source/libsmb/credentials.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 1.9.
   4    code to manipulate domain credentials
   5    Copyright (C) Andrew Tridgell 1997
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #include "includes.h"
  23
  24
  25 /****************************************************************************
  26   setup the session key.
  27 Input: 8 byte challenge block
  28        8 byte server challenge block
  29       16 byte md4 encrypted password
  30 Output:
  31       8 byte session key
  32 ****************************************************************************/
  33 void cred_session_key(char *challenge, char *srv_challenge, char *pass,
  34                        char *session_key)
  35 {
  36         uint32 sum[2];
  37         char sum2[8];
  38         char buf[8];
  39
  40         sum[0] = IVAL(challenge, 0) + IVAL(srv_challenge, 0);
  41         sum[1] = IVAL(challenge, 4) + IVAL(srv_challenge, 4);
  42
  43         SIVAL(sum2,0,sum[0]);
  44         SIVAL(sum2,4,sum[1]);
  45
  46         E1(pass,sum2,buf);
  47         E1(pass+9,buf,session_key);
  48 }
  49
  50
  51 /****************************************************************************
  52 create a credential
  53
  54 Input:
  55       8 byte sesssion key
  56       8 byte stored credential
  57       4 byte timestamp
  58
  59 Output:
  60       8 byte credential
  61 ****************************************************************************/
  62 void cred_create(char *session_key, char *stored_cred, UTIME timestamp,
  63                  char *cred)
  64 {
  65         char key2[7];
  66         char buf[8];
  67         char timecred[8];
  68
  69         memcpy(timecred, stored_cred, 8);
  70         SIVAL(timecred, 0, IVAL(stored_cred, 0) + timestamp.time);
  71
  72         E1(session_key, timecred, buf);
  73         memset(key2, 0, 7);
  74         key2[0] = session_key[7];
  75         E1(key2, buf, cred);
  76 }
  77
  78
  79 /****************************************************************************
  80   check a supplied credential
  81
  82 Input:
  83       8 byte received credential
  84       8 byte sesssion key
  85       8 byte stored credential
  86       4 byte timestamp
  87
  88 Output:
  89       returns 1 if computed credential matches received credential
  90       returns 0 otherwise
  91 ****************************************************************************/
  92 int cred_assert(char *cred, char *session_key, char *stored_cred,
  93                 NTTIME timestamp)
  94 {
  95         char cred2[8];
  96
  97         cred_create(session_key, stored_cred, timestamp, cred2);
  98
  99         return memcmp(cred, cred2, 8) == 0;
 100 }
 101