Lazarus Pascal

Create PKCS7 (CMS) EnvelopedData

Encrypt some data to a recipient by creating a PKCS7 (CMS) EnvelopedData structure. The data will be encrypted using a symmetric content-encryption algorithm (e.g., AES), and the randomly generated symmetric key will be encrypted using the recipient’s RSA public key extracted from their X.509 certificate. Lazarus Pascal

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.Cert,
  Chilkat.Crypt2;

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

procedure RunDemo;
var
  success: Boolean;
  crypt: TCrypt2;
  cert: TCert;
  toBeEncrypted: string;
  result: string;

begin
  success := False;

  crypt := TCrypt2.Create;

  //  Specify the encryption to be used.
  //  "pki" indicates "Public Key Infrastructure" and will create a PKCS7 encrypted (enveloped-data) message.
  crypt.CryptAlgorithm := 'pki';
  crypt.Pkcs7CryptAlg := 'aes';
  crypt.KeyLength := 256;
  crypt.OaepHash := 'sha256';
  crypt.OaepPadding := True;

  cert := TCert.Create;

  //  Use a certificate found in the Windows certificate store.
  success := cert.LoadByCommonName('My Certificate');
  if (success <> True) then
    begin
      WriteLn(cert.LastErrorText);
      Exit;
    end;

  //  Tell the crypt object to use the certificate.
  crypt.SetEncryptCert(cert);

  toBeEncrypted := 'This string is to be encrypted.';

  //  Get the result in multi-line BASE64 MIME format.
  crypt.EncodingMode := 'base64_mime';
  crypt.Charset := 'utf-8';

  result := crypt.EncryptStringENC(toBeEncrypted);
  if (success <> True) then
    begin
      WriteLn(crypt.LastErrorText);
      Exit;
    end;

  //  -------------------------------------------------------------------------
  //  See the following example to decrypt what was created in this example
  //  Decrypt PKCS7 (CMS) EnvelopedData
  //  -------------------------------------------------------------------------

  WriteLn(result);

  //  Sample output:

  //  MIICSgYJKoZIhvcNAQcDoIICOzCCAjcCAQAxggHiMIIB3gIBADCBljCBgTELMAkGA1UEBhMCSVQx
  //  EDAOBgNVBAgMB0JlcmdhbW8xGTAXBgNVBAcMEFBvbnRlIFNhbiBQaWV0cm8xFzAVBgNVBAoMDkFj
  //  dGFsaXMgUy5wLkEuMSwwKgYDVQQDDCNBY3RhbGlzIENsaWVudCBBdXRoZW50aWNhdGlvbiBDQSBH
  //  MwIQPCWvkSv8oQ7xRmEHJ6TzEDA8BgkqhkiG9w0BAQcwL6APMA0GCWCGSAFlAwQCAQUAoRwwGgYJ
  //  KoZIhvcNAQEIMA0GCWCGSAFlAwQCAQUABIIBAKqHAPQNSsQoX7B2NH7QyEOWQRsSVs8oCHXmy8f4
  //  MVZD2er3bvYUCIomxpwbLEAl14qjUIMynahooYGgqip7+4FqL301G+BVjZVfEhHWj+VI1dAWnWuL
  //  VHlvc/pbQNBWqV8rKVJsNIsuAZkdj4WSwLVKxYkYX43B8fh/g71XN2DTJu7Z/824v48KBmgpQBOT
  //  2q7IcDGxNPAFN2p6eavIVGn2LvhEbf/Fszyj+GR5tMcnQP1BOLJ3s3JzUBbvj8hcZrF1Vhl9HnTU
  //  YQx8G/KdW1mR+Wlhl3BWoK0LYKRTbnTx2BXOs0CY1SXOAdhKr01ZYjA+xW4nGzY0lfXS9QZjh9gw
  //  TAYJKoZIhvcNAQcBMB0GCWCGSAFlAwQBKgQQw0xTbfmnt0zjWHo5SaQIp4AgxTVY9E/Ncqy6t+RM
  //  8y4c3Av62/wB8IpPUEmtM2OeuZo=


  crypt.Free;
  cert.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.