//******************************************************************************************************//  Snmp.cs - Gbtc////  Copyright © 2020, Grid Protection Alliance.  All Rights Reserved.////  Licensed to the Grid Protection Alliance (GPA) under one or more contributor license agreements. See//  the NOTICE file distributed with this work for additional information regarding copyright ownership.//  The GPA licenses this file to you under the MIT License (MIT), the "License"; you may not use this//  file except in compliance with the License. You may obtain a copy of the License at:////      http://opensource.org/licenses/MIT////  Unless agreed to in writing, the subject software distributed under the License is distributed on an//  "AS-IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. Refer to the//  License for the specific language governing permissions and limitations.////  Code Modification History://  ----------------------------------------------------------------------------------------------------//  09/10/2020 - J. Ritchie Carroll//       Generated original version of source code.////****************************************************************************************************** using System;using System.Collections.Generic;using System.Globalization;using System.Net;using System.Threading.Tasks;using GSF.Configuration;using GSF.Diagnostics;using GSF.Net.Snmp.Messaging;using GSF.Net.Snmp.Security;using GSF.Security.Cryptography; namespace GSF.Net.Snmp{    /// <summary>    /// Exposes simple SNMP functionality for GSF.    /// </summary>    public static class Snmp    {        /// <summary>        /// Defines default IP end point for SNMP client agent.        /// </summary>        public const string DefaultIPEndPoint = "127.0.0.1:162";         /// <summary>        /// Root GSF OID (1.3.6.1.4.1.56056). This is the private enterprise number defined for the Grid Protection Alliance.        /// </summary>        public static readonly ObjectIdentifier EnterpriseRoot = new ObjectIdentifier(OID.EnterpriseRoot);         /// <summary>        /// GSF SNMP engine ID (D3F30A26E61843918ED5ABD87E).        /// </summary>        public static readonly OctetString EngineID = new OctetString(ByteTool.Convert("D3F30A26E61843918ED5ABD87E"));         /// <summary>        /// Sends an integer based SNMP version 3 trap.        /// </summary>        /// <param name="oid">Target OID.</param>        /// <param name="value">Notification value.</param>        public static void SendTrap(uint[] oid, int value) => SendTrapAsync(oid, value).Wait();         /// <summary>        /// Sends a floating-point based SNMP version 3 trap.        /// </summary>        /// <param name="oid">Target OID.</param>        /// <param name="value">Notification value.</param>        /// <remarks>        /// SNMP does not support floating point values via binary encoding, so value is encoded as a string.        /// </remarks>        public static void SendTrap(uint[] oid, double value) => SendTrapAsync(oid, value).Wait();         /// <summary>        /// Sends a string based SNMP version 3 trap.        /// </summary>        /// <param name="oid">Target OID.</param>        /// <param name="value">Notification value.</param>        public static void SendTrap(uint[] oid, string value) => SendTrapAsync(oid, value).Wait();         /// <summary>        /// Sends an SNMP version 3 trap.        /// </summary>        /// <param name="oid">Target OID.</param>        /// <param name="data">Notification data.</param>        public static void SendTrap(uint[] oid, ISnmpData data) => SendTrapAsync(oid, data).Wait();         /// <summary>        /// Sends an SNMP version 3 trap.        /// </summary>        /// <param name="variables">Variables.</param>        public static void SendTrap(params Variable[] variables) => SendTrapAsync(variables).Wait();         /// <summary>        /// Sends an integer based SNMP version 3 trap.        /// </summary>        /// <param name="oid">Target OID.</param>        /// <param name="value">Notification value.</param>        public static Task SendTrapAsync(uint[] oid, int value) => SendTrapAsync(oid, new Integer32(value));         /// <summary>        /// Sends a floating-point based SNMP version 3 trap.        /// </summary>        /// <param name="oid">Target OID.</param>        /// <param name="value">Notification value.</param>        /// <remarks>        /// SNMP does not support floating point values via binary encoding, so value is encoded as a string.        /// </remarks>        public static Task SendTrapAsync(uint[] oid, double value) => SendTrapAsync(oid, new OctetString(value.ToString(CultureInfo.InvariantCulture)));         /// <summary>        /// Sends a string based SNMP version 3 trap.        /// </summary>        /// <param name="oid">Target OID.</param>        /// <param name="value">Notification value.</param>        public static Task SendTrapAsync(uint[] oid, string value) => SendTrapAsync(oid, new OctetString(value));         /// <summary>        /// Sends an SNMP version 3 trap.        /// </summary>        /// <param name="oid">Target OID.</param>        /// <param name="data">Notification data.</param>        public static Task SendTrapAsync(uint[] oid, ISnmpData data) => SendTrapAsync(new Variable(oid, data));         /// <summary>        /// Sends an SNMP version 3 trap.        /// </summary>        /// <param name="variables">Variables.</param>        public static async Task SendTrapAsync(params Variable[] variables)        {            await new TrapV2Message            (                VersionCode.V3,                Messenger.NextMessageId,                Messenger.NextRequestId,                s_community,                EnterpriseRoot,                (uint)Environment.TickCount / 10,                new List<Variable>(variables),                s_privacyProvider,                Messenger.MaxMessageSize,                EngineID, 0, 0            )            .SendAsync(s_endPoint);        }         private static readonly OctetString s_community;        private static readonly IPEndPoint s_endPoint;        private static readonly DESPrivacyProvider s_privacyProvider;         static Snmp()        {            try            {                // Get configured SNMP agent settings                CategorizedSettingsElementCollection settings = ConfigurationFile.Current.Settings["snmpAgent"];                PasswordGenerator passwordGenerator = new PasswordGenerator(PasswordCharacterGroups);                 settings.Add("Community", "Eval(securityProvider.ApplicationName)", "Defines the SNMP agent community identifier for trap messages.");                settings.Add("IPEndPoint", DefaultIPEndPoint, "Defines the SNMP agent target IP end point for trap messages.");                settings.Add("AuthPhrase", passwordGenerator.GeneratePassword(16), "Defines the SNMP agent authentication phrase for trap messages.");                settings.Add("EncryptKey", passwordGenerator.GeneratePassword(16), "Defines the SNMP agent encryption key for trap messages.");                 s_community = new OctetString(settings["Community"].ValueAs(nameof(GSF)));                 string endPoint = settings["IPEndPoint"].ValueAs(DefaultIPEndPoint);                string[] parts = endPoint.Split(':');                 if (parts.Length != 2)                {                    parts = DefaultIPEndPoint.Split(':');                    Logger.SwallowException(new Exception($"Configured SNMP agent IP end point \"{endPoint}\" format is invalid. Using default IP end point \"{DefaultIPEndPoint}\"."));                }                 if (!IPAddress.TryParse(parts[0], out IPAddress address))                {                    address = IPAddress.Loopback;                    Logger.SwallowException(new Exception($"Configured SNMP agent IP end point \"{endPoint}\" address is invalid. Using loop-back address \"127.0.0.1\"."));                }                 if (!ushort.TryParse(parts[1], out ushort port))                {                    port = 162;                    Logger.SwallowException(new Exception($"Configured SNMP agent IP end point \"{endPoint}\" port is invalid. Using default port \"162\"."));                }                 s_endPoint = new IPEndPoint(address, port);                 string authPhrase = settings["AuthPhrase"].Value.PadRight(16, '#');                string encryptKey = settings["EncryptKey"].Value.PadRight(16, '#');                 s_privacyProvider = new DESPrivacyProvider(                    new OctetString(encryptKey),                    new MD5AuthenticationProvider(new OctetString(authPhrase)));            }            catch (Exception ex)            {                Logger.SwallowException(new Exception($"Failed to load SNMP agent configuration: {ex.Message}", ex));            }        }         private static readonly IReadOnlyList<CharacterGroup> PasswordCharacterGroups = new List<CharacterGroup>()        {            new CharacterGroup { Characters = "abcdefghijklmnopqrstuvwxyz", MinOccurrence = 1 },            new CharacterGroup { Characters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ", MinOccurrence = 1 },            new CharacterGroup { Characters = "0123456789", MinOccurrence = 1 },        };    }}