s4:kerberos Add 'net export keytab' command for wireshark decryption

It is much easier to do decryption with wireshark when the keytab is
available for every host in the domain.  Running 'net export keytab
<keytab name>' will export the current (as pointed to by the supplied
smb.conf) local Samba4 doamin.

(This uses Heimdal's 'hdb' keytab and then the existing hdb-samba4,
and so has a good chance of keeping working in the long term).

Andrew Bartlett

10 files changed, 361 insertions, 8 deletions

diff --git a/source4/auth/kerberos/config.mk b/source4/auth/kerberos/config.mk
index 822bf398a7..609b036b64 100644
--- a/source4/auth/kerberos/config.mk
+++ b/source4/auth/kerberos/config.mk
@@ -12,7 +12,8 @@ KERBEROS_OBJ_FILES = $(addprefix $(authsrcdir)/kerberos/, \
 	kerberos_heimdal.o \
 	kerberos_pac.o \
 	gssapi_parse.o \
-	krb5_init_context.o)
+	krb5_init_context.o \
+	keytab_copy.o)
 
 $(eval $(call proto_header_template,$(authsrcdir)/kerberos/proto.h,$(KERBEROS_OBJ_FILES:.o=.c)))
 
diff --git a/source4/auth/kerberos/keytab_copy.c b/source4/auth/kerberos/keytab_copy.c
new file mode 100644
index 0000000000..ba4ea2bf39
--- /dev/null
+++ b/source4/auth/kerberos/keytab_copy.c
@@ -0,0 +1,146 @@
+/*
+ * Copyright (c) 1997-2004 Kungliga Tekniska Högskolan
+ * (Royal Institute of Technology, Stockholm, Sweden).
+ * 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.
+ *
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE OR CONTRIBUTORS 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"
+#include "system/kerberos.h"
+#include "auth/kerberos/kerberos.h"
+
+static const krb5_boolean verbose_flag = FALSE;
+
+static krb5_boolean
+compare_keyblock(const krb5_keyblock *a, const krb5_keyblock *b)
+{
+    if(a->keytype != b->keytype ||
+       a->keyvalue.length != b->keyvalue.length ||
+       memcmp(a->keyvalue.data, b->keyvalue.data, a->keyvalue.length) != 0)
+	return FALSE;
+    return TRUE;
+}
+
+krb5_error_code kt_copy (krb5_context context, const char *from, const char *to)
+{
+    krb5_error_code ret;
+    krb5_keytab src_keytab, dst_keytab;
+    krb5_kt_cursor cursor;
+    krb5_keytab_entry entry, dummy;
+
+    ret = krb5_kt_resolve (context, from, &src_keytab);
+    if (ret) {
+	krb5_warn (context, ret, "resolving src keytab `%s'", from);
+	return 1;
+    }
+
+    ret = krb5_kt_resolve (context, to, &dst_keytab);
+    if (ret) {
+	krb5_kt_close (context, src_keytab);
+	krb5_warn (context, ret, "resolving dst keytab `%s'", to);
+	return 1;
+    }
+
+    ret = krb5_kt_start_seq_get (context, src_keytab, &cursor);
+    if (ret) {
+	krb5_warn (context, ret, "krb5_kt_start_seq_get %s", from);
+	goto out;
+    }
+
+    if (verbose_flag)
+	fprintf(stderr, "copying %s to %s\n", from, to);
+
+    while((ret = krb5_kt_next_entry(context, src_keytab,
+				    &entry, &cursor)) == 0) {
+	char *name_str;
+	char *etype_str;
+	ret = krb5_unparse_name (context, entry.principal, &name_str);
+	if(ret) {
+	    krb5_warn(context, ret, "krb5_unparse_name");
+	    name_str = NULL; /* XXX */
+	}
+	ret = krb5_enctype_to_string(context, entry.keyblock.keytype, &etype_str);
+	if(ret) {
+	    krb5_warn(context, ret, "krb5_enctype_to_string");
+	    etype_str = NULL; /* XXX */
+	}
+	ret = krb5_kt_get_entry(context, dst_keytab,
+				entry.principal,
+				entry.vno,
+				entry.keyblock.keytype,
+				&dummy);
+	if(ret == 0) {
+	    /* this entry is already in the new keytab, so no need to
+               copy it; if the keyblocks are not the same, something
+               is weird, so complain about that */
+	    if(!compare_keyblock(&entry.keyblock, &dummy.keyblock)) {
+		krb5_warnx(context, "entry with different keyvalue "
+			   "already exists for %s, keytype %s, kvno %d",
+			   name_str, etype_str, entry.vno);
+	    }
+	    krb5_kt_free_entry(context, &dummy);
+	    krb5_kt_free_entry (context, &entry);
+	    free(name_str);
+	    free(etype_str);
+	    continue;
+	} else if(ret != KRB5_KT_NOTFOUND) {
+	    krb5_warn (context, ret, "%s: fetching %s/%s/%u",
+		       to, name_str, etype_str, entry.vno);
+	    krb5_kt_free_entry (context, &entry);
+	    free(name_str);
+	    free(etype_str);
+	    break;
+	} 
+	if (verbose_flag)
+	    fprintf (stderr, "copying %s, keytype %s, kvno %d\n", name_str,
+		     etype_str, entry.vno);
+	ret = krb5_kt_add_entry (context, dst_keytab, &entry);
+	krb5_kt_free_entry (context, &entry);
+	if (ret) {
+	    krb5_warn (context, ret, "%s: adding %s/%s/%u",
+		       to, name_str, etype_str, entry.vno);
+	    free(name_str);
+	    free(etype_str);
+	    break;
+	}
+	free(name_str);
+	free(etype_str);
+    }
+    krb5_kt_end_seq_get (context, src_keytab, &cursor);
+
+  out:
+    krb5_kt_close (context, src_keytab);
+    krb5_kt_close (context, dst_keytab);
+    if (ret == KRB5_KT_END) {
+	return 0;
+    } else if (ret == 0) {
+	return EINVAL;
+    }
+    return ret;
+}
diff --git a/source4/kdc/config.mk b/source4/kdc/config.mk
index 03fa2db295..56199d6364 100644
--- a/source4/kdc/config.mk
+++ b/source4/kdc/config.mk
@@ -6,7 +6,7 @@
 INIT_FUNCTION = server_service_kdc_init
 SUBSYSTEM = service
 PRIVATE_DEPENDENCIES = \
-		HEIMDAL_KDC HDB_SAMBA4 LIBSAMBA-HOSTCONFIG
+		HEIMDAL_KDC HDB_SAMBA4 PAC_GLUE LIBSAMBA-HOSTCONFIG
 # End SUBSYSTEM KDC
 #######################
 
@@ -22,5 +22,17 @@ PRIVATE_DEPENDENCIES = \
 # End SUBSYSTEM KDC
 #######################
 
-HDB_SAMBA4_OBJ_FILES = $(addprefix $(kdcsrcdir)/, hdb-samba4.o pac-glue.o)
+HDB_SAMBA4_OBJ_FILES = $(addprefix $(kdcsrcdir)/, hdb-samba4.o)
+
+#######################
+# Start SUBSYSTEM KDC
+[SUBSYSTEM::PAC_GLUE]
+CFLAGS = -Iheimdal/kdc -Iheimdal/lib/hdb
+PRIVATE_DEPENDENCIES = \
+		LIBLDB auth_sam auth_sam_reply CREDENTIALS \
+		HEIMDAL_HDB LIBSAMBA-HOSTCONFIG
+# End SUBSYSTEM KDC
+#######################
+
+PAC_GLUE_OBJ_FILES = $(addprefix $(kdcsrcdir)/, pac-glue.o)
 $(eval $(call proto_header_template,$(kdcsrcdir)/pac_glue.h,$(HDB_SAMBA4_OBJ_FILES:.o=.c)))
diff --git a/source4/libnet/config.mk b/source4/libnet/config.mk
index 07d5434ebf..eede8c871d 100644
--- a/source4/libnet/config.mk
+++ b/source4/libnet/config.mk
@@ -1,5 +1,5 @@
 [SUBSYSTEM::LIBSAMBA-NET]
-PUBLIC_DEPENDENCIES = CREDENTIALS dcerpc dcerpc_samr RPC_NDR_LSA RPC_NDR_SRVSVC RPC_NDR_DRSUAPI LIBCLI_COMPOSITE LIBCLI_RESOLVE LIBCLI_FINDDCS LIBCLI_CLDAP LIBCLI_FINDDCS gensec_schannel LIBCLI_AUTH LIBNDR SMBPASSWD PROVISION LIBCLI_SAMSYNC
+PUBLIC_DEPENDENCIES = CREDENTIALS dcerpc dcerpc_samr RPC_NDR_LSA RPC_NDR_SRVSVC RPC_NDR_DRSUAPI LIBCLI_COMPOSITE LIBCLI_RESOLVE LIBCLI_FINDDCS LIBCLI_CLDAP LIBCLI_FINDDCS gensec_schannel LIBCLI_AUTH LIBNDR SMBPASSWD PROVISION LIBCLI_SAMSYNC HDB_SAMBA4
 
 LIBSAMBA-NET_OBJ_FILES = $(addprefix $(libnetsrcdir)/, \
 	libnet.o libnet_passwd.o libnet_time.o libnet_rpc.o \
@@ -7,7 +7,7 @@ LIBSAMBA-NET_OBJ_FILES = $(addprefix $(libnetsrcdir)/, \
 	libnet_vampire.o libnet_samdump.o libnet_samdump_keytab.o \
 	libnet_samsync_ldb.o libnet_user.o libnet_group.o libnet_share.o \
 	libnet_lookup.o libnet_domain.o userinfo.o groupinfo.o userman.o \
-	groupman.o prereq_domain.o libnet_samsync.o)
+	groupman.o prereq_domain.o libnet_samsync.o libnet_export_keytab.o)
 
 $(eval $(call proto_header_template,$(libnetsrcdir)/libnet_proto.h,$(LIBSAMBA-NET_OBJ_FILES:.o=.c)))
 
diff --git a/source4/libnet/libnet.h b/source4/libnet/libnet.h
index 543a131806..9964a3f526 100644
--- a/source4/libnet/libnet.h
+++ b/source4/libnet/libnet.h
@@ -75,4 +75,5 @@ struct libnet_context {
 #include "libnet/libnet_share.h"
 #include "libnet/libnet_lookup.h"
 #include "libnet/libnet_domain.h"
+#include "libnet/libnet_export_keytab.h"
 #include "libnet/libnet_proto.h"
diff --git a/source4/libnet/libnet_export_keytab.c b/source4/libnet/libnet_export_keytab.c
new file mode 100644
index 0000000000..43fd0aa30e
--- /dev/null
+++ b/source4/libnet/libnet_export_keytab.c
@@ -0,0 +1,54 @@
+#include "includes.h"
+#include "system/kerberos.h"
+#include "auth/kerberos/kerberos.h"
+#include <hdb.h>
+#include "kdc/hdb-samba4.h"
+#include "auth/kerberos/keytab_copy.h"
+#include "libnet/libnet.h"
+
+NTSTATUS libnet_export_keytab(struct libnet_context *ctx, TALLOC_CTX *mem_ctx, struct libnet_export_keytab *r)
+{
+	krb5_error_code ret;
+	struct smb_krb5_context *smb_krb5_context;
+	const char *from_keytab;
+
+	/* Register hdb-samba4 hooks for use as a keytab */
+
+	struct hdb_samba4_context *hdb_samba4_context = talloc(mem_ctx, struct hdb_samba4_context);
+	if (!hdb_samba4_context) {
+		return NT_STATUS_NO_MEMORY; 
+	}
+
+	hdb_samba4_context->ev_ctx = ctx->event_ctx;
+	hdb_samba4_context->lp_ctx = ctx->lp_ctx;
+
+	from_keytab = talloc_asprintf(hdb_samba4_context, "HDB:samba4&%p", hdb_samba4_context);
+	if (!from_keytab) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	ret = smb_krb5_init_context(ctx, ctx->event_ctx, ctx->lp_ctx, &smb_krb5_context);
+	if (ret) {
+		return NT_STATUS_NO_MEMORY; 
+	}
+
+	ret = krb5_plugin_register(smb_krb5_context->krb5_context, 
+				   PLUGIN_TYPE_DATA, "hdb",
+				   &hdb_samba4);
+	if(ret) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	ret = krb5_kt_register(smb_krb5_context->krb5_context, &hdb_kt_ops);
+	if(ret) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	ret = kt_copy(smb_krb5_context->krb5_context, from_keytab, r->in.keytab_name);
+	if(ret) {
+		r->out.error_string = smb_get_krb5_error_message(smb_krb5_context->krb5_context,
+								 ret, mem_ctx);
+		return NT_STATUS_UNSUCCESSFUL;
+	}
+	return NT_STATUS_OK;
+}
diff --git a/source4/libnet/libnet_export_keytab.h b/source4/libnet/libnet_export_keytab.h
new file mode 100644
index 0000000000..194f8907a3
--- /dev/null
+++ b/source4/libnet/libnet_export_keytab.h
@@ -0,0 +1,28 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2009
+   
+   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/>.
+*/
+
+struct libnet_export_keytab {
+	struct {
+		const char *keytab_name;
+	} in;
+	struct {
+		const char *error_string;
+	} out;
+};
+
diff --git a/source4/utils/net/config.mk b/source4/utils/net/config.mk
index b2f0fcf6b1..ff8cb2c526 100644
--- a/source4/utils/net/config.mk
+++ b/source4/utils/net/config.mk
@@ -21,7 +21,8 @@ net_OBJ_FILES = $(addprefix $(utilssrcdir)/net/,  \
 		net_time.o \
 		net_join.o \
 		net_vampire.o \
-		net_user.o)
+		net_user.o \
+		net_export_keytab.o)
 
 
 $(eval $(call proto_header_template,$(utilssrcdir)/net/net_proto.h,$(net_OBJ_FILES:.o=.c)))
diff --git a/source4/utils/net/net.c b/source4/utils/net/net.c
index d934403ade..a96c672dfd 100644
--- a/source4/utils/net/net.c
+++ b/source4/utils/net/net.c
@@ -104,11 +104,11 @@ static const struct net_functable net_functable[] = {
 	{"time", "get remote server's time\n", net_time, net_time_usage},
 	{"join", "join a domain\n", net_join, net_join_usage},
 	{"samdump", "dump the sam of a domain\n", net_samdump, net_samdump_usage},
+	{"export", "dump the sam of this domain\n", net_export, net_export_usage},
 	{"vampire", "join and syncronise an AD domain onto the local server\n", net_vampire, net_vampire_usage},
 	{"samsync", "synchronise into the local ldb the sam of an NT4 domain\n", net_samsync_ldb, net_samsync_ldb_usage},
 	{"user", "manage user accounts\n", net_user, net_user_usage},
-	{"machinepw", "Get a machine password out of our SAM\n", net_machinepw,
-	 net_machinepw_usage},
+	{"machinepw", "Get a machine password out of our SAM\n", net_machinepw, net_machinepw_usage},
 	{NULL, NULL, NULL, NULL}
 };
 
diff --git a/source4/utils/net/net_export_keytab.c b/source4/utils/net/net_export_keytab.c
new file mode 100644
index 0000000000..7f13278a9e
--- /dev/null
+++ b/source4/utils/net/net_export_keytab.c
@@ -0,0 +1,110 @@
+/* 
+   Samba Unix/Linux SMB client library 
+   Distributed SMB/CIFS Server Management Utility 
+
+   Copyright (C) 2004 Stefan Metzmacher <metze@samba.org>
+   Copyright (C) 2005 Andrew Bartlett <abartlet@samba.org>
+
+   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 "utils/net/net.h"
+#include "libnet/libnet.h"
+#include "param/param.h"
+
+static int net_export_keytab_usage(struct net_context *ctx, int argc, const char **argv)
+{
+	d_printf("net export keytab <keytab>\n");
+	return 0;	
+}
+
+static int net_export_keytab_help(struct net_context *ctx, int argc, const char **argv)
+{
+	d_printf("Dumps kerberos keys of the domain into a keytab.\n");
+	return 0;	
+}
+
+static int net_export_keytab(struct net_context *ctx, int argc, const char **argv) 
+{
+	NTSTATUS status;
+	struct libnet_context *libnetctx;
+	struct libnet_export_keytab r;
+
+	switch (argc) {
+	case 0:
+		return net_export_keytab_usage(ctx, argc, argv);
+		break;
+	case 1:
+		r.in.keytab_name = argv[0];
+		break;
+	}
+
+	libnetctx = libnet_context_init(ctx->event_ctx, ctx->lp_ctx);
+	if (!libnetctx) {
+		return -1;	
+	}
+	libnetctx->cred = ctx->credentials;
+
+	r.out.error_string = NULL;
+
+	status = libnet_export_keytab(libnetctx, ctx, &r);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0,("libnet_export_keytab returned %s: %s\n",
+			 nt_errstr(status),
+			 r.out.error_string));
+		return -1;
+	}
+
+	talloc_free(libnetctx);
+
+	return 0;
+}
+
+/* main function table */
+static const struct net_functable net_export_functable[] = {
+	{"keytab", "dump keys into a keytab\n", net_export_keytab, net_export_keytab_usage},
+	{NULL, NULL, NULL, NULL}
+};
+
+int net_export(struct net_context *ctx, int argc, const char **argv) 
+{
+	int rc;
+
+	switch (argc) {
+	case 0:
+		rc = net_export_usage(ctx, argc, argv);
+		return rc;
+	case 1:
+	default:
+		rc = net_run_function(ctx, argc, argv, net_export_functable, 
+				      net_export_usage);
+		return rc;
+	}
+
+	return 0;
+}
+
+int net_export_usage(struct net_context *ctx, int argc, const char **argv)
+{
+	d_printf("net export keytab <keytab>\n");
+	return 0;	
+}
+
+int net_export_help(struct net_context *ctx, int argc, const char **argv)
+{
+	d_printf("Dumps the sam of the domain we are joined to.\n");
+	return 0;	
+}
+