s4: add a minimal ktutil for selftest

This minimalistic version of ktutil dumps all principal names and
encryption types from a keytab, eg:

./bin/samba4ktutil test.keytab
ktpassuser@HILLHOUSE.SITE (arcfour-hmac-md5)
ktpassuser@HILLHOUSE.SITE (aes256-cts-hmac-sha1-96)
ktpassuser@HILLHOUSE.SITE (aes128-cts-hmac-sha1-96)
ktpassuser@HILLHOUSE.SITE (des-cbc-md5)
ktpassuser@HILLHOUSE.SITE (des-cbc-crc)

This is all we need to run some tests against keytabs exported with
`samba-tool domain exportkeytab`.

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>

2 files changed, 127 insertions, 0 deletions

diff --git a/source4/kdc/ktutil.c b/source4/kdc/ktutil.c
new file mode 100644
index 00000000000..2fcd79ae94d
--- /dev/null
+++ b/source4/kdc/ktutil.c
@@ -0,0 +1,122 @@
+/*
+   Unix SMB/CIFS implementation.
+
+   Minimal ktutil for selftest
+
+   Copyright (C) Ralph Boehme <slow@samba.org> 2016
+
+   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 "krb5_wrap/krb5_samba.h"
+
+static void smb_krb5_err(TALLOC_CTX *mem_ctx,
+			 krb5_context context,
+			 int exit_code,
+			 krb5_error_code code,
+			 const char *msg)
+{
+	char *krb5_err_str = smb_get_krb5_error_message(context,
+							code,
+							mem_ctx);
+	printf("%s: %s\n", msg, krb5_err_str ? krb5_err_str : "UNKOWN");
+
+	talloc_free(mem_ctx);
+	exit(exit_code);
+}
+
+int main (int argc, char **argv)
+{
+	TALLOC_CTX *mem_ctx = talloc_init("ktutil");
+	krb5_context context;
+	krb5_keytab keytab;
+	krb5_kt_cursor cursor;
+	krb5_keytab_entry entry;
+	krb5_error_code ret;
+	char *keytab_name = NULL;
+
+	if (mem_ctx == NULL) {
+		printf("talloc_init() failed\n");
+		exit(1);
+	}
+
+	if (argc != 2) {
+		printf("Usage: %s KEYTAB\n", argv[0]);
+		exit(1);
+	}
+
+	keytab_name = argv[1];
+
+	initialize_krb5_error_table();
+
+	ret = krb5_init_context(&context);
+	if (ret) {
+		smb_krb5_err(mem_ctx, context, 1, ret, "krb5_context");
+	}
+
+	ret = smb_krb5_open_keytab_relative(context, keytab_name, false, &keytab);
+	if (ret) {
+		smb_krb5_err(mem_ctx, context, 1, ret, "open keytab");
+	}
+
+	ret = krb5_kt_start_seq_get(context, keytab, &cursor);
+	if (ret) {
+		smb_krb5_err(mem_ctx, context, 1, ret, "krb5_kt_start_seq_get");
+	}
+
+	for (ret = krb5_kt_next_entry(context, keytab, &entry, &cursor);
+	     ret == 0;
+	     ret = krb5_kt_next_entry(context, keytab, &entry, &cursor))
+	{
+		char *principal = NULL;
+		char *enctype_str = NULL;
+		krb5_enctype enctype = smb_get_enctype_from_kt_entry(&entry);
+
+		ret = smb_krb5_unparse_name(mem_ctx,
+					    context,
+					    entry.principal,
+					    &principal);
+		if (ret) {
+			smb_krb5_err(mem_ctx, context, 1, ret, "krb5_enctype_to_string");
+		}
+
+		ret = smb_krb5_enctype_to_string(context,
+						 enctype,
+						 &enctype_str);
+		if (ret) {
+			smb_krb5_err(mem_ctx, context, 1, ret, "krb5_enctype_to_string");
+		}
+
+		printf("%s (%s)\n", principal, enctype_str);
+
+		TALLOC_FREE(principal);
+		SAFE_FREE(enctype_str);
+		smb_krb5_kt_free_entry(context, &entry);
+	}
+
+	ret = krb5_kt_end_seq_get(context, keytab, &cursor);
+	if (ret) {
+		smb_krb5_err(mem_ctx, context, 1, ret, "krb5_kt_end_seq_get");
+	}
+
+	ret = krb5_kt_close(context, keytab);
+	if (ret) {
+		smb_krb5_err(mem_ctx, context, 1, ret, "krb5_kt_close");
+	}
+
+	krb5_free_context(context);
+	talloc_free(mem_ctx);
+	return 0;
+}
diff --git a/source4/kdc/wscript_build b/source4/kdc/wscript_build
index 3c9c77bba0b..f0662e5026d 100755
--- a/source4/kdc/wscript_build
+++ b/source4/kdc/wscript_build
@@ -122,4 +122,9 @@ bld.SAMBA_SUBSYSTEM('MIT_SAMBA',
                          ''',
                     enabled=(not bld.CONFIG_SET('SAMBA4_USES_HEIMDAL') and bld.CONFIG_SET('HAVE_KDB_H')) )
 
+bld.SAMBA_BINARY('samba4ktutil',
+                 'ktutil.c',
+                 deps='krb5samba',
+                 install=False)
+
 bld.RECURSE('mit-kdb')