MacAlgorithmProvider Klasse

Definition

Namespace:

Windows.Security.Cryptography.Core

Stellt einen Nachrichtenauthentifizierungscode (Mac) dar. Ein MAC verwendet Kryptografie mit symmetrischem Schlüssel, um Nachrichtenmanipulationen zu verhindern. Weitere Informationen finden Sie unter MACs, Hashes und Signaturen.

public ref class MacAlgorithmProvider sealed

/// [Windows.Foundation.Metadata.ContractVersion(Windows.Foundation.UniversalApiContract, 65536)]
/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
/// [Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
class MacAlgorithmProvider final

[Windows.Foundation.Metadata.ContractVersion(typeof(Windows.Foundation.UniversalApiContract), 65536)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
[Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
public sealed class MacAlgorithmProvider

Public NotInheritable Class MacAlgorithmProvider

Vererbung

Object Platform::Object IInspectable MacAlgorithmProvider

Attribute

ContractVersionAttribute MarshalingBehaviorAttribute ThreadingAttribute

Windows-Anforderungen

Gerätefamilie	Windows 10 (eingeführt in 10.0.10240.0)
API contract	Windows.Foundation.UniversalApiContract (eingeführt in v1.0)

Beispiele

using Windows.Security.Cryptography;
using Windows.Security.Cryptography.Core;
using Windows.Storage.Streams;

namespace SampleMacAlgorithmProvider
{
    sealed partial class MacAlgProviderApp : Application
    {
        public MacAlgProviderApp()
        {
            // Initialize the application.
            this.InitializeComponent();

            // Initialize the hashing process.
            String strMsg = "This is a message to be authenticated";
            String strAlgName = MacAlgorithmNames.HmacSha384;
            IBuffer buffMsg;
            CryptographicKey hmacKey;
            IBuffer buffHMAC;

            // Create a hashed message authentication code (HMAC)
            this.CreateHMAC(
                strMsg,
                strAlgName,
                out buffMsg,
                out hmacKey,
                out buffHMAC);

            // Verify the HMAC.
            this.VerifyHMAC(
                buffMsg,
                hmacKey,
                buffHMAC);
        }

        void CreateHMAC(
            String strMsg,
            String strAlgName,
            out IBuffer buffMsg,
            out CryptographicKey hmacKey,
            out IBuffer buffHMAC)
        {
            // Create a MacAlgorithmProvider object for the specified algorithm.
            MacAlgorithmProvider objMacProv = MacAlgorithmProvider.OpenAlgorithm(strAlgName);

            // Demonstrate how to retrieve the name of the algorithm used.
            String strNameUsed = objMacProv.AlgorithmName;

            // Create a buffer that contains the message to be signed.
            BinaryStringEncoding encoding = BinaryStringEncoding.Utf8;
            buffMsg = CryptographicBuffer.ConvertStringToBinary(strMsg, encoding);

            // Create a key to be signed with the message.
            IBuffer buffKeyMaterial = CryptographicBuffer.GenerateRandom(objMacProv.MacLength);
            hmacKey = objMacProv.CreateKey(buffKeyMaterial);

            // Sign the key and message together.
            buffHMAC = CryptographicEngine.Sign(hmacKey, buffMsg);

            // Verify that the HMAC length is correct for the selected algorithm
            if (buffHMAC.Length != objMacProv.MacLength)
            {
                throw new Exception("Error computing digest");
            }
         }

        public void VerifyHMAC(
            IBuffer buffMsg,
            CryptographicKey hmacKey,
            IBuffer buffHMAC)
        {
            // The input key must be securely shared between the sender of the HMAC and 
            // the recipient. The recipient uses the CryptographicEngine.VerifySignature() 
            // method as follows to verify that the message has not been altered in transit.
            Boolean IsAuthenticated = CryptographicEngine.VerifySignature(hmacKey, buffMsg, buffHMAC);
            if (!IsAuthenticated)
            {
                throw new Exception("The message cannot be verified.");
            }
        }
    }
}

Hinweise

Sie erstellen ein MacAlgorithmProvider-Objekt, indem Sie die statische OpenAlgorithm-Methode aufrufen und einen der folgenden Algorithmusnamen angeben:

• HMAC_MD5
• HMAC_SHA1
• HMAC_SHA256
• HMAC_SHA384
• HMAC_SHA512
• AES_CMAC

Eigenschaften

AlgorithmName	Ruft den Namen des offenen MAC-Algorithmus ab.
MacLength	Ruft die Länge des Nachrichtenauthentifizierungscodes in Bytes ab.

Methoden

CreateHash(IBuffer)	Erstellt ein CryptographicHash-Objekt , das inkrementelle Hashvorgänge unterstützt.
CreateKey(IBuffer)	Erstellt einen symmetrischen Schlüssel, der zum Erstellen des MAC-Werts verwendet werden kann.
OpenAlgorithm(String)	Erstellt ein MacAlgorithmProvider-Objekt und öffnet den angegebenen Algorithmus zur Verwendung.

Weitere Informationen

• HashAlgorithmProvider