CryptographicEngine.DeriveKeyMaterial 方法

定义

命名空间:

Windows.Security.Cryptography.Core

使用密钥派生函数从另一个密钥派生密钥。 有关详细信息，请参阅 KeyDerivationAlgorithmProvider 和 KeyDerivationParameters 类。

public:
 static IBuffer ^ DeriveKeyMaterial(CryptographicKey ^ key, KeyDerivationParameters ^ parameters, unsigned int desiredKeySize);

 static IBuffer DeriveKeyMaterial(CryptographicKey const& key, KeyDerivationParameters const& parameters, uint32_t const& desiredKeySize);

public static IBuffer DeriveKeyMaterial(CryptographicKey key, KeyDerivationParameters parameters, uint desiredKeySize);

function deriveKeyMaterial(key, parameters, desiredKeySize)

Public Shared Function DeriveKeyMaterial (key As CryptographicKey, parameters As KeyDerivationParameters, desiredKeySize As UInteger) As IBuffer

参数

key

CryptographicKey

用于派生的对称密钥或密钥。

parameters

KeyDerivationParameters

派生参数。 参数因使用的 KDF 算法类型而异。

desiredKeySize

UInt32

unsigned int

uint32_t

请求的派生密钥的大小（以字节为单位）。

返回

IBuffer

包含派生密钥的缓冲区。

示例

public String SampleDeriveFromPbkdf(
    String strAlgName,
    UInt32 targetSize)
{
    // Open the specified algorithm.
    KeyDerivationAlgorithmProvider objKdfProv = KeyDerivationAlgorithmProvider.OpenAlgorithm(strAlgName);

    // Create a buffer that contains the secret used during derivation.
    String strSecret = "MyPassword";
    IBuffer buffSecret = CryptographicBuffer.ConvertStringToBinary(strSecret, BinaryStringEncoding.Utf8);

    // Create a random salt value.
    IBuffer buffSalt = CryptographicBuffer.GenerateRandom(32);

    // Specify the number of iterations to be used during derivation.
    UInt32 iterationCount = 10000;

    // Create the derivation parameters.
    KeyDerivationParameters pbkdf2Params = KeyDerivationParameters.BuildForPbkdf2(buffSalt, iterationCount);

    // 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,
        pbkdf2Params,
        targetSize);

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

    // Return the encoded string
    return strKeyHex;
}

注解

派生密钥要求使用 KeyDerivationAlgorithmProvider 和 KeyDerivationParameters 类。 可以使用以下关键派生函数：

• BuildForPbkdf2
• BuildForSP800108
• BuildForSP80056a

有关包含以下代码示例的完整示例，请参阅 KeyDerivationAlgorithmProvider 类。

另请参阅

• KeyDerivationAlgorithmProvider
• KeyDerivationParameters