KeyDerivationParameters.BuildForSP800108(IBuffer, IBuffer) 方法

  • 參考

定義

命名空間:
Windows.Security.Cryptography.Core
編輯

建立 KeyDerivationParameters 物件，以用於計數器模式、雜湊型訊息驗證程式代碼 (HMAC) 金鑰衍生函式。

public:
 static KeyDerivationParameters ^ BuildForSP800108(IBuffer ^ label, IBuffer ^ context);
 static KeyDerivationParameters BuildForSP800108(IBuffer const& label, IBuffer const& context);
public static KeyDerivationParameters BuildForSP800108(IBuffer label, IBuffer context);
function buildForSP800108(label, context)
Public Shared Function BuildForSP800108 (label As IBuffer, context As IBuffer) As KeyDerivationParameters

參數

label
IBuffer

指定衍生索引鍵材質用途的緩衝區。

context
IBuffer

指定衍生索引鍵材質相關資訊的緩衝區。 例如，內容可以識別衍生索引鍵資料的合作物件，並選擇性地識別由合作物件知道的 Nonce。

傳回

KeyDerivationParameters

參考金鑰衍生期間所使用的參數。

範例

public void SampleDeriveFromSP800108()
{
    // Create a string that contains the algorithm name.
    String strAlgName = KeyDerivationAlgorithmNames.Sp800108CtrHmacSha256;

    // Open the specified algorithm.
    KeyDerivationAlgorithmProvider objKdfProv = KeyDerivationAlgorithmProvider.OpenAlgorithm(strAlgName);

    // Specify the requested size, in bytes, of the derived key. 
    UInt32 targetSize = 32;

    // Create a buffer that contains the label value.
    String strPurpose = "Purpose";
    IBuffer buffLabel = CryptographicBuffer.ConvertStringToBinary(strPurpose, BinaryStringEncoding.Utf8);

    // Create a buffer that contains the context value.
    byte[] Nonce = { 1, 1, 0, 0, 0, 0, 0, 0};
    IBuffer buffContext = CryptographicBuffer.CreateFromByteArray(Nonce);

    // Create the derivation parameters.
    KeyDerivationParameters kdf800108Params = KeyDerivationParameters.BuildForSP800108(buffLabel, buffContext);

    // Create a secret value.
    IBuffer buffSecret = CryptographicBuffer.GenerateRandom(32);

    // Create a key from the secret value.
    CryptographicKey keyOriginal = objKdfProv.CreateKey(buffSecret);

    // Derive a key based on the original key and the derivation parameters.
    IBuffer keyDerived = CryptographicEngine.DeriveKeyMaterial(
        keyOriginal,
        kdf800108Params,
        targetSize);

    // Encode the key to a hexadecimal value (for display)
    String strKeyHex = CryptographicBuffer.EncodeToHexString(keyDerived);
}

備註

您可以使用下列演算法名稱搭配 OpenAlgorithm 函式來開啟 SP800108 KDF 演算法提供者：

適用於