(Tcl) 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>

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load ./chilkat.dll

set xml [new_CkXml]

# The sample input XML is available at http://www.chilkatsoft.com/data/fox.xml
set success [CkXml_LoadXmlFile $xml "fox.xml"]
if {$success != 1} then {
    puts [CkXml_lastErrorText $xml]
    delete_CkXml $xml
    exit
}

# Navigate to the "fox1" node, which is the 1st child:
set success [CkXml_FirstChild2 $xml]

# Encrypt the content:
set success [CkXml_EncryptContent $xml "myPassword"]

# Navigate back to the root:
CkXml_GetRoot2 $xml

# Examine the new XML document:
puts [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:
set success [CkXml_FirstChild2 $xml]
set success [CkXml_DecryptContent $xml "myPassword"]
CkXml_GetRoot2 $xml
puts [CkXml_getXml $xml]

# Now encrypt the content of the "fox2" node.
# First navigate to the "fox2" child.
set success [CkXml_FindChild2 $xml "fox2"]
set success [CkXml_EncryptContent $xml "myPassword"]
CkXml_GetRoot2 $xml
puts [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:
set success [CkXml_FindChild2 $xml "fox2"]
set success [CkXml_DecryptContent $xml "myPassword"]
CkXml_GetRoot2 $xml
puts [CkXml_getXml $xml]

delete_CkXml $xml