an implementation of the NT domain credentials protocol

source/libsmb/credentials.c

@@ -0,0 +1,101 @@
+/* 
+   Unix SMB/Netbios implementation.
+   Version 1.9.
+   code to manipulate domain credentials
+   Copyright (C) Andrew Tridgell 1997
+   
+   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., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "includes.h"
+
+
+/****************************************************************************
+  setup the session key. 
+Input: 8 byte challenge block
+       8 byte server challenge block
+      16 byte md4 encrypted password
+Output:
+      8 byte session key
+****************************************************************************/
+void cred_session_key(char *challenge, char *srv_challenge, char *pass, 
+		       char *session_key)
+{
+	uint32 sum[2];
+	char sum2[8];
+	char buf[8];
+
+	sum[0] = IVAL(challenge, 0) + IVAL(srv_challenge, 0);
+	sum[1] = IVAL(challenge, 4) + IVAL(srv_challenge, 4);
+
+	SIVAL(sum2,0,sum[0]);
+	SIVAL(sum2,4,sum[1]);
+
+	E1(pass,sum2,buf);
+	E1(pass+9,buf,session_key);
+}
+
+
+/****************************************************************************
+create a credential
+
+Input:
+      8 byte sesssion key
+      8 byte stored credential
+      4 byte timestamp
+
+Output:
+      8 byte credential
+****************************************************************************/
+void cred_create(char *session_key, char *stored_cred, uint32 time, 
+		 char *cred)
+{
+	char key2[7];
+	char buf[8];
+	char timecred[8];
+
+	memcpy(timecred, stored_cred, 8);
+	SIVAL(timecred, 0, IVAL(stored_cred, 0) + time);
+
+	E1(session_key, timecred, buf);
+	memset(key2, 0, 7);
+	key2[0] = session_key[7];
+	E1(key2, buf, cred);
+}
+
+
+/****************************************************************************
+  check a supplied credential
+
+Input:
+      8 byte received credential
+      8 byte sesssion key
+      8 byte stored credential
+      4 byte timestamp
+
+Output:
+      returns 1 if computed credential matches received credential
+      returns 0 otherwise
+****************************************************************************/
+int cred_assert(char *cred, char *session_key, char *stored_cred,
+		uint32 time)
+{
+	char cred2[8];
+
+	cred_create(session_key, stored_cred, time, cred2);
+
+	return memcmp(cred, cred2, 8) == 0;
+}
+