// Signing / Verifying example 

// This code uses the #import directive.
// Put the following line at the beginning of your module 

#import "XCEEDCRY.DLL" no_namespace named_guids 

CoInitialize( NULL );

try
{
  IXceedSigningPtr piSign; 

  piSign.CreateInstance( CLSID_XceedSigning ); 
  piSign->License( _bstr_t( L"your license key ) ); 

  IXceedRSASigningMethodPtr piRSA; 

  piRSA.CreateInstance( CLSID_XceedRSASigningMethod );  

  // The following call to SetRandomKeyPair would, in the real world,  
  // be replaced by the assignment of a Private Key to the  
  // PrivateKey property.  

  piRSA->SetRandomKeyPair( 512, NULL, 0 ); 

  piSign->SigningMethod = IXceedSignDataPtr( piRSA );   

  const char* pszSource = "This is the data to sign"; 
  DWORD dwSourceSize = lstrlen( pszSource ) + 1; // Let's say we want to sign the null-char too 
  BYTE* pcSignature = NULL; 
  short nSignatureSize = 0;  

  piSign->Sign( ( BYTE* )pszSource, dwSourceSize, TRUE );  

  piRSA->GetSignature( &pcSignature, &nSignatureSize );  

  //Do something with the Signature...  

  MessageBox( NULL, "Data signed successfully", "Signing result", MB_OK );  

  long lVerified = FALSE; 

  piSign->Verify( ( BYTE* )pszSource, dwSourceSize, TRUE, &lVerified );  

  if( lVerified ) 
  { 
    MessageBox( NULL, "Data verified successfully", "Verification result", MB_OK ); 
  } 
  else 
  { 
    // Should not happen 
    MessageBox( NULL, "Signature verification failed", "Verification result", MB_OK ); 
  }  

  CoTaskMemFree( pcSignature ); 
}
catch( const _com_error& xErr )
{
  char szMsg[50]; 
  wsprintf( szMsg, "Error %08x\n", xErr.Error() ); 
  MessageBox( NULL, szMsg, "Error", MB_OK ); 
}
catch( ... )
{
  MessageBox( NULL, "Unknown error", "Error", MB_OK ); 
} 

CoUninitialize();