Pascal (Lazarus/Delphi)

Create PKCS1 RSA Signature with PEM Private Key

See more RSA Examples

Demonstrates how to load a private key from a PEM file and create a PKCS1 RSA digital signature. Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.PrivateKey,
  Chilkat.Rsa;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  pkey: TPrivateKey;
  rsa: TRsa;
  strData: string;
  hexSig: string;

begin
  success := False;

  //  This example assumes the Chilkat API to have been previously unlocked.
  //  See Global Unlock Sample for sample code.

  pkey := TPrivateKey.Create;

  //  Load the private key from an RSA PEM file:
  success := pkey.LoadPemFile('pvkey2_rsa.pem');
  if (success = False) then
    begin
      WriteLn(pkey.LastErrorText);
      Exit;
    end;

  rsa := TRsa.Create;

  //  Import the private key into the RSA object:
  success := rsa.UsePrivateKey(pkey);
  if (success = False) then
    begin
      WriteLn(rsa.LastErrorText);
      Exit;
    end;

  //  Get the signature as hex.
  rsa.EncodingMode := 'hex';

  strData := 'This is the string to be signed.';

  //  Sign the string using the sha-1 hash algorithm.
  //  Other valid choices are "md2", "md5", "sha256",
  //  "sha384", and "sha512".
  hexSig := rsa.SignStringENC(strData,'sha-1');

  WriteLn(hexSig);

  WriteLn('Success!');


  pkey.Free;
  rsa.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.