KEX_GSS_GRP1_SHA1_ID, 
+			    sizeof(KEX_GSS_GRP1_SHA1_ID) - 1);
+			buffer_append(&buf, encoded, enclen);
+			buffer_put_char(&buf, ',');
+			buffer_append(&buf, KEX_GSS_GRP14_SHA1_ID,
+			    sizeof(KEX_GSS_GRP14_SHA1_ID) - 1);
+			buffer_append(&buf, encoded, enclen);
+
+			gss_enc2oid[oidpos].oid = &(gss_supported->elements[i]);
+			gss_enc2oid[oidpos].encoded = encoded;
+			oidpos++;
+		}
+	}
+	gss_enc2oid[oidpos].oid = NULL;
+	gss_enc2oid[oidpos].encoded = NULL;
+
+	buffer_put_char(&buf, '\0');
+
+	mechs = xmalloc(buffer_len(&buf));
+	buffer_get(&buf, mechs, buffer_len(&buf));
+	buffer_free(&buf);
+
+	if (strlen(mechs) == 0) {
+		free(mechs);
+		mechs = NULL;
+	}
+	
+	return (mechs);
+}
+
+gss_OID
+ssh_gssapi_id_kex(Gssctxt *ctx, char *name, int kex_type) {
+	int i = 0;
+	
+	switch (kex_type) {
+	case KEX_GSS_GRP1_SHA1:
+		if (strlen(name) < sizeof(KEX_GSS_GRP1_SHA1_ID))
+			return GSS_C_NO_OID;
+		name += sizeof(KEX_GSS_GRP1_SHA1_ID) - 1;
+		break;
+	case KEX_GSS_GRP14_SHA1:
+		if (strlen(name) < sizeof(KEX_GSS_GRP14_SHA1_ID))
+			return GSS_C_NO_OID;
+		name += sizeof(KEX_GSS_GRP14_SHA1_ID) - 1;
+		break;
+	case KEX_GSS_GEX_SHA1:
+		if (strlen(name) < sizeof(KEX_GSS_GEX_SHA1_ID))
+			return GSS_C_NO_OID;
+		name += sizeof(KEX_GSS_GEX_SHA1_ID) - 1;
+		break;
+	default:
+		return GSS_C_NO_OID;
+	}
+
+	while (gss_enc2oid[i].encoded != NULL &&
+	    strcmp(name, gss_enc2oid[i].encoded) != 0)
+		i++;
+
+	if (gss_enc2oid[i].oid != NULL && ctx != NULL)
+		ssh_gssapi_set_oid(ctx, gss_enc2oid[i].oid);
+
+	return gss_enc2oid[i].oid;
+}
+
 /* Check that the OID in a data stream matches that in the context */
 int
 ssh_gssapi_check_oid(Gssctxt *ctx, void *data, size_t len)
 {
 	return (ctx != NULL && ctx->oid != GSS_C_NO_OID &&
 	    ctx->oid->length == len &&
 	    memcmp(ctx->oid->elements, data, len) == 0);
 }
@@ -194,17 +349,17 @@ ssh_gssapi_init_ctx(Gssctxt *ctx, int de
 	int deleg_flag = 0;
 
 	if (deleg_creds) {
 		deleg_flag = GSS_C_DELEG_FLAG;
 		debug("Delegating credentials");
 	}
 
 	ctx->major = gss_init_sec_context(&ctx->minor,
-	    GSS_C_NO_CREDENTIAL, &ctx->context, ctx->name, ctx->oid,
+	    ctx->client_creds, &ctx->context, ctx->name, ctx->oid,
 	    GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG | deleg_flag,
 	    0, NULL, recv_tok, NULL, send_tok, flags, NULL);
 
 	if (GSS_ERROR(ctx->major))
 		ssh_gssapi_error(ctx);
 
 	return (ctx->major);
 }
@@ -224,60 +379,175 @@ ssh_gssapi_import_name(Gssctxt *ctx, con
 	    &gssbuf, GSS_C_NT_HOSTBASED_SERVICE, &ctx->name)))
 		ssh_gssapi_error(ctx);
 
 	free(gssbuf.value);
 	return (ctx->major);
 }
 
 OM_uint32
+ssh_gssapi_client_identity(Gssctxt *ctx, const char *name)
+{
+	gss_buffer_desc gssbuf;
+	gss_name_t gssname;
+	OM_uint32 status;
+	gss_OID_set oidset;
+
+	gssbuf.value = (void *) name;
+	gssbuf.length = strlen(gssbuf.value);
+
+	gss_create_empty_oid_set(&status, &oidset);
+	gss_add_oid_set_member(&status, ctx->oid, &oidset);
+
+	ctx->major = gss_import_name(&ctx->minor, &gssbuf,
+	    GSS_C_NT_USER_NAME, &gssname);
+
+	if (!ctx->major)
+		ctx->major = gss_acquire_cred(&ctx->minor, 
+		    gssname, 0, oidset, GSS_C_INITIATE, 
+		    &ctx->client_creds, NULL, NULL);
+
+	gss_release_name(&status, &gssname);
+	gss_release_oid_set(&status, &oidset);
+
+	if (ctx->major)
+		ssh_gssapi_error(ctx);
+
+	return(ctx->major);
+}
+
+OM_uint32
 ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
 {
+	if (ctx == NULL) 
+		return -1;
+
 	if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context,
 	    GSS_C_QOP_DEFAULT, buffer, hash)))
 		ssh_gssapi_error(ctx);
 
 	return (ctx->major);
 }
 
+/* Priviledged when used by server */
+OM_uint32
+ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
+{
+	if (ctx == NULL)
+		return -1;
+
+	ctx->major = gss_verify_mic(&ctx->minor, ctx->context,
+	    gssbuf, gssmic, NULL);
+
+	return (ctx->major);
+}
+
 void
 ssh_gssapi_buildmic(Buffer *b, const char *user, const char *service,
     const char *context)
 {
 	buffer_init(b);
 	buffer_put_string(b, session_id2, session_id2_len);
 	buffer_put_char(b, SSH2_MSG_USERAUTH_REQUEST);
 	buffer_put_cstring(b, user);
 	buffer_put_cstring(b, service);
 	buffer_put_cstring(b, context);
 }
 
 int
-ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host)
+ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host, 
+    const char *client)
 {
 	gss_buffer_desc token = GSS_C_EMPTY_BUFFER;
 	OM_uint32 major, minor;
 	gss_OID_desc spnego_oid = {6, (void *)"\x2B\x06\x01\x05\x05\x02"};
+	Gssctxt *intctx = NULL;
+
+	if (ctx == NULL)
+		ctx = &intctx;
 
 	/* RFC 4462 says we MUST NOT do SPNEGO */
 	if (oid->length == spnego_oid.length && 
 	    (memcmp(oid->elements, spnego_oid.elements, oid->length) == 0))
 		return 0; /* false */
 
 	ssh_gssapi_build_ctx(ctx);
 	ssh_gssapi_set_oid(*ctx, oid);
 	major = ssh_gssapi_import_name(*ctx, host);
+
+	if (!GSS_ERROR(major) && client)
+		major = ssh_gssapi_client_identity(*ctx, client);
+
 	if (!GSS_ERROR(major)) {
 		major = ssh_gssapi_init_ctx(*ctx, 0, GSS_C_NO_BUFFER, &token, 
 		    NULL);
 		gss_release_buffer(&minor, &token);
 		if ((*ctx)->context != GSS_C_NO_CONTEXT)
 			gss_delete_sec_context(&minor, &(*ctx)->context,
 			    GSS_C_NO_BUFFER);
 	}
 
-	if (GSS_ERROR(major)) 
+	if (GSS_ERROR(major) || intctx != NULL) 
 		ssh_gssapi_delete_ctx(ctx);
 
 	return (!GSS_ERROR(major));
 }
 
+int
+ssh_gssapi_credentials_updated(Gssctxt *ctxt) {
+	static gss_name_t saved_name = GSS_C_NO_NAME;
+	static OM_uint32 saved_lifetime = 0;
+	static gss_OID saved_mech = GSS_C_NO_OID;
+	static gss_name_t name;
+	static OM_uint32 last_call = 0;
+	OM_uint32 lifetime, now, major, minor;
+	int equal;
+	/* TODO: recheck
+	gss_cred_usage_t usage = GSS_C_INITIATE;
+	*/
+	
+	now = time(NULL);
+
+	if (ctxt) {
+		debug("Rekey has happened - updating saved versions");
+
+		if (saved_name != GSS_C_NO_NAME)
+			gss_release_name(&minor, &saved_name);
+
+		major = gss_inquire_cred(&minor, GSS_C_NO_CREDENTIAL,
+		    &saved_name, &saved_lifetime, NULL, NULL);
+
+		if (!GSS_ERROR(major)) {
+			saved_mech = ctxt->oid;
+		        saved_lifetime+= now;
+		} else {
+			/* Handle the error */
+		}
+		return 0;
+	}
+
+	if (now - last_call < 10)
+		return 0;
+
+	last_call = now;
+
+	if (saved_mech == GSS_C_NO_OID)
+		return 0;
+	
+	major = gss_inquire_cred(&minor, GSS_C_NO_CREDENTIAL, 
+	    &name, &lifetime, NULL, NULL);
+	if (major == GSS_S_CREDENTIALS_EXPIRED)
+		return 0;
+	else if (GSS_ERROR(major))
+		return 0;
+
+	major = gss_compare_name(&minor, saved_name, name, &equal);
+	gss_release_name(&minor, &name);
+	if (GSS_ERROR(major))
+		return 0;
+
+	if (equal && (saved_lifetime < lifetime + now - 10))
+		return 1;
+
+	return 0;
+}
+
 #endif /* GSSAPI */
diff --git a/openssh-7.2p2/gss-serv-krb5.c b/openssh-7.2p2/gss-serv-krb5.c
--- a/openssh-7.2p2/gss-serv-krb5.c
+++ b/openssh-7.2p2/gss-serv-krb5.c
@@ -1,12 +1,12 @@
 /* $OpenBSD: gss-serv-krb5.c,v 1.8 2013/07/20 01:55:13 djm 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
  * 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
@@ -116,18 +116,21 @@ ssh_gssapi_krb5_userok(ssh_gssapi_client
 
 static void
 ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client)
 {
 	krb5_ccache ccache;
 	krb5_error_code problem;
 	krb5_principal princ;
 	OM_uint32 maj_status, min_status;
+	/* TODO:
 	int len;
+	*/
 	const char *errmsg;
+	const char *new_ccname;
 
 	if (client->creds == NULL) {
 		debug("No credentials stored");
 		return;
 	}
 
 	if (ssh_gssapi_krb5_init() == 0)
 		return;
@@ -176,37 +179,108 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_cl
 
 	if ((maj_status = gss_krb5_copy_ccache(&min_status,
 	    client->creds, ccache))) {
 		logit("gss_krb5_copy_ccache() failed");
 		krb5_cc_destroy(krb_context, ccache);
 		return;
 	}
 
-	client->store.filename = xstrdup(krb5_cc_get_name(krb_context, ccache));
+	new_ccname = krb5_cc_get_name(krb_context, ccache);
+
 	client->store.envvar = "KRB5CCNAME";
-	len = strlen(client->store.filename) + 6;
-	client->store.envval = xmalloc(len);
-	snprintf(client->store.envval, len, "FILE:%s", client->store.filename);
+#ifdef USE_CCAPI
+	xasprintf(&client->store.envval, "API:%s", new_ccname);
+	client->store.filename = NULL;
+#else
+	xasprintf(&client->store.envval, "FILE:%s", new_ccname);
+	client->store.filename = xstrdup(new_ccname);
+#endif
 
 #ifdef USE_PAM
 	if (options.use_pam)
 		do_pam_putenv(client->store.envvar, client->store.envval);
 #endif
 
 	krb5_cc_close(krb_context, ccache);
 
 	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",
 	{9, "\x2A\x86\x48\x86\xF7\x12\x01\x02\x02"},
 	NULL,
 	&ssh_gssapi_krb5_userok,
 	NULL,
-	&ssh_gssapi_krb5_storecreds
+	&ssh_gssapi_krb5_storecreds,
+	&ssh_gssapi_krb5_updatecreds
 };
 
 #endif /* KRB5 */
 
 #endif /* GSSAPI */
diff --git a/openssh-7.2p2/gss-serv.c b/openssh-7.2p2/gss-serv.c
--- a/openssh-7.2p2/gss-serv.c
+++ b/openssh-7.2p2/gss-serv.c
@@ -1,12 +1,12 @@
 /* $OpenBSD: gss-serv.c,v 1.29 2015/05/22 03:50:02 djm Exp $ */
 
 /*
- * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
+ * Copyright (c) 2001-2009 Simon Wilkinson. 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
@@ -40,27 +40,29 @@
 #include "key.h"
 #include "hostfile.h"
 #include "auth.h"
 #include "log.h"
 #include "channels.h"
 #include "session.h"
 #include "misc.h"
 #include "servconf.h"
+#include "uidswap.h"
 
 #include "ssh-gss.h"
+#include "monitor_wrap.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, NULL}};
+    GSS_C_NO_CREDENTIAL, GSS_C_NO_NAME,  NULL, {NULL, NULL, NULL, NULL, NULL}, 0, 0};
 
 ssh_gssapi_mech gssapi_null_mech =
-    { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL};
+    { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL, NULL};
 
 #ifdef KRB5
 extern ssh_gssapi_mech gssapi_kerberos_mech;
 #endif
 
 ssh_gssapi_mech* supported_mechs[]= {
 #ifdef KRB5
 	&gssapi_kerberos_mech,
@@ -137,26 +139,51 @@ ssh_gssapi_server_ctx(Gssctxt **ctx, gss
 	if (*ctx)
 		ssh_gssapi_delete_ctx(ctx);
 	ssh_gssapi_build_ctx(ctx);
 	ssh_gssapi_set_oid(*ctx, oid);
 	return (ssh_gssapi_acquire_cred(*ctx));
 }
 
 /* Unprivileged */
+char *
+ssh_gssapi_server_mechanisms() {
+	gss_OID_set	supported;
+
+	ssh_gssapi_supported_oids(&supported);
+	return (ssh_gssapi_kex_mechs(supported, &ssh_gssapi_server_check_mech,
+	    NULL, NULL));
+}
+
+/* Unprivileged */
+int
+ssh_gssapi_server_check_mech(Gssctxt **dum, gss_OID oid, const char *data,
+    const char *dummy) {
+	Gssctxt *ctx = NULL;
+	int res;
+ 
+	res = !GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctx, oid)));
+	ssh_gssapi_delete_ctx(&ctx);
+
+	return (res);
+}
+
+/* Unprivileged */
 void
 ssh_gssapi_supported_oids(gss_OID_set *oidset)
 {
 	int i = 0;
 	OM_uint32 min_status;
 	int present;
 	gss_OID_set supported;
 
 	gss_create_empty_oid_set(&min_status, oidset);
-	gss_indicate_mechs(&min_status, &supported);
+
+	if (GSS_ERROR(gss_indicate_mechs(&min_status, &supported)))
+		return;
 
 	while (supported_mechs[i]->name != NULL) {
 		if (GSS_ERROR(gss_test_oid_set_member(&min_status,
 		    &supported_mechs[i]->oid, supported, &present)))
 			present = 0;
 		if (present)
 			gss_add_oid_set_member(&min_status,
 			    &supported_mechs[i]->oid, oidset);
@@ -272,32 +299,79 @@ ssh_gssapi_parse_ename(Gssctxt *ctx, gss
 /* Extract the client details from a given context. This can only reliably
  * be called once for a context */
 
 /* Privileged (called from accept_secure_ctx) */
 OM_uint32
 ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client)
 {
 	int i = 0;
+	int equal = 0;
+	gss_name_t new_name = GSS_C_NO_NAME;
+	gss_buffer_desc ename = GSS_C_EMPTY_BUFFER;
 
-	gss_buffer_desc ename;
+	if (options.gss_store_rekey && client->used && ctx->client_creds) {
+		if (client->mech->oid.length != ctx->oid->length ||
+		    (memcmp(client->mech->oid.elements,
+		     ctx->oid->elements, ctx->oid->length) !=0)) {
+			debug("Rekeyed credentials have different mechanism");
+			return GSS_S_COMPLETE;
+		}
+
+		if ((ctx->major = gss_inquire_cred_by_mech(&ctx->minor, 
+		    ctx->client_creds, ctx->oid, &new_name, 
+		    NULL, NULL, NULL))) {
+			ssh_gssapi_error(ctx);
+			return (ctx->major);
+		}
+
+		ctx->major = gss_compare_name(&ctx->minor, client->name, 
+		    new_name, &equal);
+
+		if (GSS_ERROR(ctx->major)) {
+			ssh_gssapi_error(ctx);
+			return (ctx->major);
+		}
+ 
+		if (!equal) {
+			debug("Rekeyed credentials have different name");
+			return GSS_S_COMPLETE;
+		}
+
+		debug("Marking rekeyed credentials for export");
+
+		gss_release_name(&ctx->minor, &client->name);
+		gss_release_cred(&ctx->minor, &client->creds);
+		client->name = new_name;
+		client->creds = ctx->client_creds;
+        	ctx->client_creds = GSS_C_NO_CREDENTIAL;
+		client->updated = 1;
+		return GSS_S_COMPLETE;
+	}
 
 	client->mech = NULL;
 
 	while (supported_mechs[i]->name != NULL) {
 		if (supported_mechs[i]->oid.length == ctx->oid->length &&
 		    (memcmp(supported_mechs[i]->oid.elements,
 		    ctx->oid->elements, ctx->oid->length) == 0))
 			client->mech = supported_mechs[i];
 		i++;
 	}
 
 	if (client->mech == NULL)
 		return GSS_S_FAILURE;
 
+	if (ctx->client_creds &&
+	    (ctx->major = gss_inquire_cred_by_mech(&ctx->minor,
+	     ctx->client_creds, ctx->oid, &client->name, NULL, NULL, NULL))) {
+		ssh_gssapi_error(ctx);
+		return (ctx->major);
+	}
+
 	if ((ctx->major = gss_display_name(&ctx->minor, ctx->client,
 	    &client->displayname, NULL))) {
 		ssh_gssapi_error(ctx);
 		return (ctx->major);
 	}
 
 	if ((ctx->major = gss_export_name(&ctx->minor, ctx->client,
 	    &ename))) {
@@ -305,16 +379,18 @@ ssh_gssapi_getclient(Gssctxt *ctx, ssh_g
 		return (ctx->major);
 	}
 
 	if ((ctx->major = ssh_gssapi_parse_ename(ctx,&ename,
 	    &client->exportedname))) {
 		return (ctx->major);
 	}
 
+	gss_release_buffer(&ctx->minor, &ename);
+
 	/* We can't copy this structure, so we just move the pointer to it */
 	client->creds = ctx->client_creds;
 	ctx->client_creds = GSS_C_NO_CREDENTIAL;
 	return (ctx->major);
 }
 
 /* As user - called on fatal/exit */
 void
@@ -352,45 +428,124 @@ ssh_gssapi_do_child(char ***envp, u_int 
 		    gssapi_client.store.envval);
 		child_set_env(envp, envsizep, gssapi_client.store.envvar,
 		    gssapi_client.store.envval);
 	}
 }
 
 /* Privileged */
 int
-ssh_gssapi_userok(char *user)
+ssh_gssapi_userok(char *user, struct passwd *pw)
 {
 	OM_uint32 lmin;
 
 	if (gssapi_client.exportedname.length == 0 ||
 	    gssapi_client.exportedname.value == NULL) {
 		debug("No suitable client data");
 		return 0;
 	}
 	if (gssapi_client.mech && gssapi_client.mech->userok)
-		if ((*gssapi_client.mech->userok)(&gssapi_client, user))
+		if ((*gssapi_client.mech->userok)(&gssapi_client, user)) {
+			gssapi_client.used = 1;
+			gssapi_client.store.owner = pw;
 			return 1;
-		else {
+        } else {
 			/* Destroy delegated credentials if userok fails */
 			gss_release_buffer(&lmin, &gssapi_client.displayname);
 			gss_release_buffer(&lmin, &gssapi_client.exportedname);
 			gss_release_cred(&lmin, &gssapi_client.creds);
 			explicit_bzero(&gssapi_client,
 			    sizeof(ssh_gssapi_client));
 			return 0;
 		}
 	else
 		debug("ssh_gssapi_userok: Unknown GSSAPI mechanism");
 	return (0);
 }
 
 /* Privileged */
-OM_uint32
-ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
+/* These bits are only used for rekeying. The unpriviledged child is running 
+ * as the user, the monitor is root.
+ *
+ * In the child, we want to :
+ *    *) Ask the monitor to store our credentials into the store we specify
+ *    *) If it succeeds, maybe do a PAM update
+ */
+
+/* Stuff for PAM */
+
+#ifdef USE_PAM
+static int ssh_gssapi_simple_conv(int n, const struct pam_message **msg, 
+    struct pam_response **resp, void *data)
 {
-	ctx->major = gss_verify_mic(&ctx->minor, ctx->context,
-	    gssbuf, gssmic, NULL);
+	return (PAM_CONV_ERR);
+}
+#endif
+
+void
+ssh_gssapi_rekey_creds() {
+	int ok;
+	int ret;
+#ifdef USE_PAM
+	pam_handle_t *pamh = NULL;
+	struct pam_conv pamconv = {ssh_gssapi_simple_conv, NULL};
+	char *envstr;
+#endif
+
+	if (gssapi_client.store.filename == NULL && 
+	    gssapi_client.store.envval == NULL &&
+	    gssapi_client.store.envvar == NULL)
+		return;
+ 
+	ok = PRIVSEP(ssh_gssapi_update_creds(&gssapi_client.store));
+
+	if (!ok)
+		return;
+
+	debug("Rekeyed credentials stored successfully");
 
-	return (ctx->major);
+	/* Actually managing to play with the ssh pam stack from here will
+	 * be next to impossible. In any case, we may want different options
+	 * for rekeying. So, use our own :)
+	 */
+#ifdef USE_PAM	
+	if (!use_privsep) {
+		debug("Not even going to try and do PAM with privsep disabled");
+		return;
+	}
+
+	ret = pam_start("sshd-rekey", gssapi_client.store.owner->pw_name,
+ 	    &pamconv, &pamh);
+	if (ret)
+		return;
+
+	xasprintf(&envstr, "%s=%s", gssapi_client.store.envvar, 
+	    gssapi_client.store.envval);
+
+	ret = pam_putenv(pamh, envstr);
+	if (!ret)
+		pam_setcred(pamh, PAM_REINITIALIZE_CRED);
+	pam_end(pamh, PAM_SUCCESS);
+#endif
+}
+
+int 
+ssh_gssapi_update_creds(ssh_gssapi_ccache *store) {
+	int ok = 0;
+
+	/* Check we've got credentials to store */
+	if (!gssapi_client.updated)
+		return 0;
+
+	gssapi_client.updated = 0;
+
+	temporarily_use_uid(gssapi_client.store.owner);
+	if (gssapi_client.mech && gssapi_client.mech->updatecreds)
+		ok = (*gssapi_client.mech->updatecreds)(store, &gssapi_client);
+	else
+		debug("No update function for this mechanism");
+
+	restore_uid();
+
+	return ok;
 }
 
 #endif
diff --git a/openssh-7.2p2/kex.c b/openssh-7.2p2/kex.c
--- a/openssh-7.2p2/kex.c
+++ b/openssh-7.2p2/kex.c
@@ -51,16 +51,20 @@
 #include "monitor.h"
 
 #include "ssherr.h"
 #include "sshbuf.h"
 #include "digest.h"
 
 #include "fips.h"
 
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
+
 #if OPENSSL_VERSION_NUMBER >= 0x00907000L
 # if defined(HAVE_EVP_SHA256)
 # define evp_ssh_sha256 EVP_sha256
 # else
 extern const EVP_MD *evp_ssh_sha256(void);
 # endif
 #endif
 
@@ -104,16 +108,21 @@ static const struct kexalg kexalgs_all[]
 	{ KEX_ECDH_SHA2_NISTP521, KEX_ECDH_SHA2, NID_secp521r1,
 	    SSH_DIGEST_SHA512 },
 # endif /* OPENSSL_HAS_NISTP521 */
 #endif /* OPENSSL_HAS_ECC */
 #endif /* WITH_OPENSSL */
 #if defined(HAVE_EVP_SHA256) || !defined(WITH_OPENSSL)
 	{ KEX_CURVE25519_SHA256, KEX_C25519_SHA256, 0, SSH_DIGEST_SHA256 },
 #endif /* HAVE_EVP_SHA256 || !WITH_OPENSSL */
+#ifdef GSSAPI
+	{ KEX_GSS_GEX_SHA1_ID, KEX_GSS_GEX_SHA1, 0, SSH_DIGEST_SHA1 },
+	{ KEX_GSS_GRP1_SHA1_ID, KEX_GSS_GRP1_SHA1, 0, SSH_DIGEST_SHA1 },
+	{ KEX_GSS_GRP14_SHA1_ID, KEX_GSS_GRP14_SHA1, 0, SSH_DIGEST_SHA1 },
+#endif
 	{ NULL, -1, -1, -1},
 };
 
 static const struct kexalg kexalgs_fips140_2[] = {
 #ifdef WITH_OPENSSL
 	{ KEX_DH14, KEX_DH_GRP14_SHA1, 0, SSH_DIGEST_SHA1 },
 	{ KEX_DHGEX_SHA1, KEX_DH_GEX_SHA1, 0, SSH_DIGEST_SHA1 },
 #ifdef HAVE_EVP_SHA256
@@ -125,16 +134,20 @@ static const struct kexalg kexalgs_fips1
 	{ KEX_ECDH_SHA2_NISTP384, KEX_ECDH_SHA2, NID_secp384r1,
 	    SSH_DIGEST_SHA384 },
 # ifdef OPENSSL_HAS_NISTP521
 	{ KEX_ECDH_SHA2_NISTP521, KEX_ECDH_SHA2, NID_secp521r1,
 	    SSH_DIGEST_SHA512 },
 # endif /* OPENSSL_HAS_NISTP521 */
 #endif /* OPENSSL_HAS_ECC */
 #endif /* WITH_OPENSSL */
+#ifdef GSSAPI
+	{ KEX_GSS_GEX_SHA1_ID, KEX_GSS_GEX_SHA1, 0, SSH_DIGEST_SHA1 },
+	{ KEX_GSS_GRP14_SHA1_ID, KEX_GSS_GRP14_SHA1, 0, SSH_DIGEST_SHA1 },
+#endif
 	{ NULL, -1, -1, -1},
 };
 
 /* Returns array of macs available depending on selected FIPS mode */
 static const struct kexalg *
 fips_select_kexalgs(void)
 {
 	int fips = fips_mode();
@@ -175,16 +188,22 @@ kex_alg_list(char sep)
 static const struct kexalg *
 kex_alg_by_name(const char *name)
 {
 	const struct kexalg *k;
 
 	for (k = fips_select_kexalgs(); k->name != NULL; k++) {
 		if (strcmp(k->name, name) == 0)
 			return k;
+#ifdef GSSAPI
+		if (strncmp(name, "gss-", 4) == 0) {
+			if (strncmp(k->name, name, strlen(k->name)) == 0)
+				return k;
+		}
+#endif
 	}
 	return NULL;
 }
 
 /* Validate KEX method name list */
 int
 kex_names_valid(const char *names)
 {
diff --git a/openssh-7.2p2/kex.h b/openssh-7.2p2/kex.h
--- a/openssh-7.2p2/kex.h
+++ b/openssh-7.2p2/kex.h
@@ -87,16 +87,19 @@ enum kex_modes {
 
 enum kex_exchange {
 	KEX_DH_GRP1_SHA1,
 	KEX_DH_GRP14_SHA1,
 	KEX_DH_GEX_SHA1,
 	KEX_DH_GEX_SHA256,
 	KEX_ECDH_SHA2,
 	KEX_C25519_SHA256,
+	KEX_GSS_GRP1_SHA1,
+	KEX_GSS_GRP14_SHA1,
+	KEX_GSS_GEX_SHA1,
 	KEX_MAX
 };
 
 #define KEX_INIT_SENT	0x0001
 
 struct sshenc {
 	char	*name;
 	const struct sshcipher *cipher;
@@ -135,16 +138,22 @@ struct kex {
 	int	rsa_sha2;
 	int	ext_info_c;
 	struct sshbuf *my;
 	struct sshbuf *peer;
 	sig_atomic_t done;
 	u_int	flags;
 	int	hash_alg;
 	int	ec_nid;
+#ifdef GSSAPI
+	int	gss_deleg_creds;
+	int	gss_trust_dns;
+	char    *gss_host;
+	char	*gss_client;
+#endif
 	char	*client_version_string;
 	char	*server_version_string;
 	char	*failed_choice;
 	int	(*verify_host_key)(struct sshkey *, struct ssh *);
 	struct sshkey *(*load_host_public_key)(int, int, struct ssh *);
 	struct sshkey *(*load_host_private_key)(int, int, struct ssh *);
 	int	(*host_key_index)(struct sshkey *, int, struct ssh *);
 	int	(*sign)(struct sshkey *, struct sshkey *, u_char **, size_t *,
@@ -184,16 +193,21 @@ int	 kex_start_rekex(struct ssh *);
 int	 kexdh_client(struct ssh *);
 int	 kexdh_server(struct ssh *);
 int	 kexgex_client(struct ssh *);
 int	 kexgex_server(struct ssh *);
 int	 kexecdh_client(struct ssh *);
 int	 kexecdh_server(struct ssh *);
 int	 kexc25519_client(struct ssh *);
 int	 kexc25519_server(struct ssh *);
+ 
+#ifdef GSSAPI
+int	 kexgss_client(struct ssh *);
+int	 kexgss_server(struct ssh *);
+#endif
 
 int	 kex_dh_hash(const char *, const char *,
     const u_char *, size_t, const u_char *, size_t, const u_char *, size_t,
     const BIGNUM *, const BIGNUM *, const BIGNUM *, u_char *, size_t *);
 
 int	 kexgex_hash(int, const char *, const char *,
     const u_char *, size_t, const u_char *, size_t, const u_char *, size_t,
     int, int, int,
diff --git a/openssh-7.2p2/kexgssc.c b/openssh-7.2p2/kexgssc.c
new file mode 100644
--- /dev/null
+++ b/openssh-7.2p2/kexgssc.c
@@ -0,0 +1,368 @@
+/*
+ * Copyright (c) 2001-2009 Simon Wilkinson. 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"
+
+#ifdef GSSAPI
+
+#include "includes.h"
+
+#include <openssl/crypto.h>
+#include <openssl/bn.h>
+
+#include <string.h>
+
+#include "xmalloc.h"
+#include "buffer.h"
+#include "ssh2.h"
+#include "key.h"
+#include "cipher.h"
+#include "digest.h"
+#include "kex.h"
+#include "log.h"
+#include "packet.h"
+#include "dh.h"
+
+#include "ssh-gss.h"
+
+#include "fips.h"
+
+int
+kexgss_client(struct ssh *ssh)
+{
+	struct kex *kex = ssh->kex;
+	gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
+	gss_buffer_desc recv_tok, gssbuf, msg_tok, *token_ptr;
+	Gssctxt *ctxt;
+	OM_uint32 maj_status, min_status, ret_flags;
+	u_int klen, kout, slen = 0, strlen;
+	size_t hashlen;
+	BIGNUM *dh_server_pub = NULL;
+	BIGNUM *shared_secret = NULL;
+	BIGNUM *p = NULL;
+	BIGNUM *g = NULL;	
+	u_char *kbuf;
+	u_char hash[SSH_DIGEST_MAX_LENGTH];
+	u_char *serverhostkey = NULL;
+	u_char *empty = "";
+	char *msg;
+	/* TODO:
+	char *lang;
+	*/
+	int type = 0;
+	int first = 1;
+	int nbits = 0, min = fips_dh_grp_min(), max = DH_GRP_MAX;
+	int p_bitlen;
+	int r;
+
+	/* Initialise our GSSAPI world */	
+	ssh_gssapi_build_ctx(&ctxt);
+	if (ssh_gssapi_id_kex(ctxt, kex->name, kex->kex_type) 
+	    == GSS_C_NO_OID)
+		fatal("Couldn't identify host exchange");
+
+	if (ssh_gssapi_import_name(ctxt, kex->gss_host))
+		fatal("Couldn't import hostname");
+
+	if (kex->gss_client && 
+	    ssh_gssapi_client_identity(ctxt, kex->gss_client))
+		fatal("Couldn't acquire client credentials");
+
+	switch (kex->kex_type) {
+	case KEX_GSS_GRP1_SHA1:
+		kex->dh = dh_new_group1();
+		break;
+	case KEX_GSS_GRP14_SHA1:
+		kex->dh = dh_new_group14();
+		break;
+	case KEX_GSS_GEX_SHA1:
+		debug("Doing group exchange\n");
+		nbits = dh_estimate(kex->we_need * 8);
+		packet_start(SSH2_MSG_KEXGSS_GROUPREQ);
+		packet_put_int(min);
+		packet_put_int(nbits);
+		packet_put_int(max);
+
+		packet_send();
+
+		packet_read_expect(SSH2_MSG_KEXGSS_GROUP);
+
+		if ((p = BN_new()) == NULL)
+			fatal("BN_new() failed");
+		packet_get_bignum2(p);
+		p_bitlen = BN_num_bits(p);
+		if ((g = BN_new()) == NULL)
+			fatal("BN_new() failed");
+		packet_get_bignum2(g);
+		packet_check_eom();
+
+		if (p_bitlen < min || p_bitlen > max) {
+			if (p_bitlen < min && p_bitlen >= DH_GRP_MIN_RFC)
+				logit("DH parameter offered by the server (%d bits) "
+				    "is considered insecure. "
+				    "You can lower the accepted minimum "
+				    "via the KexDHMin option.",
+				    p_bitlen);
+			fatal("GSSGRP_GEX group out of range: %d !< %d !< %d",
+			    min, p_bitlen, max);
+		}
+
+		kex->dh = dh_new_group(g, p);
+		break;
+	default:
+		fatal("%s: Unexpected KEX type %d", __func__, kex->kex_type);
+	}
+	
+	/* Step 1 - e is dh->pub_key */
+	dh_gen_key(kex->dh, kex->we_need * 8);
+
+	/* This is f, we initialise it now to make life easier */
+	dh_server_pub = BN_new();
+	if (dh_server_pub == NULL)
+		fatal("dh_server_pub == NULL");
+
+	token_ptr = GSS_C_NO_BUFFER;
+			 
+	do {
+		debug("Calling gss_init_sec_context");
+		
+		maj_status = ssh_gssapi_init_ctx(ctxt,
+		    kex->gss_deleg_creds, token_ptr, &send_tok,
+		    &ret_flags);
+
+		if (GSS_ERROR(maj_status)) {
+			if (send_tok.length != 0) {
+				packet_start(SSH2_MSG_KEXGSS_CONTINUE);
+				packet_put_string(send_tok.value,
+				    send_tok.length);
+			}
+			fatal("gss_init_context failed");
+		}
+
+		/* If we've got an old receive buffer get rid of it */
+		if (token_ptr != GSS_C_NO_BUFFER)
+			free(recv_tok.value);
+
+		if (maj_status == GSS_S_COMPLETE) {
+			/* If mutual state flag is not true, kex fails */
+			if (!(ret_flags & GSS_C_MUTUAL_FLAG))
+				fatal("Mutual authentication failed");
+
+			/* If integ avail flag is not true kex fails */
+			if (!(ret_flags & GSS_C_INTEG_FLAG))
+				fatal("Integrity check failed");
+		}
+
+		/* 
+		 * If we have data to send, then the last message that we
+		 * received cannot have been a 'complete'. 
+		 */
+		if (send_tok.length != 0) {
+			if (first) {
+				packet_start(SSH2_MSG_KEXGSS_INIT);
+				packet_put_string(send_tok.value,
+				    send_tok.length);
+				packet_put_bignum2(kex->dh->pub_key);
+				first = 0;
+			} else {
+				packet_start(SSH2_MSG_KEXGSS_CONTINUE);
+				packet_put_string(send_tok.value,
+				    send_tok.length);
+			}
+			packet_send();
+			gss_release_buffer(&min_status, &send_tok);
+
+			/* If we've sent them data, they should reply */
+			do {	
+				type = packet_read();
+				if (type == SSH2_MSG_KEXGSS_HOSTKEY) {
+					debug("Received KEXGSS_HOSTKEY");
+					if (serverhostkey)
+						fatal("Server host key received more than once");
+					serverhostkey = 
+					    packet_get_string(&slen);
+				}
+			} while (type == SSH2_MSG_KEXGSS_HOSTKEY);
+
+			switch (type) {
+			case SSH2_MSG_KEXGSS_CONTINUE:
+				debug("Received GSSAPI_CONTINUE");
+				if (maj_status == GSS_S_COMPLETE) 
+					fatal("GSSAPI Continue received from server when complete");
+				recv_tok.value = packet_get_string(&strlen);
+				recv_tok.length = strlen; 
+				break;
+			case SSH2_MSG_KEXGSS_COMPLETE:
+				debug("Received GSSAPI_COMPLETE");
+				packet_get_bignum2(dh_server_pub);
+				msg_tok.value =  packet_get_string(&strlen);
+				msg_tok.length = strlen; 
+
+				/* Is there a token included? */
+				if (packet_get_char()) {
+					recv_tok.value=
+					    packet_get_string(&strlen);
+					recv_tok.length = strlen;
+					/* If we're already complete - protocol error */
+					if (maj_status == GSS_S_COMPLETE)
+						packet_disconnect("Protocol error: received token when complete");
+					} else {
+						/* No token included */
+						if (maj_status != GSS_S_COMPLETE)
+							packet_disconnect("Protocol error: did not receive final token");
+				}
+				break;
+			case SSH2_MSG_KEXGSS_ERROR:
+				debug("Received Error");
+				maj_status = packet_get_int();
+				min_status = packet_get_int();
+				msg = packet_get_string(NULL);
+				/* TODO:
+				lang = packet_get_string(NULL);
+				*/
+				fatal("GSSAPI Error: \n%.400s",msg);
+			default:
+				packet_disconnect("Protocol error: didn't expect packet type %d",
+		    		type);
+			}
+			token_ptr = &recv_tok;
+		} else {
+			/* No data, and not complete */
+			if (maj_status != GSS_S_COMPLETE)
+				fatal("Not complete, and no token output");
+		}
+	} while (maj_status & GSS_S_CONTINUE_NEEDED);
+
+	/* 
+	 * We _must_ have received a COMPLETE message in reply from the 
+	 * server, which will have set dh_server_pub and msg_tok 
+	 */
+
+	if (type != SSH2_MSG_KEXGSS_COMPLETE)
+		fatal("Didn't receive a SSH2_MSG_KEXGSS_COMPLETE when I expected it");
+
+	/* Check f in range [1, p-1] */
+	if (!dh_pub_is_valid(kex->dh, dh_server_pub))
+		packet_disconnect("bad server public DH value");
+
+	/* compute K=f^x mod p */
+	klen = DH_size(kex->dh);
+	kbuf = xmalloc(klen);
+	kout = DH_compute_key(kbuf, dh_server_pub, kex->dh);
+	if (kout < 0)
+		fatal("DH_compute_key: failed");
+
+	shared_secret = BN_new();
+	if (shared_secret == NULL)
+		fatal("kexgss_client: BN_new failed");
+
+	if (BN_bin2bn(kbuf, kout, shared_secret) == NULL)
+		fatal("kexdh_client: BN_bin2bn failed");
+
+	memset(kbuf, 0, klen);
+	free(kbuf);
+
+	switch (kex->kex_type) {
+	case KEX_GSS_GRP1_SHA1:
+	case KEX_GSS_GRP14_SHA1:
+		kex_dh_hash( kex->client_version_string, 
+		    kex->server_version_string,
+		    buffer_ptr(kex->my), buffer_len(kex->my),
+		    buffer_ptr(kex->peer), buffer_len(kex->peer),
+		    (serverhostkey ? serverhostkey : empty), slen,
+		    kex->dh->pub_key,	/* e */
+		    dh_server_pub,	/* f */
+		    shared_secret,	/* K */
+		    hash, &hashlen
+		);
+		break;
+	case KEX_GSS_GEX_SHA1:
+		kexgex_hash(
+		    kex->hash_alg,
+		    kex->client_version_string,
+		    kex->server_version_string,
+		    buffer_ptr(kex->my), buffer_len(kex->my),
+		    buffer_ptr(kex->peer), buffer_len(kex->peer),
+		    (serverhostkey ? serverhostkey : empty), slen,
+ 		    min, nbits, max,
+		    kex->dh->p, kex->dh->g,
+		    kex->dh->pub_key,
+		    dh_server_pub,
+		    shared_secret,
+		    hash, &hashlen
+		);
+		break;
+	default:
+		fatal("%s: Unexpected KEX type %d", __func__, kex->kex_type);
+	}
+
+	gssbuf.value = hash;
+	gssbuf.length = hashlen;
+
+	/* Verify that the hash matches the MIC we just got. */
+	if (GSS_ERROR(ssh_gssapi_checkmic(ctxt, &gssbuf, &msg_tok)))
+		packet_disconnect("Hash's MIC didn't verify");
+
+	free(msg_tok.value);
+
+	if (serverhostkey)
+		free(serverhostkey);
+	BN_clear_free(dh_server_pub);
+
+	/* save session id */
+	if (kex->session_id == NULL) {
+		kex->session_id_len = hashlen;
+		kex->session_id = xmalloc(kex->session_id_len);
+		memcpy(kex->session_id, hash, kex->session_id_len);
+	}
+
+	if (kex->gss_deleg_creds)
+		ssh_gssapi_credentials_updated(ctxt);
+
+	if (gss_kex_context == NULL)
+		gss_kex_context = ctxt;
+	else
+		ssh_gssapi_delete_ctx(&ctxt);
+
+	if ((r = kex_derive_keys_bn(ssh, hash, hashlen, shared_secret)) == 0)
+		r = kex_send_newkeys(ssh);
+/* TODO:
+out:
+*/
+	explicit_bzero(hash, sizeof(hash));
+	DH_free(kex->dh);
+	kex->dh = NULL;
+	if (dh_server_pub)
+		BN_clear_free(dh_server_pub);
+	if (kbuf) {
+		explicit_bzero(kbuf, klen);
+		free(kbuf);
+	}
+	if (shared_secret)
+		BN_clear_free(shared_secret);
+	/* any errors should have finished as fatal */
+	return r;
+}
+
+#endif /* GSSAPI */
diff --git a/openssh-7.2p2/kexgsss.c b/openssh-7.2p2/kexgsss.c
new file mode 100644
--- /dev/null
+++ b/openssh-7.2p2/kexgsss.c
@@ -0,0 +1,317 @@
+/*
+ * Copyright (c) 2001-2009 Simon Wilkinson. 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"
+
+#ifdef GSSAPI
+
+#include <string.h>
+
+#include <openssl/crypto.h>
+#include <openssl/bn.h>
+
+#include "xmalloc.h"
+#include "buffer.h"
+#include "ssh2.h"
+#include "key.h"
+#include "cipher.h"
+#include "digest.h"
+#include "kex.h"
+#include "log.h"
+#include "packet.h"
+#include "dh.h"
+#include "ssh-gss.h"
+#include "monitor_wrap.h"
+#include "servconf.h"
+
+#include "fips.h"
+
+extern ServerOptions options;
+
+void	 ssh_gssapi_rekey_creds();
+
+int
+kexgss_server(struct ssh *ssh)
+{
+	struct kex *kex = ssh->kex;
+	OM_uint32 maj_status, min_status;
+
+	/* 
+	 * Some GSSAPI implementations use the input value of ret_flags (an
+ 	 * output variable) as a means of triggering mechanism specific 
+ 	 * features. Initializing it to zero avoids inadvertently 
+ 	 * activating this non-standard behaviour.
+	 */
+
+	OM_uint32 ret_flags = 0;
+	gss_buffer_desc gssbuf, recv_tok, msg_tok;
+	gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
+	Gssctxt *ctxt = NULL;
+	u_int slen, klen, kout;
+	size_t hashlen;
+	u_char *kbuf;
+	u_char hash[SSH_DIGEST_MAX_LENGTH];
+	int min = -1, max = -1, nbits = -1;
+	BIGNUM *shared_secret = NULL;
+	BIGNUM *dh_client_pub = NULL;
+	int type = 0;
+	gss_OID oid;
+	char *mechs;
+	int r;
+
+	/* Initialise GSSAPI */
+
+	/* If we're rekeying, privsep means that some of the private structures
+	 * in the GSSAPI code are no longer available. This kludges them back
+	 * into life
+	 */
+	if (!ssh_gssapi_oid_table_ok()) 
+		if ((mechs = ssh_gssapi_server_mechanisms()))
+			free(mechs);
+
+	debug2("%s: Identifying %s", __func__, kex->name);
+	oid = ssh_gssapi_id_kex(NULL, kex->name, kex->kex_type);
+	if (oid == GSS_C_NO_OID)
+	   fatal("Unknown gssapi mechanism");
+
+	debug2("%s: Acquiring credentials", __func__);
+
+	if (GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctxt, oid))))
+		fatal("Unable to acquire credentials for the server");
+
+	switch (kex->kex_type) {
+	case KEX_GSS_GRP1_SHA1:
+		kex->dh = dh_new_group1();
+		break;
+	case KEX_GSS_GRP14_SHA1:
+		kex->dh = dh_new_group14();
+		break;
+	case KEX_GSS_GEX_SHA1:
+		debug("Doing group exchange");
+		packet_read_expect(SSH2_MSG_KEXGSS_GROUPREQ);
+		min = packet_get_int();
+		nbits = packet_get_int();
+		max = packet_get_int();
+		min = MAX(fips_dh_grp_min(), min);
+		max = MIN(DH_GRP_MAX, max);
+		packet_check_eom();
+		if (max < min || nbits < min || max < nbits) {
+			if (nbits < min && nbits >= DH_GRP_MIN_RFC)
+				logit("DH parameter requested by the client (%d bits) "
+				    "is considered insecure. "
+				    "You can lower the accepted minimum "
+				    "via the KexDHMin option.",
+				    nbits);
+			fatal("GSS_GEX, bad parameters: %d !< %d !< %d",
+			    min, nbits, max);
+		}
+		kex->dh = PRIVSEP(choose_dh(min, nbits, max));
+		if (kex->dh == NULL)
+			packet_disconnect("Protocol error: no matching group found");
+
+		packet_start(SSH2_MSG_KEXGSS_GROUP);
+		packet_put_bignum2(kex->dh->p);
+		packet_put_bignum2(kex->dh->g);
+		packet_send();
+
+		packet_write_wait();
+		break;
+	default:
+		fatal("%s: Unexpected KEX type %d", __func__, kex->kex_type);
+	}
+
+	dh_gen_key(kex->dh, kex->we_need * 8);
+
+	do {
+		debug("Wait SSH2_MSG_GSSAPI_INIT");
+		type = packet_read();
+		switch(type) {
+		case SSH2_MSG_KEXGSS_INIT:
+			if (dh_client_pub != NULL) 
+				fatal("Received KEXGSS_INIT after initialising");
+			recv_tok.value = packet_get_string(&slen);
+			recv_tok.length = slen; 
+
+			if ((dh_client_pub = BN_new()) == NULL)
+				fatal("dh_client_pub == NULL");
+
+			packet_get_bignum2(dh_client_pub);
+
+			/* Send SSH_MSG_KEXGSS_HOSTKEY here, if we want */
+			break;
+		case SSH2_MSG_KEXGSS_CONTINUE:
+			recv_tok.value = packet_get_string(&slen);
+			recv_tok.length = slen; 
+			break;
+		default:
+			packet_disconnect(
+			    "Protocol error: didn't expect packet type %d",
+			    type);
+		}
+
+		maj_status = PRIVSEP(ssh_gssapi_accept_ctx(ctxt, &recv_tok, 
+		    &send_tok, &ret_flags));
+
+		free(recv_tok.value);
+
+		if (maj_status != GSS_S_COMPLETE && send_tok.length == 0)
+			fatal("Zero length token output when incomplete");
+
+		if (dh_client_pub == NULL)
+			fatal("No client public key");
+
+		if (maj_status & GSS_S_CONTINUE_NEEDED) {
+			debug("Sending GSSAPI_CONTINUE");
+			packet_start(SSH2_MSG_KEXGSS_CONTINUE);
+			packet_put_string(send_tok.value, send_tok.length);
+			packet_send();
+			gss_release_buffer(&min_status, &send_tok);
+		}
+	} while (maj_status & GSS_S_CONTINUE_NEEDED);
+
+	if (GSS_ERROR(maj_status)) {
+		if (send_tok.length > 0) {
+			packet_start(SSH2_MSG_KEXGSS_CONTINUE);
+			packet_put_string(send_tok.value, send_tok.length);
+			packet_send();
+		}
+		fatal("accept_ctx died");
+	}
+
+	if (!(ret_flags & GSS_C_MUTUAL_FLAG))
+		fatal("Mutual Authentication flag wasn't set");
+
+	if (!(ret_flags & GSS_C_INTEG_FLAG))
+		fatal("Integrity flag wasn't set");
+
+	if (!dh_pub_is_valid(kex->dh, dh_client_pub))
+		packet_disconnect("bad client public DH value");
+
+	klen = DH_size(kex->dh);
+	kbuf = xmalloc(klen); 
+	kout = DH_compute_key(kbuf, dh_client_pub, kex->dh);
+	if (kout < 0)
+		fatal("DH_compute_key: failed");
+
+	shared_secret = BN_new();
+	if (shared_secret == NULL)
+		fatal("kexgss_server: BN_new failed");
+
+	if (BN_bin2bn(kbuf, kout, shared_secret) == NULL)
+		fatal("kexgss_server: BN_bin2bn failed");
+
+	memset(kbuf, 0, klen);
+	free(kbuf);
+
+	switch (kex->kex_type) {
+	case KEX_GSS_GRP1_SHA1:
+	case KEX_GSS_GRP14_SHA1:
+		kex_dh_hash(
+		    kex->client_version_string, kex->server_version_string,
+		    buffer_ptr(kex->peer), buffer_len(kex->peer),
+		    buffer_ptr(kex->my), buffer_len(kex->my),
+		    NULL, 0, /* Change this if we start sending host keys */
+		    dh_client_pub, kex->dh->pub_key, shared_secret,
+		    hash, &hashlen
+		);
+		break;
+	case KEX_GSS_GEX_SHA1:
+		kexgex_hash(
+		    kex->hash_alg,
+		    kex->client_version_string, kex->server_version_string,
+		    buffer_ptr(kex->peer), buffer_len(kex->peer),
+		    buffer_ptr(kex->my), buffer_len(kex->my),
+		    NULL, 0,
+		    min, nbits, max,
+		    kex->dh->p, kex->dh->g,
+		    dh_client_pub,
+		    kex->dh->pub_key,
+		    shared_secret,
+		    hash, &hashlen
+		);
+		break;
+	default:
+		fatal("%s: Unexpected KEX type %d", __func__, kex->kex_type);
+	}
+
+	BN_clear_free(dh_client_pub);
+
+	if (kex->session_id == NULL) {
+		kex->session_id_len = hashlen;
+		kex->session_id = xmalloc(kex->session_id_len);
+		memcpy(kex->session_id, hash, kex->session_id_len);
+	}
+
+	gssbuf.value = hash;
+	gssbuf.length = hashlen;
+
+	if (GSS_ERROR(PRIVSEP(ssh_gssapi_sign(ctxt,&gssbuf,&msg_tok))))
+		fatal("Couldn't get MIC");
+
+	packet_start(SSH2_MSG_KEXGSS_COMPLETE);
+	packet_put_bignum2(kex->dh->pub_key);
+	packet_put_string(msg_tok.value,msg_tok.length);
+
+	if (send_tok.length != 0) {
+		packet_put_char(1); /* true */
+		packet_put_string(send_tok.value, send_tok.length);
+	} else {
+		packet_put_char(0); /* false */
+	}
+	packet_send();
+
+	gss_release_buffer(&min_status, &send_tok);
+	gss_release_buffer(&min_status, &msg_tok);
+
+	if (gss_kex_context == NULL)
+		gss_kex_context = ctxt;
+	else 
+		ssh_gssapi_delete_ctx(&ctxt);
+
+	if ((r = kex_derive_keys_bn(ssh, hash, hashlen, shared_secret)) == 0)
+		r = kex_send_newkeys(ssh);
+
+/* TODO:
+out:
+*/
+	explicit_bzero(hash, sizeof(hash));
+	DH_free(kex->dh);
+	kex->dh = NULL;
+	if (dh_client_pub)
+		BN_clear_free(dh_client_pub);
+	if (kbuf) {
+		explicit_bzero(kbuf, klen);
+		free(kbuf);
+	}
+	if (shared_secret)
+		BN_clear_free(shared_secret);
+
+	/* If this was a rekey, then save out any delegated credentials we
+	 * just exchanged.  */
+	if (options.gss_store_rekey)
+		ssh_gssapi_rekey_creds();
+
+	return r;
+}
+#endif /* GSSAPI */
diff --git a/openssh-7.2p2/monitor.c b/openssh-7.2p2/monitor.c
--- a/openssh-7.2p2/monitor.c
+++ b/openssh-7.2p2/monitor.c
@@ -151,16 +151,18 @@ int mm_answer_pam_respond(int, Buffer *)
 int mm_answer_pam_free_ctx(int, Buffer *);
 #endif
 
 #ifdef GSSAPI
 int mm_answer_gss_setup_ctx(int, Buffer *);
 int mm_answer_gss_accept_ctx(int, Buffer *);
 int mm_answer_gss_userok(int, Buffer *);
 int mm_answer_gss_checkmic(int, Buffer *);
+int mm_answer_gss_sign(int, Buffer *);
+int mm_answer_gss_updatecreds(int, Buffer *);
 #endif
 
 #ifdef SSH_AUDIT_EVENTS
 int mm_answer_audit_event(int, Buffer *);
 int mm_answer_audit_command(int, Buffer *);
 #endif
 
 static int monitor_read_log(struct monitor *);
@@ -228,21 +230,28 @@ struct mon_table mon_dispatch_proto20[] 
 #endif
     {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
     {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
 #ifdef GSSAPI
     {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
     {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
     {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
     {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
+    {MONITOR_REQ_GSSSIGN, MON_ONCE, mm_answer_gss_sign},
 #endif
     {0, 0, NULL}
 };
 
 struct mon_table mon_dispatch_postauth20[] = {
+#ifdef GSSAPI
+    {MONITOR_REQ_GSSSETUP, 0, mm_answer_gss_setup_ctx},
+    {MONITOR_REQ_GSSSTEP, 0, mm_answer_gss_accept_ctx},
+    {MONITOR_REQ_GSSSIGN, 0, mm_answer_gss_sign},
+    {MONITOR_REQ_GSSUPCREDS, 0, mm_answer_gss_updatecreds},
+#endif
 #ifdef WITH_OPENSSL
     {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
 #endif
     {MONITOR_REQ_SIGN, 0, mm_answer_sign},
     {MONITOR_REQ_PTY, 0, mm_answer_pty},
     {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
     {MONITOR_REQ_TERM, 0, mm_answer_term},
 #ifdef SSH_AUDIT_EVENTS
@@ -347,16 +356,20 @@ monitor_child_preauth(Authctxt *_authctx
 	authctxt->loginmsg = &loginmsg;
 
 	if (compat20) {
 		mon_dispatch = mon_dispatch_proto20;
 
 		/* Permit requests for moduli and signatures */
 		monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
 		monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
+#ifdef GSSAPI
+		/* and for the GSSAPI key exchange */
+		monitor_permit(mon_dispatch, MONITOR_REQ_GSSSETUP, 1);
+#endif
 	} else {
 		mon_dispatch = mon_dispatch_proto15;
 
 		monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
 	}
 
 	/* The first few requests do not require asynchronous access */
 	while (!authenticated) {
@@ -455,16 +468,20 @@ monitor_child_postauth(struct monitor *p
 
 	if (compat20) {
 		mon_dispatch = mon_dispatch_postauth20;
 
 		/* Permit requests for moduli and signatures */
 		monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
 		monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
 		monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
+#ifdef GSSAPI
+		/* and for the GSSAPI key exchange */
+		monitor_permit(mon_dispatch, MONITOR_REQ_GSSSETUP, 1);
+#endif		
 	} else {
 		mon_dispatch = mon_dispatch_postauth15;
 		monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
 	}
 	if (!no_pty_flag) {
 		monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
 		monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
 	}
@@ -1856,16 +1873,23 @@ monitor_apply_keystate(struct monitor *p
 		kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
 		kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
 		kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
 # ifdef OPENSSL_HAS_ECC
 		kex->kex[KEX_ECDH_SHA2] = kexecdh_server;
 # endif
 #endif /* WITH_OPENSSL */
 		kex->kex[KEX_C25519_SHA256] = kexc25519_server;
+#ifdef GSSAPI
+		if (options.gss_keyex) {
+			kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_server;
+			kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_server;
+			kex->kex[KEX_GSS_GEX_SHA1] = kexgss_server;
+		}
+#endif
 		kex->load_host_public_key=&get_hostkey_public_by_type;
 		kex->load_host_private_key=&get_hostkey_private_by_type;
 		kex->host_key_index=&get_hostkey_index;
 		kex->sign = sshd_hostkey_sign;
 	}
 
 	/* Update with new address */
 	if (options.compression) {
@@ -1955,16 +1979,19 @@ monitor_reinit(struct monitor *mon)
 #ifdef GSSAPI
 int
 mm_answer_gss_setup_ctx(int sock, Buffer *m)
 {
 	gss_OID_desc goid;
 	OM_uint32 major;
 	u_int len;
 
+	if (!options.gss_authentication && !options.gss_keyex)
+		fatal("In GSSAPI monitor when GSSAPI is disabled");
+
 	goid.elements = buffer_get_string(m, &len);
 	goid.length = len;
 
 	major = ssh_gssapi_server_ctx(&gsscontext, &goid);
 
 	free(goid.elements);
 
 	buffer_clear(m);
@@ -1982,16 +2009,19 @@ int
 mm_answer_gss_accept_ctx(int sock, Buffer *m)
 {
 	gss_buffer_desc in;
 	gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
 	OM_uint32 major, minor;
 	OM_uint32 flags = 0; /* GSI needs this */
 	u_int len;
 
+	if (!options.gss_authentication && !options.gss_keyex)
+		fatal("In GSSAPI monitor when GSSAPI is disabled");
+
 	in.value = buffer_get_string(m, &len);
 	in.length = len;
 	major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
 	free(in.value);
 
 	buffer_clear(m);
 	buffer_put_int(m, major);
 	buffer_put_string(m, out.value, out.length);
@@ -1999,27 +2029,31 @@ mm_answer_gss_accept_ctx(int sock, Buffe
 	mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
 
 	gss_release_buffer(&minor, &out);
 
 	if (major == GSS_S_COMPLETE) {
 		monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
 		monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
 		monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
+		monitor_permit(mon_dispatch, MONITOR_REQ_GSSSIGN, 1);
 	}
 	return (0);
 }
 
 int
 mm_answer_gss_checkmic(int sock, Buffer *m)
 {
 	gss_buffer_desc gssbuf, mic;
 	OM_uint32 ret;
 	u_int len;
 
+	if (!options.gss_authentication && !options.gss_keyex)
+		fatal("In GSSAPI monitor when GSSAPI is disabled");
+
 	gssbuf.value = buffer_get_string(m, &len);
 	gssbuf.length = len;
 	mic.value = buffer_get_string(m, &len);
 	mic.length = len;
 
 	ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
 
 	free(gssbuf.value);
@@ -2036,23 +2070,95 @@ mm_answer_gss_checkmic(int sock, Buffer 
 	return (0);
 }
 
 int
 mm_answer_gss_userok(int sock, Buffer *m)
 {
 	int authenticated;
 
-	authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
+	if (!options.gss_authentication && !options.gss_keyex)
+		fatal("In GSSAPI monitor when GSSAPI is disabled");
+
+	authenticated = authctxt->valid && 
+	    ssh_gssapi_userok(authctxt->user, authctxt->pw);
 
 	buffer_clear(m);
 	buffer_put_int(m, authenticated);
 
 	debug3("%s: sending result %d", __func__, authenticated);
 	mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
 
 	auth_method = "gssapi-with-mic";
 
 	/* Monitor loop will terminate if authenticated */
 	return (authenticated);
 }
+
+int 
+mm_answer_gss_sign(int socket, Buffer *m)
+{
+	gss_buffer_desc data;
+	gss_buffer_desc hash = GSS_C_EMPTY_BUFFER;
+	OM_uint32 major, minor;
+	u_int len;
+
+	if (!options.gss_authentication && !options.gss_keyex)
+		fatal("In GSSAPI monitor when GSSAPI is disabled");
+
+	data.value = buffer_get_string(m, &len);
+	data.length = len;
+	if (data.length != 20) 
+		fatal("%s: data length incorrect: %d", __func__, 
+		    (int) data.length);
+
+	/* Save the session ID on the first time around */
+	if (session_id2_len == 0) {
+		session_id2_len = data.length;
+		session_id2 = xmalloc(session_id2_len);
+		memcpy(session_id2, data.value, session_id2_len);
+	}
+	major = ssh_gssapi_sign(gsscontext, &data, &hash);
+
+	free(data.value);
+
+	buffer_clear(m);
+	buffer_put_int(m, major);
+	buffer_put_string(m, hash.value, hash.length);
+
+	mm_request_send(socket, MONITOR_ANS_GSSSIGN, m);
+
+	gss_release_buffer(&minor, &hash);
+
+	/* Turn on getpwnam permissions */
+	monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
+	
+	/* And credential updating, for when rekeying */
+	monitor_permit(mon_dispatch, MONITOR_REQ_GSSUPCREDS, 1);
+
+	return (0);
+}
+
+int
+mm_answer_gss_updatecreds(int socket, Buffer *m) {
+	ssh_gssapi_ccache store;
+	int ok;
+
+	store.filename = buffer_get_string(m, NULL);
+	store.envvar   = buffer_get_string(m, NULL);
+	store.envval   = buffer_get_string(m, NULL);
+
+	ok = ssh_gssapi_update_creds(&store);
+
+	free(store.filename);
+	free(store.envvar);
+	free(store.envval);
+
+	buffer_clear(m);
+	buffer_put_int(m, ok);
+
+	mm_request_send(socket, MONITOR_ANS_GSSUPCREDS, m);
+
+	return(0);
+}
+
 #endif /* GSSAPI */
 
diff --git a/openssh-7.2p2/monitor.h b/openssh-7.2p2/monitor.h
--- a/openssh-7.2p2/monitor.h
+++ b/openssh-7.2p2/monitor.h
@@ -60,16 +60,19 @@ enum monitor_reqtype {
 	MONITOR_REQ_PAM_START = 100,
 	MONITOR_REQ_PAM_ACCOUNT = 102, MONITOR_ANS_PAM_ACCOUNT = 103,
 	MONITOR_REQ_PAM_INIT_CTX = 104, MONITOR_ANS_PAM_INIT_CTX = 105,
 	MONITOR_REQ_PAM_QUERY = 106, MONITOR_ANS_PAM_QUERY = 107,
 	MONITOR_REQ_PAM_RESPOND = 108, MONITOR_ANS_PAM_RESPOND = 109,
 	MONITOR_REQ_PAM_FREE_CTX = 110, MONITOR_ANS_PAM_FREE_CTX = 111,
 	MONITOR_REQ_AUDIT_EVENT = 112, MONITOR_REQ_AUDIT_COMMAND = 113,
 
+	MONITOR_REQ_GSSSIGN = 201, MONITOR_ANS_GSSSIGN = 202,
+	MONITOR_REQ_GSSUPCREDS = 203, MONITOR_ANS_GSSUPCREDS = 204,
+
 };
 
 struct mm_master;
 struct monitor {
 	int			 m_recvfd;
 	int			 m_sendfd;
 	int			 m_log_recvfd;
 	int			 m_log_sendfd;
diff --git a/openssh-7.2p2/monitor_wrap.c b/openssh-7.2p2/monitor_wrap.c
--- a/openssh-7.2p2/monitor_wrap.c
+++ b/openssh-7.2p2/monitor_wrap.c
@@ -1063,27 +1063,72 @@ mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss
 	    &m);
 
 	major = buffer_get_int(&m);
 	buffer_free(&m);
 	return(major);
 }
 
 int
-mm_ssh_gssapi_userok(char *user)
+mm_ssh_gssapi_userok(char *user, struct passwd *pw)
 {
 	Buffer m;
 	int authenticated = 0;
 
 	buffer_init(&m);
 
 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, &m);
 	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSUSEROK,
 				  &m);
 
 	authenticated = buffer_get_int(&m);
 
 	buffer_free(&m);
 	debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not ");
 	return (authenticated);
 }
+
+OM_uint32
+mm_ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_desc *data, gss_buffer_desc *hash)
+{
+	Buffer m;
+	OM_uint32 major;
+	u_int len;
+
+	buffer_init(&m);
+	buffer_put_string(&m, data->value, data->length);
+
+	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSIGN, &m);
+	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSIGN, &m);
+
+	major = buffer_get_int(&m);
+	hash->value = buffer_get_string(&m, &len);
+	hash->length = len;
+
+	buffer_free(&m);
+
+	return(major);
+}
+
+int
+mm_ssh_gssapi_update_creds(ssh_gssapi_ccache *store)
+{
+	Buffer m;
+	int ok;
+
+	buffer_init(&m);
+
+	buffer_put_cstring(&m, store->filename ? store->filename : "");
+	buffer_put_cstring(&m, store->envvar ? store->envvar : "");
+	buffer_put_cstring(&m, store->envval ? store->envval : "");
+	
+	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUPCREDS, &m);
+	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSUPCREDS, &m);
+
+	ok = buffer_get_int(&m);
+
+	buffer_free(&m);
+	
+	return (ok);
+}
+
 #endif /* GSSAPI */
 
diff --git a/openssh-7.2p2/monitor_wrap.h b/openssh-7.2p2/monitor_wrap.h
--- a/openssh-7.2p2/monitor_wrap.h
+++ b/openssh-7.2p2/monitor_wrap.h
@@ -53,18 +53,20 @@ int mm_key_verify(Key *, u_char *, u_int
 int mm_auth_rsa_key_allowed(struct passwd *, BIGNUM *, Key **);
 int mm_auth_rsa_verify_response(Key *, BIGNUM *, u_char *);
 BIGNUM *mm_auth_rsa_generate_challenge(Key *);
 
 #ifdef GSSAPI
 OM_uint32 mm_ssh_gssapi_server_ctx(Gssctxt **, gss_OID);
 OM_uint32 mm_ssh_gssapi_accept_ctx(Gssctxt *,
    gss_buffer_desc *, gss_buffer_desc *, OM_uint32 *);
-int mm_ssh_gssapi_userok(char *user);
+int mm_ssh_gssapi_userok(char *user, struct passwd *);
 OM_uint32 mm_ssh_gssapi_checkmic(Gssctxt *, gss_buffer_t, gss_buffer_t);
+OM_uint32 mm_ssh_gssapi_sign(Gssctxt *, gss_buffer_t, gss_buffer_t);
+int mm_ssh_gssapi_update_creds(ssh_gssapi_ccache *);
 #endif
 
 #ifdef USE_PAM
 void mm_start_pam(struct Authctxt *);
 u_int mm_do_pam_account(void);
 void *mm_sshpam_init_ctx(struct Authctxt *);
 int mm_sshpam_query(void *, char **, char **, u_int *, char ***, u_int **);
 int mm_sshpam_respond(void *, u_int, char **);
diff --git a/openssh-7.2p2/readconf.c b/openssh-7.2p2/readconf.c
--- a/openssh-7.2p2/readconf.c
+++ b/openssh-7.2p2/readconf.c
@@ -145,16 +145,18 @@ typedef enum {
 	oUsePrivilegedPort, oLogLevel, oCiphers, oProtocol, oMacs,
 	oPubkeyAuthentication,
 	oKbdInteractiveAuthentication, oKbdInteractiveDevices, oHostKeyAlias,
 	oDynamicForward, oPreferredAuthentications, oHostbasedAuthentication,
 	oHostKeyAlgorithms, oBindAddress, oPKCS11Provider,
 	oClearAllForwardings, oNoHostAuthenticationForLocalhost,
 	oEnableSSHKeysign, oRekeyLimit, oVerifyHostKeyDNS, oConnectTimeout,
 	oAddressFamily, oGssAuthentication, oGssDelegateCreds,
+	oGssTrustDns, oGssKeyEx, oGssClientIdentity, oGssRenewalRekey,
+	oGssServerIdentity, 
 	oServerAliveInterval, oServerAliveCountMax, oIdentitiesOnly,
 	oSendEnv, oControlPath, oControlMaster, oControlPersist,
 	oHashKnownHosts,
 	oTunnel, oTunnelDevice, oLocalCommand, oPermitLocalCommand,
 	oVisualHostKey,
 	oKexAlgorithms, oKexDHMin,
 	oIPQoS, oRequestTTY, oIgnoreUnknown, oProxyUseFdpass,
 	oCanonicalDomains, oCanonicalizeHostname, oCanonicalizeMaxDots,
@@ -191,20 +193,30 @@ static struct {
 	{ "challengeresponseauthentication", oChallengeResponseAuthentication },
 	{ "skeyauthentication", oChallengeResponseAuthentication }, /* alias */
 	{ "tisauthentication", oChallengeResponseAuthentication },  /* alias */
 	{ "kerberosauthentication", oUnsupported },
 	{ "kerberostgtpassing", oUnsupported },
 	{ "afstokenpassing", oUnsupported },
 #if defined(GSSAPI)
 	{ "gssapiauthentication", oGssAuthentication },
+	{ "gssapikeyexchange", oGssKeyEx },
 	{ "gssapidelegatecredentials", oGssDelegateCreds },
+	{ "gssapitrustdns", oGssTrustDns },
+	{ "gssapiclientidentity", oGssClientIdentity },
+	{ "gssapiserveridentity", oGssServerIdentity },
+	{ "gssapirenewalforcesrekey", oGssRenewalRekey },
 #else
 	{ "gssapiauthentication", oUnsupported },
+	{ "gssapikeyexchange", oUnsupported },
 	{ "gssapidelegatecredentials", oUnsupported },
+	{ "gssapitrustdns", oUnsupported },
+	{ "gssapiclientidentity", oUnsupported },
+	{ "gssapiserveridentity", oUnsupported },
+	{ "gssapirenewalforcesrekey", oUnsupported },
 #endif
 	{ "fallbacktorsh", oDeprecated },
 	{ "usersh", oDeprecated },
 	{ "identityfile", oIdentityFile },
 	{ "identityfile2", oIdentityFile },			/* obsolete */
 	{ "identitiesonly", oIdentitiesOnly },
 	{ "certificatefile", oCertificateFile },
 	{ "addkeystoagent", oAddKeysToAgent },
@@ -928,20 +940,40 @@ parse_time:
 	case oChallengeResponseAuthentication:
 		intptr = &options->challenge_response_authentication;
 		goto parse_flag;
 
 	case oGssAuthentication:
 		intptr = &options->gss_authentication;
 		goto parse_flag;
 
+	case oGssKeyEx:
+		intptr = &options->gss_keyex;
+		goto parse_flag;
+
 	case oGssDelegateCreds:
 		intptr = &options->gss_deleg_creds;
 		goto parse_flag;
 
+	case oGssTrustDns:
+		intptr = &options->gss_trust_dns;
+		goto parse_flag;
+
+	case oGssClientIdentity:
+		charptr = &options->gss_client_identity;
+		goto parse_string;
+
+	case oGssServerIdentity:
+		charptr = &options->gss_server_identity;
+		goto parse_string;
+
+	case oGssRenewalRekey:
+		intptr = &options->gss_renewal_rekey;
+		goto parse_flag;
+
 	case oBatchMode:
 		intptr = &options->batch_mode;
 		goto parse_flag;
 
 	case oCheckHostIP:
 		intptr = &options->check_host_ip;
 		goto parse_flag;
 
@@ -1671,17 +1703,22 @@ initialize_options(Options * options)
 	options->fwd_opts.gateway_ports = -1;
 	options->fwd_opts.streamlocal_bind_mask = (mode_t)-1;
 	options->fwd_opts.streamlocal_bind_unlink = -1;
 	options->use_privileged_port = -1;
 	options->rsa_authentication = -1;
 	options->pubkey_authentication = -1;
 	options->challenge_response_authentication = -1;
 	options->gss_authentication = -1;
+	options->gss_keyex = -1;
 	options->gss_deleg_creds = -1;
+	options->gss_trust_dns = -1;
+	options->gss_renewal_rekey = -1;
+	options->gss_client_identity = NULL;
+	options->gss_server_identity = NULL;
 	options->password_authentication = -1;
 	options->kbd_interactive_authentication = -1;
 	options->kbd_interactive_devices = NULL;
 	options->rhosts_rsa_authentication = -1;
 	options->hostbased_authentication = -1;
 	options->batch_mode = -1;
 	options->check_host_ip = -1;
 	options->strict_host_key_checking = -1;
@@ -1801,18 +1838,24 @@ fill_default_options(Options * options)
 	if (options->rsa_authentication == -1)
 		options->rsa_authentication = 1;
 	if (options->pubkey_authentication == -1)
 		options->pubkey_authentication = 1;
 	if (options->challenge_response_authentication == -1)
 		options->challenge_response_authentication = 1;
 	if (options->gss_authentication == -1)
 		options->gss_authentication = 0;
+	if (options->gss_keyex == -1)
+		options->gss_keyex = 0;
 	if (options->gss_deleg_creds == -1)
 		options->gss_deleg_creds = 0;
+	if (options->gss_trust_dns == -1)
+		options->gss_trust_dns = 0;
+	if (options->gss_renewal_rekey == -1)
+		options->gss_renewal_rekey = 0;
 	if (options->password_authentication == -1)
 		options->password_authentication = 1;
 	if (options->kbd_interactive_authentication == -1)
 		options->kbd_interactive_authentication = 1;
 	if (options->rhosts_rsa_authentication == -1)
 		options->rhosts_rsa_authentication = 0;
 	if (options->hostbased_authentication == -1)
 		options->hostbased_authentication = 0;
diff --git a/openssh-7.2p2/readconf.h b/openssh-7.2p2/readconf.h
--- a/openssh-7.2p2/readconf.h
+++ b/openssh-7.2p2/readconf.h
@@ -40,17 +40,22 @@ typedef struct {
 	int     rhosts_rsa_authentication;	/* Try rhosts with RSA
 						 * authentication. */
 	int     rsa_authentication;	/* Try RSA authentication. */
 	int     pubkey_authentication;	/* Try ssh2 pubkey authentication. */
 	int     hostbased_authentication;	/* ssh2's rhosts_rsa */
 	int     challenge_response_authentication;
 					/* Try S/Key or TIS, authentication. */
 	int     gss_authentication;	/* Try GSS authentication */
+	int     gss_keyex;		/* Try GSS key exchange */
 	int     gss_deleg_creds;	/* Delegate GSS credentials */
+	int		gss_trust_dns;		/* Trust DNS for GSS canonicalization */
+	int		gss_renewal_rekey;	/* Credential renewal forces rekey */
+	char    *gss_client_identity;   /* Principal to initiate GSSAPI with */
+	char    *gss_server_identity;   /* GSSAPI target principal */
 	int     password_authentication;	/* Try password
 						 * authentication. */
 	int     kbd_interactive_authentication; /* Try keyboard-interactive auth. */
 	char	*kbd_interactive_devices; /* Keyboard-interactive auth devices. */
 	int     batch_mode;	/* Batch mode: do not ask for passwords. */
 	int     check_host_ip;	/* Also keep track of keys for IP address */
 	int     strict_host_key_checking;	/* Strict host key checking. */
 	int     compression;	/* Compress packets in both directions. */
diff --git a/openssh-7.2p2/servconf.c b/openssh-7.2p2/servconf.c
--- a/openssh-7.2p2/servconf.c
+++ b/openssh-7.2p2/servconf.c
@@ -118,18 +118,20 @@ initialize_server_options(ServerOptions 
 	options->rsa_authentication = -1;
 	options->pubkey_authentication = -1;
 	options->pubkey_key_types = NULL;
 	options->kerberos_authentication = -1;
 	options->kerberos_or_local_passwd = -1;
 	options->kerberos_ticket_cleanup = -1;
 	options->kerberos_get_afs_token = -1;
 	options->gss_authentication=-1;
+	options->gss_keyex = -1;
 	options->gss_cleanup_creds = -1;
 	options->gss_strict_acceptor = -1;
+	options->gss_store_rekey = -1;
 	options->password_authentication = -1;
 	options->kbd_interactive_authentication = -1;
 	options->challenge_response_authentication = -1;
 	options->permit_empty_passwd = -1;
 	options->permit_user_env = -1;
 	options->use_login = -1;
 	options->compression = -1;
 	options->rekey_limit = -1;
@@ -318,20 +320,24 @@ fill_default_server_options(ServerOption
 	if (options->kerberos_or_local_passwd == -1)
 		options->kerberos_or_local_passwd = 1;
 	if (options->kerberos_ticket_cleanup == -1)
 		options->kerberos_ticket_cleanup = 1;
 	if (options->kerberos_get_afs_token == -1)
 		options->kerberos_get_afs_token = 0;
 	if (options->gss_authentication == -1)
 		options->gss_authentication = 0;
+	if (options->gss_keyex == -1)
+		options->gss_keyex = 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->gss_store_rekey == -1)
+		options->gss_store_rekey = 0;
 	if (options->password_authentication == -1)
 		options->password_authentication = 1;
 	if (options->kbd_interactive_authentication == -1)
 		options->kbd_interactive_authentication = 0;
 	if (options->challenge_response_authentication == -1)
 		options->challenge_response_authentication = 1;
 	if (options->permit_empty_passwd == -1)
 		options->permit_empty_passwd = 0;
@@ -452,16 +458,17 @@ typedef enum {
 	sIgnoreUserKnownHosts, sCiphers, sMacs, sProtocol, sPidFile,
 	sGatewayPorts, sPubkeyAuthentication, sPubkeyAcceptedKeyTypes,
 	sXAuthLocation, sSubsystem, sMaxStartups, sMaxAuthTries, sMaxSessions,
 	sBanner, sUseDNS, sHostbasedAuthentication,
 	sHostbasedUsesNameFromPacketOnly, sHostbasedAcceptedKeyTypes,
 	sHostKeyAlgorithms,
 	sClientAliveInterval, sClientAliveCountMax, sAuthorizedKeysFile,
 	sGssAuthentication, sGssCleanupCreds, sGssStrictAcceptor,
+	sGssKeyEx, sGssStoreRekey,
 	sAcceptEnv, sPermitTunnel,
 	sMatch, sPermitOpen, sForceCommand, sChrootDirectory,
 	sUsePrivilegeSeparation, sAllowAgentForwarding,
 	sHostCertificate,
 	sRevokedKeys, sTrustedUserCAKeys, sAuthorizedPrincipalsFile,
 	sAuthorizedPrincipalsCommand, sAuthorizedPrincipalsCommandUser,
 	sKexAlgorithms, sKexDHMin,
 	sIPQoS, sVersionAddendum,
@@ -529,21 +536,27 @@ static struct {
 	{ "kerberosgetafstoken", sUnsupported, SSHCFG_GLOBAL },
 #endif
 	{ "kerberostgtpassing", sUnsupported, SSHCFG_GLOBAL },
 	{ "afstokenpassing", sUnsupported, SSHCFG_GLOBAL },
 #ifdef GSSAPI
 	{ "gssapiauthentication", sGssAuthentication, SSHCFG_ALL },
 	{ "gssapicleanupcredentials", sGssCleanupCreds, SSHCFG_GLOBAL },
 	{ "gssapistrictacceptorcheck", sGssStrictAcceptor, SSHCFG_GLOBAL },
+	{ "gssapikeyexchange", sGssKeyEx, SSHCFG_GLOBAL },
+	{ "gssapistorecredentialsonrekey", sGssStoreRekey, SSHCFG_GLOBAL },
 #else
 	{ "gssapiauthentication", sUnsupported, SSHCFG_ALL },
 	{ "gssapicleanupcredentials", sUnsupported, SSHCFG_GLOBAL },
 	{ "gssapistrictacceptorcheck", sUnsupported, SSHCFG_GLOBAL },
+	{ "gssapikeyexchange", sUnsupported, SSHCFG_GLOBAL },
+	{ "gssapistorecredentialsonrekey", sUnsupported, SSHCFG_GLOBAL },
 #endif
+	{ "gssusesessionccache", sUnsupported, SSHCFG_GLOBAL },
+	{ "gssapiusesessioncredcache", sUnsupported, SSHCFG_GLOBAL },
 	{ "passwordauthentication", sPasswordAuthentication, SSHCFG_ALL },
 	{ "kbdinteractiveauthentication", sKbdInteractiveAuthentication, SSHCFG_ALL },
 	{ "challengeresponseauthentication", sChallengeResponseAuthentication, SSHCFG_GLOBAL },
 	{ "skeyauthentication", sChallengeResponseAuthentication, SSHCFG_GLOBAL }, /* alias */
 	{ "checkmail", sDeprecated, SSHCFG_GLOBAL },
 	{ "listenaddress", sListenAddress, SSHCFG_GLOBAL },
 	{ "addressfamily", sAddressFamily, SSHCFG_GLOBAL },
 	{ "printmotd", sPrintMotd, SSHCFG_GLOBAL },
@@ -1282,24 +1295,32 @@ process_server_config_line(ServerOptions
 	case sKerberosGetAFSToken:
 		intptr = &options->kerberos_get_afs_token;
 		goto parse_flag;
 
 	case sGssAuthentication:
 		intptr = &options->gss_authentication;
 		goto parse_flag;
 
+	case sGssKeyEx:
+		intptr = &options->gss_keyex;
+		goto parse_flag;
+
 	case sGssCleanupCreds:
 		intptr = &options->gss_cleanup_creds;
 		goto parse_flag;
 
 	case sGssStrictAcceptor:
 		intptr = &options->gss_strict_acceptor;
 		goto parse_flag;
 
+	case sGssStoreRekey:
+		intptr = &options->gss_store_rekey;
+		goto parse_flag;
+
 	case sPasswordAuthentication:
 		intptr = &options->password_authentication;
 		goto parse_flag;
 
 	case sKbdInteractiveAuthentication:
 		intptr = &options->kbd_interactive_authentication;
 		goto parse_flag;
 
@@ -2051,16 +2072,20 @@ copy_set_server_options(ServerOptions *d
 {
 #define M_CP_INTOPT(n) do {\
 	if (src->n != -1) \
 		dst->n = src->n; \
 } while (0)
 
 	M_CP_INTOPT(password_authentication);
 	M_CP_INTOPT(gss_authentication);
+    M_CP_INTOPT(gss_keyex);
+    M_CP_INTOPT(gss_cleanup_creds);
+    M_CP_INTOPT(gss_strict_acceptor);
+    M_CP_INTOPT(gss_store_rekey);
 	M_CP_INTOPT(rsa_authentication);
 	M_CP_INTOPT(pubkey_authentication);
 	M_CP_INTOPT(kerberos_authentication);
 	M_CP_INTOPT(hostbased_authentication);
 	M_CP_INTOPT(hostbased_uses_name_from_packet_only);
 	M_CP_INTOPT(kbd_interactive_authentication);
 	M_CP_INTOPT(permit_root_login);
 	M_CP_INTOPT(permit_empty_passwd);
@@ -2338,17 +2363,20 @@ dump_config(ServerOptions *o)
 	dump_cfg_fmtint(sKerberosOrLocalPasswd, o->kerberos_or_local_passwd);
 	dump_cfg_fmtint(sKerberosTicketCleanup, o->kerberos_ticket_cleanup);
 # ifdef USE_AFS
 	dump_cfg_fmtint(sKerberosGetAFSToken, o->kerberos_get_afs_token);
 # endif
 #endif
 #ifdef GSSAPI
 	dump_cfg_fmtint(sGssAuthentication, o->gss_authentication);
+	dump_cfg_fmtint(sGssKeyEx, o->gss_keyex);
 	dump_cfg_fmtint(sGssCleanupCreds, o->gss_cleanup_creds);
+	dump_cfg_fmtint(sGssStrictAcceptor, o->gss_strict_acceptor);
+	dump_cfg_fmtint(sGssStoreRekey, o->gss_store_rekey);
 #endif
 	dump_cfg_fmtint(sPasswordAuthentication, o->password_authentication);
 	dump_cfg_fmtint(sKbdInteractiveAuthentication,
 	    o->kbd_interactive_authentication);
 	dump_cfg_fmtint(sChallengeResponseAuthentication,
 	    o->challenge_response_authentication);
 	dump_cfg_fmtint(sPrintMotd, o->print_motd);
 #ifndef DISABLE_LASTLOG
diff --git a/openssh-7.2p2/servconf.h b/openssh-7.2p2/servconf.h
--- a/openssh-7.2p2/servconf.h
+++ b/openssh-7.2p2/servconf.h
@@ -11,16 +11,18 @@
  * 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".
  */
 
 #ifndef SERVCONF_H
 #define SERVCONF_H
 
+#include "misc.h"
+
 #define MAX_PORTS		256	/* Max # ports. */
 
 #define MAX_ALLOW_USERS		256	/* Max # users on allow list. */
 #define MAX_DENY_USERS		256	/* Max # users on deny list. */
 #define MAX_ALLOW_GROUPS	256	/* Max # groups on allow list. */
 #define MAX_DENY_GROUPS		256	/* Max # groups on deny list. */
 #define MAX_SUBSYSTEMS		256	/* Max # subsystems. */
 #define MAX_HOSTKEYS		256	/* Max # hostkeys. */
@@ -114,18 +116,20 @@ typedef struct {
 						 * authentication mechanism,
 						 * such as SecurID or
 						 * /etc/passwd */
 	int     kerberos_ticket_cleanup;	/* If true, destroy ticket
 						 * file on logout. */
 	int     kerberos_get_afs_token;		/* If true, try to get AFS token if
 						 * authenticated with Kerberos. */
 	int     gss_authentication;	/* If true, permit GSSAPI authentication */
+	int     gss_keyex;		/* If true, permit GSSAPI key exchange */
 	int     gss_cleanup_creds;	/* If true, destroy cred cache on logout */
 	int     gss_strict_acceptor;	/* If true, restrict the GSSAPI acceptor name */
+	int 	gss_store_rekey;
 	int     password_authentication;	/* If true, permit password
 						 * authentication. */
 	int     kbd_interactive_authentication;	/* If true, permit */
 	int     challenge_response_authentication;
 	int     permit_empty_passwd;	/* If false, do not permit empty
 					 * passwords. */
 	int     permit_user_env;	/* If true, read ~/.ssh/environment */
 	int     use_login;	/* If true, login(1) is used */
diff --git a/openssh-7.2p2/ssh-gss.h b/openssh-7.2p2/ssh-gss.h
--- a/openssh-7.2p2/ssh-gss.h
+++ b/openssh-7.2p2/ssh-gss.h
@@ -1,11 +1,11 @@
 /* $OpenBSD: ssh-gss.h,v 1.11 2014/02/26 20:28:44 djm Exp $ */
 /*
- * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
+ * Copyright (c) 2001-2009 Simon Wilkinson. 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
@@ -56,53 +56,70 @@
 #define SSH2_MSG_USERAUTH_GSSAPI_TOKEN			61
 #define SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE	63
 #define SSH2_MSG_USERAUTH_GSSAPI_ERROR			64
 #define SSH2_MSG_USERAUTH_GSSAPI_ERRTOK			65
 #define SSH2_MSG_USERAUTH_GSSAPI_MIC			66
 
 #define SSH_GSS_OIDTYPE 0x06
 
+#define SSH2_MSG_KEXGSS_INIT                            30
+#define SSH2_MSG_KEXGSS_CONTINUE                        31
+#define SSH2_MSG_KEXGSS_COMPLETE                        32
+#define SSH2_MSG_KEXGSS_HOSTKEY                         33
+#define SSH2_MSG_KEXGSS_ERROR                           34
+#define SSH2_MSG_KEXGSS_GROUPREQ			40
+#define SSH2_MSG_KEXGSS_GROUP				41
+#define KEX_GSS_GRP1_SHA1_ID				"gss-group1-sha1-"
+#define KEX_GSS_GRP14_SHA1_ID				"gss-group14-sha1-"
+#define KEX_GSS_GEX_SHA1_ID				"gss-gex-sha1-"
+
 typedef struct {
 	char *filename;
 	char *envvar;
 	char *envval;
+	struct passwd *owner;
 	void *data;
 } ssh_gssapi_ccache;
 
 typedef struct {
 	gss_buffer_desc displayname;
 	gss_buffer_desc exportedname;
 	gss_cred_id_t creds;
+	gss_name_t name;
 	struct ssh_gssapi_mech_struct *mech;
 	ssh_gssapi_ccache store;
+	int used;
+	int updated;
 } ssh_gssapi_client;
 
 typedef struct ssh_gssapi_mech_struct {
 	char *enc_name;
 	char *name;
 	gss_OID_desc oid;
 	int (*dochild) (ssh_gssapi_client *);
 	int (*userok) (ssh_gssapi_client *, char *);
 	int (*localname) (ssh_gssapi_client *, char **);
 	void (*storecreds) (ssh_gssapi_client *);
+	int (*updatecreds) (ssh_gssapi_ccache *, ssh_gssapi_client *);
 } ssh_gssapi_mech;
 
 typedef struct {
 	OM_uint32	major; /* both */
 	OM_uint32	minor; /* both */
 	gss_ctx_id_t	context; /* both */
 	gss_name_t	name; /* both */
 	gss_OID		oid; /* client */
 	gss_cred_id_t	creds; /* server */
 	gss_name_t	client; /* server */
-	gss_cred_id_t	client_creds; /* server */
+	gss_cred_id_t	client_creds; /* both */
 } Gssctxt;
 
 extern ssh_gssapi_mech *supported_mechs[];
+extern Gssctxt *gss_kex_context;
 
 int  ssh_gssapi_check_oid(Gssctxt *, void *, size_t);
 void ssh_gssapi_set_oid_data(Gssctxt *, void *, size_t);
 void ssh_gssapi_set_oid(Gssctxt *, gss_OID);
 void ssh_gssapi_supported_oids(gss_OID_set *);
 ssh_gssapi_mech *ssh_gssapi_get_ctype(Gssctxt *);
 void ssh_gssapi_prepare_supported_oids(void);
 OM_uint32 ssh_gssapi_test_oid_supported(OM_uint32 *, gss_OID, int *);
@@ -114,21 +131,35 @@ OM_uint32 ssh_gssapi_accept_ctx(Gssctxt 
     gss_buffer_desc *, gss_buffer_desc *, OM_uint32 *);
 OM_uint32 ssh_gssapi_getclient(Gssctxt *, ssh_gssapi_client *);
 void ssh_gssapi_error(Gssctxt *);
 char *ssh_gssapi_last_error(Gssctxt *, OM_uint32 *, OM_uint32 *);
 void ssh_gssapi_build_ctx(Gssctxt **);
 void ssh_gssapi_delete_ctx(Gssctxt **);
 OM_uint32 ssh_gssapi_sign(Gssctxt *, gss_buffer_t, gss_buffer_t);
 void ssh_gssapi_buildmic(Buffer *, const char *, const char *, const char *);
-int ssh_gssapi_check_mechanism(Gssctxt **, gss_OID, const char *);
+int ssh_gssapi_check_mechanism(Gssctxt **, gss_OID, const char *, const char *);
+OM_uint32 ssh_gssapi_client_identity(Gssctxt *, const char *);
+int ssh_gssapi_credentials_updated(Gssctxt *);
 
 /* In the server */
+typedef int ssh_gssapi_check_fn(Gssctxt **, gss_OID, const char *, 
+    const char *);
+char *ssh_gssapi_client_mechanisms(const char *, const char *);
+char *ssh_gssapi_kex_mechs(gss_OID_set, ssh_gssapi_check_fn *, const char *,
+    const char *);
+gss_OID ssh_gssapi_id_kex(Gssctxt *, char *, int);
+int ssh_gssapi_server_check_mech(Gssctxt **,gss_OID, const char *, 
+    const char *);
 OM_uint32 ssh_gssapi_server_ctx(Gssctxt **, gss_OID);
-int ssh_gssapi_userok(char *name);
+int ssh_gssapi_userok(char *name, struct passwd *);
 OM_uint32 ssh_gssapi_checkmic(Gssctxt *, gss_buffer_t, gss_buffer_t);
 void ssh_gssapi_do_child(char ***, u_int *);
 void ssh_gssapi_cleanup_creds(void);
 void ssh_gssapi_storecreds(void);
 
+char *ssh_gssapi_server_mechanisms(void);
+int ssh_gssapi_oid_table_ok();
+
+int ssh_gssapi_update_creds(ssh_gssapi_ccache *store);
 #endif /* GSSAPI */
 
 #endif /* _SSH_GSS_H */
diff --git a/openssh-7.2p2/ssh_config b/openssh-7.2p2/ssh_config
--- a/openssh-7.2p2/ssh_config
+++ b/openssh-7.2p2/ssh_config
@@ -42,16 +42,18 @@ Host *
     SendEnv LC_IDENTIFICATION LC_ALL
 
 #   RhostsRSAAuthentication no
 #   RSAAuthentication yes
 #   PasswordAuthentication yes
 #   HostbasedAuthentication no
 #   GSSAPIAuthentication no
 #   GSSAPIDelegateCredentials no
+#   GSSAPIKeyExchange no
+#   GSSAPITrustDNS no
 #   BatchMode no
 #   CheckHostIP yes
 #   AddressFamily any
 #   ConnectTimeout 0
 #   StrictHostKeyChecking ask
 #   IdentityFile ~/.ssh/identity
 #   IdentityFile ~/.ssh/id_rsa
 #   IdentityFile ~/.ssh/id_dsa
diff --git a/openssh-7.2p2/ssh_config.0 b/openssh-7.2p2/ssh_config.0
--- a/openssh-7.2p2/ssh_config.0
+++ b/openssh-7.2p2/ssh_config.0
@@ -445,20 +445,51 @@ DESCRIPTION
              Specifies one or more files to use for the global host key
              database, separated by whitespace.  The default is
              /etc/ssh/ssh_known_hosts, /etc/ssh/ssh_known_hosts2.
 
      GSSAPIAuthentication
              Specifies whether user authentication based on GSSAPI is allowed.
              The default is M-bM-^@M-^\noM-bM-^@M-^].
 
+     GSSAPIKeyExchange
+             Specifies whether key exchange based on GSSAPI may be used. When
+             using GSSAPI key exchange the server need not have a host key.
+             The default is no.
+             Note that this option applies to protocol version 2 only.
+
+     GSSAPIClientIdentity
+             If set, specifies the GSSAPI client identity that ssh should use
+             when connecting to the server. The default is unset, which means
+             that the default identity will be used.
+
+     GSSAPIServerIdentity
+             If set, specifies the GSSAPI server identity that ssh should expect
+             when connecting to the server. The default is unset, which means
+             that the expected GSSAPI server identity will be determined from
+             the target hostname.
+
      GSSAPIDelegateCredentials
              Forward (delegate) credentials to the server.  The default is
              M-bM-^@M-^\noM-bM-^@M-^].
 
+     GSSAPIRenewalForcesRekey
+             If set to yes then renewal of the client's GSSAPI credentials will
+             force the rekeying of the ssh connection. With a compatible server,
+             this can delegate the renewed credentials to a session on the
+             server. The default is no.
+
+     GSSAPITrustDns
+             Set to yes to indicate that the DNS is trusted to securely
+             canonicalize the name of the host being connected to. If no, the
+             hostname entered on the command line will be passed untouched to
+             the GSSAPI library.  The default is no.
+             This option only applies to protocol version 2 connections using
+             GSSAPI.
+
      HashKnownHosts
              Indicates that ssh(1) should hash host names and addresses when
              they are added to ~/.ssh/known_hosts.  These hashed names may be
              used normally by ssh(1) and sshd(8), but they do not reveal
              identifying information should the file's contents be disclosed.
              The default is M-bM-^@M-^\noM-bM-^@M-^].  Note that existing names and addresses in
              known hosts files will not be converted automatically, but may be
              manually hashed using ssh-keygen(1).
diff --git a/openssh-7.2p2/ssh_config.5 b/openssh-7.2p2/ssh_config.5
--- a/openssh-7.2p2/ssh_config.5
+++ b/openssh-7.2p2/ssh_config.5
@@ -823,20 +823,52 @@ Specifies one or more files to use for t
 host key database, separated by whitespace.
 The default is
 .Pa /etc/ssh/ssh_known_hosts ,
 .Pa /etc/ssh/ssh_known_hosts2 .
 .It Cm GSSAPIAuthentication
 Specifies whether user authentication based on GSSAPI is allowed.
 The default is
 .Dq no .
+.It Cm GSSAPIKeyExchange
+Specifies whether key exchange based on GSSAPI may be used. When using
+GSSAPI key exchange the server need not have a host key.
+The default is
+.Dq no .
+Note that this option applies to protocol version 2 only.
+.It Cm GSSAPIClientIdentity
+If set, specifies the GSSAPI client identity that ssh should use when 
+connecting to the server. The default is unset, which means that the default 
+identity will be used.
+.It Cm GSSAPIServerIdentity
+If set, specifies the GSSAPI server identity that ssh should expect when 
+connecting to the server. The default is unset, which means that the
+expected GSSAPI server identity will be determined from the target
+hostname.
 .It Cm GSSAPIDelegateCredentials
 Forward (delegate) credentials to the server.
 The default is
 .Dq no .
+.It Cm GSSAPIRenewalForcesRekey
+If set to 
+.Dq yes
+then renewal of the client's GSSAPI credentials will force the rekeying of the
+ssh connection. With a compatible server, this can delegate the renewed 
+credentials to a session on the server.
+The default is
+.Dq no .
+.It Cm GSSAPITrustDns
+Set to 
+.Dq yes to indicate that the DNS is trusted to securely canonicalize
+the name of the host being connected to. If 
+.Dq no, the hostname entered on the
+command line will be passed untouched to the GSSAPI library.
+The default is
+.Dq no .
+This option only applies to protocol version 2 connections using GSSAPI.
 .It Cm HashKnownHosts
 Indicates that
 .Xr ssh 1
 should hash host names and addresses when they are added to
 .Pa ~/.ssh/known_hosts .
 These hashed names may be used normally by
 .Xr ssh 1
 and
diff --git a/openssh-7.2p2/sshconnect2.c b/openssh-7.2p2/sshconnect2.c
--- a/openssh-7.2p2/sshconnect2.c
+++ b/openssh-7.2p2/sshconnect2.c
@@ -155,20 +155,44 @@ order_hostkeyalgs(char *host, struct soc
 
 void
 ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
 {
 	char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
 	char *s;
 	struct kex *kex;
 	int r;
+#ifdef GSSAPI
+	char *orig = NULL, *gss = NULL;
+	char *gss_host = NULL;
+#endif
 
 	xxx_host = host;
 	xxx_hostaddr = hostaddr;
 
+#ifdef GSSAPI
+	if (options.gss_keyex) {
+		/* Add the GSSAPI mechanisms currently supported on this 
+		 * client to the key exchange algorithm proposal */
+		orig = myproposal[PROPOSAL_KEX_ALGS];
+
+		if (options.gss_trust_dns)
+			gss_host = (char *)get_canonical_hostname(1);
+		else
+			gss_host = host;
+
+		gss = ssh_gssapi_client_mechanisms(gss_host, options.gss_client_identity);
+		if (gss) {
+			debug("Offering GSSAPI proposal: %s", gss);
+			xasprintf(&myproposal[PROPOSAL_KEX_ALGS],
+			    "%s,%s", gss, orig);
+		}
+	}
+#endif
+
 	if ((s = kex_names_cat(options.kex_algorithms, "ext-info-c")) == NULL)
 		fatal("%s: kex_names_cat", __func__);
 	myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(s);
 	myproposal[PROPOSAL_ENC_ALGS_CTOS] =
 	    compat_cipher_proposal(options.ciphers);
 	myproposal[PROPOSAL_ENC_ALGS_STOC] =
 	    compat_cipher_proposal(options.ciphers);
 	if (options.compression) {
@@ -190,16 +214,27 @@ ssh_kex2(char *host, struct sockaddr *ho
 		/* Enforce default */
 		options.hostkeyalgorithms = xstrdup(KEX_DEFAULT_PK_ALG);
 		/* Prefer algorithms that we already have keys for */
 		myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
 		    compat_pkalg_proposal(
 		    order_hostkeyalgs(host, hostaddr, port));
 	}
 
+#ifdef GSSAPI
+	/* If we've got GSSAPI algorithms, then we also support the
+	 * 'null' hostkey, as a last resort */
+	if (options.gss_keyex && gss) {
+		orig = myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS];
+		xasprintf(&myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS], 
+		    "%s,null", orig);
+		free(gss);
+	}
+#endif
+
 	if (options.rekey_limit || options.rekey_interval)
 		packet_set_rekey_limits((u_int32_t)options.rekey_limit,
 		    (time_t)options.rekey_interval);
 
 	/* start key exchange */
 	if ((r = kex_setup(active_state, myproposal)) != 0)
 		fatal("kex_setup: %s", ssh_err(r));
 	kex = active_state->kex;
@@ -208,20 +243,40 @@ ssh_kex2(char *host, struct sockaddr *ho
 	kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
 	kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
 	kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
 # ifdef OPENSSL_HAS_ECC
 	kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
 # endif
 #endif
 	kex->kex[KEX_C25519_SHA256] = kexc25519_client;
+#ifdef GSSAPI
+	if (options.gss_keyex) {
+		kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_client;
+		kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_client;
+		kex->kex[KEX_GSS_GEX_SHA1] = kexgss_client;
+	}
+#endif
 	kex->client_version_string=client_version_string;
 	kex->server_version_string=server_version_string;
 	kex->verify_host_key=&verify_host_key_callback;
 
+#ifdef GSSAPI
+	if (options.gss_keyex) {
+		kex->gss_deleg_creds = options.gss_deleg_creds;
+		kex->gss_trust_dns = options.gss_trust_dns;
+		kex->gss_client = options.gss_client_identity;
+		if (options.gss_server_identity) {
+			kex->gss_host = options.gss_server_identity;
+		} else {
+			kex->gss_host = gss_host;
+		}
+	}
+#endif
+
 	dispatch_run(DISPATCH_BLOCK, &kex->done, active_state);
 
 	/* remove ext-info from the KEX proposals for rekeying */
 	myproposal[PROPOSAL_KEX_ALGS] =
 	    compat_kex_proposal(options.kex_algorithms);
 	if ((r = kex_prop2buf(kex->my, myproposal)) != 0)
 		fatal("kex_prop2buf: %s", ssh_err(r));
 
@@ -306,31 +361,37 @@ int	userauth_hostbased(Authctxt *);
 
 #ifdef GSSAPI
 int	userauth_gssapi(Authctxt *authctxt);
 int	input_gssapi_response(int type, u_int32_t, void *);
 int	input_gssapi_token(int type, u_int32_t, void *);
 int	input_gssapi_hash(int type, u_int32_t, void *);
 int	input_gssapi_error(int, u_int32_t, void *);
 int	input_gssapi_errtok(int, u_int32_t, void *);
+int	userauth_gsskeyex(Authctxt *authctxt);
 #endif
 
 void	userauth(Authctxt *, char *);
 
 static int sign_and_send_pubkey(Authctxt *, Identity *);
 static void pubkey_prepare(Authctxt *);
 static void pubkey_cleanup(Authctxt *);
 static Key *load_identity_file(Identity *);
 
 static Authmethod *authmethod_get(char *authlist);
 static Authmethod *authmethod_lookup(const char *name);
 static char *authmethods_get(void);
 
 Authmethod authmethods[] = {
 #ifdef GSSAPI
+	{"gssapi-keyex",
+		userauth_gsskeyex,
+		NULL,
+		&options.gss_authentication,
+		NULL},
 	{"gssapi-with-mic",
 		userauth_gssapi,
 		NULL,
 		&options.gss_authentication,
 		NULL},
 #endif
 	{"hostbased",
 		userauth_hostbased,
@@ -651,29 +712,41 @@ done:
 int
 userauth_gssapi(Authctxt *authctxt)
 {
 	Gssctxt *gssctxt = NULL;
 	static gss_OID_set gss_supported = NULL;
 	static u_int mech = 0;
 	OM_uint32 min;
 	int ok = 0;
+	const char *gss_host;
+
+	if (options.gss_server_identity)
+		gss_host = options.gss_server_identity;
+	else if (options.gss_trust_dns)
+		gss_host = get_canonical_hostname(1);
+	else
+		gss_host = authctxt->host;
 
 	/* Try one GSSAPI method at a time, rather than sending them all at
 	 * once. */
 
 	if (gss_supported == NULL)
-		gss_indicate_mechs(&min, &gss_supported);
+		if (GSS_ERROR(gss_indicate_mechs(&min, &gss_supported))) {
+			gss_supported = NULL;
+			return 0;
+		}
 
 	/* Check to see if the mechanism is usable before we offer it */
 	while (mech < gss_supported->count && !ok) {
 		/* My DER encoding requires length<128 */
 		if (gss_supported->elements[mech].length < 128 &&
 		    ssh_gssapi_check_mechanism(&gssctxt, 
-		    &gss_supported->elements[mech], authctxt->host)) {
+		    &gss_supported->elements[mech], gss_host, 
+                    options.gss_client_identity)) {
 			ok = 1; /* Mechanism works */
 		} else {
 			mech++;
 		}
 	}
 
 	if (!ok)
 		return 0;
@@ -760,18 +833,18 @@ process_gssapi_token(void *ctxt, gss_buf
 }
 
 /* ARGSUSED */
 int
 input_gssapi_response(int type, u_int32_t plen, void *ctxt)
 {
 	Authctxt *authctxt = ctxt;
 	Gssctxt *gssctxt;
-	int oidlen;
-	char *oidv;
+	u_int oidlen;
+	u_char *oidv;
 
 	if (authctxt == NULL)
 		fatal("input_gssapi_response: no authentication context");
 	gssctxt = authctxt->methoddata;
 
 	/* Setup our OID */
 	oidv = packet_get_string(&oidlen);
 
@@ -874,16 +947,58 @@ input_gssapi_error(int type, u_int32_t p
 
 	packet_check_eom();
 
 	debug("Server GSSAPI Error:\n%s", msg);
 	free(msg);
 	free(lang);
 	return 0;
 }
+
+int
+userauth_gsskeyex(Authctxt *authctxt)
+{
+	Buffer b;
+	gss_buffer_desc gssbuf;
+	gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
+	OM_uint32 ms;
+
+	static int attempt = 0;
+	if (attempt++ >= 1)
+		return (0);
+
+	if (gss_kex_context == NULL) {
+		debug("No valid Key exchange context"); 
+		return (0);
+	}
+
+	ssh_gssapi_buildmic(&b, authctxt->server_user, authctxt->service,
+	    "gssapi-keyex");
+
+	gssbuf.value = buffer_ptr(&b);
+	gssbuf.length = buffer_len(&b);
+
+	if (GSS_ERROR(ssh_gssapi_sign(gss_kex_context, &gssbuf, &mic))) {
+		buffer_free(&b);
+		return (0);
+	}
+
+	packet_start(SSH2_MSG_USERAUTH_REQUEST);
+	packet_put_cstring(authctxt->server_user);
+	packet_put_cstring(authctxt->service);
+	packet_put_cstring(authctxt->method->name);
+	packet_put_string(mic.value, mic.length);
+	packet_send();
+
+	buffer_free(&b);
+	gss_release_buffer(&ms, &mic);
+
+	return (1);
+}
+
 #endif /* GSSAPI */
 
 int
 userauth_none(Authctxt *authctxt)
 {
 	/* initial userauth request */
 	packet_start(SSH2_MSG_USERAUTH_REQUEST);
 	packet_put_cstring(authctxt->server_user);
diff --git a/openssh-7.2p2/sshd.c b/openssh-7.2p2/sshd.c
--- a/openssh-7.2p2/sshd.c
+++ b/openssh-7.2p2/sshd.c
@@ -124,16 +124,20 @@
 #endif
 #include "monitor_wrap.h"
 #include "ssh-sandbox.h"
 #include "version.h"
 #include "ssherr.h"
 
 #include "fips.h"
 
+#ifdef USE_SECURITY_SESSION_API
+#include <Security/AuthSession.h>
+#endif
+
 #ifndef O_NOCTTY
 #define O_NOCTTY	0
 #endif
 
 /* Re-exec fds */
 #define REEXEC_DEVCRYPTO_RESERVED_FD	(STDERR_FILENO + 1)
 #define REEXEC_STARTUP_PIPE_FD		(STDERR_FILENO + 2)
 #define REEXEC_CONFIG_PASS_FD		(STDERR_FILENO + 3)
@@ -1847,20 +1851,23 @@ main(int ac, char **av)
 	if ((options.protocol & SSH_PROTO_1) && fips_mode()) {
 		logit("Disabling protocol version 1. Not allowed in the FIPS mode.");
 		options.protocol &= ~SSH_PROTO_1;
 	}
 	if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) {
 		logit("Disabling protocol version 1. Could not load host key");
 		options.protocol &= ~SSH_PROTO_1;
 	}
+#ifndef GSSAPI
+	/* The GSSAPI key exchange can run without a host key */
 	if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) {
 		logit("Disabling protocol version 2. Could not load host key");
 		options.protocol &= ~SSH_PROTO_2;
 	}
+#endif
 	if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) {
 		logit("sshd: no hostkeys available -- exiting.");
 		exit(1);
 	}
 
 	/*
 	 * Load certificates. They are stored in an array at identical
 	 * indices to the public keys that they relate to.
@@ -2055,16 +2062,70 @@ main(int ac, char **av)
 		/* Accept a connection and return in a forked child */
 		server_accept_loop(&sock_in, &sock_out,
 		    &newsock, config_s);
 	}
 
 	/* This is the child processing a new connection. */
 	setproctitle("%s", "[accepted]");
 
+#ifdef USE_SECURITY_SESSION_API
+	/*
+	 * Create a new security session for use by the new user login if
+	 * the current session is the root session or we are not launched
+	 * by inetd (eg: debugging mode or server mode).  We do not
+	 * necessarily need to create a session if we are launched from
+	 * inetd because Panther xinetd will create a session for us.
+	 *
+	 * The only case where this logic will fail is if there is an
+	 * inetd running in a non-root session which is not creating
+	 * new sessions for us.  Then all the users will end up in the
+	 * same session (bad).
+	 *
+	 * When the client exits, the session will be destroyed for us
+	 * automatically.
+	 *
+	 * We must create the session before any credentials are stored
+	 * (including AFS pags, which happens a few lines below).
+	 */
+	{
+		OSStatus err = 0;
+		SecuritySessionId sid = 0;
+		SessionAttributeBits sattrs = 0;
+
+		err = SessionGetInfo(callerSecuritySession, &sid, &sattrs);
+		if (err)
+			error("SessionGetInfo() failed with error %.8X",
+			    (unsigned) err);
+		else
+			debug("Current Session ID is %.8X / Session Attributes are %.8X",
+			    (unsigned) sid, (unsigned) sattrs);
+
+		if (inetd_flag && !(sattrs & sessionIsRoot))
+			debug("Running in inetd mode in a non-root session... "
+			    "assuming inetd created the session for us.");
+		else {
+			debug("Creating new security session...");
+			err = SessionCreate(0, sessionHasTTY | sessionIsRemote);
+			if (err)
+				error("SessionCreate() failed with error %.8X",
+				    (unsigned) err);
+
+			err = SessionGetInfo(callerSecuritySession, &sid, 
+			    &sattrs);
+			if (err)
+				error("SessionGetInfo() failed with error %.8X",
+				    (unsigned) err);
+			else
+				debug("New Session ID is %.8X / Session Attributes are %.8X",
+				    (unsigned) sid, (unsigned) sattrs);
+		}
+	}
+#endif
+
 	/*
 	 * Create a new session and process group since the 4.4BSD
 	 * setlogin() affects the entire process group.  We don't
 	 * want the child to be able to affect the parent.
 	 */
 #if !defined(SSHD_ACQUIRES_CTTY)
 	/*
 	 * If setsid is called, on some platforms sshd will later acquire a
@@ -2165,16 +2226,70 @@ main(int ac, char **av)
 #endif
 
 	/* Log the connection. */
 	laddr = get_local_ipaddr(sock_in);
 	verbose("Connection from %s port %d on %s port %d",
 	    remote_ip, remote_port, laddr,  get_local_port());
 	free(laddr);
 
+#ifdef USE_SECURITY_SESSION_API
+	/*
+	 * Create a new security session for use by the new user login if
+	 * the current session is the root session or we are not launched
+	 * by inetd (eg: debugging mode or server mode).  We do not
+	 * necessarily need to create a session if we are launched from
+	 * inetd because Panther xinetd will create a session for us.
+	 *
+	 * The only case where this logic will fail is if there is an
+	 * inetd running in a non-root session which is not creating
+	 * new sessions for us.  Then all the users will end up in the
+	 * same session (bad).
+	 *
+	 * When the client exits, the session will be destroyed for us
+	 * automatically.
+	 *
+	 * We must create the session before any credentials are stored
+	 * (including AFS pags, which happens a few lines below).
+	 */
+	{
+		OSStatus err = 0;
+		SecuritySessionId sid = 0;
+		SessionAttributeBits sattrs = 0;
+
+		err = SessionGetInfo(callerSecuritySession, &sid, &sattrs);
+		if (err)
+			error("SessionGetInfo() failed with error %.8X",
+			    (unsigned) err);
+		else
+			debug("Current Session ID is %.8X / Session Attributes are %.8X",
+			    (unsigned) sid, (unsigned) sattrs);
+
+		if (inetd_flag && !(sattrs & sessionIsRoot))
+			debug("Running in inetd mode in a non-root session... "
+			    "assuming inetd created the session for us.");
+		else {
+			debug("Creating new security session...");
+			err = SessionCreate(0, sessionHasTTY | sessionIsRemote);
+			if (err)
+				error("SessionCreate() failed with error %.8X",
+				    (unsigned) err);
+
+			err = SessionGetInfo(callerSecuritySession, &sid, 
+			    &sattrs);
+			if (err)
+				error("SessionGetInfo() failed with error %.8X",
+				    (unsigned) err);
+			else
+				debug("New Session ID is %.8X / Session Attributes are %.8X",
+				    (unsigned) sid, (unsigned) sattrs);
+		}
+	}
+#endif
+
 	/*
 	 * We don't want to listen forever unless the other side
 	 * successfully authenticates itself.  So we set up an alarm which is
 	 * cleared after successful authentication.  A limit of zero
 	 * indicates no limit. Note that we don't set the alarm in debugging
 	 * mode; it is just annoying to have the server exit just when you
 	 * are about to discover the bug.
 	 */
@@ -2585,30 +2700,79 @@ do_ssh2_kex(void)
 
 	if (options.rekey_limit || options.rekey_interval)
 		packet_set_rekey_limits(options.rekey_limit,
 		    (time_t)options.rekey_interval);
 
 	myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = compat_pkalg_proposal(
 	    list_hostkey_types());
 
+#ifdef GSSAPI
+	{
+	char *orig;
+	char *gss = NULL;
+	char *newstr = NULL;
+	orig = myproposal[PROPOSAL_KEX_ALGS];
+
+	/* 
+	 * If we don't have a host key, then there's no point advertising
+	 * the other key exchange algorithms
+	 */
+
+	if (strlen(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]) == 0)
+		orig = NULL;
+
+	if (options.gss_keyex)
+		gss = ssh_gssapi_server_mechanisms();
+	else
+		gss = NULL;
+
+	if (gss && orig)
+		xasprintf(&newstr, "%s,%s", gss, orig);
+	else if (gss)
+		newstr = gss;
+	else if (orig)
+		newstr = orig;
+
+	/* 
+	 * If we've got GSSAPI mechanisms, then we've got the 'null' host
+	 * key alg, but we can't tell people about it unless its the only
+  	 * host key algorithm we support
+	 */
+	if (gss && (strlen(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS])) == 0)
+		myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = "null";
+
+	if (newstr)
+		myproposal[PROPOSAL_KEX_ALGS] = newstr;
+	else
+		fatal("No supported key exchange algorithms");
+	}
+#endif
+
 	/* start key exchange */
 	if ((r = kex_setup(active_state, myproposal)) != 0)
 		fatal("kex_setup: %s", ssh_err(r));
 	kex = active_state->kex;
 #ifdef WITH_OPENSSL
 	kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
 	kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
 	kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
 	kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
 # ifdef OPENSSL_HAS_ECC
 	kex->kex[KEX_ECDH_SHA2] = kexecdh_server;
 # endif
 #endif
 	kex->kex[KEX_C25519_SHA256] = kexc25519_server;
+#ifdef GSSAPI
+	if (options.gss_keyex) {
+		kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_server;
+		kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_server;
+		kex->kex[KEX_GSS_GEX_SHA1] = kexgss_server;
+	}
+#endif
 	kex->server = 1;
 	kex->client_version_string=client_version_string;
 	kex->server_version_string=server_version_string;
 	kex->load_host_public_key=&get_hostkey_public_by_type;
 	kex->load_host_private_key=&get_hostkey_private_by_type;
 	kex->host_key_index=&get_hostkey_index;
 	kex->sign = sshd_hostkey_sign;
 
diff --git a/openssh-7.2p2/sshd_config b/openssh-7.2p2/sshd_config
--- a/openssh-7.2p2/sshd_config
+++ b/openssh-7.2p2/sshd_config
@@ -84,16 +84,18 @@ PasswordAuthentication no
 #KerberosAuthentication no
 #KerberosOrLocalPasswd yes
 #KerberosTicketCleanup yes
 #KerberosGetAFSToken no
 
 # GSSAPI options
 #GSSAPIAuthentication no
 #GSSAPICleanupCredentials yes
+#GSSAPIStrictAcceptorCheck yes
+#GSSAPIKeyExchange no
 
 # Set this to 'yes' to enable PAM authentication, account processing,
 # and session processing. If this is enabled, PAM authentication will
 # be allowed through the ChallengeResponseAuthentication and
 # PasswordAuthentication.  Depending on your PAM configuration,
 # PAM authentication via ChallengeResponseAuthentication may bypass
 # the setting of "PermitRootLogin without-password".
 # If you just want the PAM account and session checks to run without
diff --git a/openssh-7.2p2/sshd_config.0 b/openssh-7.2p2/sshd_config.0
--- a/openssh-7.2p2/sshd_config.0
+++ b/openssh-7.2p2/sshd_config.0
@@ -375,29 +375,41 @@ DESCRIPTION
              force remote port forwardings to bind to the wildcard address, or
              M-bM-^@M-^\clientspecifiedM-bM-^@M-^] to allow the client to select the address to
              which the forwarding is bound.  The default is M-bM-^@M-^\noM-bM-^@M-^].
 
      GSSAPIAuthentication
              Specifies whether user authentication based on GSSAPI is allowed.
              The default is M-bM-^@M-^\noM-bM-^@M-^].
 
+     GSSAPIKeyExchange
+             Specifies whether key exchange based on GSSAPI is allowed. GSSAPI
+             key exchange doesn't rely on ssh keys to verify host identity.  The
+             default is no.
+             Note that this option applies to protocol version 2 only.
+
      GSSAPICleanupCredentials
              Specifies whether to automatically destroy the user's credentials
              cache on logout.  The default is M-bM-^@M-^\yesM-bM-^@M-^].
 
      GSSAPIStrictAcceptorCheck
              Determines whether to be strict about the identity of the GSSAPI
              acceptor a client authenticates against.  If set to M-bM-^@M-^\yesM-bM-^@M-^] then
              the client must authenticate against the host service on the
              current hostname.  If set to M-bM-^@M-^\noM-bM-^@M-^] 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 M-bM-^@M-^\yesM-bM-^@M-^].
 
+     GSSAPIStoreCredentialsOnRekey
+             Controls whether the user's GSSAPI credentials should be updated
+             following a successful connection rekeying. This option can be used
+             to accepted renewed or updated credentials from a compatible
+             client. The default is no.
+
      HostbasedAcceptedKeyTypes
              Specifies the key types that will be accepted for hostbased
              authentication as a comma-separated pattern list.  Alternately if
              the specified value begins with a M-bM-^@M-^X+M-bM-^@M-^Y character, then the
              specified key types will be appended to the default set instead
              of replacing them.  The default for this option is:
 
                 ecdsa-sha2-nistp256-cert-v01@openssh.com,
diff --git a/openssh-7.2p2/sshd_config.5 b/openssh-7.2p2/sshd_config.5
--- a/openssh-7.2p2/sshd_config.5
+++ b/openssh-7.2p2/sshd_config.5
@@ -619,16 +619,22 @@ to force remote port forwardings to bind
 .Dq clientspecified
 to allow the client to select the address to which the forwarding is bound.
 The default is
 .Dq no .
 .It Cm GSSAPIAuthentication
 Specifies whether user authentication based on GSSAPI is allowed.
 The default is
 .Dq no .
+.It Cm GSSAPIKeyExchange
+Specifies whether key exchange based on GSSAPI is allowed. GSSAPI key exchange
+doesn't rely on ssh keys to verify host identity.
+The default is
+.Dq no .
+Note that this option applies to protocol version 2 only.
 .It Cm GSSAPICleanupCredentials
 Specifies whether to automatically destroy the user's credentials cache
 on logout.
 The default is
 .Dq yes .
 .It Cm GSSAPIStrictAcceptorCheck
 Determines whether to be strict about the identity of the GSSAPI acceptor
 a client authenticates against.
@@ -639,16 +645,21 @@ then the client must authenticate agains
 service on the current hostname.
 If set to
 .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 .
+.It Cm GSSAPIStoreCredentialsOnRekey
+Controls whether the user's GSSAPI credentials should be updated following a 
+successful connection rekeying. This option can be used to accepted renewed 
+or updated credentials from a compatible client. The default is
+.Dq no .
 .It Cm HostbasedAcceptedKeyTypes
 Specifies the key types that will be accepted for hostbased authentication
 as a comma-separated pattern list.
 Alternately if the specified value begins with a
 .Sq +
 character, then the specified key types will be appended to the default set
 instead of replacing them.
 The default for this option is:
diff --git a/openssh-7.2p2/sshkey.c b/openssh-7.2p2/sshkey.c
--- a/openssh-7.2p2/sshkey.c
+++ b/openssh-7.2p2/sshkey.c
@@ -110,16 +110,18 @@ static const struct keytype keytypes[] =
 	{ "ecdsa-sha2-nistp384-cert-v01@openssh.com", "ECDSA-CERT",
 	    KEY_ECDSA_CERT, NID_secp384r1, 1, 0 },
 #  ifdef OPENSSL_HAS_NISTP521
 	{ "ecdsa-sha2-nistp521-cert-v01@openssh.com", "ECDSA-CERT",
 	    KEY_ECDSA_CERT, NID_secp521r1, 1, 0 },
 #  endif /* OPENSSL_HAS_NISTP521 */
 # endif /* OPENSSL_HAS_ECC */
 #endif /* WITH_OPENSSL */
+	{ "null", "null",
+	    KEY_NULL, 0, 0 },
 	{ NULL, NULL, -1, -1, 0, 0 }
 };
 
 const char *
 sshkey_type(const struct sshkey *k)
 {
 	const struct keytype *kt;
 
diff --git a/openssh-7.2p2/sshkey.h b/openssh-7.2p2/sshkey.h
--- a/openssh-7.2p2/sshkey.h
+++ b/openssh-7.2p2/sshkey.h
@@ -57,16 +57,17 @@ enum sshkey_types {
 	KEY_RSA,
 	KEY_DSA,
 	KEY_ECDSA,
 	KEY_ED25519,
 	KEY_RSA_CERT,
 	KEY_DSA_CERT,
 	KEY_ECDSA_CERT,
 	KEY_ED25519_CERT,
+	KEY_NULL,
 	KEY_UNSPEC
 };
 
 /* Default fingerprint hash */
 #define SSH_FP_HASH_DEFAULT	SSH_DIGEST_SHA256
 
 /* Fingerprint representation formats */
 enum sshkey_fp_rep {