prep for encrypting xml

This commit is contained in:
Tim Young 2017-07-31 11:26:49 -05:00
parent 7f8879a19b
commit 3bed5e7210
2 changed files with 124 additions and 0 deletions

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@ -72,6 +72,7 @@
<ItemGroup>
<Reference Include="System" />
<Reference Include="System.Core" />
<Reference Include="System.Security" />
<Reference Include="System.Xml.Linq" />
<Reference Include="System.Data.DataSetExtensions" />
<Reference Include="Microsoft.CSharp" />
@ -175,6 +176,7 @@
<DependentUpon>RTFWindow.cs</DependentUpon>
</Compile>
<Compile Include="SchoolworkClass.cs" />
<Compile Include="TrippleDESDocumentEncryption.cs" />
<Compile Include="VLANConfig.cs">
<SubType>Form</SubType>
</Compile>

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@ -0,0 +1,122 @@
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Security.Cryptography;
using System.Security.Cryptography.Xml;
using System.Xml;
namespace EduNetworkBuilder
{
/// <summary>
/// Copied from https://msdn.microsoft.com/en-us/library/system.security.cryptography.xml.encryptedxml(v=vs.110).aspx
/// </summary>
class TrippleDESDocumentEncryption
{
protected XmlDocument docValue;
protected TripleDES algValue;
public TrippleDESDocumentEncryption(XmlDocument Doc, TripleDES Key)
{
if (Doc != null)
{
docValue = Doc;
}
else
{
throw new ArgumentNullException("Doc");
}
if (Key != null)
{
algValue = Key;
}
else
{
throw new ArgumentNullException("Key");
}
}
public XmlDocument Doc { set { docValue = value; } get { return docValue; } }
public TripleDES Alg { set { algValue = value; } get { return algValue; } }
public void Clear()
{
if (algValue != null)
{
algValue.Clear();
}
else
{
throw new Exception("No TripleDES key was found to clear.");
}
}
public void Encrypt(string Element)
{
// Find the element by name and create a new
// XmlElement object.
XmlElement inputElement = docValue.GetElementsByTagName(Element)[0] as XmlElement;
// If the element was not found, throw an exception.
if (inputElement == null)
{
throw new Exception("The element was not found.");
}
// Create a new EncryptedXml object.
EncryptedXml exml = new EncryptedXml(docValue);
// Encrypt the element using the symmetric key.
byte[] rgbOutput = exml.EncryptData(inputElement, algValue, false);
// Create an EncryptedData object and populate it.
EncryptedData ed = new EncryptedData();
// Specify the namespace URI for XML encryption elements.
ed.Type = EncryptedXml.XmlEncElementUrl;
// Specify the namespace URI for the TrippleDES algorithm.
ed.EncryptionMethod = new EncryptionMethod(EncryptedXml.XmlEncTripleDESUrl);
// Create a CipherData element.
ed.CipherData = new CipherData();
// Set the CipherData element to the value of the encrypted XML element.
ed.CipherData.CipherValue = rgbOutput;
// Replace the plaintext XML elemnt with an EncryptedData element.
EncryptedXml.ReplaceElement(inputElement, ed, false);
}
public void Decrypt()
{
// XmlElement object.
XmlElement encryptedElement = docValue.GetElementsByTagName("EncryptedData")[0] as XmlElement;
// If the EncryptedData element was not found, throw an exception.
if (encryptedElement == null)
{
throw new Exception("The EncryptedData element was not found.");
}
// Create an EncryptedData object and populate it.
EncryptedData ed = new EncryptedData();
ed.LoadXml(encryptedElement);
// Create a new EncryptedXml object.
EncryptedXml exml = new EncryptedXml();
// Decrypt the element using the symmetric key.
byte[] rgbOutput = exml.DecryptData(ed, algValue);
// Replace the encryptedData element with the plaintext XML elemnt.
exml.ReplaceData(encryptedElement, rgbOutput);
}
}
}