program when decrypting XML - Unable to retrieve the decryption key

**Elliot** · Jun 27 '08, 07:59 PM

Re: program when decrypting XML - Unable to retrieve the decryption key

Any idea?

"Elliot" <elliot_barclay @hotmail.co.ukw rote in message
news:EF147447-E721-4E78-886F-7BAA2E27FF6E@mi crosoft.com...

When decrypt the xml, output "Unable to retrieve the decryption key."
Can anyone help me solve the problem?
>
I got the code from http://msdn.microsoft.com/en-us/library/ms229746.aspx
>
>
using System;
using System.Xml;
using System.Security .Cryptography;
using System.Security .Cryptography.X ml;
>
class Program
{
static void Main(string[] args)
{
// Create an XmlDocument object.
XmlDocument xmlDoc = new XmlDocument();
>
// Load an XML file into the XmlDocument object.
try
{
xmlDoc.Preserve Whitespace = true;
xmlDoc.Load("te st.xml");
}
catch (Exception e)
{
Console.WriteLi ne(e.Message);
}
>
// Create a new CspParameters object to specify
// a key container.
CspParameters cspParams = new CspParameters() ;
cspParams.KeyCo ntainerName = "XML_ENC_RSA_KE Y";
>
// Create a new RSA key and save it in the container. This key
will encrypt
// a symmetric key, which will then be encryped in the XML
document.
RSACryptoServic eProvider rsaKey = new
RSACryptoServic eProvider(cspPa rams);
>
try
{
// Encrypt the "creditcard " element.
Encrypt(xmlDoc, "creditcard ", "EncryptedEleme nt1", rsaKey,
"rsaKey");
>
>
// Save the XML document.
xmlDoc.Save("te st_Encrypted.xm l");
>
// Display the encrypted XML to the console.
Console.WriteLi ne("Encrypted XML:");
Console.WriteLi ne();
Console.WriteLi ne(xmlDoc.Outer Xml);
>
}
catch (Exception e)
{
Console.WriteLi ne(e.Message);
}
finally
{
// Clear the RSA key.
rsaKey.Clear();
}
>
>
// Create an XmlDocument object.
xmlDoc = new XmlDocument();
>
// Load an XML file into the XmlDocument object.
try
{
xmlDoc.Preserve Whitespace = true;
xmlDoc.Load("te st_Encrypted.xm l");
}
catch (Exception e)
{
Console.WriteLi ne(e.Message);
}
cspParams = new CspParameters() ;
cspParams.KeyCo ntainerName = "XML_ENC_RSA_KE Y";
>
// Get the RSA key from the key container. This key will decrypt
// a symmetric key that was imbedded in the XML document.
rsaKey = new RSACryptoServic eProvider(cspPa rams);
>
try
{
>
// Decrypt the elements.
Decrypt(xmlDoc, rsaKey, "rsaKey");
>
>
// Display the encrypted XML to the console.
Console.WriteLi ne();
Console.WriteLi ne("Decrypted XML:");
Console.WriteLi ne();
Console.WriteLi ne(xmlDoc.Outer Xml);
}
catch (Exception e)
{
Console.WriteLi ne(e.Message);
}
finally
{
// Clear the RSA key.
rsaKey.Clear();
}
>
Console.ReadLin e();
}
>
public static void Encrypt(XmlDocu ment Doc, string ElementToEncryp t,
string EncryptionEleme ntID, RSA Alg, string KeyName)
{
// Check the arguments.
if (Doc == null)
throw new ArgumentNullExc eption("Doc");
if (ElementToEncry pt == null)
throw new ArgumentNullExc eption("Element ToEncrypt");
if (EncryptionElem entID == null)
throw new ArgumentNullExc eption("Encrypt ionElementID");
if (Alg == null)
throw new ArgumentNullExc eption("Alg");
if (KeyName == null)
throw new ArgumentNullExc eption("KeyName ");
>
////////////////////////////////////////////////
// Find the specified element in the XmlDocument
// object and create a new XmlElemnt object.
////////////////////////////////////////////////
XmlElement elementToEncryp t =
Doc.GetElements ByTagName(Eleme ntToEncrypt)[0] as XmlElement;
>
// Throw an XmlException if the element was not found.
if (elementToEncry pt == null)
{
throw new XmlException("T he specified element was not found");
>
}
RijndaelManaged sessionKey = null;
>
try
{
//////////////////////////////////////////////////
// Create a new instance of the EncryptedXml class
// and use it to encrypt the XmlElement with the
// a new random symmetric key.
//////////////////////////////////////////////////
>
// Create a 256 bit Rijndael key.
sessionKey = new RijndaelManaged ();
sessionKey.KeyS ize = 256;
>
EncryptedXml eXml = new EncryptedXml();
>
byte[] encryptedElemen t = eXml.EncryptDat a(elementToEncr ypt,
sessionKey, false);
////////////////////////////////////////////////
// Construct an EncryptedData object and populate
// it with the desired encryption information.
////////////////////////////////////////////////
>
EncryptedData edElement = new EncryptedData() ;
edElement.Type = EncryptedXml.Xm lEncElementUrl;
edElement.Id = EncryptionEleme ntID;
// Create an EncryptionMetho d element so that the
// receiver knows which algorithm to use for decryption.
>
edElement.Encry ptionMethod = new
EncryptionMetho d(EncryptedXml. XmlEncAES256Url );
// Encrypt the session key and add it to an EncryptedKey
element.
EncryptedKey ek = new EncryptedKey();
>
byte[] encryptedKey = EncryptedXml.En cryptKey(sessio nKey.Key,
Alg, false);
>
ek.CipherData = new CipherData(encr yptedKey);
>
ek.EncryptionMe thod = new
EncryptionMetho d(EncryptedXml. XmlEncRSA15Url) ;
>
// Create a new DataReference element
// for the KeyInfo element. This optional
// element specifies which EncryptedData
// uses this key. An XML document can have
// multiple EncryptedData elements that use
// different keys.
DataReference dRef = new DataReference() ;
>
// Specify the EncryptedData URI.
dRef.Uri = "#" + EncryptionEleme ntID;
>
// Add the DataReference to the EncryptedKey.
ek.AddReference (dRef);
// Add the encrypted key to the
// EncryptedData object.
>
edElement.KeyIn fo.AddClause(ne w KeyInfoEncrypte dKey(ek));
// Set the KeyInfo element to specify the
// name of the RSA key.
>
// Create a new KeyInfo element.
edElement.KeyIn fo = new KeyInfo();
>
// Create a new KeyInfoName element.
KeyInfoName kin = new KeyInfoName();
>
// Specify a name for the key.
kin.Value = KeyName;
>
// Add the KeyInfoName element to the
// EncryptedKey object.
ek.KeyInfo.AddC lause(kin);
// Add the encrypted element data to the
// EncryptedData object.
edElement.Ciphe rData.CipherVal ue = encryptedElemen t;
////////////////////////////////////////////////////
// Replace the element from the original XmlDocument
// object with the EncryptedData element.
////////////////////////////////////////////////////
EncryptedXml.Re placeElement(el ementToEncrypt, edElement,
false);
}
catch (Exception e)
{
// re-throw the exception.
throw e;
}
finally
{
if (sessionKey != null)
{
sessionKey.Clea r();
}
>
}
>
}
>
>
public static void Decrypt(XmlDocu ment Doc, RSA Alg, string KeyName)
{
// Check the arguments.
if (Doc == null)
throw new ArgumentNullExc eption("Doc");
if (Alg == null)
throw new ArgumentNullExc eption("Alg");
if (KeyName == null)
throw new ArgumentNullExc eption("KeyName ");
// Create a new EncryptedXml object.
EncryptedXml exml = new EncryptedXml(Do c);
>
// Add a key-name mapping.
// This method can only decrypt documents
// that present the specified key name.
exml.AddKeyName Mapping(KeyName , Alg);
>
// Decrypt the element.
exml.DecryptDoc ument();
>
}
>
}
>
>

program when decrypting XML - Unable to retrieve the decryption key

program when decrypting XML - Unable to retrieve the decryption key

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