CryptographicEngine.EncryptAndAuthenticate 方法

定義

命名空間:

Windows.Security.Cryptography.Core

執行已驗證的加密。

public:
 static EncryptedAndAuthenticatedData ^ EncryptAndAuthenticate(CryptographicKey ^ key, IBuffer ^ data, IBuffer ^ nonce, IBuffer ^ authenticatedData);

 static EncryptedAndAuthenticatedData EncryptAndAuthenticate(CryptographicKey const& key, IBuffer const& data, IBuffer const& nonce, IBuffer const& authenticatedData);

public static EncryptedAndAuthenticatedData EncryptAndAuthenticate(CryptographicKey key, IBuffer data, IBuffer nonce, IBuffer authenticatedData);

function encryptAndAuthenticate(key, data, nonce, authenticatedData)

Public Shared Function EncryptAndAuthenticate (key As CryptographicKey, data As IBuffer, nonce As IBuffer, authenticatedData As IBuffer) As EncryptedAndAuthenticatedData

參數

key

CryptographicKey

用於加密的對稱金鑰。

data

IBuffer

要加密和驗證的資料。

nonce

IBuffer

要使用的 Nonce。 Nonce 是具有最少重複機率的變數。 例如，您可以使用針對每個用途新產生的隨機值、時間戳記、序號或其中一些組合。 Microsoft GCM 實作需要 12 位元組 nonce。 CCM 實作需要 7 到 13 位元組 nonce。

authenticatedData

IBuffer

已驗證的資料。 這可以是 Null。

傳回

EncryptedAndAuthenticatedData

加密和已驗證的資料。如果方法失敗，驗證就會失敗;如果方法成功，驗證也會成功。

範例

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);

}

備註

已驗證的加密會加密，並在一項作業中驗證內容。 驗證器也稱為標記，會在加密期間使用，而進程的輸出包含標籤加密文字組。 如需詳細資訊，請參閱 AuthenticationTag 和 EncryptedData 屬性。 解密程式會針對 標記驗證加密文字。

您可以在SymmetricKeyAlgorithmProvider類別上呼叫OpenAlgorithm方法並指定要開啟的演算法名稱之後，使用已驗證的加密演算法。 已驗證的加密和解密支援下列演算法名稱：

• SymmetricAlgorithmNames.AesGcm
• SymmetricAlgorithmNames.AesCcm 如需包含下列程式碼範例的完整範例，請參閱 EncryptedAndAuthenticatedData 類別。

另請參閱

• EncryptedAndAuthenticatedData
• SymmetricKeyAlgorithmProvider