EncryptedAndAuthenticatedData Kelas
Definisi
Penting
Beberapa informasi terkait produk prarilis yang dapat diubah secara signifikan sebelum dirilis. Microsoft tidak memberikan jaminan, tersirat maupun tersurat, sehubungan dengan informasi yang diberikan di sini.
Berisi data yang dapat diambil dari data terenkripsi dan terautentikasi. Algoritma enkripsi terautentikasi dibuka dengan menggunakan kelas SymmetricKeyAlgorithmProvider .
public ref class EncryptedAndAuthenticatedData sealed
/// [Windows.Foundation.Metadata.ContractVersion(Windows.Foundation.UniversalApiContract, 65536)]
/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
class EncryptedAndAuthenticatedData final
[Windows.Foundation.Metadata.ContractVersion(typeof(Windows.Foundation.UniversalApiContract), 65536)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
public sealed class EncryptedAndAuthenticatedData
Public NotInheritable Class EncryptedAndAuthenticatedData
- Warisan
- Atribut
Persyaratan Windows
Rangkaian perangkat |
Windows 10 (diperkenalkan dalam 10.0.10240.0)
|
API contract |
Windows.Foundation.UniversalApiContract (diperkenalkan dalam v1.0)
|
Contoh
using Windows.Security.Cryptography;
using Windows.Security.Cryptography.Core;
using Windows.Storage.Streams;
namespace SampleEncryptedAndAuthenticatedData
{
sealed partial class EncryptedAuthenticatedDataApp : Application
{
// Initialize a static nonce value.
static byte[] NonceBytes = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
public EncryptedAuthenticatedDataApp()
{
// Initialize the application.
this.InitializeComponent();
// Initialize the encryption method.
String strMsg = "This is a message."; // Message to encrypt and authenticate.
String strAlgName = SymmetricAlgorithmNames.AesGcm;
UInt32 keyLength = 32; // Length of the key, in bytes
BinaryStringEncoding encoding; // Binary encoding
IBuffer buffNonce; // Nonce
CryptographicKey key; // Symmetric key
// Encrypt and authenticate the message.
EncryptedAndAuthenticatedData objEncrypted = this.AuthenticatedEncryption(
strMsg,
strAlgName,
keyLength,
out encoding,
out buffNonce,
out key);
// Decrypt the encrypted data.
this.AuthenticatedDecryption(
strAlgName,
key,
objEncrypted,
encoding,
buffNonce);
}
public EncryptedAndAuthenticatedData AuthenticatedEncryption(
String strMsg,
String strAlgName,
UInt32 keyLength,
out BinaryStringEncoding encoding,
out IBuffer buffNonce,
out CryptographicKey key)
{
// Open a SymmetricKeyAlgorithmProvider object for the specified algorithm.
SymmetricKeyAlgorithmProvider objAlgProv = SymmetricKeyAlgorithmProvider.OpenAlgorithm(strAlgName);
// Create a buffer that contains the data to be encrypted.
encoding = BinaryStringEncoding.Utf8;
IBuffer buffMsg = CryptographicBuffer.ConvertStringToBinary(strMsg, encoding);
// Generate a symmetric key.
IBuffer keyMaterial = CryptographicBuffer.GenerateRandom(keyLength);
key = objAlgProv.CreateSymmetricKey(keyMaterial);
// Generate a new nonce value.
buffNonce = GetNonce();
// Encrypt and authenticate the message.
EncryptedAndAuthenticatedData objEncrypted = CryptographicEngine.EncryptAndAuthenticate(
key,
buffMsg,
buffNonce,
null);
return objEncrypted;
}
public void AuthenticatedDecryption(
String strAlgName,
CryptographicKey key,
EncryptedAndAuthenticatedData objEncrypted,
BinaryStringEncoding encoding,
IBuffer buffNonce)
{
// Declare a buffer to contain the decrypted data.
IBuffer buffDecrypted;
// Open a SymmetricKeyAlgorithmProvider object for the specified algorithm.
SymmetricKeyAlgorithmProvider objAlgProv = SymmetricKeyAlgorithmProvider.OpenAlgorithm(strAlgName);
// The input key must be securely shared between the sender of the encrypted message
// and the recipient. The nonce must also be shared but does not need to be shared
// in a secure manner. If the sender encodes the message string to a buffer, the
// binary encoding method must also be shared with the recipient.
// The recipient uses the DecryptAndAuthenticate() method as follows to decrypt the
// message, authenticate it, and verify that it has not been altered in transit.
buffDecrypted = CryptographicEngine.DecryptAndAuthenticate(
key,
objEncrypted.EncryptedData,
buffNonce,
objEncrypted.AuthenticationTag,
null);
// Convert the decrypted buffer to a string (for display). If the sender created the
// original message buffer from a string, the sender must tell the recipient what
// BinaryStringEncoding value was used. Here, BinaryStringEncoding.Utf8 is used to
// convert the message to a buffer before encryption and to convert the decrypted
// buffer back to the original plaintext.
String strDecrypted = CryptographicBuffer.ConvertBinaryToString(encoding, buffDecrypted);
}
IBuffer GetNonce()
{
// Security best practises require that an ecryption operation not
// be called more than once with the same nonce for the same key.
// A nonce value can be predictable, but must be unique for each
// secure session.
NonceBytes[0]++;
for (int i = 0; i < NonceBytes.Length - 1; i++)
{
if (NonceBytes[i] == 255)
{
NonceBytes[i + 1]++;
}
}
return CryptographicBuffer.CreateFromByteArray(NonceBytes);
}
}
}
Keterangan
Enkripsi terautentikasi mengenkripsi dan mengautentikasi konten dalam satu operasi. Pengautentikasi, juga disebut tag, digunakan selama enkripsi dan output proses berisi pasangan tag-ciphertext. Untuk informasi selengkapnya, lihat properti AuthenticationTag dan EncryptedData . Proses dekripsi memverifikasi ciphertext terhadap tag.
Anda dapat menggunakan algoritma enkripsi terautentikasi setelah memanggil metode OpenAlgorithm pada kelas SymmetricKeyAlgorithmProvider dan menentukan nama algoritma yang akan dibuka. Nama algoritma berikut didukung untuk enkripsi dan dekripsi terautentikasi:
- AES_GCM
- AES_CCM
Properti
AuthenticationTag |
Mendapatkan tag autentikasi. |
EncryptedData |
Mendapatkan data terenkripsi. |
Berlaku untuk
Lihat juga
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