private static Collection <string> GetCertEKU(X509Certificate2 cert)
        {
            Collection <string> collection = new Collection <string>();
            IntPtr handle   = cert.Handle;
            int    pcbUsage = 0;
            IntPtr pUsage   = IntPtr.Zero;

            if (!CRYPT32.CertGetEnhancedKeyUsage(handle, 0U, pUsage, out pcbUsage))
            {
                throw new Win32Exception(Marshal.GetLastWin32Error());
            }
            if (pcbUsage > 0)
            {
                IntPtr num = Marshal.AllocHGlobal(pcbUsage);
                try
                {
                    if (!CRYPT32.CertGetEnhancedKeyUsage(handle, 0U, num, out pcbUsage))
                    {
                        throw new Win32Exception(Marshal.GetLastWin32Error());
                    }
                    NativeStructs.CERT_ENHKEY_USAGE certEnhkeyUsage = (NativeStructs.CERT_ENHKEY_USAGE)Marshal.PtrToStructure(num, typeof(NativeStructs.CERT_ENHKEY_USAGE));
                    IntPtr ptr = certEnhkeyUsage.rgpszUsageIdentifier;
                    for (int index = 0; (long)index < (long)certEnhkeyUsage.cUsageIdentifier; ++index)
                    {
                        string str = Marshal.PtrToStringAnsi(Marshal.ReadIntPtr(ptr, index * Marshal.SizeOf((object)ptr)));
                        collection.Add(str);
                    }
                }
                finally
                {
                    Marshal.FreeHGlobal(num);
                }
            }
            return(collection);
        }
        private static Signature SignFile(NativeStructs.SigningOption option, string fileName, X509Certificate2 certificate, string timeStampServerUrl, string hashAlgorithm)
        {
            System.Management.Automation.Signature signature = (System.Management.Automation.Signature)null;
            IntPtr num            = IntPtr.Zero;
            uint   error          = 0U;
            string hashAlgorithm1 = (string)null;

            CheckArgForNullOrEmpty(fileName, "fileName");
            CheckArgForNull((object)certificate, "certificate");

            if (!string.IsNullOrEmpty(timeStampServerUrl) && (timeStampServerUrl.Length <= 7 || timeStampServerUrl.IndexOf("http://", StringComparison.OrdinalIgnoreCase) != 0))
            {
                throw new ArgumentException("Time stamp server url required");
            }

            if (!string.IsNullOrEmpty(hashAlgorithm))
            {
                IntPtr oidInfo = CRYPT32.CryptFindOIDInfo(2U, Marshal.StringToHGlobalUni(hashAlgorithm), 0U);
                if (oidInfo == IntPtr.Zero)
                {
                    throw new ArgumentException("Invalid hash algorithm");
                }

                hashAlgorithm1 = ((NativeStructs.CRYPT_OID_INFO)Marshal.PtrToStructure(oidInfo, typeof(NativeStructs.CRYPT_OID_INFO))).pszOID;
            }
            if (!CertIsGoodForSigning(certificate))
            {
                throw new ArgumentException("Supplied certificate cannot be used to sign files.");
            }

            CheckIfFileExists(fileName);
            try
            {
                string timeStampServerUrl1 = (string)null;
                if (!string.IsNullOrEmpty(timeStampServerUrl))
                {
                    timeStampServerUrl1 = timeStampServerUrl;
                }
                NativeStructs.CRYPTUI_WIZ_DIGITAL_SIGN_INFO wizDigitalSignInfo = NativeStructs.InitSignInfoStruct(fileName, certificate, timeStampServerUrl1, hashAlgorithm1, option);
                num = Marshal.AllocCoTaskMem(Marshal.SizeOf((object)wizDigitalSignInfo));
                Marshal.StructureToPtr((object)wizDigitalSignInfo, num, false);
                bool flag = CRYPTUI.CryptUIWizDigitalSign(1U, IntPtr.Zero, IntPtr.Zero, num, IntPtr.Zero);
                Marshal.DestroyStructure(wizDigitalSignInfo.pSignExtInfo, typeof(NativeStructs.CRYPTUI_WIZ_DIGITAL_SIGN_EXTENDED_INFO));
                Marshal.FreeCoTaskMem(wizDigitalSignInfo.pSignExtInfo);
                if (!flag)
                {
                    error = SignatureHelper.GetLastWin32Error();
                    switch (error)
                    {
                    case 2147500037U:
                    case 2147942401U:
                    case 2147954407U:
                        flag = true;
                        break;

                    case 2148073480U:
                        throw new ArgumentException("InvalidHashAlgorithm");

                    default:
                        throw new ArgumentException(string.Format("CryptUIWizDigitalSign: failed: {0:x}", new object[1]
                        {
                            (object)error
                        }));
                    }
                }
                signature = !flag?SignatureProxy.GenerateSignature(fileName, error) : SignatureHelper.GetSignature(fileName);
            }
            finally
            {
                Marshal.DestroyStructure(num, typeof(NativeStructs.CRYPTUI_WIZ_DIGITAL_SIGN_INFO));
                Marshal.FreeCoTaskMem(num);
            }
            return(signature);
        }