Delphi ActiveX

Export a Public Key as PEM

Demonstrates the Chilkat PublicKey.GetPem method, which returns the public key in PEM format. The only argument selects the underlying DER representation: true prefers the traditional PKCS #1 form (RSA), false uses the SubjectPublicKeyInfo form.

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: PEM is the most portable way to share a public key — the Base64 text block most tooling reads. The boolean picks the encoding: false produces the modern, algorithm-independent PUBLIC KEY (SubjectPublicKeyInfo), which is the usual choice; true produces the older RSA-specific RSA PUBLIC KEY for tools that require it. A public key is not sensitive, so the PEM can be distributed openly.

Chilkat Delphi ActiveX Downloads

Download Chilkat for Delphi ActiveX

Delphi ActiveX

var
success: Integer;
pubKey: TPublicKey;
preferPkcs1: Integer;
pem: WideString;

begin
success := 0;

//  Load a public key to export.  LoadFromFile inspects the content, so it accepts DER, PEM, XML,
//  JWK, and other supported representations.
pubKey := TPublicKey.Create(Self);
success := pubKey.LoadFromFile('qa_data/public.pem');
if (success = 0) then
  begin
    Memo1.Lines.Add(pubKey.LastErrorText);
    Exit;
  end;

//  Export the public key in PEM format.  The argument selects the underlying DER representation:
//  1 prefers the traditional PKCS #1 form (RSA), 0 uses the SubjectPublicKeyInfo form.
preferPkcs1 := 0;
pem := pubKey.GetPem(preferPkcs1);
if (pubKey.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(pubKey.LastErrorText);
    Exit;
  end;
Memo1.Lines.Add(pem);