diff -up openssh-5.9p0/auth-krb5.c.kuserok openssh-5.9p0/auth-krb5.c

--- openssh-5.9p0/auth-krb5.c.kuserok	2011-08-30 16:37:32.651150128 +0200

+++ openssh-5.9p0/auth-krb5.c	2011-08-30 16:37:37.549087368 +0200

@@ -54,6 +54,20 @@

 extern ServerOptions	 options;

+int

+ssh_krb5_kuserok(krb5_context krb5_ctx, krb5_principal krb5_user, const char *client)

+{

+	if (options.use_kuserok)

+		return krb5_kuserok(krb5_ctx, krb5_user, client);

+	else {

+		char kuser[65];

+

+		if (krb5_aname_to_localname(krb5_ctx, krb5_user, sizeof(kuser), kuser))

+			return 0;

+		return strcmp(kuser, client) == 0;

+	}

+}

+

 static int

 krb5_init(void *context)

 {

@@ -146,7 +160,7 @@ auth_krb5_password(Authctxt *authctxt, c

 	if (problem)

 		goto out;

-	if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user, client)) {

+	if (!ssh_krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user, client)) {

 		problem = -1;

 		goto out;

 	}

diff -up openssh-5.9p0/gss-serv-krb5.c.kuserok openssh-5.9p0/gss-serv-krb5.c

--- openssh-5.9p0/gss-serv-krb5.c.kuserok	2011-08-30 16:37:36.988024804 +0200

+++ openssh-5.9p0/gss-serv-krb5.c	2011-08-30 16:37:37.659088030 +0200

@@ -68,6 +68,7 @@ static int ssh_gssapi_krb5_cmdok(krb5_pr

     int);

 static krb5_context krb_context = NULL;

+extern int ssh_krb5_kuserok(krb5_context, krb5_principal, const char *);

 /* Initialise the krb5 library, for the stuff that GSSAPI won't do */

@@ -115,7 +116,7 @@ ssh_gssapi_krb5_userok(ssh_gssapi_client

 	/* NOTE: .k5login and .k5users must opened as root, not the user,

 	 * because if they are on a krb5-protected filesystem, user credentials

 	 * to access these files aren't available yet. */

-	if (krb5_kuserok(krb_context, princ, luser) && k5login_exists) {

+	if (ssh_krb5_kuserok(krb_context, princ, luser) && k5login_exists) {

 		retval = 1;

 		logit("Authorized to %s, krb5 principal %s (krb5_kuserok)",

 		    luser, (char *)client->displayname.value);

diff -up openssh-5.9p0/servconf.c.kuserok openssh-5.9p0/servconf.c

--- openssh-5.9p0/servconf.c.kuserok	2011-08-30 16:37:35.093073603 +0200

+++ openssh-5.9p0/servconf.c	2011-08-30 16:41:13.568087145 +0200

@@ -144,6 +144,7 @@ initialize_server_options(ServerOptions

 	options->authorized_principals_file = NULL;

 	options->ip_qos_interactive = -1;

 	options->ip_qos_bulk = -1;

+	options->use_kuserok = -1;

 }

 void

@@ -291,6 +292,8 @@ fill_default_server_options(ServerOption

 		options->ip_qos_bulk = IPTOS_THROUGHPUT;

 	if (options->show_patchlevel == -1)

  		options->show_patchlevel = 0;

+	if (options->use_kuserok == -1)

+		options->use_kuserok = 1;

 	/* Turn privilege separation on by default */

 	if (use_privsep == -1)

@@ -317,7 +320,7 @@ typedef enum {

 	sPermitRootLogin, sLogFacility, sLogLevel,

 	sRhostsRSAAuthentication, sRSAAuthentication,

 	sKerberosAuthentication, sKerberosOrLocalPasswd, sKerberosTicketCleanup,

-	sKerberosGetAFSToken,

+	sKerberosGetAFSToken, sKerberosUseKuserok,

 	sKerberosTgtPassing, sChallengeResponseAuthentication,

 	sPasswordAuthentication, sKbdInteractiveAuthentication,

 	sListenAddress, sAddressFamily,

@@ -388,11 +391,13 @@ static struct {

 #else

 	{ "kerberosgetafstoken", sUnsupported, SSHCFG_GLOBAL },

 #endif

+	{ "kerberosusekuserok", sKerberosUseKuserok, SSHCFG_ALL },

 #else

 	{ "kerberosauthentication", sUnsupported, SSHCFG_ALL },

 	{ "kerberosorlocalpasswd", sUnsupported, SSHCFG_GLOBAL },

 	{ "kerberosticketcleanup", sUnsupported, SSHCFG_GLOBAL },

 	{ "kerberosgetafstoken", sUnsupported, SSHCFG_GLOBAL },

+	{ "kerberosusekuserok", sUnsupported, SSHCFG_ALL },

 #endif

 	{ "kerberostgtpassing", sUnsupported, SSHCFG_GLOBAL },

 	{ "afstokenpassing", sUnsupported, SSHCFG_GLOBAL },

@@ -1371,6 +1376,10 @@ process_server_config_line(ServerOptions

 		*activep = value;

 		break;

+	case sKerberosUseKuserok:

+		intptr = &options->use_kuserok;

+		goto parse_flag;

+

 	case sPermitOpen:

 		arg = strdelim(&cp;;

 		if (!arg || *arg == '\0')

@@ -1580,6 +1589,7 @@ copy_set_server_options(ServerOptions *d

 	M_CP_INTOPT(max_authtries);

 	M_CP_INTOPT(ip_qos_interactive);

 	M_CP_INTOPT(ip_qos_bulk);

+	M_CP_INTOPT(use_kuserok);

 	/* See comment in servconf.h */

 	COPY_MATCH_STRING_OPTS();

@@ -1816,6 +1826,7 @@ dump_config(ServerOptions *o)

 	dump_cfg_fmtint(sUseDNS, o->use_dns);

 	dump_cfg_fmtint(sAllowTcpForwarding, o->allow_tcp_forwarding);

 	dump_cfg_fmtint(sUsePrivilegeSeparation, use_privsep);

+	dump_cfg_fmtint(sKerberosUseKuserok, o->use_kuserok);

 	/* string arguments */

 	dump_cfg_string(sPidFile, o->pid_file);

diff -up openssh-5.9p0/servconf.h.kuserok openssh-5.9p0/servconf.h

--- openssh-5.9p0/servconf.h.kuserok	2011-08-30 16:37:35.201051957 +0200

+++ openssh-5.9p0/servconf.h	2011-08-30 16:37:37.926087431 +0200

@@ -166,6 +166,7 @@ typedef struct {

 	int	num_permitted_opens;

+	int	use_kuserok;

 	char   *chroot_directory;

 	char   *revoked_keys_file;

 	char   *trusted_user_ca_keys;

diff -up openssh-5.9p0/sshd_config.5.kuserok openssh-5.9p0/sshd_config.5

--- openssh-5.9p0/sshd_config.5.kuserok	2011-08-30 16:37:35.979024607 +0200

+++ openssh-5.9p0/sshd_config.5	2011-08-30 16:37:38.040087843 +0200

@@ -603,6 +603,10 @@ Specifies whether to automatically destr

 file on logout.

 The default is

 .Dq yes .

+.It Cm KerberosUseKuserok

+Specifies whether to look at .k5login file for user's aliases.

+The default is

+.Dq yes .

 .It Cm KexAlgorithms

 Specifies the available KEX (Key Exchange) algorithms.

 Multiple algorithms must be comma-separated.

@@ -746,6 +750,7 @@ Available keywords are

 .Cm HostbasedUsesNameFromPacketOnly ,

 .Cm KbdInteractiveAuthentication ,

 .Cm KerberosAuthentication ,

+.Cm KerberosUseKuserok ,

 .Cm MaxAuthTries ,

 .Cm MaxSessions ,

 .Cm PubkeyAuthentication ,

diff -up openssh-5.9p0/sshd_config.kuserok openssh-5.9p0/sshd_config

--- openssh-5.9p0/sshd_config.kuserok	2011-08-30 16:37:36.808026328 +0200

+++ openssh-5.9p0/sshd_config	2011-08-30 16:37:38.148071520 +0200

@@ -77,6 +77,7 @@ ChallengeResponseAuthentication no

 #KerberosOrLocalPasswd yes

 #KerberosTicketCleanup yes

 #KerberosGetAFSToken no

+#KerberosUseKuserok yes

 # GSSAPI options

 #GSSAPIAuthentication no