(Delphi DLL) RSA Sign utf-8 Bytes of String to get Base64 RSA Signature

See more Apple Keychain Examples

Demonstrates how RSA sign the utf-8 byte representation of a string to get the signature in base64 format.

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
cert: HCkCert;
success: Boolean;
sb: HCkStringBuilder;
crlfLineEnding: Boolean;
i: Integer;
rsa: HCkRsa;
stringToSign: PWideChar;
sigBase64: PWideChar;

begin
// Assuming the smartcard/USB token is installed with the correct drivers from the manufacturer,
// this code can work on multiple platforms including Windows, MacOS, Linux, and iOS.

// Chilkat automatically detects and determines the way in which the HSM is used,
// which can be by PKCS11, Apple Keychain, Microsoft CNG / Crypto API, or ScMinidriver.

cert := CkCert_Create();

// Set the token/smartcard PIN prior to loading.
CkCert_putSmartCardPin(cert,'123456');

// Specify the certificate by its common name.
success := CkCert_LoadFromSmartcard(cert,'cn=chilkat-rsa-2048');
if (success = False) then
  begin
    Memo1.Lines.Add(CkCert__lastErrorText(cert));
    Exit;
  end;

Memo1.Lines.Add('Signing with cert: ' + CkCert__subjectCN(cert));

// Create a string to be hashed and signed.
sb := CkStringBuilder_Create();
crlfLineEnding := True;

for i := 0 to 10 do
  begin
    CkStringBuilder_AppendLine(sb,'This is a test.',crlfLineEnding);
  end;

rsa := CkRsa_Create();

// Use the certificate's private key for signing.
success := CkRsa_SetX509Cert(rsa,cert,True);
if (success = False) then
  begin
    Memo1.Lines.Add(CkRsa__lastErrorText(rsa));
    Exit;
  end;

// Sign the SHA-256 hash of the utf-8 byte representation of the contents of sb
// Return the signature in base64 format.
CkRsa_putEncodingMode(rsa,'base64');
CkRsa_putCharset(rsa,'utf-8');
stringToSign := CkStringBuilder__getAsString(sb);
sigBase64 := CkRsa__signStringENC(rsa,stringToSign,'sha256');
if (CkRsa_getLastMethodSuccess(rsa) = False) then
  begin
    Memo1.Lines.Add(CkRsa__lastErrorText(rsa));
    Exit;
  end;

Memo1.Lines.Add('RSA signature as base64: ' + sigBase64);

CkCert_Dispose(cert);
CkStringBuilder_Dispose(sb);
CkRsa_Dispose(rsa);

end;