Delphi ActiveX

Specify a Certificate for Encrypted Email

Demonstrates the Chilkat Email.AddEncryptCert method, which explicitly specifies a certificate to use when sending encrypted email. Call it once per recipient certificate; ClearEncryptCerts clears the list. This example loads a recipient certificate, registers it, and enables encrypted sending.

Background: When encrypting to multiple people, each recipient needs to be able to decrypt with their own private key. S/MIME handles this by encrypting the message's one-time content key separately under each recipient's public certificate and including all of those wrapped keys in the message. AddEncryptCert is how you build that recipient list — one call per certificate — giving explicit control over exactly whose certificates are used rather than relying on automatic lookup.

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var
success: Integer;
email: TChilkatEmail;
cert: TChilkatCert;

begin
success := 0;

//  Demonstrates the AddEncryptCert method, which explicitly specifies a certificate for
//  sending encrypted email.  Call it once per recipient certificate.  Use ClearEncryptCerts
//  to clear the list.

email := TChilkatEmail.Create(Self);
email.Subject := 'Encrypted email';
email.Body := 'Encrypted to the specified recipient certificate(s).';
email.From := 'alice@example.com';
email.AddTo('Bob','bob@example.com');

//  Load a recipient certificate (public key) and add it to the encryption cert list.
cert := TChilkatCert.Create(Self);
success := cert.LoadFromFile('qa_data/certs/recipient.cer');
if (success = 0) then
  begin
    Memo1.Lines.Add(cert.LastErrorText);
    Exit;
  end;

success := email.AddEncryptCert(cert.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(email.LastErrorText);
    Exit;
  end;

//  Request encrypted sending.
email.SendEncrypted := 1;

Memo1.Lines.Add('Added the recipient''s encryption certificate.');

//  Note: The path "qa_data/certs/recipient.cer" is a relative local filesystem path,
//  relative to the current working directory of the running application.