EncryptionMethod Construtores

Definição

Inicializa uma nova instância da classe EncryptionMethod.

Sobrecargas

EncryptionMethod()

Inicializa uma nova instância da classe EncryptionMethod.

EncryptionMethod(String)

Inicializa uma nova instância da classe EncryptionMethod especificando um URI (Uniform Resource Identifier) do algoritmo.

EncryptionMethod()

Origem:
EncryptionMethod.cs
Origem:
EncryptionMethod.cs
Origem:
EncryptionMethod.cs
Origem:
EncryptionMethod.cs
Origem:
EncryptionMethod.cs

Inicializa uma nova instância da classe EncryptionMethod.

C#
public EncryptionMethod ();

Comentários

Esse construtor inicializa uma nova instância da EncryptionMethod classe sem especificar o URI (Uniform Resource Identifier) de um algoritmo de criptografia.

Aplica-se a

.NET 9 (package-provided) e outras versões
Produto Versões
.NET 8 (package-provided), 9 (package-provided)
.NET Framework 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7 (package-provided), 4.7, 4.7.1 (package-provided), 4.7.1, 4.7.2 (package-provided), 4.7.2, 4.8 (package-provided), 4.8, 4.8.1
.NET Standard 2.0 (package-provided)
Windows Desktop 3.0, 3.1, 5, 6, 7, 8, 9

EncryptionMethod(String)

Origem:
EncryptionMethod.cs
Origem:
EncryptionMethod.cs
Origem:
EncryptionMethod.cs
Origem:
EncryptionMethod.cs
Origem:
EncryptionMethod.cs

Inicializa uma nova instância da classe EncryptionMethod especificando um URI (Uniform Resource Identifier) do algoritmo.

C#
public EncryptionMethod (string? algorithm);
C#
public EncryptionMethod (string algorithm);

Parâmetros

algorithm
String

O URI (Uniform Resource Identifier) que descreve o algoritmo representado por uma instância da classe EncryptionMethod.

Exemplos

O exemplo de código a seguir demonstra como criar uma classe de utilitário simples que usa o TripleDES algoritmo para criptografar um documento XML.

C#
using System;
using System.Xml;
using System.Security.Cryptography;
using System.Security.Cryptography.Xml;

    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.PreserveWhitespace = true;
                xmlDoc.Load("test.xml");
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
                return;
            }

            // Create a new TripleDES key.
            TripleDESCryptoServiceProvider tDESkey = new TripleDESCryptoServiceProvider();

            // Create a new instance of the TrippleDESDocumentEncryption object
            // defined in this sample.
            TrippleDESDocumentEncryption xmlTDES = new TrippleDESDocumentEncryption(xmlDoc, tDESkey);
            
            try
            {
                // Encrypt the "creditcard" element.
                xmlTDES.Encrypt("creditcard");

                // Display the encrypted XML to the console.
                Console.WriteLine("Encrypted XML:");
                Console.WriteLine();
                Console.WriteLine(xmlTDES.Doc.OuterXml);

                // Decrypt the "creditcard" element.
                xmlTDES.Decrypt();

                // Display the encrypted XML to the console.
                Console.WriteLine();
                Console.WriteLine("Decrypted XML:");
                Console.WriteLine();
                Console.WriteLine(xmlTDES.Doc.OuterXml);
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
            finally
            {
                // Clear the TripleDES key.
                xmlTDES.Clear();
            }
        }
    }

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);
    }
}

O exemplo de código a seguir demonstra como criptografar um documento XML usando uma chave simétrica. Este exemplo não inclui nenhuma informação de chave no documento XML criptografado.

C#
using System;
using System.Xml;
using System.Security.Cryptography;
using System.Security.Cryptography.Xml;

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.PreserveWhitespace = true;
            xmlDoc.Load("test.xml");
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
            return;
        }

        // Create a new TripleDES key.
        TripleDESCryptoServiceProvider tDESkey = new TripleDESCryptoServiceProvider();

        try
        {
            // Encrypt the "creditcard" element.
            Encrypt(xmlDoc, "creditcard", tDESkey);

            // Display the encrypted XML to the console.
            Console.WriteLine("Encrypted XML:");
            Console.WriteLine();
            Console.WriteLine(xmlDoc.OuterXml);

            // Decrypt the "creditcard" element.
            Decrypt(xmlDoc, tDESkey);

            // Display the encrypted XML to the console.
            Console.WriteLine();
            Console.WriteLine("Decrypted XML:");
            Console.WriteLine();
            Console.WriteLine(xmlDoc.OuterXml);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
        finally
        {
            // Clear the TripleDES key.
            tDESkey.Clear();
        }
    }

    public static void Encrypt(XmlDocument Doc, string ElementToEncrypt, SymmetricAlgorithm Alg)
    {
        // Check the arguments.
        if (Doc == null)
            throw new ArgumentNullException("Doc");
        if (ElementToEncrypt == null)
            throw new ArgumentNullException("ElementToEncrypt");
        if (Alg == null)
            throw new ArgumentNullException("Alg");

        ////////////////////////////////////////////////
        // Find the specified element in the XmlDocument
        // object and create a new XmlElemnt object.
        ////////////////////////////////////////////////

        XmlElement elementToEncrypt = Doc.GetElementsByTagName(ElementToEncrypt)[0] as XmlElement;

        // Throw an XmlException if the element was not found.
        if (elementToEncrypt == null)
        {
            throw new XmlException("The specified element was not found");
        }

        //////////////////////////////////////////////////
        // Create a new instance of the EncryptedXml class
        // and use it to encrypt the XmlElement with the
        // symmetric key.
        //////////////////////////////////////////////////

        EncryptedXml eXml = new EncryptedXml();

        byte[] encryptedElement = eXml.EncryptData(elementToEncrypt, Alg, false);

        ////////////////////////////////////////////////
        // Construct an EncryptedData object and populate
        // it with the desired encryption information.
        ////////////////////////////////////////////////

        EncryptedData edElement = new EncryptedData();
        edElement.Type = EncryptedXml.XmlEncElementUrl;

        // Create an EncryptionMethod element so that the
        // receiver knows which algorithm to use for decryption.
        // Determine what kind of algorithm is being used and
        // supply the appropriate URL to the EncryptionMethod element.

        string encryptionMethod = null;

        if (Alg is TripleDES)
        {
            encryptionMethod = EncryptedXml.XmlEncTripleDESUrl;
        }
        else if (Alg is DES)
        {
            encryptionMethod = EncryptedXml.XmlEncDESUrl;
        }
        else if (Alg is Aes)
        {
            switch (Alg.KeySize)
            {
                case 128:
                    encryptionMethod = EncryptedXml.XmlEncAES128Url;
                    break;
                case 192:
                    encryptionMethod = EncryptedXml.XmlEncAES192Url;
                    break;
                case 256:
                    encryptionMethod = EncryptedXml.XmlEncAES256Url;
                    break;
            }
        }
        else
        {
            // Throw an exception if the transform is not in the previous categories
            throw new CryptographicException("The specified algorithm is not supported for XML Encryption.");
        }

        edElement.EncryptionMethod = new EncryptionMethod(encryptionMethod);

        // Add the encrypted element data to the
        // EncryptedData object.
        edElement.CipherData.CipherValue = encryptedElement;

        ////////////////////////////////////////////////////
        // Replace the element from the original XmlDocument
        // object with the EncryptedData element.
        ////////////////////////////////////////////////////

        EncryptedXml.ReplaceElement(elementToEncrypt, edElement, false);
    }

    public static void Decrypt(XmlDocument Doc, SymmetricAlgorithm Alg)
    {
        // Check the arguments.
        if (Doc == null)
            throw new ArgumentNullException("Doc");
        if (Alg == null)
            throw new ArgumentNullException("Alg");

        // Find the EncryptedData element in the XmlDocument.
        XmlElement encryptedElement = Doc.GetElementsByTagName("EncryptedData")[0] as XmlElement;

        // If the EncryptedData element was not found, throw an exception.
        if (encryptedElement == null)
        {
            throw new XmlException("The EncryptedData element was not found.");
        }

        // Create an EncryptedData object and populate it.
        EncryptedData edElement = new EncryptedData();
        edElement.LoadXml(encryptedElement);

        // Create a new EncryptedXml object.
        EncryptedXml exml = new EncryptedXml();

        // Decrypt the element using the symmetric key.
        byte[] rgbOutput = exml.DecryptData(edElement, Alg);

        // Replace the encryptedData element with the plaintext XML element.
        exml.ReplaceData(encryptedElement, rgbOutput);
    }
}

Comentários

Esse construtor inicializa uma nova instância da EncryptionMethod classe usando o URI de um algoritmo de criptografia.

Use um dos identificadores de URI definidos pela Especificação de Sintaxe e Processamento de Criptografia XML do World Wide Web Consortium. Todos os identificadores de URI são acessíveis como campos estáticos da EncryptedXml classe .

Aplica-se a

.NET 9 (package-provided) e outras versões
Produto Versões
.NET 8 (package-provided), 9 (package-provided)
.NET Framework 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7 (package-provided), 4.7, 4.7.1 (package-provided), 4.7.1, 4.7.2 (package-provided), 4.7.2, 4.8 (package-provided), 4.8, 4.8.1
.NET Standard 2.0 (package-provided)
Windows Desktop 3.0, 3.1, 5, 6, 7, 8, 9