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

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
mime: HCkMime;
part0: HCkMime;
part1: HCkMime;
sbMime: HCkStringBuilder;
cert: HCkCert;

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

mime := CkMime_Create();

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

part0 := CkMime_Create();
CkMime_AddHeaderField(part0,'hdrA','Some value A');
CkMime_AddHeaderField(part0,'hdrB','Some value B');
CkMime_putContentType(part0,'text/plain');
CkMime_SetBody(part0,'This is the plain-text body.');

part1 := CkMime_Create();
CkMime_AddHeaderField(part1,'hdrX','Some value X');
CkMime_AddHeaderField(part1,'hdrY','Some value Y');
CkMime_putContentType(part1,'text/xml');
CkMime_SetBody(part1,'<a>This is the XML body</a>');

CkMime_AppendPart(mime,part0);
CkMime_AppendPart(mime,part1);

// The MIME to be encrypted:
sbMime := CkStringBuilder_Create();
CkMime_GetMimeSb(mime,sbMime);
Memo1.Lines.Add(CkStringBuilder__getAsString(sbMime));

// 	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 := CkCert_Create();
success := CkCert_LoadFromFile(cert,'qa_data/rsaes-oaep/cert.pem');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkCert__lastErrorText(cert));
    Exit;
  end;

// Set the email object properties to indicate the desired encryption.
CkMime_putPkcs7CryptAlg(mime,'aes');
// If AES-256 is desired, set the following property to 256.
CkMime_putPkcs7KeyLength(mime,128);
CkMime_putOaepPadding(mime,True);
// Other choices for the OAEP hash algorithm are "sha1", "sha384", and "sha512"
CkMime_putOaepHash(mime,'sha256');

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

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

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

CkMime_Dispose(mime);
CkMime_Dispose(part0);
CkMime_Dispose(part1);
CkStringBuilder_Dispose(sbMime);
CkCert_Dispose(cert);

end;