(Delphi ActiveX) Encrypt MIME using RSAES-OAEP with SHA256 and AES-128 content encryption

Demonstrates how to encrypt MIME using RSAES-OAEP with SHA256 and AES-128 content encryption.

Note: This example requires Chilkat v9.5.0.67 or greater.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Integer;
mime: TChilkatMime;
part0: TChilkatMime;
part1: TChilkatMime;
sbMime: TChilkatStringBuilder;
cert: TChilkatCert;

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

mime := TChilkatMime.Create(Self);

// Create a MIME message to encrypt.
mime.NewMultipartMixed();
mime.AddHeaderField('someHeader1','Some value 1');
mime.AddHeaderField('someHeader2','Some value 2');

part0 := TChilkatMime.Create(Self);
part0.AddHeaderField('hdrA','Some value A');
part0.AddHeaderField('hdrB','Some value B');
part0.ContentType := 'text/plain';
part0.SetBody('This is the plain-text body.');

part1 := TChilkatMime.Create(Self);
part1.AddHeaderField('hdrX','Some value X');
part1.AddHeaderField('hdrY','Some value Y');
part1.ContentType := 'text/xml';
part1.SetBody('<a>This is the XML body</a>');

mime.AppendPart(part0.ControlInterface);
mime.AppendPart(part1.ControlInterface);

// The MIME to be encrypted:
sbMime := TChilkatStringBuilder.Create(Self);
mime.GetMimeSb(sbMime.ControlInterface);
Memo1.Lines.Add(sbMime.GetAsString());

// 	Content-Type: multipart/mixed; boundary="------------080303020600020604010008"
// 	someHeader1: Some value 1
// 	someHeader2: Some value 2
// 
// 	--------------080303020600020604010008
// 	hdrA: Some value A
// 	hdrB: Some value B
// 	Content-Type: text/plain
// 
// 	This is the plain-text body.
// 	--------------080303020600020604010008
// 	hdrX: Some value X
// 	hdrY: Some value Y
// 	Content-Type: text/xml
// 
// 	<a>This is the XML body</a>
// 	--------------080303020600020604010008--
// 

// Load an RSA-based certificate.
// (Encrypting MIME only requires the public key.  Decrypting MIME requires the private key.)
cert := TChilkatCert.Create(Self);
success := cert.LoadFromFile('qa_data/rsaes-oaep/cert.pem');
if (success <> 1) then
  begin
    Memo1.Lines.Add(cert.LastErrorText);
    Exit;
  end;

// Set the email object properties to indicate the desired encryption.
mime.Pkcs7CryptAlg := 'aes';
// If AES-256 is desired, set the following property to 256.
mime.Pkcs7KeyLength := 128;
mime.OaepPadding := 1;
// Other choices for the OAEP hash algorithm are "sha1", "sha384", and "sha512"
mime.OaepHash := 'sha256';

// Encrypt the MIME (to create S/MIME, which stands for "Secure MIME")
success := mime.Encrypt(cert.ControlInterface);
if (success <> 1) then
  begin
    Memo1.Lines.Add(mime.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add('---------------');
Memo1.Lines.Add('Encrypted MIME:');
Memo1.Lines.Add('---------------');
Memo1.Lines.Add(mime.GetMime());

Memo1.Lines.Add('Success.');

// ---------------------------------------------------
// This is sample output for RSAES-OAEP encrypted MIME:
// ---------------------------------------------------

// Content-Type: application/x-pkcs7-mime; name="smime.p7m"; smime-type="enveloped-data"
// someHeader1: Some value 1
// someHeader2: Some value 2
// Content-Disposition: attachment; filename="smime.p7m"
// Content-Transfer-Encoding: base64
// 
// MIIDvAYJKoZIhvcNAQcDoIIDrTCCA6kCAQAxggGgMIIBnAIBADB1MGgxCzAJBgNVBAYTAlVTMQsw
// CQYDVQQIDAJJTDEQMA4GA1UEBwwHV2hlYXRvbjEhMB8GA1UECgwYSW50ZXJuZXQgV2lkZ2l0cyBQ
// dHkgTHRkMRcwFQYDVQQDDA5DaGlsa2F0V2lkZ2V0cwIJAMRwugDmvniwMBwGCSqGSIb3DQEBBzAP
// oA0wCwYJYIZIAWUDBAIBBIIBAFaUL1ga1bOrdqYKcMm+FHUacBvzfBxk0fnPA0AMBdN8BvTWT3CN
// YuqBhjOGyq0FpYD9pVZybUuFMCVsVyIW2O62HnsOK58YaPEUUcdH2sI+yjqX9UAn0P0nVDSsVdeK
// W8x9kMfZg+3UP+y1q+lu7VRJO3f2C9oLQpTkc4VW4n7UOcUI0waykLCjCTL8lFDb7/J3GeuMKyhH
// 5riNz50kpbzqn7m2Ks9yA+QmcTdXclclGFr2vwEUFzSdT2pxh/vaUrogCxkYWbQ2eV7vZg6O4kV0
// aqHBqySkPTAzHKiHH8K8GVdlTuJ8350CpICa4T8w7/Ht5I7dyOPPKy4C+rVtrvcwggH+BgkqhkiG
// 9w0BBwEwHQYJYIZIAWUDBAECBBDTC2WNBN+z2I47/4Feu9YqgIIB0MZvl3nC/q/Wzil6HtfQTr12
// Q5moHY+ORzAa1P9XvX2ZUFhW530mV395mQw/A4o4ekmX9eRPEZquYzZPLT8hNeZIuNdhpcSQUmad
// rKnKkR0wKJ3jJ3LhOIohVBQSYs8kVDZKq6lJBIznlsurFelZoNEhyRschhteDZx5rb7fCe8c2+/O
// DHxaqaHCAzm/Bd7kcg6FFfuTZy3tu0PgP5IsXN4OFA3kkvwjAs4XsVS8jdIcmDNBkYieE8WmJOIm
// Mz7mh/CHWLgWfGKa0Dkb9RcbFgLwYNT3GzuXFw9XPbKkEZjEAtJajWbN6P0WQl96YYd9qZxUpGxZ
// zjTHEYzViUdUXolfpLufttrRXyxN1RFWhNFMFbv66xYqklMSgpdM/Mbk+EuvX6eXayDPvDBpfYMw
// NoRAzv1Ony2c0ez9rBemJICicxAzpuvHbRxdjYs63Dnv+TYgpBK12AxWWpPIjXvw0WQKgTC3Tg8s
// EnuGhpENqso/clJBEBSn4+2WhYtYbdI5sVme67lvqQl1Xxy3r18SWaQbyDOwgYi1E+54lMDOxMy0
// y0FPHk5pP45DnXWj+XORPp5LhuZr5mf62YOXSSUwR5P0cXy4Rc+pN5lhRQPCf5z2
end;