(Delphi DLL) Encrypting and Decrypting Content

Demonstrates how to encrypt and decrypt the content of an XML node using 128-bit CBC AES encryption.

The input XML, available at http://www.chilkatsoft.com/data/fox.xml, is this:

<root>
    <fox1>The quick brown fox jumps over the lazy dog</fox1>
    <fox2>The quick brown fox jumps over the lazy dog
        <child1>ABC</child1>
        <child2>XYZ</child2>
    </fox2>
</root>

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, Xml;

...

procedure TForm1.Button1Click(Sender: TObject);
var
xml: HCkXml;
success: Boolean;

begin
xml := CkXml_Create();

// The sample input XML is available at http://www.chilkatsoft.com/data/fox.xml
success := CkXml_LoadXmlFile(xml,'fox.xml');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkXml__lastErrorText(xml));
    Exit;
  end;

// Navigate to the "fox1" node, which is the 1st child:
success := CkXml_FirstChild2(xml);

// Encrypt the content:
success := CkXml_EncryptContent(xml,'myPassword');

// Navigate back to the root:
CkXml_GetRoot2(xml);

// Examine the new XML document:
Memo1.Lines.Add(CkXml__getXml(xml));

// This is the XML w/ the encrypted content:
// <root>
//     <fox1>1hTtf7XmO+78H+OIr5eWHIuXxP78KPeYrZbsD0HX4negO9ZRqYMBY4s46sPNp+Q+
//     </fox1>
//     <fox2>The quick brown fox jumps over the lazy dog
//         <child1>ABC</child1>
//         <child2>XYZ</child2>
//     </fox2>
// </root>

// Now decrypt and show that the original content was restored:
success := CkXml_FirstChild2(xml);
success := CkXml_DecryptContent(xml,'myPassword');
CkXml_GetRoot2(xml);
Memo1.Lines.Add(CkXml__getXml(xml));

// Now encrypt the content of the "fox2" node.
// First navigate to the "fox2" child.
success := CkXml_FindChild2(xml,'fox2');
success := CkXml_EncryptContent(xml,'myPassword');
CkXml_GetRoot2(xml);
Memo1.Lines.Add(CkXml__getXml(xml));

// This is the XML w/ the "fox2" encrypted content:

// <root>
//     <fox1>The quick brown fox jumps over the lazy dog</fox1>
//     <fox2>1hTtf7XmO+78H+OIr5eWHIuXxP78KPeYrZbsD0HX4negO9ZRqYMBY4s46sPNp+Q+
// 
//         <child1>ABC</child1>
//         <child2>XYZ</child2>
//     </fox2>
// </root>

// Notice that the *content* of the node is encrypted.  The child nodes are NOT encrypted.
// This is intentional.  To encrypt the content + the subtrees rooted at a given node, 
// one would call ZipTree to transform the content and subtrees
// to Base64-encoded compressed content, and then call
// EncryptContent to encrypt.

// Finally, decrypt the "fox2" content:
success := CkXml_FindChild2(xml,'fox2');
success := CkXml_DecryptContent(xml,'myPassword');
CkXml_GetRoot2(xml);
Memo1.Lines.Add(CkXml__getXml(xml));

CkXml_Dispose(xml);

end;