/// <summary>
/// Computes a derived key.
/// </summary>
/// <param name="hmacAlgorithm">
/// </param>
/// <param name="salt">
/// The salt.
/// A unique salt means a unique derived key, even if the original key is identical.
/// </param>
/// <param name="iterations">The number of iterations to apply.</param>
/// <param name="derivedKeyLength">The desired length of the derived key.</param>
/// <returns>The derived key.</returns>
#if USEBC || WINDOWS_UWP || NETCORE
public static byte[] ComputeDerivedKey(nStratis.BouncyCastle.crypto.IMac hmacAlgorithm, byte[] salt, int iterations,
int derivedKeyLength)
{
nStratis.Crypto.Cryptsharp.Check.Range("derivedKeyLength", derivedKeyLength, 0, int.MaxValue);
using (Pbkdf2 kdf = new Pbkdf2(hmacAlgorithm, salt, iterations))
{
return(kdf.Read(derivedKeyLength));
}
}
/// <summary>
/// Creates a new PBKDF2 stream.
/// </summary>
/// <param name="hmacAlgorithm">
/// </param>
/// <param name="salt">
/// The salt.
/// A unique salt means a unique PBKDF2 stream, even if the original key is identical.
/// </param>
/// <param name="iterations">The number of iterations to apply.</param>
#if USEBC || WINDOWS_UWP || NETCORE
public Pbkdf2(nStratis.BouncyCastle.crypto.IMac hmacAlgorithm, byte[] salt, int iterations)
{
nStratis.Crypto.Cryptsharp.Check.Null("hmacAlgorithm", hmacAlgorithm);
nStratis.Crypto.Cryptsharp.Check.Null("salt", salt);
nStratis.Crypto.Cryptsharp.Check.Length("salt", salt, 0, int.MaxValue - 4);
nStratis.Crypto.Cryptsharp.Check.Range("iterations", iterations, 1, int.MaxValue);
int hmacLength = hmacAlgorithm.GetMacSize();
_saltBuffer = new byte[salt.Length + 4];
Array.Copy(salt, _saltBuffer, salt.Length);
_iterations = iterations;
_hmacAlgorithm = hmacAlgorithm;
_digest = new byte[hmacLength];
_digestT1 = new byte[hmacLength];
}
public Pbkdf2(KeyedHashAlgorithm hmacAlgorithm, byte[] salt, int iterations)
{
Check.Null("hmacAlgorithm", hmacAlgorithm);
Check.Null("salt", salt);
Check.Length("salt", salt, 0, int.MaxValue - 4);
Check.Range("iterations", iterations, 1, int.MaxValue);
if (hmacAlgorithm.HashSize == 0 || hmacAlgorithm.HashSize % 8 != 0)
{
throw Exceptions.Argument("hmacAlgorithm", "Unsupported hash size.");
}
int hmacLength = hmacAlgorithm.HashSize / 8;
_saltBuffer = new byte[salt.Length + 4]; Array.Copy(salt, _saltBuffer, salt.Length);
_iterations = iterations; _hmacAlgorithm = hmacAlgorithm;
_digest = new byte[hmacLength]; _digestT1 = new byte[hmacLength];
}
