KeyDerivationParameters KeyDerivationParameters KeyDerivationParameters KeyDerivationParameters Class

Gets or sets the Capi1KdfTargetAlgorithm.

public : Capi1KdfTargetAlgorithm Capi1KdfTargetAlgorithm { get; set; }public Capi1KdfTargetAlgorithm Capi1KdfTargetAlgorithm { get; set; }Public ReadWrite Property Capi1KdfTargetAlgorithm As Capi1KdfTargetAlgorithm// You can use this property in JavaScript.

Retrieves the number of iterations used to derive the key. For more information, see BuildForPbkdf2.

public : unsigned int IterationCount { get; }public uint IterationCount { get; }Public ReadOnly Property IterationCount As uint// You can use this property in JavaScript.

Remarks

The number of iterations is specified in the BuildForPbkdf2 method.

Gets or sets the parameters used by the key derivation algorithm.

public : IBuffer KdfGenericBinary { get; set; }public IBuffer KdfGenericBinary { get; set; }Public ReadWrite Property KdfGenericBinary As IBuffer// You can use this property in JavaScript.

Creates a KeyDerivationParameters object for use in the target algorithm.

public : static KeyDerivationParameters BuildForCapi1Kdf(Capi1KdfTargetAlgorithm capi1KdfTargetAlgorithm)public static KeyDerivationParameters BuildForCapi1Kdf(Capi1KdfTargetAlgorithm capi1KdfTargetAlgorithm)Public Static Function BuildForCapi1Kdf(capi1KdfTargetAlgorithm As Capi1KdfTargetAlgorithm) As KeyDerivationParameters// You can use this method in JavaScript.

Creates a KeyDerivationParameters object for use in the password-based key derivation function 2 (PBKDF2).

public : static KeyDerivationParameters BuildForPbkdf2(IBuffer pbkdf2Salt, unsigned int iterationCount)public static KeyDerivationParameters BuildForPbkdf2(IBuffer pbkdf2Salt, UInt32 iterationCount)Public Static Function BuildForPbkdf2(pbkdf2Salt As IBuffer, iterationCount As UInt32) As KeyDerivationParameters// You can use this method in JavaScript.

Examples

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;
}

Remarks

You can use the following algorithm names with the OpenAlgorithm function to open a PBKDF2 algorithm provider:

• KeyDerivationAlgorithmNames.Pbkdf2Md5
• KeyDerivationAlgorithmNames.Pbkdf2Sha1
• KeyDerivationAlgorithmNames.Pbkdf2Sha256
• KeyDerivationAlgorithmNames.Pbkdf2Sha384
• KeyDerivationAlgorithmNames.Pbkdf2Sha512

Creates a KeyDerivationParameters object for use in a counter mode, hash-based message authentication code (HMAC) key derivation function.

public : static KeyDerivationParameters BuildForSP800108(IBuffer label, IBuffer context)public static KeyDerivationParameters BuildForSP800108(IBuffer label, IBuffer context)Public Static Function BuildForSP800108(label As IBuffer, context As IBuffer) As KeyDerivationParameters// You can use this method in JavaScript.

Examples

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);
}

Remarks

You can use the following algorithm names with the OpenAlgorithm function to open a SP800108 KDF algorithm provider:

• KeyDerivationAlgorithmNames.Sp800108CtrHmacMd5
• KeyDerivationAlgorithmNames.Sp800108CtrHmacSha1
• KeyDerivationAlgorithmNames.Sp800108CtrHmacSha256
• KeyDerivationAlgorithmNames.Sp800108CtrHmacSha384
• KeyDerivationAlgorithmNames.Sp800108CtrHmacSha512

Creates a KeyDerivationParameters object for use in the SP800-56A key derivation function.

public : static KeyDerivationParameters BuildForSP80056a(IBuffer algorithmId, IBuffer partyUInfo, IBuffer partyVInfo, IBuffer suppPubInfo, IBuffer suppPrivInfo)public static KeyDerivationParameters BuildForSP80056a(IBuffer algorithmId, IBuffer partyUInfo, IBuffer partyVInfo, IBuffer suppPubInfo, IBuffer suppPrivInfo)Public Static Function BuildForSP80056a(algorithmId As IBuffer, partyUInfo As IBuffer, partyVInfo As IBuffer, suppPubInfo As IBuffer, suppPrivInfo As IBuffer) As KeyDerivationParameters// You can use this method in JavaScript.

Examples

!code-csharp[

public void SampleDeriveFromSP80056a()
{
    // Create a string that contains the algorithm name.
    String strAlgName = KeyDerivationAlgorithmNames.Sp80056aConcatSha512;

    // 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 secret to be used during derivation.
    IBuffer buffSecret = CryptographicBuffer.GenerateRandom(32);

    // Create a buffer that contains the intended purpose of the derived key.
    String strAlgId = "Purpose";
    IBuffer buffAlgId = CryptographicBuffer.ConvertStringToBinary(strAlgId, BinaryStringEncoding.Utf8);

    // Create a buffer that contains public information contributed by the initiator.
    String strPartyUInfo = "Initiator public info";
    IBuffer buffPartyUInfo = CryptographicBuffer.ConvertStringToBinary(strPartyUInfo, BinaryStringEncoding.Utf8);

    // Create a buffer that contains public information contributed by the responder.
    String strPartyVInfo = "Responder public info";
    IBuffer buffPartyVInfo = CryptographicBuffer.ConvertStringToBinary(strPartyVInfo, BinaryStringEncoding.Utf8);

    // Create a buffer that contains public information known to both parties.
    String strSuppPubInfo = "Two party public info";
    IBuffer buffSuppPubInfo = CryptographicBuffer.ConvertStringToBinary(strSuppPubInfo, BinaryStringEncoding.Utf8);

    // Create a buffer that contains a shared private secret.
    IBuffer buffSuppPrivInfo = CryptographicBuffer.GenerateRandom(32);

    // Create the derivation parameters.
    KeyDerivationParameters kdf80056AParamsEx = KeyDerivationParameters.BuildForSP80056a(
        buffAlgId,
        buffPartyUInfo,
        buffPartyVInfo,
        buffSuppPubInfo,
        buffSuppPrivInfo);

    // 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,
        kdf80056AParamsEx,
        targetSize);

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

]

Remarks

You can use the following algorithm names with the OpenAlgorithm function to open a SP80056a KDF algorithm provider:

• KeyDerivationAlgorithmNames.Sp80056aConcatMd5
• KeyDerivationAlgorithmNames.Sp80056aConcatSha1
• KeyDerivationAlgorithmNames.Sp80056aConcatSha256
• KeyDerivationAlgorithmNames.Sp80056aConcatSha384
• KeyDerivationAlgorithmNames.Sp80056aConcatSha512