diff -Nur squid-3/bootstrap.sh squid-3-krb5/bootstrap.sh
--- squid-3/bootstrap.sh	2008-11-05 01:10:41.000000000 +0000
+++ squid-3-krb5/bootstrap.sh	2009-08-30 16:38:03.000000000 +0100
@@ -108,8 +108,7 @@
 
 for dir in \
 	"" \
-	lib/libTrie \
-	helpers/negotiate_auth/squid_kerb_auth
+	lib/libTrie
 do
     if [ -z "$dir" ] || [ -d $dir ]; then
 	if (
diff -Nur squid-3/configure.in squid-3-krb5/configure.in
--- squid-3/configure.in	2008-11-05 01:11:55.000000000 +0000
+++ squid-3-krb5/configure.in	2009-09-08 19:25:10.000000000 +0100
@@ -1626,15 +1626,6 @@
 	else
 	    AC_MSG_ERROR(Negotiate Auth helper $helper does not exist)
 	fi
-	# Kerberos helper has its own configure system
-	if test "$srcdir/helpers/negotiate_auth/$helper/configure" ; then
-	    if test $helper = squid_kerb_auth; then
-		AC_CONFIG_SUBDIRS(helpers/negotiate_auth/squid_kerb_auth)
-	    else
-		echo "ERROR: configure.in needs to be extended to support $helper!"
-		exit 1
-	    fi
-	fi
     done
     echo "Negotiate auth helpers built: $NEGOTIATE_AUTH_HELPERS"
 fi
@@ -1683,6 +1674,209 @@
 fi
 AC_SUBST(DIGEST_AUTH_HELPERS)
 
+dnl 
+dnl Check Kerberos/GSSAPI/SPNEGO
+dnl 
+SAVED_CPPFLAGS=$CPPFLAGS
+SAVED_LIBS=$LIBS
+AC_ARG_WITH(krb5-config,
+ [  --with-krb5-config=PATH specify path to krb5-config @<:@default=detect@:>@],
+[ if test "$withval" = "yes"; then
+     unset krb5confpath
+  elif test "$withval" != "no"; then
+     krb5confpath=$withval
+  else
+     krb5confpath=no
+  fi
+])
+if test x"$krb5confpath" != xno; then
+    if test x"$krb5confpath" != x; then
+        if ! test -x "$krb5confpath"; then
+            AC_MSG_WARN([krb5-config '$krb5confpath' not executable, ignoring])
+            AC_CHECK_PROG(ac_krb5_config, krb5-config, yes, no)
+            krb5confpath=krb5-config
+        fi
+        krb5_config_path=`dirname $krb5confpath`
+        AC_CHECK_PROG(ac_krb5_config, krb5-config, yes, no, $krb5_config_path)
+    else
+    AC_CHECK_PROG(ac_krb5_config,krb5-config,yes,no)
+        krb5confpath=krb5-config
+    fi
+fi
+if test "$ac_krb5_config" = "yes" ; then
+    ac_heimdal="`$krb5confpath --version 2>/dev/null | grep -i heimdal`"
+    ac_solaris="`$krb5confpath --version 2>/dev/null | grep -i solaris`"
+    if test "x$ac_heimdal" != "x" ; then
+        AC_DEFINE(HAVE_HEIMDAL_KERBEROS,1,[Define to 1 if you have Heimdal Kerberos])
+    else
+        AC_DEFINE(HAVE_MIT_KERBEROS,1,[Define to 1 if you have MIT Kerberos])
+    fi
+    if test "$ac_solaris" != "" ; then
+        KRB5INCS="`$krb5confpath --cflags krb5 2>/dev/null`"
+        KRB5LIBS="`$krb5confpath --libs krb5 2>/dev/null`"
+        KRB5INCS="-I/usr/include/gssapi $KRB5INCS"
+        KRB5LIBS="-L/usr/lib -R/usr/lib -lgss -lresolv -lsocket -lnsl $KRB5LIBS"
+    else
+        KRB5INCS=`$krb5confpath --cflags krb5 2>/dev/null`
+        KRB5LIBS=`$krb5confpath --libs krb5 2>/dev/null`
+        KRB5INCS="`$krb5confpath --cflags gssapi 2>/dev/null` $KRB5INCS"
+        KRB5LIBS="`$krb5confpath --libs gssapi 2>/dev/null` $KRB5LIBS"
+    fi
+    CPPFLAGS="$CPPFLAGS $KRB5INCS"
+    LIBS="$LIBS $KRB5LIBS"
+    AC_CHECK_HEADERS(gssapi.h gssapi/gssapi.h gssapi/gssapi_krb5.h)
+    if test "x$ac_heimdal" == "x" ; then
+        AC_CHECK_HEADERS(gssapi/gssapi_generic.h)
+    fi
+    AC_CHECK_HEADERS(krb5.h com_err.h)
+    AC_MSG_CHECKING([for max_skew in struct krb5_context])
+AC_TRY_COMPILE([
+#include <krb5.h>
+                ],
+                [ krb5_context kc; kc->max_skew = 1; ],
+                [ AC_DEFINE(HAVE_MAX_SKEW_IN_KRB5_CONTEXT, 1, [Define to 1 if max_skew in struct krb5_context])
+                  AC_MSG_RESULT(yes) ],
+                [ AC_MSG_RESULT(no) ]
+        )
+
+    if test "x$ac_heimdal" == "x" ; then
+        AC_CHECK_HEADERS(profile.h)
+    fi
+    AC_CHECK_LIB(com_err,error_message,
+        AC_DEFINE(HAVE_ERROR_MESSAGE,1,[Define to 1 if you have error_message]),)
+    AC_CHECK_LIB(krb5,krb5_get_err_text,
+        AC_DEFINE(HAVE_KRB5_GET_ERR_TEXT,1,[Define to 1 if you have krb5_get_err_text]),)
+    AC_CHECK_LIB(krb5,krb5_get_error_message,
+        AC_DEFINE(HAVE_KRB5_GET_ERROR_MESSAGE,1,[Define to 1 if you have krb5_get_error_message]),)
+    AC_CHECK_LIB(krb5,krb5_kt_free_entry,
+        AC_DEFINE(HAVE_KRB5_KT_FREE_ENTRY,1,[Define to 1 if you have krb5_kt_free_entry]),)
+    AC_CHECK_LIB(krb5,krb5_get_init_creds_keytab,
+        AC_DEFINE(HAVE_GET_INIT_CREDS_KEYTAB,1,[Define to 1 if you have krb5_get_init_creds_keytab]),)
+    AC_CHECK_LIB(krb5,krb5_get_max_time_skew,
+        AC_DEFINE(HAVE_KRB5_GET_MAX_TIME_SKEW,1,[Define to 1 if you have krb5_get_max_time_skew]),)
+    AC_CHECK_LIB(krb5,krb5_get_profile,
+        AC_DEFINE(HAVE_KRB5_GET_PROFILE,1,[Define to 1 if you have krb5_get_profile]),)
+    AC_CHECK_LIB(krb5,profile_get_integer,
+        AC_DEFINE(HAVE_PROFILE_GET_INTEGER,1,[Define to 1 if you have profile_get_integer]),)
+    AC_CHECK_LIB(krb5,profile_release,
+        AC_DEFINE(HAVE_PROFILE_RELEASE,1,[Define to 1 if you have profile_release]),)
+    AC_MSG_CHECKING([for memory cache])
+    AC_TRY_RUN([
+#include<krb5.h>
+main()
+{
+    krb5_context context;
+    krb5_ccache cc;
+
+    krb5_init_context(&context);
+    return krb5_cc_resolve(context, "MEMORY:test_cache", &cc);
+}],
+    [AC_DEFINE(HAVE_KRB5_MEMORY_CACHE,1, [Define to 1 if you have MEMORY: cache support])
+     AC_MSG_RESULT(yes)],
+    AC_MSG_RESULT(no))
+
+    AC_MSG_CHECKING([for working gssapi])
+    AC_TRY_RUN([
+#ifdef HAVE_GSSAPI_GSSAPI_H
+#include <gssapi/gssapi.h>
+#elif HAVE_GSSAPI_H
+#include <gssapi.h>
+#endif
+
+#ifdef HAVE_GSSAPI_GSSAPI_EXT_H
+#include <gssapi/gssapi_ext.h>
+#endif
+
+#ifdef HAVE_GSSAPI_GSSAPI_KRB5_H
+#include <gssapi/gssapi_krb5.h>
+#endif
+
+#ifdef HAVE_GSSAPI_GSSAPI_GENERIC_H
+#include <gssapi/gssapi_generic.h>
+#endif
+int
+main(void)
+{
+        OM_uint32 val;
+        gss_OID_set set;
+
+        gss_create_empty_oid_set(&val, &set);
+
+        return 0;
+}
+],  [AC_DEFINE(HAVE_GSSAPI, 1, [GSSAPI support])
+     AC_MSG_RESULT(yes)],
+    AC_MSG_RESULT(no))
+    AC_MSG_CHECKING([for spnego support])
+    AC_TRY_RUN([
+#ifdef HAVE_HEIMDAL_KERBEROS
+#ifdef HAVE_GSSAPI_GSSAPI_H
+#include <gssapi/gssapi.h>
+#elif defined(HAVE_GSSAPI_H)
+#include <gssapi.h>
+#endif
+#else
+#ifdef HAVE_GSSAPI_GSSAPI_H
+#include <gssapi/gssapi.h>
+#elif defined(HAVE_GSSAPI_H)
+#include <gssapi.h>
+#endif
+#ifdef HAVE_GSSAPI_GSSAPI_KRB5_H
+#include <gssapi/gssapi_krb5.h>
+#endif
+#ifdef HAVE_GSSAPI_GSSAPI_GENERIC_H
+#include <gssapi/gssapi_generic.h>
+#endif
+#endif
+#include <string.h>
+int main(int argc, char *argv[]) {
+ OM_uint32 major_status,minor_status;
+ gss_OID_set gss_mech_set;
+ int i;
+
+static gss_OID_desc _gss_mech_spnego  = {6, (void *)"\x2b\x06\x01\x05\x05\x02"};
+gss_OID gss_mech_spnego = &_gss_mech_spnego;
+
+ major_status = gss_indicate_mechs( &minor_status, &gss_mech_set);
+
+ for (i=0;i<gss_mech_set->count;i++) {
+     if (!memcmp(gss_mech_set->elements[i].elements,gss_mech_spnego->elements,gss_mech_set->elements[i].length)) {
+        return 0;
+     }
+ }
+
+ return 1;
+}],
+    [ac_cv_have_spnego=yes
+     AC_DEFINE(HAVE_SPNEGO,1, [Define to 1 if you have SPNEGO support])
+     AC_MSG_RESULT(yes)],
+    [ac_cv_have_spnego=no
+     AC_MSG_RESULT(no)])
+    AC_MSG_CHECKING([for working krb5])
+    AC_TRY_RUN([
+#ifdef HAVE_KRB5_H
+#include <krb5.h>
+#endif
+
+int
+main(void)
+{
+        krb5_context context;
+
+        krb5_init_context(&context);
+
+        return 0;
+}
+],  [AC_DEFINE(HAVE_KRB5, 1, [KRB5 support])
+     AC_MSG_RESULT(yes)],
+    AC_MSG_RESULT(no))
+   LIBS=$SAVED_LIBS
+   CPPFLAGS=$SAVED_CPPFLAGS
+   AC_SUBST(KRB5INCS)
+   AC_SUBST(KRB5LIBS)
+fi
+AM_CONDITIONAL(HAVE_SPNEGO, test x"$ac_cv_have_spnego" = x"yes" )
+
 dnl Enable "NTLM fail open"
 AC_ARG_ENABLE(ntlm-fail-open,
   AC_HELP_STRING([--enable-ntlm-fail-open],
@@ -3814,6 +4008,7 @@
 	helpers/ntlm_auth/mswin_sspi/Makefile \
 	helpers/negotiate_auth/Makefile \
 	helpers/negotiate_auth/mswin_sspi/Makefile \
+        helpers/negotiate_auth/squid_kerb_auth/Makefile \
 	helpers/external_acl/Makefile \
 	helpers/external_acl/ip_user/Makefile \
 	helpers/external_acl/ldap_group/Makefile \
diff -Nur squid-3/src/cf.data.pre squid-3-krb5/src/cf.data.pre
--- squid-3/src/cf.data.pre	2008-11-05 01:10:51.000000000 +0000
+++ squid-3-krb5/src/cf.data.pre	2009-08-30 23:10:26.000000000 +0100
@@ -1602,7 +1602,7 @@
 		     no-digest
 		     no-netdb-exchange
 		     no-delay
-		     login=user:password | PASS | *:password
+		     login=user:password | PASS | *:password | NEGOTIATE | NEGOTIATE:principal
 		     connect-timeout=nn
 		     digest-url=url
 		     allow-miss
@@ -1725,6 +1725,16 @@
 		     be used to identify this proxy to the peer, similar to
 		     the login=username:password option above.
 
+		     use 'login=NEGOTIATE' if this is a personal/workgroup
+                     proxy and your parent requires a secure proxy authentication. 
+		     The first principal from the default keytab or defined by
+		     the environment variable KRB5_KTNAME will be used. 
+
+		     use 'login=NEGOTIATE:principal_name' if this is a personal/workgroup
+                     proxy and your parent requires a secure proxy authentication. 
+		     The principal principal_name from the default keytab or defined by
+		     the environment variable KRB5_KTNAME will be used. 
+
 		     use 'connect-timeout=nn' to specify a peer
 		     specific connect timeout (also see the
 		     peer_connect_timeout directive)
diff -Nur squid-3/src/http.cc squid-3-krb5/src/http.cc
--- squid-3/src/http.cc	2008-11-05 01:10:51.000000000 +0000
+++ squid-3-krb5/src/http.cc	2009-08-30 13:12:18.000000000 +0100
@@ -1551,6 +1551,18 @@
             }
         } else if (strcmp(orig_request->peer_login, "PROXYPASS") == 0) {
             /* Nothing to do */
+#if HAVE_KRB5 && HAVE_GSSAPI
+        } else if (strncmp(orig_request->peer_login, "NEGOTIATE",strlen("NEGOTIATE")) == 0) {
+             char *Token=NULL;
+             char *PrincipalName=NULL,*p;
+             if ((p=strchr(orig_request->peer_login,':')) != NULL ) {
+                 PrincipalName=++p;
+             }
+             Token = peer_proxy_negotiate_auth(PrincipalName,request->peer_host);
+             if (Token) {
+                 httpHeaderPutStrf(hdr_out, HDR_PROXY_AUTHORIZATION, "Negotiate %s",Token);
+             }
+#endif /* HAVE_KRB5 && HAVE_GSSAPI */
         } else {
             httpHeaderPutStrf(hdr_out, HDR_PROXY_AUTHORIZATION, "Basic %s",
                               base64_encode(orig_request->peer_login));
@@ -1900,6 +1912,7 @@
     }
 
     mb.init();
+    request->peer_host=_peer?_peer->host:NULL;
     buildRequestPrefix(request, orig_request, entry, &mb, flags);
     debugs(11, 6, "httpSendRequest: FD " << fd << ":\n" << mb.buf);
     comm_write_mbuf(fd, &mb, requestSender);
diff -Nur squid-3/src/HttpRequest.h squid-3-krb5/src/HttpRequest.h
--- squid-3/src/HttpRequest.h	2008-11-05 01:10:50.000000000 +0000
+++ squid-3-krb5/src/HttpRequest.h	2009-08-30 00:27:55.000000000 +0100
@@ -139,6 +139,8 @@
 
     char *peer_login;		/* Configured peer login:password */
 
+    char *peer_host;           /* Selected peer host*/
+
     time_t lastmod;		/* Used on refreshes */
 
     const char *vary_headers;	/* Used when varying entities are detected. Changes how the store key is calculated */
diff -Nur squid-3/src/Makefile.am squid-3-krb5/src/Makefile.am
--- squid-3/src/Makefile.am	2008-11-05 01:10:50.000000000 +0000
+++ squid-3-krb5/src/Makefile.am	2009-08-30 00:31:20.000000000 +0100
@@ -215,6 +215,7 @@
 INCLUDES        = -I. -I$(srcdir) -I$(top_builddir)/include -I$(top_srcdir)/include -I$(top_srcdir)/lib/libTrie/include
 INCLUDES        += -I$(top_builddir)/lib -I$(top_srcdir)/lib
 INCLUDES	+= @SQUID_CPPUNIT_INC@
+INCLUDES	+= @KRB5INCS@
 
 EXTRA_PROGRAMS = \
 	DiskIO/DiskDaemon/diskd \
@@ -578,6 +579,7 @@
 	pconn.h \
 	PeerDigest.h \
 	peer_digest.cc \
+	peer_proxy_negotiate_auth.cc \
 	peer_select.cc \
 	peer_sourcehash.cc \
 	peer_userhash.cc \
@@ -700,7 +702,8 @@
 	-lmiscutil \
 	@XTRA_LIBS@ \
 	@EPOLL_LIBS@ \
-	@MINGW_LIBS@ 
+	@MINGW_LIBS@ \
+	@KRB5LIBS@
 squid_DEPENDENCIES = $(top_builddir)/lib/libmiscutil.a \
 	@STORE_OBJS@ \
 	@STORE_LINKOBJS@ \
@@ -859,6 +862,7 @@
 	$(XPROF_STATS_SOURCE) \
 	pconn.cc \
 	peer_digest.cc \
+	peer_proxy_negotiate_auth.cc \
 	peer_select.cc \
 	peer_sourcehash.cc \
 	peer_userhash.cc \
@@ -919,7 +923,8 @@
 	-lmiscutil \
 	@XTRA_LIBS@ \
 	@EPOLL_LIBS@ \
-	@MINGW_LIBS@ 
+	@MINGW_LIBS@ \
+	@KRB5LIBS@
 ufsdump_DEPENDENCIES = $(top_builddir)/lib/libmiscutil.a \
 	@STORE_OBJS@ \
 	@STORE_LINKOBJS@ \
diff -Nur squid-3/src/peer_proxy_negotiate_auth.cc squid-3-krb5/src/peer_proxy_negotiate_auth.cc
--- squid-3/src/peer_proxy_negotiate_auth.cc	1970-01-01 01:00:00.000000000 +0100
+++ squid-3-krb5/src/peer_proxy_negotiate_auth.cc	2009-09-08 19:44:28.000000000 +0100
@@ -0,0 +1,549 @@
+/*
+ * -----------------------------------------------------------------------------
+ *
+ * Author: Markus Moeller (markus_moeller at compuserve.com)
+ *
+ * Copyright (C) 2007 Markus Moeller. All rights reserved.
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307, USA.
+ *
+ * -----------------------------------------------------------------------------
+ */
+/*
+ * Hosted at http://sourceforge.net/projects/squidkerbauth
+ */
+
+#include <squid.h>
+
+#if HAVE_KRB5 && HAVE_GSSAPI
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+#if HAVE_PROFILE_H
+#include <profile.h>
+#endif				/* HAVE_PROFILE_H */
+#if HAVE_KRB5_H
+#include <krb5.h>
+#endif				/* HAVE_KRB5_H */
+#if HAVE_COM_ERR_H
+#include <com_err.h>
+#elif HAVE_ET_COM_ERR_H
+#include <et/com_err.h>
+#endif				/* HAVE_COM_ERR_H */
+
+#if HAVE_GSSAPI_GSSAPI_H
+#include <gssapi/gssapi.h>
+#elif HAVE_GSSAPI_H
+#include <gssapi.h>
+#endif				/* HAVE_GSSAPI_H */
+#if HAVE_GSSAPI_GSSAPI_EXT_H
+#include <gssapi/gssapi_ext.h>
+#endif				/* HAVE_GSSAPI_GSSAPI_EXT_H */
+#if HAVE_GSSAPI_GSSAPI_KRB5_H
+#include <gssapi/gssapi_krb5.h>
+#endif				/* HAVE_GSSAPI_GSSAPI_KRB5_H */
+#if HAVE_GSSAPI_GSSAPI_GENERIC_H
+#include <gssapi/gssapi_generic.h>
+#endif				/* HAVE_GSSAPI_GSSAPI_GENERIC_H */
+
+#ifndef gss_nt_service_name
+#define gss_nt_service_name GSS_C_NT_HOSTBASED_SERVICE
+#endif
+
+#if !HAVE_ERROR_MESSAGE && HAVE_KRB5_GET_ERR_TEXT
+#define error_message(code) krb5_get_err_text(kparam.context,code)
+#elif  !HAVE_ERROR_MESSAGE && HAVE_KRB5_GET_ERROR_MESSAGE
+#define error_message(code) krb5_get_error_message(kparam.context,code)
+#elif !HAVE_ERROR_MESSAGE
+static char err_code[17];
+    const char *KRB5_CALLCONV error_message(long code)
+    {
+       snprintf(err_code,16,"%ld",code);
+       return err_code;
+    }  
+#endif
+
+#ifndef gss_mech_spnego
+    static gss_OID_desc _gss_mech_spnego =
+	{ 6, (void *) "\x2b\x06\x01\x05\x05\x02" };
+    gss_OID gss_mech_spnego = &_gss_mech_spnego;
+#endif
+
+#if HAVE_NAS_KERBEROS
+#include <ibm_svc/krb5_svc.h>
+    const char *KRB5_CALLCONV error_message(long code)
+    {
+	char *msg = NULL;
+	krb5_svc_get_msg(code, &msg);
+	return msg;
+    }
+#endif
+
+/*
+ * Kerberos context and cache structure
+ * Caches authentication details to reduce
+ * number of authentication requests to kdc
+ */
+    static struct kstruct
+    {
+	krb5_context context;
+	krb5_ccache cc;
+    } kparam = {
+    NULL, NULL};
+
+/*
+ * krb5_create_cache creates a Kerberos file credential cache or a memory 
+ * credential cache if supported. The initial key for the principal 
+ * principal_name is extracted from the keytab keytab_filename.
+ *
+ * If keytab_filename is NULL the default will be used.
+ * If principal_name is NULL the first working entry of the keytab will be used.
+ */
+    int krb5_create_cache(char *keytab_filename, char *principal_name);
+
+/*
+ * krb5_cleanup clears used Keberos memory
+ */
+    void krb5_cleanup(void);
+
+/*
+ * check_gss_err checks for gssapi error codes, extracts the error message 
+ * and prints it.
+ */
+    int check_gss_err(OM_uint32 major_status, OM_uint32 minor_status,
+	const char *function);
+
+    int check_gss_err(OM_uint32 major_status, OM_uint32 minor_status,
+	const char *function)
+    {
+	if (GSS_ERROR(major_status)) {
+	    OM_uint32 maj_stat, min_stat;
+	    OM_uint32 msg_ctx = 0;
+	    gss_buffer_desc status_string;
+	    char buf[1024];
+	    size_t len;
+
+	    len = 0;
+	    msg_ctx = 0;
+	    while (!msg_ctx) {
+		/* convert major status code (GSS-API error) to text */
+		maj_stat = gss_display_status(&min_stat, major_status,
+		    GSS_C_GSS_CODE, GSS_C_NULL_OID, &msg_ctx, &status_string);
+		if (maj_stat == GSS_S_COMPLETE) {
+		    if (sizeof(buf) > len + status_string.length + 1) {
+			memcpy(buf + len, status_string.value,
+			    status_string.length);
+			len += status_string.length;
+		    }
+		    gss_release_buffer(&min_stat, &status_string);
+		    break;
+		}
+		gss_release_buffer(&min_stat, &status_string);
+	    }
+	    if (sizeof(buf) > len + 2) {
+		strcpy(buf + len, ". ");
+		len += 2;
+	    }
+	    msg_ctx = 0;
+	    while (!msg_ctx) {
+		/* convert minor status code (underlying routine error) to text */
+		maj_stat = gss_display_status(&min_stat, minor_status,
+		    GSS_C_MECH_CODE, GSS_C_NULL_OID, &msg_ctx, &status_string);
+		if (maj_stat == GSS_S_COMPLETE) {
+		    if (sizeof(buf) > len + status_string.length) {
+			memcpy(buf + len, status_string.value,
+			    status_string.length);
+			len += status_string.length;
+		    }
+		    gss_release_buffer(&min_stat, &status_string);
+		    break;
+		}
+		gss_release_buffer(&min_stat, &status_string);
+	    }
+	    debugs(11, 5, HERE << function << "failed: " << buf);
+	    return (1);
+	}
+	return (0);
+    }
+
+    void krb5_cleanup()
+    {
+	debugs(11, 5, HERE << "Cleanup kerberos context");
+	if (kparam.context) {
+	    if (kparam.cc)
+		krb5_cc_destroy(kparam.context, kparam.cc);
+	    kparam.cc = NULL;
+	    krb5_free_context(kparam.context);
+	    kparam.context = NULL;
+	}
+    }
+
+    int krb5_create_cache(char *kf, char *pn)
+    {
+
+#define KT_PATH_MAX 256
+#define MAX_RENEW_TIME "365d"
+#define DEFAULT_SKEW (krb5_deltat) 600
+
+	static char *keytab_filename = NULL, *principal_name = NULL;
+	static krb5_keytab keytab = 0;
+	static krb5_keytab_entry entry;
+	static krb5_kt_cursor cursor;
+	static krb5_creds *creds = NULL;
+#if HAVE_HEIMDAL_KERBEROS
+	static krb5_creds creds2;
+#endif
+	static krb5_principal principal = NULL;
+	static krb5_deltat skew;
+
+	krb5_get_init_creds_opt options;
+	krb5_error_code code = 0;
+	krb5_deltat rlife;
+#if HAVE_PROFILE_H && HAVE_KRB5_GET_PROFILE && HAVE_PROFILE_GET_INTEGER && HAVE_PROFILE_RELEASE 
+	profile_t profile;
+#endif
+#if HAVE_HEIMDAL_KERBEROS
+	krb5_kdc_flags flags;
+	krb5_realm *client_realm;
+#endif
+	char *mem_cache;
+
+      restart:
+/*
+ * Check if credentials need to be renewed
+ */
+	if (creds &&
+	    (creds->times.endtime - time(0) > skew) &&
+	    (creds->times.renew_till - time(0) > 2 * skew)) {
+	    if (creds->times.endtime - time(0) < 2 * skew) {
+#if !HAVE_HEIMDAL_KERBEROS
+		/* renew ticket */
+		code =
+		    krb5_get_renewed_creds(kparam.context, creds, principal,
+		    kparam.cc, NULL);
+#else
+		/* renew ticket */
+		flags.i = 0;
+		flags.b.renewable = flags.b.renew = 1;
+
+		code =
+		    krb5_cc_get_principal(kparam.context, kparam.cc,
+		    &creds2.client);
+		if (code) {
+		    debugs(11, 5,
+			HERE <<
+			"Error while getting principal from credential cache : "
+			<< error_message(code));
+		    return (1);
+		}
+		client_realm = krb5_princ_realm(kparam.context, creds2.client);
+		code =
+		    krb5_make_principal(kparam.context, &creds2.server,
+		    *client_realm, KRB5_TGS_NAME, *client_realm, NULL);
+		if (code) {
+		    debugs(11, 5,
+			HERE << "Error while getting krbtgt principal : " <<
+			error_message(code));
+		    return (1);
+		}
+		code =
+		    krb5_get_kdc_cred(kparam.context, kparam.cc, flags, NULL,
+		    NULL, &creds2, &creds);
+		krb5_free_creds(kparam.context, &creds2);
+#endif
+		if (code) {
+		    if (code == KRB5KRB_AP_ERR_TKT_EXPIRED) {
+			krb5_free_creds(kparam.context, creds);
+			creds = NULL;
+			/* this can happen because of clock skew */
+			goto restart;
+		    }
+		    debugs(11, 5,
+			HERE << "Error while get credentials : " <<
+			error_message(code));
+		    return (1);
+		}
+	    }
+	} else {
+	    /* reinit */
+	    if (!kparam.context) {
+		code = krb5_init_context(&kparam.context);
+		if (code) {
+		    debugs(11, 5,
+			HERE << "Error while initialising Kerberos library : "
+			<< error_message(code));
+		    return (1);
+		}
+	    }
+#if HAVE_PROFILE_H && HAVE_KRB5_GET_PROFILE && HAVE_PROFILE_GET_INTEGER && HAVE_PROFILE_RELEASE 
+	    code = krb5_get_profile(kparam.context, &profile);
+	    if (code) {
+		if (profile)
+		    profile_release(profile);
+		debugs(11, 5,
+		    HERE << "Error while getting profile : " <<
+		    error_message(code));
+		return (1);
+	    }
+	    code =
+		profile_get_integer(profile, "libdefaults", "clockskew", 0,
+		5 * 60, &skew);
+	    if (profile)
+		profile_release(profile);
+	    if (code) {
+		debugs(11, 5,
+		    HERE << "Error while getting clockskew : " <<
+		    error_message(code));
+		return (1);
+	    }
+#elif HAVE_KRB5_GET_MAX_TIME_SKEW && HAVE_HEIMDAL_KERBEROS
+	    skew = krb5_get_max_time_skew(kparam.context);
+#elif HAVE_MAX_SKEW_IN_KRB5_CONTEXT && HAVE_HEIMDAL_KERBEROS
+	    skew = kparam.context->max_skew;
+#else
+	    skew = DEFAULT_SKEW;
+#endif
+
+	    if (!kf) {
+		char buf[KT_PATH_MAX], *p;
+
+		krb5_kt_default_name(kparam.context, buf, KT_PATH_MAX);
+		p = strchr(buf, ':');
+		if (p)
+		    p++;
+		if (keytab_filename)
+		    xfree(keytab_filename);
+		keytab_filename = xstrdup(p ? p : buf);
+	    } else {
+		keytab_filename = xstrdup(kf);
+	    }
+
+	    code = krb5_kt_resolve(kparam.context, keytab_filename, &keytab);
+	    if (code) {
+		debugs(11, 5,
+		    HERE << "Error while resolving keytab filename " <<
+		    keytab_filename << " : " << error_message(code));
+		return (1);
+	    }
+
+	    if (!pn) {
+		code = krb5_kt_start_seq_get(kparam.context, keytab, &cursor);
+		if (code) {
+		    debugs(11, 5,
+			HERE << "Error while starting keytab scan : " <<
+			error_message(code));
+		    return (1);
+		}
+		code =
+		    krb5_kt_next_entry(kparam.context, keytab, &entry, &cursor);
+		krb5_copy_principal(kparam.context, entry.principal,
+		    &principal);
+		if (code && code != KRB5_KT_END) {
+		    debugs(11, 5,
+			HERE << "Error while scanning keytab : " <<
+			error_message(code));
+		    return (1);
+		}
+
+		code = krb5_kt_end_seq_get(kparam.context, keytab, &cursor);
+		if (code) {
+		    debugs(11, 5,
+			HERE << "Error while ending keytab scan : " <<
+			error_message(code));
+		    return (1);
+		}
+#if HAVE_HEIMDAL_KERBEROS || ( HAVE_KRB5_KT_FREE_ENTRY && HAVE_DECL_KRB5_KT_FREE_ENTRY)
+		code = krb5_kt_free_entry(kparam.context, &entry);
+#else
+		code = krb5_free_keytab_entry_contents(kparam.context, &entry);
+#endif
+		if (code) {
+		    debugs(11, 5,
+			HERE << "Error while freeing keytab entry : " <<
+			error_message(code));
+		    return (1);
+		}
+
+	    } else {
+		principal_name = xstrdup(pn);
+	    }
+
+	    if (!principal) {
+		code =
+		    krb5_parse_name(kparam.context, principal_name, &principal);
+		if (code) {
+		    debugs(11, 5,
+			HERE << "Error while parsing principal name " <<
+			principal_name << " : " << error_message(code));
+		    return (1);
+		}
+	    }
+
+	    creds = (krb5_creds *) xmalloc(sizeof(*creds));
+	    memset(creds, 0, sizeof(*creds));
+	    krb5_get_init_creds_opt_init(&options);
+	    code = krb5_string_to_deltat((char *) MAX_RENEW_TIME, &rlife);
+	    if (code != 0 || rlife == 0) {
+		debugs(11, 5,
+		    HERE << "Error bad lifetime value " << MAX_RENEW_TIME <<
+		    " : " << error_message(code));
+		return (1);
+	    }
+	    krb5_get_init_creds_opt_set_renew_life(&options, rlife);
+
+	    code =
+		krb5_get_init_creds_keytab(kparam.context, creds, principal,
+		keytab, 0, NULL, &options);
+	    if (code) {
+		debugs(11, 5,
+		    HERE <<
+		    "Error while initializing credentials from keytab : " <<
+		    error_message(code));
+		return (1);
+	    }
+#if !HAVE_KRB5_MEMORY_CACHE
+	    mem_cache =
+		(char *) xmalloc(strlen("FILE:/tmp/peer_proxy_negotiate_auth_")
+		+ 16);
+	    snprintf(mem_cache,
+		strlen("FILE:/tmp/peer_proxy_negotiate_auth_") + 16,
+		"FILE:/tmp/peer_proxy_negotiate_auth_%d", (int) getpid());
+#else
+	    mem_cache =
+		(char *) xmalloc(strlen("MEMORY:peer_proxy_negotiate_auth_") +
+		16);
+	    snprintf(mem_cache,
+		strlen("MEMORY:peer_proxy_negotiate_auth_") + 16,
+		"MEMORY:peer_proxy_negotiate_auth_%d", (int) getpid());
+#endif
+
+	    setenv("KRB5CCNAME", mem_cache, 1);
+	    code = krb5_cc_resolve(kparam.context, mem_cache, &kparam.cc);
+	    if (mem_cache)
+		xfree(mem_cache);
+	    if (code) {
+		debugs(11, 5,
+		    HERE << "Error while resolving memory credential cache : "
+		    << error_message(code));
+		return (1);
+	    }
+	    code = krb5_cc_initialize(kparam.context, kparam.cc, principal);
+	    if (code) {
+		debugs(11, 5,
+		    HERE <<
+		    "Error while initializing memory credential cache : " <<
+		    error_message(code));
+		return (1);
+	    }
+	    code = krb5_cc_store_cred(kparam.context, kparam.cc, creds);
+	    if (code) {
+		debugs(11, 5,
+		    HERE << "Error while storing credentials : " <<
+		    error_message(code));
+		return (1);
+	    }
+
+	    if (!creds->times.starttime)
+		creds->times.starttime = creds->times.authtime;
+	}
+	return (0);
+    }
+
+/*
+ * peer_proxy_negotiate_auth gets a GSSAPI token for principal_name
+ * and base64 encodes it.
+ */
+    char *peer_proxy_negotiate_auth(char *principal_name, char *proxy)
+    {
+	int rc = 0;
+	OM_uint32 major_status, minor_status;
+	gss_ctx_id_t gss_context = GSS_C_NO_CONTEXT;
+	gss_name_t server_name = GSS_C_NO_NAME;
+	gss_buffer_desc service = GSS_C_EMPTY_BUFFER;
+	gss_buffer_desc input_token = GSS_C_EMPTY_BUFFER;
+	gss_buffer_desc output_token = GSS_C_EMPTY_BUFFER;
+	char *token = NULL;
+
+	setbuf(stdout, NULL);
+	setbuf(stdin, NULL);
+
+	if (!proxy) {
+	    debugs(11, 5, HERE << "Error : No proxy server name");
+	    return NULL;
+	}
+
+	if (principal_name)
+	    debugs(11, 5,
+		HERE << "Creating credential cache for " << principal_name);
+	else
+	    debugs(11, 5, HERE << "Creating credential cache");
+	rc = krb5_create_cache(NULL, principal_name);
+	if (rc) {
+	    debugs(11, 5, HERE << "Error : Failed to create Kerberos cache");
+	    krb5_cleanup();
+	    return NULL;
+	}
+
+	service.value = (void *) xmalloc(strlen("HTTP") + strlen(proxy) + 2);
+	snprintf((char *) service.value, strlen("HTTP") + strlen(proxy) + 2,
+	    "%s@%s", "HTTP", proxy);
+	service.length = strlen((char *) service.value);
+
+	debugs(11, 5, HERE << "Import gss name");
+	major_status = gss_import_name(&minor_status, &service,
+	    gss_nt_service_name, &server_name);
+
+	if (check_gss_err(major_status, minor_status, "gss_import_name()"))
+	    goto cleanup;
+
+	debugs(11, 5, HERE << "Initialize gss security context");
+	major_status = gss_init_sec_context(&minor_status,
+	    GSS_C_NO_CREDENTIAL,
+	    &gss_context,
+	    server_name,
+	    gss_mech_spnego,
+	    0,
+	    0,
+	    GSS_C_NO_CHANNEL_BINDINGS,
+	    &input_token, NULL, &output_token, NULL, NULL);
+
+	if (check_gss_err(major_status, minor_status, "gss_init_sec_context()"))
+	    goto cleanup;
+
+	debugs(11, 5, HERE << "Got token with length " << output_token.length);
+	if (output_token.length) {
+
+	    token =
+		(char *) base64_encode_bin((const char *) output_token.value,
+		output_token.length);
+	}
+
+
+      cleanup:
+	gss_delete_sec_context(&minor_status, &gss_context, NULL);
+	gss_release_buffer(&minor_status, &service);
+	gss_release_buffer(&minor_status, &input_token);
+	gss_release_buffer(&minor_status, &output_token);
+	gss_release_name(&minor_status, &server_name);
+
+	return token;
+    }
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* HAVE_KRB5 && HAVE_GSSAPI */
diff -Nur squid-3/src/protos.h squid-3-krb5/src/protos.h
--- squid-3/src/protos.h	2008-11-05 01:10:51.000000000 +0000
+++ squid-3-krb5/src/protos.h	2009-08-30 01:27:07.000000000 +0100
@@ -817,4 +817,8 @@
 
 #endif
 
+#if HAVE_KRB5 && HAVE_GSSAPI
+            /* upstream proxy authentication */
+            SQUIDCEXTERN char *peer_proxy_negotiate_auth(char *principal_name, char *proxy);
+#endif
 #endif /* SQUID_PROTOS_H */
diff -Nur squid-3/src/tunnel.cc squid-3-krb5/src/tunnel.cc
--- squid-3/src/tunnel.cc	2008-11-05 01:10:52.000000000 +0000
+++ squid-3-krb5/src/tunnel.cc	2009-08-30 00:36:22.000000000 +0100
@@ -736,6 +736,7 @@
 
     tunnelState->servers = fs;
     tunnelState->host = fs->_peer ? fs->_peer->host : xstrdup(request->GetHost());
+    request->peer_host = fs->_peer ? fs->_peer->host : NULL;
 
     if (fs->_peer == NULL) {
         tunnelState->port = request->port;
