xenadmin/XenAdmin/Core/Registry.cs

/* Copyright (c) Cloud Software Group, Inc. 
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using System;
using Microsoft.Win32;


namespace XenAdmin.Core
{
    public static class Registry
    {
        private static readonly log4net.ILog log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);

        internal static bool AllowCredentialSave => ReadBool(ALLOW_CREDENTIAL_SAVE, true);

        internal static bool DisablePlugins => ReadBool(DISABLE_PLUGINS, false);

        internal static bool ForceSystemFonts => ReadBool(FORCE_SYSTEM_FONTS, false);

        internal static bool DontSudo => ReadBool(DONT_SUDO, false);

        public static SSLCertificateTypes SSLCertificateTypes
        {
            get
            {
                string v = ReadString(SSL_CERTIFICATES_KEY);

                if (v != null && v.ToUpperInvariant() == SSL_CERTIFICATES_CHANGED_ONLY)
                    return SSLCertificateTypes.Changed;

                if (v != null && v.ToUpperInvariant() == SSL_CERTIFICATES_ALL)
                    return SSLCertificateTypes.All;

                return SSLCertificateTypes.None;
            }
        }

        public static void AssertPowerShellInstalled()
        {
            string v = ReadRegistryValue(Microsoft.Win32.Registry.LocalMachine, PowerShellKey, PowerShellStamp);

            if (!int.TryParse(v, out var result) || result != 1)
                throw new I18NException(I18NExceptionType.PowerShellNotPresent);
        }

        public static void AssertPowerShellExecutionPolicyNonRestricted()
        {
            var val = ReadRegistryValue(Microsoft.Win32.Registry.LocalMachine, PSExecutionPolicyKey, PSExecutionPolicyName) ??
                      ReadRegistryValue(Microsoft.Win32.Registry.CurrentUser, PSExecutionPolicyKey, PSExecutionPolicyName);

            if (val == "Restricted")
                throw new I18NException(I18NExceptionType.PowerShellExecutionPolicyRestricted);
        }

        /// <summary>
        /// Reads a bool value key under HKEY_LOCAL_MACHINE\XENCENTER_LOCAL_KEYS
        /// </summary>
        /// <returns>False if the value is "false" (case insensitive), true if the key is present but not
        /// "false", defaultVal otherwise.</returns>
        private static bool ReadBool(string k, bool defaultVal)
        {
            var v = ReadRegistryValue(Microsoft.Win32.Registry.LocalMachine, XENCENTER_LOCAL_KEYS, k);
            return v == null ? defaultVal : v.ToUpperInvariant() != "FALSE";
        }

        /// <summary>
        /// Reads a string value k under HKEY_LOCAL_MACHINE\XENCENTER_LOCAL_KEYS
        /// </summary>
        private static string ReadString(string k)
        {
            return ReadRegistryValue(Microsoft.Win32.Registry.LocalMachine, XENCENTER_LOCAL_KEYS, k);
        }

        private static string ReadRegistryValue(RegistryKey baseKey, string subKey, string k)
        {
            if (baseKey == null)
                return null;

            try
            {
                using (var mainKey = baseKey.OpenSubKey(subKey))
                {
                    if (mainKey == null)
                        return null;

                    var v = mainKey.GetValue(k);
                    if (v != null)
                        return v.ToString();
                }
            }
            catch (Exception e)
            {
                log.Debug($"Failed to read {baseKey.Name}\\{subKey}\\{k} from registry; assuming NULL.", e);
            }

            return null;
        }

        private static string ReadRegistryValue(RegistryHive hKey, string subKey, string k, RegistryView rView = RegistryView.Default)
        {
            try
            {
                using (var baseKey = RegistryKey.OpenBaseKey(hKey, rView))
                    return ReadRegistryValue(baseKey, subKey, k);
            }
            catch (Exception e)
            {
                log.Debug($"Failed to read {hKey}\\{subKey}\\{k} from registry view {rView}; assuming NULL.", e);
            }

            return null;
        }

        /// <summary>
        /// Reads a string value k under XENCENTER_LOCAL_KEYS, targeting the 32-bit
        /// registry view, and trying CurrentUser first and then LocalMachine
        /// </summary>
        private static string ReadInstalledKey(string k, RegistryView rView = RegistryView.Default)
        {
            var val = ReadRegistryValue(RegistryHive.CurrentUser, XENCENTER_LOCAL_KEYS, k, rView);

            if (string.IsNullOrEmpty(val))
                val = ReadRegistryValue(RegistryHive.LocalMachine, XENCENTER_LOCAL_KEYS, k, rView);

            return string.IsNullOrEmpty(val) ? null : val;
        }

        public static string HiddenFeatures => ReadInstalledKey(HIDDEN_FEATURES, RegistryView.Registry32);

        public static string AdditionalFeatures => ReadInstalledKey(ADDITIONAL_FEATURES, RegistryView.Registry32);

        public static string AuthTokenName => INTERNAL_STAGE_AUTH_TOKEN;

        public static string GetCustomUpdatesXmlLocation()
        {
            return ReadInstalledKey(CUSTOM_UPDATES_XML_LOCATION);
        }

        public static string GetInternalStageAuthToken()
        {
            return ReadInstalledKey(INTERNAL_STAGE_AUTH_TOKEN);
        }

        public static string CustomHelpUrl => ReadString(HELP_URL_OVERRIDE);

        private const string SSL_CERTIFICATES_CHANGED_ONLY = "CHANGED";
        private const string SSL_CERTIFICATES_ALL = "ALL";
        private const string SSL_CERTIFICATES_KEY = "ForceSSLCertificates";
        private const string ALLOW_CREDENTIAL_SAVE = "AllowCredentialSave";
        private const string FORCE_SYSTEM_FONTS = "ForceSystemFonts";
        private const string DISABLE_PLUGINS = "DisablePlugins";
        private const string DONT_SUDO = "DontSudo";
        private static readonly string XENCENTER_LOCAL_KEYS = $"SOFTWARE\\{BrandManager.ProductBrand}\\{BrandManager.BrandConsoleNoSpace}";
        private const string PSExecutionPolicyKey = @"Software\Microsoft\PowerShell\1\ShellIds\Microsoft.PowerShell";
        private const string PSExecutionPolicyName = "ExecutionPolicy";
        private const string PowerShellKey = @"Software\Microsoft\PowerShell\1";
        private const string PowerShellStamp = "Install";
        private const string HIDDEN_FEATURES = "HiddenFeatures";
        private const string ADDITIONAL_FEATURES = "AdditionalFeatures";
        private const string CUSTOM_UPDATES_XML_LOCATION = "CheckForUpdatesXmlLocationOverride";
        private const string INTERNAL_STAGE_AUTH_TOKEN = "InternalStageAuthToken";
        private const string HELP_URL_OVERRIDE = "HelpUrlOverride";
    }

    public enum SSLCertificateTypes { None, Changed, All }
}