Delphi DLL

RSA Sign an Encoded Hash

See more RSA Examples

Demonstrates signing a hash (e.g., SHA256) provided as an encoded string (e.g., base64 or hex). Delphi DLL

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
cert: HCkCert;
bd: HCkBinData;
i: Integer;
rsa: HCkRsa;
sha256_base64: PWideChar;
rsaSig_base64: PWideChar;

begin
success := False;

// 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 the private key for this cert: ' + CkCert__subjectCN(cert));

// Create data to be hashed and signed.
bd := CkBinData_Create();

for i := 0 to 100 do
  begin
    CkBinData_AppendEncoded(bd,'000102030405060708090A0B0C0D0E0F','hex');
  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;

// We'll first compute the hash and then pass the encoded hash to be signed.
sha256_base64 := CkBinData__getHash(bd,'sha256','base64');
Memo1.Lines.Add('sha256 hash in base64 format: ' + sha256_base64);

// Pass in the base64 hash and return a base64 signature.
CkRsa_putEncodingMode(rsa,'base64');
rsaSig_base64 := CkRsa__signHashENC(rsa,sha256_base64,'sha256');
if (success = False) then
  begin
    Memo1.Lines.Add(CkRsa__lastErrorText(rsa));
    Exit;
  end;

Memo1.Lines.Add('RSA signature as base64: ' + rsaSig_base64);

CkCert_Dispose(cert);
CkBinData_Dispose(bd);
CkRsa_Dispose(rsa);

end;