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/*
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"
extern int DEBUGLEVEL;
/****************************************************************************
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(DOM_CHAL *clnt_chal, DOM_CHAL *srv_chal, char *pass,
uint32 session_key[2])
{
uint32 sum[2];
unsigned char sum2[8];
unsigned char netsesskey[8];
sum[0] = IVAL(clnt_chal->data, 0) + IVAL(srv_chal->data, 0);
sum[1] = IVAL(clnt_chal->data, 4) + IVAL(srv_chal->data, 4);
SIVAL(sum2,0,sum[0]);
SIVAL(sum2,4,sum[1]);
cred_hash1(netsesskey, sum2,(unsigned char *)pass);
session_key[0] = IVAL(netsesskey, 0);
session_key[1] = IVAL(netsesskey, 4);
/* debug output */
DEBUG(4,("cred_session_key\n"));
DEBUG(5,(" clnt_chal: %lx %lx\n", clnt_chal->data[0], clnt_chal->data[1]));
DEBUG(5,(" srv_chal : %lx %lx\n", srv_chal ->data[0], srv_chal ->data[1]));
DEBUG(5,(" clnt+srv : %lx %lx\n", sum [0], sum [1]));
DEBUG(5,(" sess_key : %lx %lx\n", session_key [0], session_key [1]));
}
/****************************************************************************
create a credential
Input:
8 byte sesssion key
8 byte stored credential
4 byte timestamp
Output:
8 byte credential
****************************************************************************/
void cred_create(uint32 session_key[2], DOM_CHAL *stor_cred, UTIME timestamp,
DOM_CHAL *cred)
{
DOM_CHAL time_cred;
unsigned char calc_cred[8];
unsigned char timecred[8];
unsigned char netsesskey[8];
SIVAL(netsesskey, 0, session_key[0]);
SIVAL(netsesskey, 4, session_key[1]);
SIVAL(timecred, 0, IVAL(stor_cred, 0) + timestamp.time);
SIVAL(timecred, 4, IVAL(stor_cred, 4));
cred_hash2(calc_cred, timecred, netsesskey);
cred->data[0] = IVAL(calc_cred, 0);
cred->data[1] = IVAL(calc_cred, 4);
time_cred.data[0] = IVAL(timecred, 0);
time_cred.data[1] = IVAL(timecred, 4);
/* debug output*/
DEBUG(4,("cred_create\n"));
DEBUG(5,(" sess_key : %lx %lx\n", session_key [0], session_key [1]));
DEBUG(5,(" stor_cred: %lx %lx\n", stor_cred->data[0], stor_cred->data[1]));
DEBUG(5,(" timestamp: %lx\n" , timestamp.time));
DEBUG(5,(" timecred : %lx %lx\n", time_cred .data[0], time_cred .data[1]));
DEBUG(5,(" calc_cred: %lx %lx\n", cred ->data[0], cred ->data[1]));
}
/****************************************************************************
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(DOM_CHAL *cred, uint32 session_key[2], DOM_CHAL *stored_cred,
UTIME timestamp)
{
DOM_CHAL cred2;
cred_create(session_key, stored_cred, timestamp, &cred2);
/* debug output*/
DEBUG(4,("cred_assert\n"));
DEBUG(5,(" challenge : %lx %lx\n", cred->data[0], cred->data[1]));
DEBUG(5,(" calculated: %lx %lx\n", cred2.data[0], cred2.data[1]));
if (memcmp(cred->data, cred2.data, 8) == 0)
{
DEBUG(5, ("credentials check ok\n"));
return True;
}
else
{
DEBUG(5, ("credentials check wrong\n"));
return False;
}
}
/****************************************************************************
checks credentials; generates next step in the credential chain
****************************************************************************/
BOOL clnt_deal_with_creds(uint32 sess_key[2],
DOM_CRED *sto_clnt_cred, DOM_CRED *rcv_srv_cred)
{
UTIME new_clnt_time;
uint32 new_cred;
DEBUG(5,("clnt_deal_with_creds: %d\n", __LINE__));
/* increment client time by one second */
new_clnt_time.time = sto_clnt_cred->timestamp.time + 1;
/* check that the received server credentials are valid */
if (!cred_assert(&(rcv_srv_cred->challenge), sess_key,
&(sto_clnt_cred->challenge), new_clnt_time))
{
return False;
}
/* first 4 bytes of the new seed is old client 4 bytes + clnt time + 1 */
new_cred = IVAL(sto_clnt_cred->challenge.data, 0);
new_cred += new_clnt_time.time;
/* store new seed in client credentials */
SIVAL(sto_clnt_cred->challenge.data, 0, new_cred);
DEBUG(5,(" new clnt cred: %lx %lx\n", sto_clnt_cred->challenge.data[0],
sto_clnt_cred->challenge.data[1]));
return True;
}
/****************************************************************************
checks credentials; generates next step in the credential chain
****************************************************************************/
BOOL deal_with_creds(uint32 sess_key[2],
DOM_CRED *sto_clnt_cred,
DOM_CRED *rcv_clnt_cred, DOM_CRED *rtn_srv_cred)
{
UTIME new_clnt_time;
uint32 new_cred;
DEBUG(5,("deal_with_creds: %d\n", __LINE__));
/* check that the received client credentials are valid */
if (!cred_assert(&(rcv_clnt_cred->challenge), sess_key,
&(sto_clnt_cred->challenge), rcv_clnt_cred->timestamp))
{
return False;
}
/* increment client time by one second */
new_clnt_time.time = rcv_clnt_cred->timestamp.time + 1;
/* first 4 bytes of the new seed is old client 4 bytes + clnt time + 1 */
new_cred = IVAL(sto_clnt_cred->challenge.data, 0);
new_cred += new_clnt_time.time;
DEBUG(5,("deal_with_creds: new_cred[0]=%lx\n", new_cred));
/* doesn't matter that server time is 0 */
rtn_srv_cred->timestamp.time = 0;
DEBUG(5,("deal_with_creds: new_clnt_time=%lx\n", new_clnt_time.time));
/* create return credentials for inclusion in the reply */
cred_create(sess_key, &(sto_clnt_cred->challenge), new_clnt_time,
&(rtn_srv_cred->challenge));
DEBUG(5,("deal_with_creds: clnt_cred[0]=%lx\n",
sto_clnt_cred->challenge.data[0]));
/* store new seed in client credentials */
SIVAL(sto_clnt_cred->challenge.data, 0, new_cred);
return True;
}
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