Delphi DLL

RSA Sign with PKCS8 Encrypted Key

See more RSA Examples

Demonstrates how to load a private key from an encrypted PKCS8 file and create an RSA digital signature. Delphi DLL

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
pkey: HCkPrivateKey;
rsa: HCkRsa;
strData: PWideChar;
hexSig: PWideChar;

begin
success := False;

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

pkey := CkPrivateKey_Create();

// Load the private key from an RSA PEM file:
success := CkPrivateKey_LoadPkcs8EncryptedFile(pkey,'privateKey.key','myPassword');

rsa := CkRsa_Create();

// Import the private key into the RSA object:
success := CkRsa_UsePrivateKey(rsa,pkey);
if (success = False) then
  begin
    Memo1.Lines.Add(CkRsa__lastErrorText(rsa));
    Exit;
  end;

// Return the signature in hex
CkRsa_putEncodingMode(rsa,'hex');

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

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

Memo1.Lines.Add(hexSig);

CkPrivateKey_Dispose(pkey);
CkRsa_Dispose(rsa);

end;