// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using Internal.NativeCrypto;

namespace System.Security.Cryptography
{
    //
    // Internal interface that allows CngSymmetricAlgorithmCore to communicate back with the SymmetricAlgorithm it's embedded in.
    // Any class that implements interface also derives from SymmetricAlgorithm so they'll implement most of these methods already.
    // In addition to exposing a way to call the Key property non-virtually, this interface limits access to the outer object's
    // methods to only what's needed, which is always handy in avoiding introducing infinite-recursion bugs.
    //
    internal interface ICngSymmetricAlgorithm
    {
        // SymmetricAlgorithm members used by the core.
        int BlockSize { get; }
        int FeedbackSize { get; }
        CipherMode Mode { get; }
        PaddingMode Padding { get; }
        byte[] IV { get; set; }
        KeySizes[] LegalKeySizes { get; }

        // SymmetricAlgorithm members that need to be called non-virtually to avoid infinite recursion.
        byte[] BaseKey { get; set; }
        int BaseKeySize { get; set; }

        // Other members.
        bool IsWeakKey(byte[] key);
        SafeAlgorithmHandle GetEphemeralModeHandle(CipherMode mode, int feedbackSizeInBits);
        string GetNCryptAlgorithmIdentifier();
        byte[] PreprocessKey(byte[] key);
        int GetPaddingSize(CipherMode mode, int feedbackSizeBits);
        bool IsValidEphemeralFeedbackSize(int feedbackSizeInBits);
    }
}