Adding upstream version 2:4.17.12+dfsg.upstream/2%4.17.12+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1133 insertions, 0 deletions

diff --git a/source4/auth/gensec/gensec_krb5.c b/source4/auth/gensec/gensec_krb5.c
new file mode 100644
index 0000000..104e463
--- /dev/null
+++ b/source4/auth/gensec/gensec_krb5.c
@@ -0,0 +1,1133 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   Kerberos backend for GENSEC
+   
+   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004
+   Copyright (C) Andrew Tridgell 2001
+   Copyright (C) Luke Howard 2002-2003
+   Copyright (C) Stefan Metzmacher 2004-2005
+
+   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 3 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, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include <tevent.h>
+#include "lib/util/tevent_ntstatus.h"
+#include "system/kerberos.h"
+#include "auth/kerberos/kerberos.h"
+#include "auth/auth.h"
+#include "lib/tsocket/tsocket.h"
+#include "librpc/gen_ndr/dcerpc.h"
+#include "auth/credentials/credentials.h"
+#include "auth/credentials/credentials_krb5.h"
+#include "auth/kerberos/kerberos_credentials.h"
+#include "auth/gensec/gensec.h"
+#include "auth/gensec/gensec_internal.h"
+#include "auth/gensec/gensec_proto.h"
+#include "auth/gensec/gensec_toplevel_proto.h"
+#include "param/param.h"
+#include "auth/auth_sam_reply.h"
+#include "lib/util/util_net.h"
+#include "../lib/util/asn1.h"
+#include "auth/kerberos/pac_utils.h"
+#include "gensec_krb5.h"
+#include "gensec_krb5_internal.h"
+#include "gensec_krb5_helpers.h"
+
+_PUBLIC_ NTSTATUS gensec_krb5_init(TALLOC_CTX *);
+
+static int gensec_krb5_destroy(struct gensec_krb5_state *gensec_krb5_state)
+{
+	if (!gensec_krb5_state->smb_krb5_context) {
+		/* We can't clean anything else up unless we started up this far */
+		return 0;
+	}
+	if (gensec_krb5_state->enc_ticket.length) { 
+		smb_krb5_free_data_contents(gensec_krb5_state->smb_krb5_context->krb5_context,
+					    &gensec_krb5_state->enc_ticket); 
+	}
+
+	if (gensec_krb5_state->ticket) {
+		krb5_free_ticket(gensec_krb5_state->smb_krb5_context->krb5_context, 
+				 gensec_krb5_state->ticket);
+	}
+
+	/* ccache freed in a child destructor */
+
+	krb5_free_keyblock(gensec_krb5_state->smb_krb5_context->krb5_context, 
+			   gensec_krb5_state->keyblock);
+		
+	if (gensec_krb5_state->auth_context) {
+		krb5_auth_con_free(gensec_krb5_state->smb_krb5_context->krb5_context, 
+				   gensec_krb5_state->auth_context);
+	}
+
+	return 0;
+}
+
+static NTSTATUS gensec_krb5_start(struct gensec_security *gensec_security, bool gssapi)
+{
+	krb5_error_code ret;
+	struct gensec_krb5_state *gensec_krb5_state;
+	struct cli_credentials *creds;
+	const struct tsocket_address *tlocal_addr, *tremote_addr;
+	krb5_address my_krb5_addr, peer_krb5_addr;
+	
+	creds = gensec_get_credentials(gensec_security);
+	if (!creds) {
+		return NT_STATUS_INVALID_PARAMETER;
+	}
+
+	gensec_krb5_state = talloc_zero(gensec_security, struct gensec_krb5_state);
+	if (!gensec_krb5_state) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	gensec_security->private_data = gensec_krb5_state;
+	gensec_krb5_state->gssapi = gssapi;
+
+	talloc_set_destructor(gensec_krb5_state, gensec_krb5_destroy); 
+
+	if (cli_credentials_get_krb5_context(creds, 
+					     gensec_security->settings->lp_ctx, &gensec_krb5_state->smb_krb5_context)) {
+		talloc_free(gensec_krb5_state);
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	ret = krb5_auth_con_init(gensec_krb5_state->smb_krb5_context->krb5_context, &gensec_krb5_state->auth_context);
+	if (ret) {
+		DEBUG(1,("gensec_krb5_start: krb5_auth_con_init failed (%s)\n", 
+			 smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, 
+						    ret, gensec_krb5_state)));
+		talloc_free(gensec_krb5_state);
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	ret = krb5_auth_con_setflags(gensec_krb5_state->smb_krb5_context->krb5_context, 
+				     gensec_krb5_state->auth_context,
+				     KRB5_AUTH_CONTEXT_DO_SEQUENCE);
+	if (ret) {
+		DEBUG(1,("gensec_krb5_start: krb5_auth_con_setflags failed (%s)\n", 
+			 smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, 
+						    ret, gensec_krb5_state)));
+		talloc_free(gensec_krb5_state);
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	tlocal_addr = gensec_get_local_address(gensec_security);
+	if (tlocal_addr) {
+		ssize_t sockaddr_ret;
+		struct samba_sockaddr addr;
+		bool ok;
+
+		addr.sa_socklen = sizeof(addr.u);
+		sockaddr_ret = tsocket_address_bsd_sockaddr(
+			tlocal_addr, &addr.u.sa, addr.sa_socklen);
+		if (sockaddr_ret < 0) {
+			talloc_free(gensec_krb5_state);
+			return NT_STATUS_INTERNAL_ERROR;
+		}
+		addr.sa_socklen = sockaddr_ret;
+		ok = smb_krb5_sockaddr_to_kaddr(&addr.u.ss, &my_krb5_addr);
+		if (!ok) {
+			DBG_WARNING("smb_krb5_sockaddr_to_kaddr (local) failed\n");
+			talloc_free(gensec_krb5_state);
+			return NT_STATUS_INTERNAL_ERROR;
+		}
+	}
+
+	tremote_addr = gensec_get_remote_address(gensec_security);
+	if (tremote_addr) {
+		ssize_t sockaddr_ret;
+		struct samba_sockaddr addr;
+		bool ok;
+
+		addr.sa_socklen = sizeof(addr.u);
+		sockaddr_ret = tsocket_address_bsd_sockaddr(
+			tremote_addr, &addr.u.sa, addr.sa_socklen);
+		if (sockaddr_ret < 0) {
+			talloc_free(gensec_krb5_state);
+			return NT_STATUS_INTERNAL_ERROR;
+		}
+		addr.sa_socklen = sockaddr_ret;
+		ok = smb_krb5_sockaddr_to_kaddr(&addr.u.ss, &peer_krb5_addr);
+		if (!ok) {
+			DBG_WARNING("smb_krb5_sockaddr_to_kaddr (remote) failed\n");
+			talloc_free(gensec_krb5_state);
+			return NT_STATUS_INTERNAL_ERROR;
+		}
+	}
+
+	ret = krb5_auth_con_setaddrs(gensec_krb5_state->smb_krb5_context->krb5_context, 
+				     gensec_krb5_state->auth_context,
+				     tlocal_addr ? &my_krb5_addr : NULL,
+				     tremote_addr ? &peer_krb5_addr : NULL);
+	if (ret) {
+		DEBUG(1,("gensec_krb5_start: krb5_auth_con_setaddrs failed (%s)\n", 
+			 smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, 
+						    ret, gensec_krb5_state)));
+		talloc_free(gensec_krb5_state);
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	return NT_STATUS_OK;
+}
+
+static NTSTATUS gensec_krb5_common_server_start(struct gensec_security *gensec_security, bool gssapi)
+{
+	NTSTATUS nt_status;
+	struct gensec_krb5_state *gensec_krb5_state;
+
+	nt_status = gensec_krb5_start(gensec_security, gssapi);
+	if (!NT_STATUS_IS_OK(nt_status)) {
+		return nt_status;
+	}
+	
+	gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
+	gensec_krb5_state->state_position = GENSEC_KRB5_SERVER_START;
+
+	return NT_STATUS_OK;
+}
+
+static NTSTATUS gensec_krb5_server_start(struct gensec_security *gensec_security)
+{
+	return gensec_krb5_common_server_start(gensec_security, false);
+}
+
+static NTSTATUS gensec_fake_gssapi_krb5_server_start(struct gensec_security *gensec_security)
+{
+	return gensec_krb5_common_server_start(gensec_security, true);
+}
+
+static NTSTATUS gensec_krb5_common_client_start(struct gensec_security *gensec_security, bool gssapi)
+{
+	const char *hostname;
+	struct gensec_krb5_state *gensec_krb5_state;
+	NTSTATUS nt_status;
+	hostname = gensec_get_target_hostname(gensec_security);
+	if (!hostname) {
+		DEBUG(3, ("No hostname for target computer passed in, cannot use kerberos for this connection\n"));
+		return NT_STATUS_INVALID_PARAMETER;
+	}
+	if (is_ipaddress(hostname)) {
+		DEBUG(2, ("Cannot do krb5 to an IP address"));
+		return NT_STATUS_INVALID_PARAMETER;
+	}
+	if (strcmp(hostname, "localhost") == 0) {
+		DEBUG(2, ("krb5 to 'localhost' does not make sense"));
+		return NT_STATUS_INVALID_PARAMETER;
+	}
+			
+	nt_status = gensec_krb5_start(gensec_security, gssapi);
+	if (!NT_STATUS_IS_OK(nt_status)) {
+		return nt_status;
+	}
+
+	gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
+	gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_START;
+	gensec_krb5_state->ap_req_options = AP_OPTS_USE_SUBKEY;
+
+	if (gensec_krb5_state->gssapi) {
+		/* The Fake GSSAPI model emulates Samba3, which does not do mutual authentication */
+		if (gensec_setting_bool(gensec_security->settings, "gensec_fake_gssapi_krb5", "mutual", false)) {
+			gensec_krb5_state->ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
+		}
+	} else {
+		/* The wrapping for KPASSWD (a user of the raw KRB5 API) should be mutually authenticated */
+		if (gensec_setting_bool(gensec_security->settings, "gensec_krb5", "mutual", true)) {
+			gensec_krb5_state->ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
+		}
+	}
+	return NT_STATUS_OK;
+}
+
+static NTSTATUS gensec_krb5_common_client_creds(struct gensec_security *gensec_security,
+						struct tevent_context *ev)
+{
+	struct gensec_krb5_state *gensec_krb5_state;
+	krb5_error_code ret;
+	struct ccache_container *ccache_container;
+	const char *error_string;
+	const char *principal;
+	const char *hostname;
+	krb5_data in_data = { .length = 0 };
+	krb5_data *in_data_p = NULL;
+#ifdef SAMBA4_USES_HEIMDAL
+	struct tevent_context *previous_ev;
+#endif
+
+	if (lpcfg_parm_bool(gensec_security->settings->lp_ctx,
+			    NULL, "gensec_krb5", "send_authenticator_checksum", true)) {
+		in_data_p = &in_data;
+	}
+	
+	gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
+
+	principal = gensec_get_target_principal(gensec_security);
+	hostname = gensec_get_target_hostname(gensec_security);
+
+	ret = cli_credentials_get_ccache(gensec_get_credentials(gensec_security), 
+				         ev,
+					 gensec_security->settings->lp_ctx, &ccache_container, &error_string);
+	switch (ret) {
+	case 0:
+		break;
+	case KRB5KDC_ERR_PREAUTH_FAILED:
+	case KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN:
+		return NT_STATUS_LOGON_FAILURE;
+	case KRB5_KDC_UNREACH:
+		DEBUG(3, ("Cannot reach a KDC we require to contact %s: %s\n", principal, error_string));
+		return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
+	case KRB5_CC_NOTFOUND:
+	case KRB5_CC_END:
+		DEBUG(3, ("Error preparing credentials we require to contact %s : %s\n", principal, error_string));
+		return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
+	default:
+		DEBUG(1, ("gensec_krb5_start: Aquiring initiator credentials failed: %s\n", error_string));
+		return NT_STATUS_UNSUCCESSFUL;
+	}
+	
+#ifdef SAMBA4_USES_HEIMDAL
+	/* Do this every time, in case we have weird recursive issues here */
+	ret = smb_krb5_context_set_event_ctx(gensec_krb5_state->smb_krb5_context, ev, &previous_ev);
+	if (ret != 0) {
+		DEBUG(1, ("gensec_krb5_start: Setting event context failed\n"));
+		return NT_STATUS_NO_MEMORY;
+	}
+#endif
+	if (principal) {
+		krb5_principal target_principal;
+		ret = krb5_parse_name(gensec_krb5_state->smb_krb5_context->krb5_context, principal,
+				      &target_principal);
+		if (ret == 0) {
+			krb5_creds this_cred;
+			krb5_creds *cred;
+
+			ZERO_STRUCT(this_cred);
+			ret = krb5_cc_get_principal(gensec_krb5_state->smb_krb5_context->krb5_context,
+						    ccache_container->ccache,
+						    &this_cred.client);
+			if (ret != 0) {
+				krb5_free_principal(gensec_krb5_state->smb_krb5_context->krb5_context,
+						    target_principal);
+				return NT_STATUS_UNSUCCESSFUL;
+			}
+
+			ret = krb5_copy_principal(gensec_krb5_state->smb_krb5_context->krb5_context,
+						  target_principal,
+						  &this_cred.server);
+			krb5_free_principal(gensec_krb5_state->smb_krb5_context->krb5_context,
+					    target_principal);
+			if (ret != 0) {
+				krb5_free_cred_contents(gensec_krb5_state->smb_krb5_context->krb5_context,
+							&this_cred);
+				return NT_STATUS_UNSUCCESSFUL;
+			}
+			this_cred.times.endtime = 0;
+
+			ret = krb5_get_credentials(gensec_krb5_state->smb_krb5_context->krb5_context,
+						   0,
+						   ccache_container->ccache,
+						   &this_cred,
+						   &cred);
+			krb5_free_cred_contents(gensec_krb5_state->smb_krb5_context->krb5_context,
+						&this_cred);
+			if (ret != 0) {
+				return NT_STATUS_UNSUCCESSFUL;
+			}
+
+			ret = krb5_mk_req_extended(gensec_krb5_state->smb_krb5_context->krb5_context,
+						   &gensec_krb5_state->auth_context,
+						   gensec_krb5_state->ap_req_options,
+						   in_data_p,
+						   cred,
+						   &gensec_krb5_state->enc_ticket);
+		}
+	} else {
+		ret = krb5_mk_req(gensec_krb5_state->smb_krb5_context->krb5_context, 
+				  &gensec_krb5_state->auth_context,
+				  gensec_krb5_state->ap_req_options,
+				  discard_const_p(char, gensec_get_target_service(gensec_security)),
+				  discard_const_p(char, hostname),
+				  in_data_p, ccache_container->ccache, 
+				  &gensec_krb5_state->enc_ticket);
+	}
+
+#ifdef SAMBA4_USES_HEIMDAL
+	smb_krb5_context_remove_event_ctx(gensec_krb5_state->smb_krb5_context, previous_ev, ev);
+#endif
+
+	switch (ret) {
+	case 0:
+		return NT_STATUS_OK;
+	case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
+		DEBUG(3, ("Server [%s] is not registered with our KDC: %s\n", 
+			  hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
+		return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
+	case KRB5_KDC_UNREACH:
+		DEBUG(3, ("Cannot reach a KDC we require to contact host [%s]: %s\n",
+			  hostname, smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
+		return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
+	case KRB5KDC_ERR_PREAUTH_FAILED:
+	case KRB5KRB_AP_ERR_TKT_EXPIRED:
+	case KRB5_CC_END:
+		/* Too much clock skew - we will need to kinit to re-skew the clock */
+	case KRB5KRB_AP_ERR_SKEW:
+	case KRB5_KDCREP_SKEW:
+		DEBUG(3, ("kerberos (mk_req) failed: %s\n", 
+			  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
+		FALL_THROUGH;
+	/* just don't print a message for these really ordinary messages */
+	case KRB5_FCC_NOFILE:
+	case KRB5_CC_NOTFOUND:
+	case ENOENT:
+		
+		return NT_STATUS_UNSUCCESSFUL;
+		break;
+		
+	default:
+		DEBUG(0, ("kerberos: %s\n", 
+			  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, gensec_krb5_state)));
+		return NT_STATUS_UNSUCCESSFUL;
+	}
+}
+
+static NTSTATUS gensec_krb5_client_start(struct gensec_security *gensec_security)
+{
+	return gensec_krb5_common_client_start(gensec_security, false);
+}
+
+static NTSTATUS gensec_fake_gssapi_krb5_client_start(struct gensec_security *gensec_security)
+{
+	return gensec_krb5_common_client_start(gensec_security, true);
+}
+
+
+/*
+  generate a krb5 GSS-API wrapper packet given a ticket
+*/
+static DATA_BLOB gensec_gssapi_gen_krb5_wrap(TALLOC_CTX *mem_ctx, const DATA_BLOB *ticket, const uint8_t tok_id[2])
+{
+	struct asn1_data *data;
+	DATA_BLOB ret = data_blob_null;
+
+	data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
+	if (!data || !ticket->data) {
+		return ret;
+	}
+
+	if (!asn1_push_tag(data, ASN1_APPLICATION(0))) goto err;
+	if (!asn1_write_OID(data, GENSEC_OID_KERBEROS5)) goto err;
+
+	if (!asn1_write(data, tok_id, 2)) goto err;
+	if (!asn1_write(data, ticket->data, ticket->length)) goto err;
+	if (!asn1_pop_tag(data)) goto err;
+
+
+	if (!asn1_extract_blob(data, mem_ctx, &ret)) {
+		goto err;
+	}
+	asn1_free(data);
+
+	return ret;
+
+  err:
+
+	DEBUG(1, ("Failed to build krb5 wrapper at offset %d\n",
+		  (int)asn1_current_ofs(data)));
+	asn1_free(data);
+	return ret;
+}
+
+/*
+  parse a krb5 GSS-API wrapper packet giving a ticket
+*/
+static bool gensec_gssapi_parse_krb5_wrap(TALLOC_CTX *mem_ctx, const DATA_BLOB *blob, DATA_BLOB *ticket, uint8_t tok_id[2])
+{
+	bool ret = false;
+	struct asn1_data *data = asn1_init(mem_ctx, ASN1_MAX_TREE_DEPTH);
+	int data_remaining;
+
+	if (!data) {
+		return false;
+	}
+
+	if (!asn1_load(data, *blob)) goto err;
+	if (!asn1_start_tag(data, ASN1_APPLICATION(0))) goto err;
+	if (!asn1_check_OID(data, GENSEC_OID_KERBEROS5)) goto err;
+
+	data_remaining = asn1_tag_remaining(data);
+
+	if (data_remaining < 3) {
+		asn1_set_error(data);
+	} else {
+		if (!asn1_read(data, tok_id, 2)) goto err;
+		data_remaining -= 2;
+		*ticket = data_blob_talloc(mem_ctx, NULL, data_remaining);
+		if (!asn1_read(data, ticket->data, ticket->length)) goto err;
+	}
+
+	if (!asn1_end_tag(data)) goto err;
+
+	ret = !asn1_has_error(data);
+
+  err:
+
+	asn1_free(data);
+
+	return ret;
+}
+
+static NTSTATUS gensec_krb5_update_internal(struct gensec_security *gensec_security,
+					    TALLOC_CTX *out_mem_ctx,
+					    struct tevent_context *ev,
+					    const DATA_BLOB in, DATA_BLOB *out)
+{
+	struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
+	krb5_error_code ret = 0;
+	NTSTATUS nt_status;
+
+	switch (gensec_krb5_state->state_position) {
+	case GENSEC_KRB5_CLIENT_START:
+	{
+		DATA_BLOB unwrapped_out;
+		
+		nt_status = gensec_krb5_common_client_creds(gensec_security, ev);
+		if (!NT_STATUS_IS_OK(nt_status)) {
+			return nt_status;
+		}
+
+		if (gensec_krb5_state->gssapi) {
+			unwrapped_out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
+			
+			/* wrap that up in a nice GSS-API wrapping */
+			*out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REQ);
+		} else {
+			*out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
+		}
+		if (gensec_krb5_state->ap_req_options & AP_OPTS_MUTUAL_REQUIRED) {
+			gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_MUTUAL_AUTH;
+			nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
+		} else {
+			gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
+			nt_status = NT_STATUS_OK;
+		}
+		return nt_status;
+	}
+		
+	case GENSEC_KRB5_CLIENT_MUTUAL_AUTH:
+	{
+		DATA_BLOB unwrapped_in;
+		krb5_data inbuf;
+		krb5_ap_rep_enc_part *repl = NULL;
+		uint8_t tok_id[2];
+
+		if (gensec_krb5_state->gssapi) {
+			if (!gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
+				DEBUG(1,("gensec_gssapi_parse_krb5_wrap(mutual authentication) failed to parse\n"));
+				dump_data_pw("Mutual authentication message:\n", in.data, in.length);
+				return NT_STATUS_INVALID_PARAMETER;
+			}
+		} else {
+			unwrapped_in = in;
+		}
+		/* TODO: check the tok_id */
+
+		inbuf.data = (char *)unwrapped_in.data;
+		inbuf.length = unwrapped_in.length;
+		ret = krb5_rd_rep(gensec_krb5_state->smb_krb5_context->krb5_context, 
+				  gensec_krb5_state->auth_context,
+				  &inbuf, &repl);
+		if (ret) {
+			DEBUG(1,("krb5_rd_rep (mutual authentication) failed (%s)\n",
+				 smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, out_mem_ctx)));
+			dump_data_pw("Mutual authentication message:\n", (uint8_t *)inbuf.data, inbuf.length);
+			nt_status = NT_STATUS_ACCESS_DENIED;
+		} else {
+			*out = data_blob(NULL, 0);
+			nt_status = NT_STATUS_OK;
+			gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
+		}
+		if (repl) {
+			krb5_free_ap_rep_enc_part(gensec_krb5_state->smb_krb5_context->krb5_context, repl);
+		}
+		return nt_status;
+	}
+
+	case GENSEC_KRB5_SERVER_START:
+	{
+		DATA_BLOB unwrapped_in;
+		DATA_BLOB unwrapped_out = data_blob(NULL, 0);
+		krb5_data inbuf, outbuf;
+		uint8_t tok_id[2];
+		struct keytab_container *keytab;
+		krb5_principal server_in_keytab;
+		const char *error_string;
+		enum credentials_obtained obtained;
+
+		if (!in.data) {
+			return NT_STATUS_INVALID_PARAMETER;
+		}	
+
+		/* Grab the keytab, however generated */
+		ret = cli_credentials_get_keytab(gensec_get_credentials(gensec_security), 
+						 gensec_security->settings->lp_ctx, &keytab);
+		if (ret) {
+			return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
+		}
+		
+		/* This ensures we lookup the correct entry in that
+		 * keytab.  A NULL principal is acceptable, and means
+		 * that the krb5 libs should search the keytab at
+		 * accept time for any matching key */
+		ret = principal_from_credentials(out_mem_ctx, gensec_get_credentials(gensec_security), 
+						 gensec_krb5_state->smb_krb5_context, 
+						 &server_in_keytab, &obtained, &error_string);
+
+		if (ret) {
+			DEBUG(2,("Failed to make credentials from principal: %s\n", error_string));
+			return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
+		}
+
+		if (keytab->password_based || obtained < CRED_SPECIFIED) {
+			/* 
+			 * Use match-by-key in this case (matches
+			 * cli_credentials_get_server_gss_creds()
+			 * behaviour).  No need to free the memory,
+			 * this is handled with a talloc destructor.
+			 */
+			server_in_keytab = NULL;
+		}
+
+		/* Parse the GSSAPI wrapping, if it's there... (win2k3 allows it to be omited) */
+		if (gensec_krb5_state->gssapi
+		    && gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
+			inbuf.data = (char *)unwrapped_in.data;
+			inbuf.length = unwrapped_in.length;
+		} else {
+			inbuf.data = (char *)in.data;
+			inbuf.length = in.length;
+		}
+
+		ret = smb_krb5_rd_req_decoded(gensec_krb5_state->smb_krb5_context->krb5_context,
+					      &gensec_krb5_state->auth_context,
+					      &inbuf,
+					      keytab->keytab,
+					      server_in_keytab,
+					      &outbuf,
+					      &gensec_krb5_state->ticket,
+					      &gensec_krb5_state->keyblock);
+
+		if (ret) {
+			DBG_WARNING("smb_krb5_rd_req_decoded failed\n");
+			return NT_STATUS_LOGON_FAILURE;
+		}
+		unwrapped_out.data = (uint8_t *)outbuf.data;
+		unwrapped_out.length = outbuf.length;
+		gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
+		/* wrap that up in a nice GSS-API wrapping */
+		if (gensec_krb5_state->gssapi) {
+			*out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REP);
+		} else {
+			*out = data_blob_talloc(out_mem_ctx, outbuf.data, outbuf.length);
+		}
+		smb_krb5_free_data_contents(gensec_krb5_state->smb_krb5_context->krb5_context,
+					    &outbuf);
+		return NT_STATUS_OK;
+	}
+
+	case GENSEC_KRB5_DONE:
+	default:
+		/* Asking too many times... */
+		return NT_STATUS_INVALID_PARAMETER;
+	}
+}
+
+struct gensec_krb5_update_state {
+	NTSTATUS status;
+	DATA_BLOB out;
+};
+
+static struct tevent_req *gensec_krb5_update_send(TALLOC_CTX *mem_ctx,
+						  struct tevent_context *ev,
+						  struct gensec_security *gensec_security,
+						  const DATA_BLOB in)
+{
+	struct tevent_req *req = NULL;
+	struct gensec_krb5_update_state *state = NULL;
+	NTSTATUS status;
+
+	req = tevent_req_create(mem_ctx, &state,
+				struct gensec_krb5_update_state);
+	if (req == NULL) {
+		return NULL;
+	}
+
+	status = gensec_krb5_update_internal(gensec_security,
+					     state, ev, in,
+					     &state->out);
+	state->status = status;
+	if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
+		tevent_req_done(req);
+		return tevent_req_post(req, ev);
+	}
+	if (tevent_req_nterror(req, status)) {
+		return tevent_req_post(req, ev);
+	}
+
+	tevent_req_done(req);
+	return tevent_req_post(req, ev);
+}
+
+static NTSTATUS gensec_krb5_update_recv(struct tevent_req *req,
+					TALLOC_CTX *out_mem_ctx,
+					DATA_BLOB *out)
+{
+	struct gensec_krb5_update_state *state =
+		tevent_req_data(req,
+		struct gensec_krb5_update_state);
+	NTSTATUS status;
+
+	*out = data_blob_null;
+
+	if (tevent_req_is_nterror(req, &status)) {
+		tevent_req_received(req);
+		return status;
+	}
+
+	*out = state->out;
+	talloc_steal(out_mem_ctx, state->out.data);
+	status = state->status;
+	tevent_req_received(req);
+	return status;
+}
+
+static NTSTATUS gensec_krb5_session_key(struct gensec_security *gensec_security, 
+					TALLOC_CTX *mem_ctx,
+					DATA_BLOB *session_key) 
+{
+	struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
+	krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
+	krb5_auth_context auth_context = gensec_krb5_state->auth_context;
+	krb5_error_code err = -1;
+	bool remote = false;
+	bool ok;
+
+	if (gensec_krb5_state->state_position != GENSEC_KRB5_DONE) {
+		return NT_STATUS_NO_USER_SESSION_KEY;
+	}
+
+	switch (gensec_security->gensec_role) {
+	case GENSEC_CLIENT:
+		remote = false;
+		break;
+	case GENSEC_SERVER:
+		remote = true;
+		break;
+	}
+
+	ok = smb_krb5_get_smb_session_key(mem_ctx,
+					  context,
+					  auth_context,
+					  session_key,
+					  remote);
+	if (!ok) {
+		DEBUG(10, ("KRB5 error getting session key %d\n", err));
+		return NT_STATUS_NO_USER_SESSION_KEY;
+	}
+
+	return NT_STATUS_OK;
+}
+
+#ifdef SAMBA4_USES_HEIMDAL
+static NTSTATUS gensec_krb5_session_info(struct gensec_security *gensec_security,
+					 TALLOC_CTX *mem_ctx,
+					 struct auth_session_info **_session_info) 
+{
+	NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
+	struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
+	krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
+	struct auth_session_info *session_info = NULL;
+
+	krb5_principal client_principal;
+	char *principal_string = NULL;
+	
+	DATA_BLOB pac_blob, *pac_blob_ptr = NULL;
+	krb5_data pac_data;
+
+	krb5_error_code ret;
+
+	TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
+	if (!tmp_ctx) {
+		return NT_STATUS_NO_MEMORY;
+	}
+	
+	ret = krb5_ticket_get_client(context, gensec_krb5_state->ticket, &client_principal);
+	if (ret) {
+		DEBUG(5, ("krb5_ticket_get_client failed to get client principal: %s\n", 
+			  smb_get_krb5_error_message(context, 
+						     ret, tmp_ctx)));
+		talloc_free(tmp_ctx);
+		return NT_STATUS_NO_MEMORY;
+	}
+	
+	ret = krb5_unparse_name(gensec_krb5_state->smb_krb5_context->krb5_context, 
+				client_principal, &principal_string);
+	if (ret) {
+		DEBUG(1, ("Unable to parse client principal: %s\n",
+			  smb_get_krb5_error_message(context, 
+						     ret, tmp_ctx)));
+		krb5_free_principal(context, client_principal);
+		talloc_free(tmp_ctx);
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	ret = krb5_ticket_get_authorization_data_type(context, gensec_krb5_state->ticket, 
+						      KRB5_AUTHDATA_WIN2K_PAC, 
+						      &pac_data);
+	
+	if (ret) {
+		/* NO pac */
+		DEBUG(5, ("krb5_ticket_get_authorization_data_type failed to find PAC: %s\n", 
+			  smb_get_krb5_error_message(context, 
+						     ret, tmp_ctx)));
+	} else {
+		/* Found pac */
+		pac_blob = data_blob_talloc(tmp_ctx, pac_data.data, pac_data.length);
+		smb_krb5_free_data_contents(context, &pac_data);
+		if (!pac_blob.data) {
+			free(principal_string);
+			krb5_free_principal(context, client_principal);
+			talloc_free(tmp_ctx);
+			return NT_STATUS_NO_MEMORY;
+		}
+
+		/* decode and verify the pac */
+		nt_status = kerberos_decode_pac(gensec_krb5_state,
+						pac_blob,
+						gensec_krb5_state->smb_krb5_context->krb5_context,
+						NULL, gensec_krb5_state->keyblock,
+						client_principal,
+						gensec_krb5_state->ticket->ticket.authtime, NULL);
+
+		if (!NT_STATUS_IS_OK(nt_status)) {
+			free(principal_string);
+			krb5_free_principal(context, client_principal);
+			talloc_free(tmp_ctx);
+			return nt_status;
+		}
+
+		pac_blob_ptr = &pac_blob;
+	}
+
+	nt_status = gensec_generate_session_info_pac(tmp_ctx,
+						     gensec_security,
+						     gensec_krb5_state->smb_krb5_context,
+						     pac_blob_ptr, principal_string,
+						     gensec_get_remote_address(gensec_security),
+						     &session_info);
+
+	free(principal_string);
+	krb5_free_principal(context, client_principal);
+
+	if (!NT_STATUS_IS_OK(nt_status)) {
+		talloc_free(tmp_ctx);
+		return nt_status;
+	}
+
+	nt_status = gensec_krb5_session_key(gensec_security, session_info, &session_info->session_key);
+
+	if (!NT_STATUS_IS_OK(nt_status)) {
+		talloc_free(tmp_ctx);
+		return nt_status;
+	}
+
+	*_session_info = talloc_steal(mem_ctx, session_info);
+
+	talloc_free(tmp_ctx);
+	return NT_STATUS_OK;
+}
+#else /* MIT KERBEROS */
+static NTSTATUS gensec_krb5_session_info(struct gensec_security *gensec_security,
+					 TALLOC_CTX *mem_ctx,
+					 struct auth_session_info **psession_info)
+{
+	NTSTATUS status = NT_STATUS_UNSUCCESSFUL;
+	struct gensec_krb5_state *gensec_krb5_state =
+		(struct gensec_krb5_state *)gensec_security->private_data;
+	krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
+	struct auth_session_info *session_info = NULL;
+
+	krb5_principal client_principal;
+	char *principal_string = NULL;
+
+	krb5_authdata **auth_pac_data = NULL;
+	DATA_BLOB pac_blob, *pac_blob_ptr = NULL;
+
+	krb5_error_code code;
+
+	TALLOC_CTX *tmp_ctx;
+
+	tmp_ctx = talloc_new(mem_ctx);
+	if (tmp_ctx == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	code = krb5_copy_principal(context,
+				   gensec_krb5_state->ticket->enc_part2->client,
+				   &client_principal);
+	if (code != 0) {
+		DBG_INFO("krb5_copy_principal failed to copy client "
+			 "principal: %s\n",
+			 smb_get_krb5_error_message(context, code, tmp_ctx));
+		talloc_free(tmp_ctx);
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	code = krb5_unparse_name(context, client_principal, &principal_string);
+	if (code != 0) {
+		DBG_WARNING("Unable to parse client principal: %s\n",
+			    smb_get_krb5_error_message(context, code, tmp_ctx));
+		krb5_free_principal(context, client_principal);
+		talloc_free(tmp_ctx);
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	code = krb5_find_authdata(context,
+				  gensec_krb5_state->ticket->enc_part2->authorization_data,
+				  NULL,
+				  KRB5_AUTHDATA_WIN2K_PAC,
+				  &auth_pac_data);
+	if (code != 0) {
+		/* NO pac */
+		DBG_INFO("krb5_find_authdata failed to find PAC: %s\n",
+			 smb_get_krb5_error_message(context, code, tmp_ctx));
+	} else {
+		krb5_timestamp ticket_authtime =
+			gensec_krb5_state->ticket->enc_part2->times.authtime;
+
+		/* Found pac */
+		pac_blob = data_blob_talloc(tmp_ctx,
+					    auth_pac_data[0]->contents,
+					    auth_pac_data[0]->length);
+		krb5_free_authdata(context, auth_pac_data);
+		if (pac_blob.data == NULL) {
+			free(principal_string);
+			krb5_free_principal(context, client_principal);
+			talloc_free(tmp_ctx);
+			return NT_STATUS_NO_MEMORY;
+		}
+
+		/* decode and verify the pac */
+		status = kerberos_decode_pac(gensec_krb5_state,
+					     pac_blob,
+					     context,
+					     NULL,
+					     gensec_krb5_state->keyblock,
+					     client_principal,
+					     ticket_authtime,
+					     NULL);
+
+		if (!NT_STATUS_IS_OK(status)) {
+			free(principal_string);
+			krb5_free_principal(context, client_principal);
+			talloc_free(tmp_ctx);
+			return status;
+		}
+
+		pac_blob_ptr = &pac_blob;
+	}
+	krb5_free_principal(context, client_principal);
+
+	status = gensec_generate_session_info_pac(tmp_ctx,
+						  gensec_security,
+						  gensec_krb5_state->smb_krb5_context,
+						  pac_blob_ptr,
+						  principal_string,
+						  gensec_get_remote_address(gensec_security),
+						  &session_info);
+	SAFE_FREE(principal_string);
+	if (!NT_STATUS_IS_OK(status)) {
+		talloc_free(tmp_ctx);
+		return status;
+	}
+
+	status = gensec_krb5_session_key(gensec_security,
+					 session_info,
+					 &session_info->session_key);
+	if (!NT_STATUS_IS_OK(status)) {
+		talloc_free(tmp_ctx);
+		return status;
+	}
+
+	*psession_info = talloc_steal(mem_ctx, session_info);
+	talloc_free(tmp_ctx);
+
+	return NT_STATUS_OK;
+}
+#endif /* SAMBA4_USES_HEIMDAL */
+
+static NTSTATUS gensec_krb5_wrap(struct gensec_security *gensec_security, 
+				   TALLOC_CTX *mem_ctx, 
+				   const DATA_BLOB *in, 
+				   DATA_BLOB *out)
+{
+	struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
+	krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
+	krb5_auth_context auth_context = gensec_krb5_state->auth_context;
+	krb5_error_code ret;
+	krb5_data input, output;
+	input.length = in->length;
+	input.data = (char *)in->data;
+	
+	if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
+		ret = krb5_mk_priv(context, auth_context, &input, &output, NULL);
+		if (ret) {
+			DEBUG(1, ("krb5_mk_priv failed: %s\n", 
+				  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, 
+							     ret, mem_ctx)));
+			return NT_STATUS_ACCESS_DENIED;
+		}
+		*out = data_blob_talloc(mem_ctx, output.data, output.length);
+		
+		smb_krb5_free_data_contents(context, &output);
+	} else {
+		return NT_STATUS_ACCESS_DENIED;
+	}
+	return NT_STATUS_OK;
+}
+
+static NTSTATUS gensec_krb5_unwrap(struct gensec_security *gensec_security, 
+				     TALLOC_CTX *mem_ctx, 
+				     const DATA_BLOB *in, 
+				     DATA_BLOB *out)
+{
+	struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
+	krb5_context context = gensec_krb5_state->smb_krb5_context->krb5_context;
+	krb5_auth_context auth_context = gensec_krb5_state->auth_context;
+	krb5_error_code ret;
+	krb5_data input, output;
+	krb5_replay_data replay;
+	input.length = in->length;
+	input.data = (char *)in->data;
+	
+	if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
+		ret = krb5_rd_priv(context, auth_context, &input, &output, &replay);
+		if (ret) {
+			DEBUG(1, ("krb5_rd_priv failed: %s\n", 
+				  smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, 
+							     ret, mem_ctx)));
+			return NT_STATUS_ACCESS_DENIED;
+		}
+		*out = data_blob_talloc(mem_ctx, output.data, output.length);
+		
+		smb_krb5_free_data_contents(context, &output);
+	} else {
+		return NT_STATUS_ACCESS_DENIED;
+	}
+	return NT_STATUS_OK;
+}
+
+static bool gensec_krb5_have_feature(struct gensec_security *gensec_security,
+				     uint32_t feature)
+{
+	struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
+	if (feature & GENSEC_FEATURE_SESSION_KEY) {
+		return true;
+	} 
+	if (gensec_krb5_state->gssapi) {
+		return false;
+	}
+
+	/*
+	 * krb5_mk_priv provides SIGN and SEAL
+	 */
+	if (feature & GENSEC_FEATURE_SIGN) {
+		return true;
+	}
+	if (feature & GENSEC_FEATURE_SEAL) {
+		return true;
+	}
+
+	return false;
+}
+
+static const char *gensec_krb5_final_auth_type(struct gensec_security *gensec_security)
+{
+	return GENSEC_FINAL_AUTH_TYPE_KRB5;
+}
+
+static const char *gensec_krb5_oids[] = { 
+	GENSEC_OID_KERBEROS5,
+	GENSEC_OID_KERBEROS5_OLD,
+	NULL 
+};
+
+static const struct gensec_security_ops gensec_fake_gssapi_krb5_security_ops = {
+	.name		= "fake_gssapi_krb5",
+	.auth_type	= DCERPC_AUTH_TYPE_KRB5,
+	.oid            = gensec_krb5_oids,
+	.client_start   = gensec_fake_gssapi_krb5_client_start,
+	.server_start   = gensec_fake_gssapi_krb5_server_start,
+	.update_send	= gensec_krb5_update_send,
+	.update_recv	= gensec_krb5_update_recv,
+	.magic   	= gensec_magic_check_krb5_oid,
+	.session_key	= gensec_krb5_session_key,
+	.session_info	= gensec_krb5_session_info,
+	.have_feature   = gensec_krb5_have_feature,
+	.final_auth_type = gensec_krb5_final_auth_type,
+	.enabled        = false,
+	.kerberos       = true,
+	.priority       = GENSEC_KRB5,
+};
+
+static const struct gensec_security_ops gensec_krb5_security_ops = {
+	.name		= "krb5",
+	.client_start   = gensec_krb5_client_start,
+	.server_start   = gensec_krb5_server_start,
+	.update_send	= gensec_krb5_update_send,
+	.update_recv	= gensec_krb5_update_recv,
+	.session_key	= gensec_krb5_session_key,
+	.session_info	= gensec_krb5_session_info,
+	.have_feature   = gensec_krb5_have_feature,
+	.wrap           = gensec_krb5_wrap,
+	.unwrap         = gensec_krb5_unwrap,
+	.final_auth_type = gensec_krb5_final_auth_type,
+	.enabled        = true,
+	.kerberos       = true,
+	.priority       = GENSEC_KRB5
+};
+
+_PUBLIC_ NTSTATUS gensec_krb5_init(TALLOC_CTX *ctx)
+{
+	NTSTATUS ret;
+
+	ret = gensec_register(ctx, &gensec_krb5_security_ops);
+	if (!NT_STATUS_IS_OK(ret)) {
+		DEBUG(0,("Failed to register '%s' gensec backend!\n",
+			gensec_krb5_security_ops.name));
+		return ret;
+	}
+
+	ret = gensec_register(ctx, &gensec_fake_gssapi_krb5_security_ops);
+	if (!NT_STATUS_IS_OK(ret)) {
+		DEBUG(0,("Failed to register '%s' gensec backend!\n",
+			gensec_fake_gssapi_krb5_security_ops.name));
+		return ret;
+	}
+
+	return ret;
+}