(VB.NET) 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>

Download: Chilkat .NET Assemblies

Dim xml As New Chilkat.Xml()

Dim success As Boolean
'  The sample input XML is available at http://www.chilkatsoft.com/data/fox.xml
success = xml.LoadXmlFile("fox.xml")
If (success <> true) Then
    TextBox1.Text = TextBox1.Text & xml.LastErrorText & vbCrLf
    Exit Sub
End If


'  Navigate to the "fox1" node, which is the 1st child:
xml.FirstChild2()

'  Encrypt the content:
xml.EncryptContent("myPassword")

'  Navigate back to the root:
xml.GetRoot2()

'  Examine the new XML document:
TextBox1.Text = TextBox1.Text & xml.GetXml() & vbCrLf

'  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:
xml.FirstChild2()
xml.DecryptContent("myPassword")
xml.GetRoot2()
TextBox1.Text = TextBox1.Text & xml.GetXml() & vbCrLf


'  Now encrypt the content of the "fox2" node.
'  First navigate to the "fox2" child.
xml.FindChild2("fox2")
xml.EncryptContent("myPassword")
xml.GetRoot2()
TextBox1.Text = TextBox1.Text & xml.GetXml() & vbCrLf

'  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:
xml.FindChild2("fox2")
xml.DecryptContent("myPassword")
xml.GetRoot2()
TextBox1.Text = TextBox1.Text & xml.GetXml() & vbCrLf