Sign a JWS with a Private Key

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.SetPrivateKey, which sets the private key used to create a signature. The example uses RS256 (RSASSA-PKCS1-v1_5 with SHA-256).

The file path is relative to the application's current working directory. An absolute path may also be used. Supply the path appropriate to your own environment.

var
success: Integer;
jws: TChilkatJws;
header: TChilkatJsonObject;
bIncludeBom: Integer;
privKey: TPrivateKey;
jwsCompact: WideString;

begin
success := 0;

jws := TChilkatJws.Create(Self);

//  Protected header specifying RSASSA-PKCS1-v1_5 with SHA-256 (RS256).
header := TChilkatJsonObject.Create(Self);
header.UpdateString('alg','RS256');
success := jws.SetProtectedHeader(0,header.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(jws.LastErrorText);
    Exit;
  end;

bIncludeBom := 0;
success := jws.SetPayload('This is the content to sign.','utf-8',bIncludeBom);
if (success = 0) then
  begin
    Memo1.Lines.Add(jws.LastErrorText);
    Exit;
  end;

//  The file path is relative to the application's current working directory.  An absolute path
//  may also be used.  Supply the path appropriate to your own environment.
//  Load the signer's private key and set it for signature 0.
privKey := TPrivateKey.Create(Self);
success := privKey.LoadPemFile('qa_data/signer_privkey.pem');
if (success = 0) then
  begin
    Memo1.Lines.Add(privKey.LastErrorText);
    Exit;
  end;
success := jws.SetPrivateKey(0,privKey.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(jws.LastErrorText);
    Exit;
  end;

jwsCompact := jws.CreateJws();
if (jws.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(jws.LastErrorText);
    Exit;
  end;
Memo1.Lines.Add(jwsCompact);