Delphi ActiveX

Create a JWS into a StringBuilder

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.CreateJwsSb, which creates a JWS and writes it into a StringBuilder.

Background. JWS (JSON Web Signature) integrity-protects a payload with a signature or MAC. The header alg names the algorithm; this example uses HMAC-SHA256 (HS256) with a symmetric MAC key.

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var
success: Integer;
jws: TChilkatJws;
header: TChilkatJsonObject;
bIncludeBom: Integer;
base64Key: WideString;
sbJws: TChilkatStringBuilder;

begin
success := 0;

jws := TChilkatJws.Create(Self);

//  Set the protected header for signer 0, specifying the signature algorithm (alg).
header := TChilkatJsonObject.Create(Self);
header.UpdateString('alg','HS256');
success := jws.SetProtectedHeader(0,header.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(jws.LastErrorText);
    Exit;
  end;

//  Set the payload to be signed.
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;

//  Provide the HMAC key (base64) for signer 0.  In production, obtain the key from a secure source
//  rather than hard-coding it.
base64Key := 'YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU=';
success := jws.SetMacKey(0,base64Key,'base64');
if (success = 0) then
  begin
    Memo1.Lines.Add(jws.LastErrorText);
    Exit;
  end;

//  Create the JWS and write it into a StringBuilder.
sbJws := TChilkatStringBuilder.Create(Self);
success := jws.CreateJwsSb(sbJws.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(jws.LastErrorText);
    Exit;
  end;
Memo1.Lines.Add(sbJws.GetAsString());