Delphi ActiveX

Create PEM-encoded PKCS#7 Detached Signature

See more Digital Signatures Examples

Demonstrates how to create a PKCS7 PEM-encoded object containing a detached signature. Delphi ActiveX

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Integer;
cert: TChilkatCert;
crypt: TChilkatCrypt2;
textToSign: WideString;
sigBase64: WideString;
sb: TChilkatStringBuilder;
crlf: Integer;

begin
success := 0;

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

cert := TChilkatCert.Create(Self);

// Load the cert and private key.
success := cert.LoadPfxFile('qa_data/pfx/myCertAndKey.p12','password');
if (success <> 1) then
  begin
    Memo1.Lines.Add(cert.LastErrorText);
    Exit;
  end;

crypt := TChilkatCrypt2.Create(Self);

success := crypt.SetSigningCert(cert.ControlInterface);
if (success <> 1) then
  begin
    Memo1.Lines.Add(crypt.LastErrorText);
    Exit;
  end;

// Use SHA-256
crypt.HashAlgorithm := 'sha256';

// Hash the utf-8 byte representation of the string
crypt.Charset := 'utf-8';

// Return the result in base64
crypt.EncodingMode := 'base64Mime';

// Sign some text to create a detached signature (i.e. a signature that does not include the signed data)
textToSign := 'This is the text to be hashed and signed.';
sigBase64 := crypt.SignStringENC(textToSign);
if (crypt.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(crypt.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add(sigBase64);

// The result:

// MIIWbgYJKoZIhvcNAQcCoIIWXzCCFlsCAQExDzANBglghkgBZQMEAgEFADALBgkqhkiG9w0BBwGg
// ghMXMIIFuzCCA6OgAwIBAgIIVwoRl0LE48wwDQYJKoZIhvcNAQELBQAwazELMAkGA1UEBhMCSVQx
// ...
// ...

// If we want it in PEM format with just LF line-endings:
sb := TChilkatStringBuilder.Create(Self);
// Just LF line endings, not CRLF.
crlf := 0;
sb.AppendLine('-----BEGIN PKCS7-----',crlf);
sb.Append(sigBase64);
sb.AppendLine('-----END PKCS7-----',crlf);
sb.ToLF();

// Save to a file.
sb.WriteFile('c:/temp/qa_output/sig.pem','utf-8',0);

// Examine..
Memo1.Lines.Add(sb.GetAsString());

// Result is:

// -----BEGIN PKCS7-----
// MIIWbgYJKoZIhvcNAQcCoIIWXzCCFlsCAQExDzANBglghkgBZQMEAgEFADALBgkqhkiG9w0BBwGg
// ghMXMIIFuzCCA6OgAwIBAgIIVwoRl0LE48wwDQYJKoZIhvcNAQELBQAwazELMAkGA1UEBhMCSVQx
// DjAMBgNVBAcMBU1pbGFuMSMwIQYDVQQKDBpBY3RhbGlzIFMucC5BLi8wMzM1ODUyMDk2NzEnMCUG
// A1UEAwweQWN0YWxpcyBBdXRoZW50aWNhdGlvbiBSb290IENBMB4XDTExMDkyMjExMjIwMloXDTMw
// MDkyMjExMjIwMlowazELMAkGA1UEBhMCSVQxDjAMBgNVBAcMBU1pbGFuMSMwIQYDVQQKDBpBY3Rh
// bGlzIFMucC5BLi8wMzM1ODUyMDk2NzEnMCUGA1UEAwweQWN0YWxpcyBBdXRoZW50aWNhdGlvbiBS
// b290IENBMIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEAp8bEpSmkLO/lGMWwUKNvUTuf
// ClrJwkg4CsIcoBh/kbWHuUA/3R1oHwiD1S0eiKD4j1aPbZkCkpAW1V8IbInX4ay8IMKx4INRimlN
// AJZaby/ARH6jDuSRzVju3PvHHkVH3Se5CAGfpiEd9UEtL0z9KK3giq0itFZljoZUj5NDKd45Rnij
// MCO6zfB9E1fAXdKDa0hMxKufgFpbOr3JpyI/gCczWw63igxdBzcIy2zSekciRDXFzMwujt0q7bd9
// ...
// ...
// -----END PKCS7-----
end;