SEBWIN-314: Completed infrastructure for browser request filtering.

SafeExamBrowser.Browser.Contracts/Filters/IRequestFilter.cs

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using SafeExamBrowser.Settings.Browser;
+
+namespace SafeExamBrowser.Browser.Contracts.Filters
+{
+	/// <summary>
+	/// Defines the filter for browser requests.
+	/// </summary>
+	public interface IRequestFilter
+	{
+		/// <summary>
+		/// The default result to be returned by <see cref="Process(Request)"/> if no rule matches.
+		/// </summary>
+		FilterResult Default { get; set; }
+
+		/// <summary>
+		/// Loads the given filter rule to be used when processing requests.
+		/// </summary>
+		void Load(IRule rule);
+
+		/// <summary>
+		/// Filters the given request according to the loaded rules.
+		/// </summary>
+		FilterResult Process(Request request);
+	}
+}

SafeExamBrowser.Browser.Contracts/Filters/IRule.cs

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using SafeExamBrowser.Settings.Browser;
+
+namespace SafeExamBrowser.Browser.Contracts.Filters
+{
+	/// <summary>
+	/// Defines a request filter rule.
+	/// </summary>
+	public interface IRule
+	{
+		/// <summary>
+		/// The filter result to be used if the rule matches a request.
+		/// </summary>
+		FilterResult Result { get; }
+
+		/// <summary>
+		/// Initializes the rule for processing requests.
+		/// </summary>
+		void Initialize(FilterRuleSettings settings);
+
+		/// <summary>
+		/// Indicates whether the rule applies for the given request.
+		/// </summary>
+		bool IsMatch(Request request);
+	}
+}

SafeExamBrowser.Browser.Contracts/Filters/IRuleFactory.cs

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using SafeExamBrowser.Settings.Browser;
+
+namespace SafeExamBrowser.Browser.Contracts.Filters
+{
+	/// <summary>
+	/// Builds request filter rules.
+	/// </summary>
+	public interface IRuleFactory
+	{
+		/// <summary>
+		/// Creates a filter rule for the given type.
+		/// </summary>
+		IRule CreateRule(FilterRuleType type);
+	}
+}

SafeExamBrowser.Browser.Contracts/Filters/Request.cs

@@ -6,16 +6,16 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-namespace SafeExamBrowser.Browser.Filters.Rules
+namespace SafeExamBrowser.Browser.Contracts.Filters
 {
-	internal abstract class Rule
+	/// <summary>
+	/// Holds data relevant for filtering requests.
+	/// </summary>
+	public class Request
 	{
-		internal Rule(string expression)
+		/// <summary>
-		{
+		/// The full URL of the request.
-			Initialize(expression);
+		/// </summary>
-		}
+		public string Url { get; set; }
-
-		internal abstract bool IsMatch(string url);
-		protected abstract void Initialize(string expression);
 	}
 }

SafeExamBrowser.Browser.Contracts/SafeExamBrowser.Browser.Contracts.csproj

@@ -56,6 +56,10 @@
     <Compile Include="Events\DownloadEventArgs.cs" />
     <Compile Include="Events\DownloadFinishedCallback.cs" />
     <Compile Include="Events\DownloadRequestedEventHandler.cs" />
+    <Compile Include="Filters\IRequestFilter.cs" />
+    <Compile Include="Filters\IRule.cs" />
+    <Compile Include="Filters\IRuleFactory.cs" />
+    <Compile Include="Filters\Request.cs" />
     <Compile Include="IBrowserApplication.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>
@@ -64,6 +68,10 @@
       <Project>{ac77745d-3b41-43e2-8e84-d40e5a4ee77f}</Project>
       <Name>SafeExamBrowser.Applications.Contracts</Name>
     </ProjectReference>
+    <ProjectReference Include="..\SafeExamBrowser.Settings\SafeExamBrowser.Settings.csproj">
+      <Project>{30b2d907-5861-4f39-abad-c4abf1b3470e}</Project>
+      <Name>SafeExamBrowser.Settings</Name>
+    </ProjectReference>
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
 </Project>

SafeExamBrowser.Browser.UnitTests/Filters/RequestFilterTests.cs

@@ -8,6 +8,8 @@
 
 using System;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Moq;
+using SafeExamBrowser.Browser.Contracts.Filters;
 using SafeExamBrowser.Browser.Filters;
 using SafeExamBrowser.Settings.Browser;
 
@@ -27,13 +29,20 @@ namespace SafeExamBrowser.Browser.UnitTests.Filters
 		[TestMethod]
 		public void MustProcessBlockRulesFirst()
 		{
-			var allow = new FilterRuleSettings { Expression = "*", Type = FilterType.Simplified, Result = FilterResult.Allow };
+			var allow = new Mock<IRule>();
-			var block = new FilterRuleSettings { Expression = "*", Type = FilterType.Simplified, Result = FilterResult.Block };
+			var block = new Mock<IRule>();
 
-			sut.Load(allow);
+			allow.SetupGet(r => r.Result).Returns(FilterResult.Allow);
-			sut.Load(block);
+			block.SetupGet(r => r.Result).Returns(FilterResult.Block);
+			block.Setup(r => r.IsMatch(It.IsAny<Request>())).Returns(true);
 
-			var result = sut.Process("safeexambrowser.org");
+			sut.Load(allow.Object);
+			sut.Load(block.Object);
+
+			var result = sut.Process(new Request());
+
+			allow.Verify(r => r.IsMatch(It.IsAny<Request>()), Times.Never);
+			block.Verify(r => r.IsMatch(It.IsAny<Request>()), Times.Once);
 
 			Assert.AreEqual(FilterResult.Block, result);
 		}
@@ -41,28 +50,41 @@ namespace SafeExamBrowser.Browser.UnitTests.Filters
 		[TestMethod]
 		public void MustProcessAllowRulesSecond()
 		{
-			var allow = new FilterRuleSettings { Expression = "*", Type = FilterType.Simplified, Result = FilterResult.Allow };
+			var allow = new Mock<IRule>();
-			var block = new FilterRuleSettings { Expression = "xyz", Type = FilterType.Simplified, Result = FilterResult.Block };
+			var block = new Mock<IRule>();
 
-			sut.Load(allow);
+			allow.SetupGet(r => r.Result).Returns(FilterResult.Allow);
-			sut.Load(block);
+			allow.Setup(r => r.IsMatch(It.IsAny<Request>())).Returns(true);
+			block.SetupGet(r => r.Result).Returns(FilterResult.Block);
 
-			var result = sut.Process("safeexambrowser.org");
+			sut.Load(allow.Object);
+			sut.Load(block.Object);
+
+			var result = sut.Process(new Request());
+
+			allow.Verify(r => r.IsMatch(It.IsAny<Request>()), Times.Once);
+			block.Verify(r => r.IsMatch(It.IsAny<Request>()), Times.Once);
 
 			Assert.AreEqual(FilterResult.Allow, result);
 		}
 
 		[TestMethod]
-		public void MustReturnDefault()
+		public void MustReturnDefaultWithoutMatch()
 		{
-			var allow = new FilterRuleSettings { Expression = "xyz", Type = FilterType.Simplified, Result = FilterResult.Allow };
+			var allow = new Mock<IRule>();
-			var block = new FilterRuleSettings { Expression = "xyz", Type = FilterType.Simplified, Result = FilterResult.Block };
+			var block = new Mock<IRule>();
+
+			allow.SetupGet(r => r.Result).Returns(FilterResult.Allow);
+			block.SetupGet(r => r.Result).Returns(FilterResult.Block);
 
 			sut.Default = (FilterResult) (-1);
-			sut.Load(allow);
+			sut.Load(allow.Object);
-			sut.Load(block);
+			sut.Load(block.Object);
 
-			var result = sut.Process("safeexambrowser.org");
+			var result = sut.Process(new Request());
+
+			allow.Verify(r => r.IsMatch(It.IsAny<Request>()), Times.Once);
+			block.Verify(r => r.IsMatch(It.IsAny<Request>()), Times.Once);
 
 			Assert.AreEqual((FilterResult) (-1), result);
 		}
@@ -71,11 +93,11 @@ namespace SafeExamBrowser.Browser.UnitTests.Filters
 		public void MustReturnDefaultWithoutRules()
 		{
 			sut.Default = FilterResult.Allow;
-			var result = sut.Process("safeexambrowser.org");
+			var result = sut.Process(new Request());
 			Assert.AreEqual(FilterResult.Allow, result);
 
 			sut.Default = FilterResult.Block;
-			result = sut.Process("safeexambrowser.org");
+			result = sut.Process(new Request());
 			Assert.AreEqual(FilterResult.Block, result);
 		}
 
@@ -83,14 +105,10 @@ namespace SafeExamBrowser.Browser.UnitTests.Filters
 		[ExpectedException(typeof(NotImplementedException))]
 		public void MustNotAllowUnsupportedResult()
 		{
-			sut.Load(new FilterRuleSettings { Result = (FilterResult) (-1) });
+			var rule = new Mock<IRule>();
-		}
 
-		[TestMethod]
+			rule.SetupGet(r => r.Result).Returns((FilterResult) (-1));
-		[ExpectedException(typeof(NotImplementedException))]
+			sut.Load(rule.Object);
-		public void MustNotAllowUnsupportedFilterType()
-		{
-			sut.Load(new FilterRuleSettings { Type = (FilterType) (-1) });
 		}
 	}
 }

SafeExamBrowser.Browser.UnitTests/Filters/RuleFactoryTests.cs

@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using System;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using SafeExamBrowser.Browser.Filters;
+using SafeExamBrowser.Browser.Filters.Rules;
+using SafeExamBrowser.Settings.Browser;
+
+namespace SafeExamBrowser.Browser.UnitTests.Filters
+{
+	[TestClass]
+	public class RuleFactoryTests
+	{
+		private RuleFactory sut;
+
+		[TestInitialize]
+		public void Initialize()
+		{
+			sut = new RuleFactory();
+		}
+
+		[TestMethod]
+		public void MustCreateCorrectRules()
+		{
+			Assert.IsInstanceOfType(sut.CreateRule(FilterRuleType.Regex), typeof(RegexRule));
+			Assert.IsInstanceOfType(sut.CreateRule(FilterRuleType.Simplified), typeof(SimplifiedRule));
+		}
+
+		[TestMethod]
+		[ExpectedException(typeof(NotImplementedException))]
+		public void MustNotAllowUnsupportedFilterType()
+		{
+			sut.CreateRule((FilterRuleType) (-1));
+		}
+	}
+}

SafeExamBrowser.Browser.UnitTests/Filters/Rules/RegexRuleTests.cs

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using SafeExamBrowser.Browser.Filters.Rules;
+
+namespace SafeExamBrowser.Browser.UnitTests.Filters.Rules
+{
+	[TestClass]
+	public class RegexRuleTests
+	{
+		private RegexRule sut;
+
+		[TestInitialize]
+		public void Initialize()
+		{
+			sut = new RegexRule();
+		}
+	}
+}

SafeExamBrowser.Browser.UnitTests/Filters/Rules/SimplifiedRuleTests.cs

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using SafeExamBrowser.Browser.Filters.Rules;
+
+namespace SafeExamBrowser.Browser.UnitTests.Filters.Rules
+{
+	[TestClass]
+	public class SimplifiedRuleTests
+	{
+		private SimplifiedRule sut;
+
+		[TestInitialize]
+		public void Initialize()
+		{
+			sut = new SimplifiedRule();
+		}
+	}
+}

SafeExamBrowser.Browser.UnitTests/SafeExamBrowser.Browser.UnitTests.csproj

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="15.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\packages\MSTest.TestAdapter.1.3.2\build\net45\MSTest.TestAdapter.props" Condition="Exists('..\packages\MSTest.TestAdapter.1.3.2\build\net45\MSTest.TestAdapter.props')" />
+  <Import Project="..\packages\MSTest.TestAdapter.2.0.0\build\net45\MSTest.TestAdapter.props" Condition="Exists('..\packages\MSTest.TestAdapter.2.0.0\build\net45\MSTest.TestAdapter.props')" />
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -57,20 +57,37 @@
     <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
   </PropertyGroup>
   <ItemGroup>
+    <Reference Include="Castle.Core, Version=4.0.0.0, Culture=neutral, PublicKeyToken=407dd0808d44fbdc, processorArchitecture=MSIL">
+      <HintPath>..\packages\Castle.Core.4.4.0\lib\net45\Castle.Core.dll</HintPath>
+    </Reference>
     <Reference Include="Microsoft.VisualStudio.TestPlatform.TestFramework, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
-      <HintPath>..\packages\MSTest.TestFramework.1.3.2\lib\net45\Microsoft.VisualStudio.TestPlatform.TestFramework.dll</HintPath>
+      <HintPath>..\packages\MSTest.TestFramework.2.0.0\lib\net45\Microsoft.VisualStudio.TestPlatform.TestFramework.dll</HintPath>
     </Reference>
     <Reference Include="Microsoft.VisualStudio.TestPlatform.TestFramework.Extensions, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
-      <HintPath>..\packages\MSTest.TestFramework.1.3.2\lib\net45\Microsoft.VisualStudio.TestPlatform.TestFramework.Extensions.dll</HintPath>
+      <HintPath>..\packages\MSTest.TestFramework.2.0.0\lib\net45\Microsoft.VisualStudio.TestPlatform.TestFramework.Extensions.dll</HintPath>
+    </Reference>
+    <Reference Include="Moq, Version=4.13.0.0, Culture=neutral, PublicKeyToken=69f491c39445e920, processorArchitecture=MSIL">
+      <HintPath>..\packages\Moq.4.13.0\lib\net45\Moq.dll</HintPath>
     </Reference>
     <Reference Include="System" />
+    <Reference Include="System.Configuration" />
     <Reference Include="System.Core" />
+    <Reference Include="System.Runtime.CompilerServices.Unsafe, Version=4.0.4.1, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
+      <HintPath>..\packages\System.Runtime.CompilerServices.Unsafe.4.5.2\lib\netstandard2.0\System.Runtime.CompilerServices.Unsafe.dll</HintPath>
+    </Reference>
+    <Reference Include="System.Threading.Tasks.Extensions, Version=4.2.0.1, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL">
+      <HintPath>..\packages\System.Threading.Tasks.Extensions.4.5.3\lib\netstandard2.0\System.Threading.Tasks.Extensions.dll</HintPath>
+    </Reference>
   </ItemGroup>
   <ItemGroup>
     <Compile Include="Filters\RequestFilterTests.cs" />
+    <Compile Include="Filters\RuleFactoryTests.cs" />
+    <Compile Include="Filters\Rules\RegexRuleTests.cs" />
+    <Compile Include="Filters\Rules\SimplifiedRuleTests.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>
   <ItemGroup>
+    <None Include="app.config" />
     <None Include="packages.config" />
   </ItemGroup>
   <ItemGroup>
@@ -93,8 +110,8 @@
     <PropertyGroup>
       <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
     </PropertyGroup>
-    <Error Condition="!Exists('..\packages\MSTest.TestAdapter.1.3.2\build\net45\MSTest.TestAdapter.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\MSTest.TestAdapter.1.3.2\build\net45\MSTest.TestAdapter.props'))" />
+    <Error Condition="!Exists('..\packages\MSTest.TestAdapter.2.0.0\build\net45\MSTest.TestAdapter.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\MSTest.TestAdapter.2.0.0\build\net45\MSTest.TestAdapter.props'))" />
-    <Error Condition="!Exists('..\packages\MSTest.TestAdapter.1.3.2\build\net45\MSTest.TestAdapter.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\MSTest.TestAdapter.1.3.2\build\net45\MSTest.TestAdapter.targets'))" />
+    <Error Condition="!Exists('..\packages\MSTest.TestAdapter.2.0.0\build\net45\MSTest.TestAdapter.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\MSTest.TestAdapter.2.0.0\build\net45\MSTest.TestAdapter.targets'))" />
   </Target>
-  <Import Project="..\packages\MSTest.TestAdapter.1.3.2\build\net45\MSTest.TestAdapter.targets" Condition="Exists('..\packages\MSTest.TestAdapter.1.3.2\build\net45\MSTest.TestAdapter.targets')" />
+  <Import Project="..\packages\MSTest.TestAdapter.2.0.0\build\net45\MSTest.TestAdapter.targets" Condition="Exists('..\packages\MSTest.TestAdapter.2.0.0\build\net45\MSTest.TestAdapter.targets')" />
 </Project>

SafeExamBrowser.Browser.UnitTests/app.config

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+  <runtime>
+    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
+      <dependentAssembly>
+        <assemblyIdentity name="System.Threading.Tasks.Extensions" publicKeyToken="cc7b13ffcd2ddd51" culture="neutral" />
+        <bindingRedirect oldVersion="0.0.0.0-4.2.0.1" newVersion="4.2.0.1" />
+      </dependentAssembly>
+    </assemblyBinding>
+  </runtime>
+</configuration>

SafeExamBrowser.Browser.UnitTests/packages.config

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="MSTest.TestAdapter" version="1.3.2" targetFramework="net472" />
+  <package id="Castle.Core" version="4.4.0" targetFramework="net472" />
-  <package id="MSTest.TestFramework" version="1.3.2" targetFramework="net472" />
+  <package id="Moq" version="4.13.0" targetFramework="net472" />
+  <package id="MSTest.TestAdapter" version="2.0.0" targetFramework="net472" />
+  <package id="MSTest.TestFramework" version="2.0.0" targetFramework="net472" />
+  <package id="System.Runtime.CompilerServices.Unsafe" version="4.5.2" targetFramework="net472" />
+  <package id="System.Threading.Tasks.Extensions" version="4.5.3" targetFramework="net472" />
 </packages>

SafeExamBrowser.Browser/BrowserApplicationInstance.cs

@@ -13,6 +13,7 @@ using SafeExamBrowser.Applications.Contracts;
 using SafeExamBrowser.Applications.Contracts.Events;
 using SafeExamBrowser.Browser.Contracts.Events;
 using SafeExamBrowser.Browser.Events;
+using SafeExamBrowser.Browser.Filters;
 using SafeExamBrowser.Browser.Handlers;
 using SafeExamBrowser.Configuration.Contracts;
 using SafeExamBrowser.I18n.Contracts;
@@ -102,8 +103,9 @@ namespace SafeExamBrowser.Browser
 			var downloadHandler = new DownloadHandler(appConfig, settings, downloadLogger);
 			var keyboardHandler = new KeyboardHandler();
 			var lifeSpanHandler = new LifeSpanHandler();
+			var requestFilter = new RequestFilter();
 			var requestLogger = logger.CloneFor($"{nameof(RequestHandler)} {Id}");
-			var requestHandler = new RequestHandler(appConfig, settings.Filter, requestLogger, text);
+			var requestHandler = new RequestHandler(appConfig, settings.Filter, requestFilter, requestLogger, text);
 
 			displayHandler.FaviconChanged += DisplayHandler_FaviconChanged;
 			displayHandler.ProgressChanged += DisplayHandler_ProgressChanged;
@@ -115,14 +117,27 @@ namespace SafeExamBrowser.Browser
 			lifeSpanHandler.PopupRequested += LifeSpanHandler_PopupRequested;
 			requestHandler.RequestBlocked += RequestHandler_RequestBlocked;
 
+			if (settings.Filter.ProcessContentRequests || settings.Filter.ProcessMainRequests)
+			{
+				var factory = new RuleFactory();
+
+				foreach (var settings in settings.Filter.Rules)
+				{
+					var rule = factory.CreateRule(settings.Type);
+
+					rule.Initialize(settings);
+					requestFilter.Load(rule);
+				}
+
+				logger.Debug($"Initialized request filter with {settings.Filter.Rules.Count} rule(s).");
+			}
+
 			control = new BrowserControl(contextMenuHandler, displayHandler, downloadHandler, keyboardHandler, lifeSpanHandler, requestHandler, url);
 			control.AddressChanged += Control_AddressChanged;
 			control.LoadingStateChanged += Control_LoadingStateChanged;
 			control.TitleChanged += Control_TitleChanged;
 
-			requestHandler.Initiailize();
 			control.Initialize();
-
 			logger.Debug("Initialized browser control.");
 		}
 

SafeExamBrowser.Browser/Filters/RequestFilter.cs

@@ -8,42 +8,28 @@
 
 using System;
 using System.Collections.Generic;
-using SafeExamBrowser.Browser.Filters.Rules;
+using SafeExamBrowser.Browser.Contracts.Filters;
 using SafeExamBrowser.Settings.Browser;
 
 namespace SafeExamBrowser.Browser.Filters
 {
-	internal class RequestFilter
+	internal class RequestFilter : IRequestFilter
 	{
-		private IList<Rule> allowRules;
+		private IList<IRule> allowRules;
-		private IList<Rule> blockRules;
+		private IList<IRule> blockRules;
 
-		internal FilterResult Default { get; set; }
+		public FilterResult Default { get; set; }
 
 		internal RequestFilter()
 		{
-			allowRules = new List<Rule>();
+			allowRules = new List<IRule>();
-			blockRules = new List<Rule>();
+			blockRules = new List<IRule>();
 			Default = FilterResult.Block;
 		}
 
-		internal void Load(FilterRuleSettings settings)
+		public void Load(IRule rule)
 		{
-			var rule = default(Rule);
+			switch (rule.Result)
-
-			switch (settings.Type)
-			{
-				case FilterType.Regex:
-					rule = new RegexRule(settings.Expression);
-					break;
-				case FilterType.Simplified:
-					rule = new SimpleRule(settings.Expression);
-					break;
-				default:
-					throw new NotImplementedException($"Filter rule of type '{settings.Type}' is not yet implemented!");
-			}
-
-			switch (settings.Result)
 			{
 				case FilterResult.Allow:
 					allowRules.Add(rule);
@@ -52,15 +38,15 @@ namespace SafeExamBrowser.Browser.Filters
 					blockRules.Add(rule);
 					break;
 				default:
-					throw new NotImplementedException($"Filter result '{settings.Result}' is not yet implemented!");
+					throw new NotImplementedException($"Filter processing for result '{rule.Result}' is not yet implemented!");
 			}
 		}
 
-		internal FilterResult Process(string url)
+		public FilterResult Process(Request request)
 		{
 			foreach (var rule in blockRules)
 			{
-				if (rule.IsMatch(url))
+				if (rule.IsMatch(request))
 				{
 					return FilterResult.Block;
 				}
@@ -68,7 +54,7 @@ namespace SafeExamBrowser.Browser.Filters
 
 			foreach (var rule in allowRules)
 			{
-				if (rule.IsMatch(url))
+				if (rule.IsMatch(request))
 				{
 					return FilterResult.Allow;
 				}

SafeExamBrowser.Browser/Filters/RuleFactory.cs

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using System;
+using SafeExamBrowser.Browser.Contracts.Filters;
+using SafeExamBrowser.Browser.Filters.Rules;
+using SafeExamBrowser.Settings.Browser;
+
+namespace SafeExamBrowser.Browser.Filters
+{
+	internal class RuleFactory : IRuleFactory
+	{
+		public IRule CreateRule(FilterRuleType type)
+		{
+			switch (type)
+			{
+				case FilterRuleType.Regex:
+					return new RegexRule();
+				case FilterRuleType.Simplified:
+					return new SimplifiedRule();
+				default:
+					throw new NotImplementedException($"Filter rule of type '{type}' is not yet implemented!");
+			}
+		}
+	}
+}

SafeExamBrowser.Browser/Filters/Rules/RegexRule.cs

@@ -7,25 +7,26 @@
  */
 
 using System.Text.RegularExpressions;
+using SafeExamBrowser.Browser.Contracts.Filters;
+using SafeExamBrowser.Settings.Browser;
 
 namespace SafeExamBrowser.Browser.Filters.Rules
 {
-	internal class RegexRule : Rule
+	internal class RegexRule : IRule
 	{
 		private string expression;
 
-		public RegexRule(string expression) : base(expression)
+		public FilterResult Result { get; private set; }
+
+		public void Initialize(FilterRuleSettings settings)
 		{
+			expression = settings.Expression;
+			Result = settings.Result;
 		}
 
-		protected override void Initialize(string expression)
+		public bool IsMatch(Request request)
 		{
-			this.expression = expression;
+			return Regex.IsMatch(request.Url, expression, RegexOptions.IgnoreCase);
-		}
-
-		internal override bool IsMatch(string url)
-		{
-			return Regex.IsMatch(url, expression, RegexOptions.IgnoreCase);
 		}
 	}
 }

SafeExamBrowser.Browser/Filters/Rules/SimplifiedRule.cs

@@ -7,25 +7,26 @@
  */
 
 using System.Text.RegularExpressions;
+using SafeExamBrowser.Browser.Contracts.Filters;
+using SafeExamBrowser.Settings.Browser;
 
 namespace SafeExamBrowser.Browser.Filters.Rules
 {
-	internal class SimpleRule : Rule
+	internal class SimplifiedRule : IRule
 	{
 		private string expression;
 
-		public SimpleRule(string expression) : base(expression)
+		public FilterResult Result { get; private set; }
+
+		public void Initialize(FilterRuleSettings settings)
 		{
+			expression = settings.Expression.Replace("*", @".*");
+			Result = settings.Result;
 		}
 
-		protected override void Initialize(string expression)
+		public bool IsMatch(Request request)
 		{
-			this.expression = expression.Replace("*", @".*");
+			return Regex.IsMatch(request.Url, expression, RegexOptions.IgnoreCase);
-		}
-
-		internal override bool IsMatch(string url)
-		{
-			return Regex.IsMatch(url, expression, RegexOptions.IgnoreCase);
 		}
 	}
 }

SafeExamBrowser.Browser/Handlers/RequestHandler.cs

@@ -7,8 +7,8 @@
  */
 
 using CefSharp;
+using SafeExamBrowser.Browser.Contracts.Filters;
 using SafeExamBrowser.Browser.Events;
-using SafeExamBrowser.Browser.Filters;
 using SafeExamBrowser.Configuration.Contracts;
 using SafeExamBrowser.I18n.Contracts;
 using SafeExamBrowser.Logging.Contracts;
@@ -18,31 +18,21 @@ namespace SafeExamBrowser.Browser.Handlers
 {
 	internal class RequestHandler : CefSharp.Handler.RequestHandler
 	{
-		private RequestFilter filter;
+		private IRequestFilter filter;
 		private ILogger logger;
 		private ResourceHandler resourceHandler;
 		private BrowserFilterSettings settings;
 
 		internal event RequestBlockedEventHandler RequestBlocked;
 
-		internal RequestHandler(AppConfig appConfig, BrowserFilterSettings settings, ILogger logger, IText text)
+		internal RequestHandler(AppConfig appConfig, BrowserFilterSettings settings, IRequestFilter filter, ILogger logger, IText text)
 		{
-			this.filter = new RequestFilter();
+			this.filter = filter;
 			this.logger = logger;
 			this.resourceHandler = new ResourceHandler(appConfig, settings, filter, logger, text);
 			this.settings = settings;
 		}
 
-		internal void Initiailize()
-		{
-			if (settings.FilterMainRequests || settings.FilterContentRequests)
-			{
-				InitializeFilter();
-			}
-
-			resourceHandler.Initialize();
-		}
-
 		protected override IResourceRequestHandler GetResourceRequestHandler(IWebBrowser webBrowser, IBrowser browser, IFrame frame, IRequest request, 	bool isNavigation, bool isDownload, string requestInitiator, ref bool disableDefaultHandling)
 		{
 			return resourceHandler;
@@ -62,9 +52,9 @@ namespace SafeExamBrowser.Browser.Handlers
 
 		private bool Block(IRequest request)
 		{
-			if (settings.FilterMainRequests)
+			if (settings.ProcessMainRequests)
 			{
-				var result = filter.Process(request.Url);
+				var result = filter.Process(new Request { Url = request.Url });
 				var block = result == FilterResult.Block;
 
 				if (block)
@@ -77,15 +67,5 @@ namespace SafeExamBrowser.Browser.Handlers
 
 			return false;
 		}
-
-		private void InitializeFilter()
-		{
-			foreach (var rule in settings.Rules)
-			{
-				filter.Load(rule);
-			}
-
-			logger.Debug($"Initialized request filter with {settings.Rules.Count} rules.");
-		}
 	}
 }

SafeExamBrowser.Browser/Handlers/ResourceHandler.cs

@@ -11,6 +11,7 @@ using System.Collections.Specialized;
 using System.IO;
 using System.Reflection;
 using CefSharp;
+using SafeExamBrowser.Browser.Contracts.Filters;
 using SafeExamBrowser.Browser.Filters;
 using SafeExamBrowser.Configuration.Contracts;
 using SafeExamBrowser.I18n.Contracts;
@@ -24,12 +25,12 @@ namespace SafeExamBrowser.Browser.Handlers
 		private AppConfig appConfig;
 		private BrowserFilterSettings settings;
 		private ILogger logger;
-		private RequestFilter filter;
+		private IRequestFilter filter;
 		private IResourceHandler contentHandler;
 		private IResourceHandler pageHandler;
 		private IText text;
 
-		internal ResourceHandler(AppConfig appConfig, BrowserFilterSettings settings, RequestFilter filter, ILogger logger, IText text)
+		internal ResourceHandler(AppConfig appConfig, BrowserFilterSettings settings, IRequestFilter filter, ILogger logger, IText text)
 		{
 			this.appConfig = appConfig;
 			this.filter = filter;
@@ -38,14 +39,6 @@ namespace SafeExamBrowser.Browser.Handlers
 			this.text = text;
 		}
 
-		internal void Initialize()
-		{
-			if (settings.FilterContentRequests)
-			{
-				InitializeResourceHandlers();
-			}
-		}
-
 		protected override IResourceHandler GetResourceHandler(IWebBrowser chromiumWebBrowser, IBrowser browser, IFrame frame, IRequest request)
 		{
 			if (Block(request))
@@ -84,9 +77,9 @@ namespace SafeExamBrowser.Browser.Handlers
 
 		private bool Block(IRequest request)
 		{
-			if (settings.FilterContentRequests)
+			if (settings.ProcessContentRequests)
 			{
-				var result = filter.Process(request.Url);
+				var result = filter.Process(new Request { Url = request.Url });
 				var block = result == FilterResult.Block;
 
 				if (block)
@@ -100,27 +93,6 @@ namespace SafeExamBrowser.Browser.Handlers
 			return false;
 		}
 
-		private void InitializeResourceHandlers()
-		{
-			var assembly = Assembly.GetAssembly(typeof(RequestFilter));
-			var contentMessage = text.Get(TextKey.Browser_BlockedContentMessage);
-			var contentStream = assembly.GetManifestResourceStream($"{typeof(RequestFilter).Namespace}.BlockedContent.html");
-			var pageButton = text.Get(TextKey.Browser_BlockedPageButton);
-			var pageMessage = text.Get(TextKey.Browser_BlockedPageMessage);
-			var pageTitle = text.Get(TextKey.Browser_BlockedPageTitle);
-			var pageStream = assembly.GetManifestResourceStream($"{typeof(RequestFilter).Namespace}.BlockedPage.html");
-			var contentHtml = new StreamReader(contentStream).ReadToEnd();
-			var pageHtml = new StreamReader(pageStream).ReadToEnd();
-
-			contentHtml = contentHtml.Replace("%%MESSAGE%%", contentMessage);
-			contentHandler = CefSharp.ResourceHandler.FromString(contentHtml);
-
-			pageHtml = pageHtml.Replace("%%MESSAGE%%", pageMessage).Replace("%%TITLE%%", pageTitle).Replace("%%BACK_BUTTON%%", pageButton);
-			pageHandler = CefSharp.ResourceHandler.FromString(pageHtml);
-
-			logger.Debug("Initialized resource handlers for blocked requests.");
-		}
-
 		private bool IsMailtoUrl(string url)
 		{
 			return url.StartsWith(Uri.UriSchemeMailto);
@@ -145,6 +117,11 @@ namespace SafeExamBrowser.Browser.Handlers
 
 		private IResourceHandler ResourceHandlerFor(ResourceType resourceType)
 		{
+			if (contentHandler == default(IResourceHandler) || pageHandler == default(IResourceHandler))
+			{
+				InitializeResourceHandlers();
+			}
+
 			switch (resourceType)
 			{
 				case ResourceType.MainFrame:
@@ -154,5 +131,26 @@ namespace SafeExamBrowser.Browser.Handlers
 					return contentHandler;
 			}
 		}
+
+		private void InitializeResourceHandlers()
+		{
+			var assembly = Assembly.GetAssembly(typeof(RequestFilter));
+			var contentMessage = text.Get(TextKey.Browser_BlockedContentMessage);
+			var contentStream = assembly.GetManifestResourceStream($"{typeof(RequestFilter).Namespace}.BlockedContent.html");
+			var pageButton = text.Get(TextKey.Browser_BlockedPageButton);
+			var pageMessage = text.Get(TextKey.Browser_BlockedPageMessage);
+			var pageTitle = text.Get(TextKey.Browser_BlockedPageTitle);
+			var pageStream = assembly.GetManifestResourceStream($"{typeof(RequestFilter).Namespace}.BlockedPage.html");
+			var contentHtml = new StreamReader(contentStream).ReadToEnd();
+			var pageHtml = new StreamReader(pageStream).ReadToEnd();
+
+			contentHtml = contentHtml.Replace("%%MESSAGE%%", contentMessage);
+			contentHandler = CefSharp.ResourceHandler.FromString(contentHtml);
+
+			pageHtml = pageHtml.Replace("%%MESSAGE%%", pageMessage).Replace("%%TITLE%%", pageTitle).Replace("%%BACK_BUTTON%%", pageButton);
+			pageHandler = CefSharp.ResourceHandler.FromString(pageHtml);
+
+			logger.Debug("Initialized resource handlers for blocked requests.");
+		}
 	}
 }

SafeExamBrowser.Browser/SafeExamBrowser.Browser.csproj

@@ -75,9 +75,9 @@
     <Compile Include="Events\ProgressChangedEventHandler.cs" />
     <Compile Include="Events\RequestBlockedEventHandler.cs" />
     <Compile Include="Filters\RequestFilter.cs" />
-    <Compile Include="Filters\Rules\Rule.cs" />
     <Compile Include="Filters\Rules\RegexRule.cs" />
-    <Compile Include="Filters\Rules\SimpleRule.cs" />
+    <Compile Include="Filters\RuleFactory.cs" />
+    <Compile Include="Filters\Rules\SimplifiedRule.cs" />
     <Compile Include="Handlers\ContextMenuHandler.cs" />
     <Compile Include="BrowserControl.cs">
       <SubType>Component</SubType>

SafeExamBrowser.Configuration/ConfigurationData/DataMapper.Browser.cs

@@ -108,17 +108,17 @@ namespace SafeExamBrowser.Configuration.ConfigurationData
 
 		private void MapEnableContentRequestFilter(ApplicationSettings settings, object value)
 		{
-			if (value is bool filter)
+			if (value is bool process)
 			{
-				settings.Browser.Filter.FilterContentRequests = filter;
+				settings.Browser.Filter.ProcessContentRequests = process;
 			}
 		}
 
 		private void MapEnableMainRequestFilter(ApplicationSettings settings, object value)
 		{
-			if (value is bool filter)
+			if (value is bool process)
 			{
-				settings.Browser.Filter.FilterMainRequests = filter;
+				settings.Browser.Filter.ProcessMainRequests = process;
 			}
 		}
 
@@ -148,7 +148,7 @@ namespace SafeExamBrowser.Configuration.ConfigurationData
 
 							if (ruleData.TryGetValue(Keys.Browser.Filter.RuleExpressionIsRegex, out v) && v is bool regex)
 							{
-								rule.Type = regex ? FilterType.Regex : FilterType.Simplified;
+								rule.Type = regex ? FilterRuleType.Regex : FilterRuleType.Simplified;
 							}
 
 							settings.Browser.Filter.Rules.Add(rule);

SafeExamBrowser.Settings/Browser/BrowserFilterSettings.cs

@@ -18,14 +18,14 @@ namespace SafeExamBrowser.Settings.Browser
 	public class BrowserFilterSettings
 	{
 		/// <summary>
-		/// Defines whether all content requests for a web page should be filtered according to the defined <see cref="Rules"/>.
+		/// Defines whether content requests for a web page should be filtered according to the defined <see cref="Rules"/>.
 		/// </summary>
-		public bool FilterContentRequests { get; set; }
+		public bool ProcessContentRequests { get; set; }
 
 		/// <summary>
 		/// Defines whether the main request for a web page should be filtered according to the defined <see cref="Rules"/>.
 		/// </summary>
-		public bool FilterMainRequests { get; set; }
+		public bool ProcessMainRequests { get; set; }
 
 		/// <summary>
 		/// Defines all rules to be used to filter web requests.

SafeExamBrowser.Settings/Browser/FilterRuleSettings.cs

@@ -29,6 +29,6 @@ namespace SafeExamBrowser.Settings.Browser
 		/// <summary>
 		/// The filter type which defines how the <see cref="Expression"/> is processed.
 		/// </summary>
-		public FilterType Type { get; set; }
+		public FilterRuleType Type { get; set; }
 	}
 }

SafeExamBrowser.Settings/Browser/FilterRuleType.cs

@@ -9,17 +9,17 @@
 namespace SafeExamBrowser.Settings.Browser
 {
 	/// <summary>
-	/// Defines all possible request filter types.
+	/// Defines all possible filter rule types.
 	/// </summary>
-	public enum FilterType
+	public enum FilterRuleType
 	{
 		/// <summary>
-		/// The filter is based on a regular expression.
+		/// The filter rule is based on a regular expression.
 		/// </summary>
 		Regex,
 
 		/// <summary>
-		/// The filter is based on a simplified expression with wildcards.
+		/// The filter rule is based on a simplified expression with wildcards.
 		/// </summary>
 		Simplified
 	}

SafeExamBrowser.Settings/SafeExamBrowser.Settings.csproj

@@ -58,7 +58,7 @@
     <Compile Include="Browser\BrowserWindowSettings.cs" />
     <Compile Include="Browser\FilterResult.cs" />
     <Compile Include="Browser\FilterRuleSettings.cs" />
-    <Compile Include="Browser\FilterType.cs" />
+    <Compile Include="Browser\FilterRuleType.cs" />
     <Compile Include="ConfigurationMode.cs" />
     <Compile Include="KioskMode.cs" />
     <Compile Include="Logging\LogLevel.cs" />