Feature(settings):Add credentials and recipient validation settings a…

…nd add more existing settings to the UI (#1349)

Rnwood.Smtp4dev/ApiModel/Server.cs

@@ -27,6 +27,11 @@ public class Server
         public int? ImapPortNumber { get; set; }
 
         public bool DisableMessageSanitisation { get; set; }
+        public string TlsMode { get; set; }
+        public bool AuthenticationRequired { get; set; }
+        public string CredentialsValidationExpression { get; set; }
+        public bool SecureConnectionRequired { get; set; }
+        public string RecipientValidationExpression { get; set; }
     }
 
 }

Rnwood.Smtp4dev/ClientApp/src/ApiClient/Server.ts

@@ -3,7 +3,9 @@
 import ServerRelayOptions from './ServerRelayOptions';
 export default class Server {
 
-    constructor(isRunning: boolean, exception: string, portNumber: number, hostName: string, allowRemoteConnections: boolean, numberOfMessagesToKeep: number, numberOfSessionsToKeep: number, relayOptions: ServerRelayOptions, imapPortNumber: number, settingsAreEditable: boolean, disableMessageSanitisation: boolean, automaticRelayExpression: string) {
+    constructor(isRunning: boolean, exception: string, portNumber: number, hostName: string, allowRemoteConnections: boolean, numberOfMessagesToKeep: number, numberOfSessionsToKeep: number, relayOptions: ServerRelayOptions, imapPortNumber: number, settingsAreEditable: boolean, disableMessageSanitisation: boolean, automaticRelayExpression: string, tlsMode: string,     credentialsValidationExpression: string,
+    authenticationRequired: boolean,
+    secureConnectionRequired: boolean, recipientValidationExpression: string) {
 
         this.isRunning = isRunning; 
         this.exception = exception; 
@@ -16,7 +18,12 @@ export default class Server {
         this.imapPortNumber = imapPortNumber;
         this.settingsAreEditable = settingsAreEditable;
         this.disableMessageSanitisation = disableMessageSanitisation;
-        this.automaticRelayExpression = automaticRelayExpression
+        this.automaticRelayExpression = automaticRelayExpression;
+        this.tlsMode = tlsMode;
+        this.credentialsValidationExpression = credentialsValidationExpression;
+        this.authenticationRequired = authenticationRequired;
+        this.secureConnectionRequired = secureConnectionRequired;
+        this.recipientValidationExpression = recipientValidationExpression;
     }
 
 
@@ -32,4 +39,9 @@ export default class Server {
     settingsAreEditable: boolean;
     disableMessageSanitisation: boolean;
     automaticRelayExpression: string;
+    tlsMode: string;
+    credentialsValidationExpression: string;
+    authenticationRequired: boolean;
+    secureConnectionRequired: boolean;
+    recipientValidationExpression: string;
 }

Rnwood.Smtp4dev/ClientApp/src/components/settingsdialog.vue

@@ -19,6 +19,30 @@
                         <el-form-item label="Allow Remote Connections" prop="server.allowRemoteConnections">
                             <el-switch v-model="server.allowRemoteConnections" />
                         </el-form-item>
+
+                      <el-form-item label="TLS mode" prop="server.tlsMode">
+                        <el-select v-model="server.tlsMode" style="width: 100%;">
+                          <el-option key="None" label="None" value="None"></el-option>
+                          <el-option key="StartTls" label="STARTTLS (client requests TLS after session starts)" value="StartTls"></el-option>
+                          <el-option key="ImplicitTls" label="Implicit TLS (TLS immediately)" value="ImplicitTls"></el-option>
+                        </el-select>
+                      </el-form-item>
+
+                      <el-form-item label="Require Secure Connection" prop="server.secureConnectionRequired">
+                        <el-switch v-model="server.secureConnectionRequired" />
+                      </el-form-item>
+
+                      <el-form-item label="Require Authentication" prop="server.authenticationRequired">
+                        <el-switch v-model="server.authenticationRequired" />
+                      </el-form-item>
+
+                      <el-form-item label="Credentials validation expression (see comments in appsettings.json)" prop="server.credentialsValidationExpression">
+                        <el-input v-model="server.credentialsValidationExpression" />
+                      </el-form-item>
+
+                      <el-form-item label="Recipient validation expression (see comments in appsettings.json)" prop="server.recipientValidationExpression">
+                        <el-input v-model="server.recipientValidationExpression" />
+                      </el-form-item>
                     </el-tab-pane>
 
 
@@ -51,13 +75,13 @@
                             <el-input-number :min=1 :max=65535 controls-position="right" v-model="server.relayOptions.smtpPort" />
                         </el-form-item>
 
-                        <el-form-item label="Tls mode" prop="server.relayOptions.tlsMode" v-show="isRelayEnabled">
+                        <el-form-item label="TLS mode" prop="server.relayOptions.tlsMode" v-show="isRelayEnabled">
                             <el-select v-model="server.relayOptions.tlsMode">
                                 <el-option key="None" label="None" value="None"></el-option>
                                 <el-option key="Auto" label="Auto" value="Auto"></el-option>
-                                <el-option key="SslOnConnect" label="SslOnConnect" value="SslOnConnect"></el-option>
-                                <el-option key="StartTls" label="StartTls" value="StartTls"></el-option>
-                                <el-option key="StartTlsWhenAvailable" label="StartTlsWhenAvailable" value="StartTlsWhenAvailable"></el-option>
+                                <el-option key="SslOnConnect" label="TLS on connect" value="SslOnConnect"></el-option>
+                                <el-option key="StartTls" label="STARTTLS" value="StartTls"></el-option>
+                                <el-option key="StartTlsWhenAvailable" label="STARTTLS if available" value="StartTlsWhenAvailable"></el-option>
                             </el-select>
                         </el-form-item>
 

Rnwood.Smtp4dev/CommandLineParser.cs

@@ -44,9 +44,9 @@ public static MapOptions<CommandLineOptions> TryParseCommandLine(IEnumerable<str
                 { "locksettings", "Locks settings from being changed by user via web interface", data => map.Add((data !=null).ToString(), x=> x.ServerOptions.LockSettings) },
                 { "installpath=", "Sets path to folder containing wwwroot and other files", data => map.Add(data, x=> x.InstallPath) },
                 { "disablemessagesanitisation", "Disables message HTML sanitisation.", data => map.Add((data !=null).ToString(), x=> x.ServerOptions.DisableMessageSanitisation) },
-                {"applicationName=","",  data => map.Add(data, x => x.ApplicationName)}
-
-
+                { "applicationName=","",  data => map.Add(data, x => x.ApplicationName), true},
+                { "authenticationrequired", "Requires that SMTP clients authenticate", data => map.Add((data !=null).ToString(), x=> x.ServerOptions.AuthenticationRequired) },
+                { "secureconnectionrequired", "Requires that SMTP clients use SSL/TLS", data => map.Add((data !=null).ToString(), x=> x.ServerOptions.SecureConnectionRequired) }
             };
 
             if (!isDesktopApp)

Rnwood.Smtp4dev/Controllers/ServerController.cs

@@ -57,8 +57,12 @@ public ApiModel.Server GetServer()
                     AutomaticRelayExpression = relayOptions.CurrentValue.AutomaticRelayExpression
                 },
                 SettingsAreEditable = hostingEnvironmentHelper.SettingsAreEditable,
-                DisableMessageSanitisation = serverOptions.CurrentValue.DisableMessageSanitisation
-
+                DisableMessageSanitisation = serverOptions.CurrentValue.DisableMessageSanitisation,
+                TlsMode = serverOptions.CurrentValue.TlsMode.ToString(),
+                AuthenticationRequired = serverOptions.CurrentValue.AuthenticationRequired,
+                SecureConnectionRequired = serverOptions.CurrentValue.SecureConnectionRequired,
+                CredentialsValidationExpression = serverOptions.CurrentValue.CredentialsValidationExpression,
+                RecipientValidationExpression = serverOptions.CurrentValue.RecipientValidationExpression
             };
         }
 
@@ -79,6 +83,11 @@ public ActionResult UpdateServer(ApiModel.Server serverUpdate)
             newSettings.NumberOfSessionsToKeep = serverUpdate.NumberOfSessionsToKeep;
             newSettings.ImapPort = serverUpdate.ImapPortNumber;
             newSettings.DisableMessageSanitisation = serverUpdate.DisableMessageSanitisation;
+            newSettings.TlsMode = Enum.Parse<TlsMode>(serverUpdate.TlsMode);
+            newSettings.AuthenticationRequired = serverUpdate.AuthenticationRequired;
+            newSettings.SecureConnectionRequired = serverUpdate.SecureConnectionRequired;
+            newSettings.CredentialsValidationExpression = serverUpdate.CredentialsValidationExpression;
+            newSettings.RecipientValidationExpression = serverUpdate.RecipientValidationExpression;
 
             newRelaySettings.SmtpServer = serverUpdate.RelayOptions.SmtpServer;
             newRelaySettings.SmtpPort = serverUpdate.RelayOptions.SmtpPort;

Rnwood.Smtp4dev/Program.cs

@@ -153,7 +153,7 @@ private static IHost BuildWebHost(string[] args, CommandLineOptions cmdLineOptio
                         IConfigurationBuilder cb = configBuilder
                             .SetBasePath(env.ContentRootPath)
                             .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true);
-
+                        
                         if (!cmdLineOptions.NoUserSettings)
                         {
                             cb = cb.AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true, reloadOnChange: true);

Rnwood.Smtp4dev/Rnwood.Smtp4dev.csproj

@@ -55,7 +55,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Rnwood.SmtpServer" Version="3.1.0-ci0837" />
+    <PackageReference Include="Rnwood.SmtpServer" Version="3.1.0-ci0843" />
   </ItemGroup>
 
   <ItemGroup>

Rnwood.Smtp4dev/Server/ScriptingHost.cs

@@ -8,7 +8,9 @@
 using Jint.Native;
 using Jint.Runtime;
 using Microsoft.Extensions.Options;
+using Rnwood.Smtp4dev.DbModel;
 using Rnwood.SmtpServer;
+using Rnwood.SmtpServer.Extensions.Auth;
 using Serilog;
 
 namespace Rnwood.Smtp4dev.Server;
@@ -19,39 +21,56 @@ internal class ScriptingHost
 
 
 
-    private IOptionsMonitor<RelayOptions> _relayOptions;
+    private IOptionsMonitor<RelayOptions> relayOptions;
+    private IOptionsMonitor<ServerOptions> serverOptions;
 
-    public ScriptingHost(IOptionsMonitor<RelayOptions> relayOptions)
+    public ScriptingHost(IOptionsMonitor<RelayOptions> relayOptions, IOptionsMonitor<ServerOptions> serverOptions)
     {
-        _relayOptions = relayOptions;
-        _relayOptions.OnChange(o => ParseScripts(o));
-        ParseScripts(relayOptions.CurrentValue);
+        this.relayOptions = relayOptions;
+        this.serverOptions = serverOptions;
+        this.relayOptions.OnChange(_ => ParseScripts(relayOptions.CurrentValue, serverOptions.CurrentValue));
+        this.serverOptions.OnChange(_ => ParseScripts(relayOptions.CurrentValue, serverOptions.CurrentValue));
+        ParseScripts(relayOptions.CurrentValue, serverOptions.CurrentValue);
     }
 
-    private void ParseScripts(RelayOptions relayOptionsCurrentValue)
+    private void ParseScript(string type, string expression, ref Script script, ref string source)
     {
-        if (shouldRelaySource != relayOptionsCurrentValue.AutomaticRelayExpression)
+        if (source != expression)
         {
-            var autoRelayExpression = relayOptionsCurrentValue.AutomaticRelayExpression ?? "";
-            log.Information("Parsing AutomaticRelayExpression {autoRelayExpression}", autoRelayExpression);
+            expression = expression ?? "";
+            log.Information("Parsing {type} {expression}", type, expression);
 
-            if (string.IsNullOrWhiteSpace(autoRelayExpression))
+            if (string.IsNullOrWhiteSpace(expression))
             {
-                shouldRelayScript = null;
+                script = null;
             }
             else
             {
                 var parser = new JavaScriptParser();
-                shouldRelayScript = parser.ParseScript(autoRelayExpression);
+                script = parser.ParseScript(expression);
             }
 
-            shouldRelaySource = autoRelayExpression;
+            source = expression;
         }
     }
 
+    private void ParseScripts(RelayOptions relayOptionsCurrentValue, ServerOptions serverOptionsCurrentValue)
+    {
+        ParseScript("AutomaticRelayExpression", relayOptionsCurrentValue.AutomaticRelayExpression, ref shouldRelayScript, ref shouldRelaySource);
+        ParseScript("CredentialsValidationExpression", serverOptionsCurrentValue.CredentialsValidationExpression, ref credValidationScript,
+            ref credValidationSource);
+        ParseScript("RecipientValidationExpression", serverOptionsCurrentValue.RecipientValidationExpression, ref recipValidationScript,
+            ref recipValidationSource);
+    }
+
     private string shouldRelaySource;
     private Script shouldRelayScript;
-
+    private string credValidationSource;
+    private Script credValidationScript;
+    private string recipValidationSource;
+    private Script recipValidationScript;
+
+
     public IReadOnlyCollection<string> GetAutoRelayRecipients(ApiModel.Message message, string recipient, ApiModel.Session session)
     {
         if (shouldRelayScript == null)
@@ -104,4 +123,76 @@ public IReadOnlyCollection<string> GetAutoRelayRecipients(ApiModel.Message messa
         }
 
     }
+
+    public AuthenticationResult ValidateCredentials(Session session, IAuthenticationCredentials credentials)
+    {
+        if (credValidationScript == null)
+        {
+            return AuthenticationResult.Success;
+        }
+
+        Engine jsEngine = new Engine();
+
+        jsEngine.SetValue("credentials", credentials);
+        jsEngine.SetValue("session", session);
+
+        try
+        {
+            JsValue result = jsEngine.Evaluate(credValidationScript);
+
+            bool success = result.AsBoolean();
+
+            log.Information("CredentialValidationExpression: (credentials: {credentials}, session: {session.Id}) => {result} => {success}", credentials,
+                session.Id, result, success);
+
+            return success ? AuthenticationResult.Success : AuthenticationResult.Failure;
+
+        }
+        catch (JavaScriptException ex)
+        {
+            log.Error("Error executing CredentialValidationExpression : {error}", ex.Error);
+            return AuthenticationResult.TemporaryFailure;
+        }
+        catch (Exception ex)
+        {
+            log.Error("Error executing CredentialValidationExpression : {error}", ex.ToString());
+            return AuthenticationResult.TemporaryFailure;
+        }
+    }
+
+    public bool ValidateRecipient(Session session, string recipient)
+    {
+        if (recipValidationScript == null)
+        {
+            return true;
+        }
+
+        Engine jsEngine = new Engine();
+
+        jsEngine.SetValue("recipient", recipient);
+        jsEngine.SetValue("session", session);
+
+        try
+        {
+            JsValue result = jsEngine.Evaluate(recipValidationScript);
+
+            bool success = result.AsBoolean();
+
+            log.Information("RecipientValidationExpression: (recipient: {recipient}, session: {session.Id}) => {result} => {success}", recipient,
+                session.Id, result, success);
+
+            return success;
+
+        }
+        catch (JavaScriptException ex)
+        {
+            log.Error("Error executing RecipientValidationExpression : {error}", ex.Error);
+            return false;
+        }
+        catch (Exception ex)
+        {
+            log.Error("Error executing RecipientValidationExpression : {error}", ex.ToString());
+            return false;
+        }
+    }
 }

Rnwood.Smtp4dev/Server/ServerOptions.cs

@@ -1,4 +1,5 @@
 using System.Net;
+using Esprima.Ast;
 
 namespace Rnwood.Smtp4dev.Server
 {
@@ -30,5 +31,9 @@ public class ServerOptions
         public bool LockSettings { get; set; } = false;
 
         public bool DisableMessageSanitisation { get; set; } = false;
+        public string CredentialsValidationExpression { get; set; }
+        public bool AuthenticationRequired { get; set; } = false;
+        public bool SecureConnectionRequired { get; set; } = false;
+        public string RecipientValidationExpression { get; set; }
     }
 }

Rnwood.Smtp4dev/Server/Smtp4devServer.cs

@@ -19,6 +19,7 @@
 using Jint.Runtime;
 using Microsoft.Extensions.DependencyInjection;
 using Rnwood.Smtp4dev.Data;
+using Rnwood.SmtpServer.Extensions.Auth;
 using Serilog;
 using SmtpResponse = Rnwood.SmtpServer.SmtpResponse;
 
@@ -81,6 +82,39 @@ private void CreateSmtpServer()
             this.smtpServer.SessionStartedHandler += OnSessionStarted;
             this.smtpServer.AuthenticationCredentialsValidationRequiredEventHandler += OnAuthenticationCredentialsValidationRequired;
             this.smtpServer.IsRunningChanged += OnIsRunningChanged;
+            ((DefaultServerBehaviour)this.smtpServer.Behaviour).MessageStartEventHandler += OnMessageStart;
+
+            ((DefaultServerBehaviour)this.smtpServer.Behaviour).MessageRecipientAddingEventHandler += OnMessageRecipientAddingEventHandler;
+        }
+
+        private Task OnMessageRecipientAddingEventHandler(object sender, RecipientAddingEventArgs e)
+        {
+            var sessionId = activeSessionsToDbId[e.Message.Session];
+            using var scope = serviceScopeFactory.CreateScope();
+            Smtp4devDbContext dbContext = scope.ServiceProvider.GetService<Smtp4devDbContext>();
+            var session = dbContext.Sessions.Single(s => s.Id == sessionId);
+
+            if (!this.scriptingHost.ValidateRecipient(session, e.Recipient))
+            {
+                throw new SmtpServerException(new SmtpResponse(StandardSmtpResponseCode.RecipientRejected, "Recipient rejected"));
+            }
+
+            return Task.CompletedTask;
+        }
+
+        private Task OnMessageStart(object sender, MessageStartEventArgs e)
+        {
+            if (this.serverOptions.CurrentValue.SecureConnectionRequired && !e.Session.SecureConnection)
+            {
+                throw new SmtpServerException(new SmtpResponse(451, "Secure connection required"));
+            }
+
+            if (this.serverOptions.CurrentValue.AuthenticationRequired && !e.Session.Authenticated)
+            {
+                throw new SmtpServerException(new SmtpResponse(StandardSmtpResponseCode.AuthenticationRequired, "Authentication is required"));
+            }
+
+            return Task.CompletedTask;
         }
 
         private void OnIsRunningChanged(object sender, EventArgs e)
@@ -130,7 +164,14 @@ private void QueueCleanup()
 
         private Task OnAuthenticationCredentialsValidationRequired(object sender, AuthenticationCredentialsValidationEventArgs e)
         {
-            e.AuthenticationResult = AuthenticationResult.Success;
+            var sessionId = activeSessionsToDbId[e.Session];
+            using var scope = serviceScopeFactory.CreateScope();
+            Smtp4devDbContext dbContext = scope.ServiceProvider.GetService<Smtp4devDbContext>();
+            var session = dbContext.Sessions.Single(s => s.Id == sessionId);
+
+            AuthenticationResult result = scriptingHost.ValidateCredentials(session, e.Credentials);
+
+            e.AuthenticationResult = result;
             return Task.CompletedTask;
         }