GetKeyContainerNames.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Runtime.InteropServices;
using System.Text;
using Microsoft.Win32.SafeHandles;

public static class CryptographicUtils
{
    public static IEnumerable<string> GetKeyContainerNames(bool machine)
    {
        if (!CryptAcquireContext(
            out CryptoServiceProviderHandle provider,
            null,
            null,
            PROV.RSA_FULL,
            CryptAcquireContextFlags.VERIFYCONTEXT | (machine ? CryptAcquireContextFlags.MACHINE_KEYSET : 0)))
        {
            throw new Win32Exception();
        }
        using (provider)
        {
            var buffer = new StringBuilder(512);

            var size = buffer.Capacity;
            if (!CryptGetProvParam(provider, PP.ENUMCONTAINERS, buffer, ref size, CryptGetProvParamFlags.ENUMCONTAINERS_FIRST))
            {
                var errorCode = Marshal.GetLastWin32Error();
                if ((ERROR)errorCode == ERROR.NO_MORE_ITEMS) yield break;
                throw new Win32Exception(errorCode);
            }

            yield return buffer.ToString();

            for (;;)
            {
                size = buffer.Capacity;
                if (!CryptGetProvParam(provider, PP.ENUMCONTAINERS, buffer, ref size, CryptGetProvParamFlags.ENUMCONTAINERS_NEXT))
                {
                    var errorCode = Marshal.GetLastWin32Error();
                    if ((ERROR)errorCode == ERROR.NO_MORE_ITEMS) yield break;
                    throw new Win32Exception(errorCode);
                }

                yield return buffer.ToString();
            }
        }
    }


    #region P/invoke
    // ReSharper disable UnusedMember.Local
    // ReSharper disable ClassNeverInstantiated.Local
    // ReSharper disable InconsistentNaming

    [DllImport("advapi32.dll", SetLastError = true, CharSet = CharSet.Auto)]
    private static extern bool CryptAcquireContext(out CryptoServiceProviderHandle hProv, string pszContainer, string pszProvider, PROV dwProvType, CryptAcquireContextFlags dwFlags);

    private sealed class CryptoServiceProviderHandle : SafeHandleZeroOrMinusOneIsInvalid
    {
        private CryptoServiceProviderHandle() : base(true)
        {
        }

        protected override bool ReleaseHandle()
        {
            return CryptReleaseContext(handle, 0);
        }

        [DllImport("advapi32.dll", SetLastError = true)]
        private static extern bool CryptReleaseContext(IntPtr hProv, uint dwFlags);
    }

    private enum PROV : uint
    {
        RSA_FULL = 1
    }

    [Flags]
    private enum CryptAcquireContextFlags : uint
    {
        VERIFYCONTEXT = 0xF0000000,
        NEWKEYSET = 0x8,
        DELETEKEYSET = 0x10,
        MACHINE_KEYSET = 0x20,
        SILENT = 0x40,
        DEFAULT_CONTAINER_OPTIONAL = 0x80
    }


        
    [DllImport("advapi32.dll", SetLastError = true, CharSet = CharSet.Ansi)]
    private static extern bool CryptGetProvParam(CryptoServiceProviderHandle hProv, PP dwParam, [Out] StringBuilder pbData, ref int dwDataLen, CryptGetProvParamFlags dwFlags);

    private enum PP : uint
    {
        ENUMCONTAINERS = 2
    }

    private enum CryptGetProvParamFlags : uint
    {
        ENUMCONTAINERS_FIRST = 1,
        ENUMCONTAINERS_NEXT = 2
    }

    private enum ERROR
    {
        NO_MORE_ITEMS = 259
    }

    // ReSharper restore UnusedMember.Local
    // ReSharper restore ClassNeverInstantiated.Local
    // ReSharper restore InconsistentNaming
    #endregion
}