DesBCryptModes.cs

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using System;
using System.Security.Cryptography;
using Internal.NativeCrypto;
 
namespace Internal.Cryptography;
 
internal static class DesBCryptModes
{
    private static readonly Lazy<SafeAlgorithmHandle> s_hAlgCbc = OpenDesAlgorithm("ChainingModeCBC");
 
    private static readonly Lazy<SafeAlgorithmHandle> s_hAlgEcb = OpenDesAlgorithm("ChainingModeECB");
 
    private static readonly Lazy<SafeAlgorithmHandle> s_hAlgCfb8 = OpenDesAlgorithm("ChainingModeCFB");
 
    internal static SafeAlgorithmHandle GetSharedHandle(CipherMode cipherMode, int feedback)
    {
        switch (cipherMode)
        {
        case CipherMode.CFB:
            if (feedback != 1)
            {
                break;
            }
            return s_hAlgCfb8.Value;
        case CipherMode.CBC:
            return s_hAlgCbc.Value;
        case CipherMode.ECB:
            return s_hAlgEcb.Value;
        }
        throw new NotSupportedException();
    }
    internal static SafeAlgorithmHandle GetSharedHandle(CipherMode cipherMode, int feedback) {…}
 
    private static Lazy<SafeAlgorithmHandle> OpenDesAlgorithm(string cipherMode)
    {
        return new Lazy<SafeAlgorithmHandle>(delegate
        {
            SafeAlgorithmHandle safeAlgorithmHandle = Cng.BCryptOpenAlgorithmProvider("DES", null, Cng.OpenAlgorithmProviderFlags.NONE);
            safeAlgorithmHandle.SetCipherMode(cipherMode);
            return safeAlgorithmHandle;
        });
    }
    private static Lazy<SafeAlgorithmHandle> OpenDesAlgorithm(string cipherMode) {…}
}
internal static class DesBCryptModes {…};