Add Interecptors, ConnectionProviderFactory, and integration test tar…

…get (#4)

* - Moved over the three common interceptor classes: APIKey, IAM, OIDC.
  Refactored the initialization methods to allow consumers to use without taking on a dependency on the auth provider classes vended by AppSync client.
  The reason for this is to prevent a breaking change, we cannot move the auth provider classes over to AppSyncRealTimeClient or AppSyncClient consumers will
  have to take on AppSyncRealTimeClient as a dependency.
- Add ConnectionProviderFactory class for creating connection providers with auth interceptors.
  This is the entry point for consumers to pass (url, authInterceptor) to get a connection provider back.
- Add integration test target with AppSync backend provisioned

* Moved out IAMAuthInterceptor to remove dependency on AWSCore

* removed AWSCore from podspec

AppSyncRealTimeClient.podspec

@@ -1,7 +1,7 @@
 Pod::Spec.new do |s|
 
     s.name         = 'AppSyncRealTimeClient'
-    s.version      = '1.0.1'
+    s.version      = '1.0.2'
     s.summary      = 'Amazon Web Services AppSync RealTime Client for iOS.'
 
     s.description  = 'AppSync RealTime Client provides subscription connections to AppSync websocket endpoints'
@@ -17,5 +17,4 @@ Pod::Spec.new do |s|
 
     s.source_files = 'AppSyncRealTimeClient/**/*.swift'
     s.dependency 'Starscream', '~> 3.0.2'
-
-  end
+  end

AppSyncRealTimeClient.xcodeproj/xcshareddata/xcschemes/AppSyncRealTimeClientIntegrationTests.xcscheme

@@ -0,0 +1,52 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Scheme
+   LastUpgradeVersion = "1130"
+   version = "1.3">
+   <BuildAction
+      parallelizeBuildables = "YES"
+      buildImplicitDependencies = "YES">
+   </BuildAction>
+   <TestAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      shouldUseLaunchSchemeArgsEnv = "YES">
+      <Testables>
+         <TestableReference
+            skipped = "NO">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "21D38B3D2409AFBD00EC2A8D"
+               BuildableName = "AppSyncRealTimeClientIntegrationTests.xctest"
+               BlueprintName = "AppSyncRealTimeClientIntegrationTests"
+               ReferencedContainer = "container:AppSyncRealTimeClient.xcodeproj">
+            </BuildableReference>
+         </TestableReference>
+      </Testables>
+   </TestAction>
+   <LaunchAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      launchStyle = "0"
+      useCustomWorkingDirectory = "NO"
+      ignoresPersistentStateOnLaunch = "NO"
+      debugDocumentVersioning = "YES"
+      debugServiceExtension = "internal"
+      allowLocationSimulation = "YES">
+   </LaunchAction>
+   <ProfileAction
+      buildConfiguration = "Release"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      savedToolIdentifier = ""
+      useCustomWorkingDirectory = "NO"
+      debugDocumentVersioning = "YES">
+   </ProfileAction>
+   <AnalyzeAction
+      buildConfiguration = "Debug">
+   </AnalyzeAction>
+   <ArchiveAction
+      buildConfiguration = "Release"
+      revealArchiveInOrganizer = "YES">
+   </ArchiveAction>
+</Scheme>

AppSyncRealTimeClient.xcodeproj/xcshareddata/xcschemes/HostApp.xcscheme

@@ -0,0 +1,88 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Scheme
+   LastUpgradeVersion = "1130"
+   version = "1.3">
+   <BuildAction
+      parallelizeBuildables = "YES"
+      buildImplicitDependencies = "YES">
+      <BuildActionEntries>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "21D38B522409B93F00EC2A8D"
+               BuildableName = "HostApp.app"
+               BlueprintName = "HostApp"
+               ReferencedContainer = "container:AppSyncRealTimeClient.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
+      </BuildActionEntries>
+   </BuildAction>
+   <TestAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      shouldUseLaunchSchemeArgsEnv = "YES">
+      <Testables>
+         <TestableReference
+            skipped = "NO">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "21D38B3D2409AFBD00EC2A8D"
+               BuildableName = "AppSyncRealTimeClientIntegrationTests.xctest"
+               BlueprintName = "AppSyncRealTimeClientIntegrationTests"
+               ReferencedContainer = "container:AppSyncRealTimeClient.xcodeproj">
+            </BuildableReference>
+         </TestableReference>
+      </Testables>
+   </TestAction>
+   <LaunchAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      launchStyle = "0"
+      useCustomWorkingDirectory = "NO"
+      ignoresPersistentStateOnLaunch = "NO"
+      debugDocumentVersioning = "YES"
+      debugServiceExtension = "internal"
+      allowLocationSimulation = "YES">
+      <BuildableProductRunnable
+         runnableDebuggingMode = "0">
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "21D38B522409B93F00EC2A8D"
+            BuildableName = "HostApp.app"
+            BlueprintName = "HostApp"
+            ReferencedContainer = "container:AppSyncRealTimeClient.xcodeproj">
+         </BuildableReference>
+      </BuildableProductRunnable>
+   </LaunchAction>
+   <ProfileAction
+      buildConfiguration = "Release"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      savedToolIdentifier = ""
+      useCustomWorkingDirectory = "NO"
+      debugDocumentVersioning = "YES">
+      <BuildableProductRunnable
+         runnableDebuggingMode = "0">
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "21D38B522409B93F00EC2A8D"
+            BuildableName = "HostApp.app"
+            BlueprintName = "HostApp"
+            ReferencedContainer = "container:AppSyncRealTimeClient.xcodeproj">
+         </BuildableReference>
+      </BuildableProductRunnable>
+   </ProfileAction>
+   <AnalyzeAction
+      buildConfiguration = "Debug">
+   </AnalyzeAction>
+   <ArchiveAction
+      buildConfiguration = "Release"
+      revealArchiveInOrganizer = "YES">
+   </ArchiveAction>
+</Scheme>

AppSyncRealTimeClient/ConnectionProvider/ConnectionProviderFactory.swift

@@ -0,0 +1,37 @@
+//
+// Copyright 2018-2020 Amazon.com,
+// Inc. or its affiliates. All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+import Foundation
+
+/// Create connection providers to connect to the websocket endpoint of the AppSync endpoint.
+public struct ConnectionProviderFactory {
+
+    public static func createConnectionProvider(for url: URL,
+                                                authInterceptor: AuthInterceptor,
+                                                connectionType: SubscriptionConnectionType) -> ConnectionProvider {
+        let provider = ConnectionProviderFactory.createConnectionProvider(for: url, connectionType: connectionType)
+
+        if let messageInterceptable = provider as? MessageInterceptable {
+            messageInterceptable.addInterceptor(authInterceptor)
+        }
+        if let connectionInterceptable = provider as? ConnectionInterceptable {
+            connectionInterceptable.addInterceptor(RealtimeGatewayURLInterceptor())
+            connectionInterceptable.addInterceptor(authInterceptor)
+        }
+
+        return provider
+    }
+
+    static func createConnectionProvider(for url: URL, connectionType: SubscriptionConnectionType) -> ConnectionProvider {
+        switch connectionType {
+        case .appSyncRealtime:
+            let websocketProvider = StarscreamAdapter()
+            let connectionProvider = RealtimeConnectionProvider(for: url, websocket: websocketProvider)
+            return connectionProvider
+        }
+    }
+}

AppSyncRealTimeClient/Interceptor/APIKeyAuthInterceptor.swift

@@ -0,0 +1,99 @@
+//
+// Copyright 2018-2020 Amazon.com,
+// Inc. or its affiliates. All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+import Foundation
+
+/// Auth interceptor for API Key based authentication
+public class APIKeyAuthInterceptor: AuthInterceptor {
+
+    let apiKey: String
+
+    public init(_ apiKey: String) {
+        self.apiKey = apiKey
+    }
+
+    /// Intercept the connection and adds header, payload query to the request url.
+    ///
+    /// The value of header should be the base64 string of the following:
+    /// * "host": <string> : this is the host for the AppSync endpoint
+    /// * "x-amz-date": <string> : UTC timestamp in the following ISO 8601 format: YYYYMMDD'T'HHMMSS'Z'
+    /// * "x-api-key": <string> : Api key configured for AppSync API
+    /// The value of payload is {}
+    /// - Parameter request: Signed request
+    public func interceptConnection(_ request: AppSyncConnectionRequest,
+                             for endpoint: URL) -> AppSyncConnectionRequest {
+        let host = endpoint.host!
+        let authHeader = APIKeyAuthenticationHeader(apiKey: apiKey, host: host)
+        let base64Auth = AppSyncJSONHelper.base64AuthenticationBlob(authHeader)
+
+        let payloadData = SubscriptionConstants.emptyPayload.data(using: .utf8)
+        let payloadBase64 = payloadData?.base64EncodedString()
+
+        guard var urlComponents = URLComponents(url: request.url, resolvingAgainstBaseURL: false) else {
+            return request
+        }
+        let headerQuery = URLQueryItem(name: RealtimeProviderConstants.header, value: base64Auth)
+        let payloadQuery = URLQueryItem(name: RealtimeProviderConstants.payload, value: payloadBase64)
+        urlComponents.queryItems = [headerQuery, payloadQuery]
+        guard let url = urlComponents.url else {
+            return request
+        }
+        let signedRequest = AppSyncConnectionRequest(url: url)
+        return signedRequest
+    }
+
+    public func interceptMessage(_ message: AppSyncMessage, for endpoint: URL) -> AppSyncMessage {
+        let host = endpoint.host!
+        switch message.messageType {
+        case .subscribe:
+            let authHeader = APIKeyAuthenticationHeader(apiKey: apiKey, host: host)
+            var payload = message.payload ?? AppSyncMessage.Payload()
+            payload.authHeader = authHeader
+
+            let signedMessage = AppSyncMessage(id: message.id,
+                                               payload: payload,
+                                               type: message.messageType)
+            return signedMessage
+        default:
+            AppSyncLogger.debug("Message type does not need signing - \(message.messageType)")
+        }
+        return message
+    }
+}
+
+/// Authentication header for API key based auth
+private class APIKeyAuthenticationHeader: AuthenticationHeader {
+    static let ISO8601DateFormat: String = "yyyyMMdd'T'HHmmss'Z'"
+    let date: String?
+    let apiKey: String
+
+    var formatter: DateFormatter = {
+        var formatter = DateFormatter()
+        formatter.timeZone = TimeZone(secondsFromGMT: 0)
+        formatter.locale = Locale(identifier: "en_US_POSIX")
+        formatter.dateFormat = ISO8601DateFormat
+        return formatter
+    }()
+
+    init(apiKey: String, host: String) {
+        self.date = formatter.string(from: Date())
+        self.apiKey = apiKey
+        super.init(host: host)
+    }
+
+    private enum CodingKeys: String, CodingKey {
+        case date = "x-amz-date"
+        case apiKey = "x-api-key"
+    }
+
+    override func encode(to encoder: Encoder) throws {
+        var container = encoder.container(keyedBy: CodingKeys.self)
+        try container.encode(date, forKey: .date)
+        try container.encode(apiKey, forKey: .apiKey)
+        try super.encode(to: encoder)
+    }
+}

AppSyncRealTimeClient/Interceptor/OIDCAuthInterceptor.swift

@@ -0,0 +1,91 @@
+//
+// Copyright 2018-2020 Amazon.com,
+// Inc. or its affiliates. All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+import Foundation
+
+public class OIDCAuthInterceptor: AuthInterceptor {
+
+    let authProvider: OIDCAuthProvider
+
+    public init (_ authProvider: OIDCAuthProvider) {
+        self.authProvider = authProvider
+    }
+
+    public func interceptMessage(_ message: AppSyncMessage, for endpoint: URL) -> AppSyncMessage {
+        let host = endpoint.host!
+        let jwtToken: String
+        switch authProvider.getLatestAuthToken() {
+        case .success(let token):
+            jwtToken = token
+        case .failure:
+            return message
+        }
+        switch message.messageType {
+        case .subscribe:
+            let authHeader = UserPoolsAuthenticationHeader(token: jwtToken, host: host)
+            var payload = message.payload ?? AppSyncMessage.Payload()
+            payload.authHeader = authHeader
+
+            let signedMessage = AppSyncMessage(id: message.id,
+                                               payload: payload,
+                                               type: message.messageType)
+            return signedMessage
+        default:
+            AppSyncLogger.debug("Message type does not need signing - \(message.messageType)")
+        }
+        return message
+    }
+
+    public func interceptConnection(_ request: AppSyncConnectionRequest, for endpoint: URL) -> AppSyncConnectionRequest {
+        let host = endpoint.host!
+        let jwtToken: String
+        switch authProvider.getLatestAuthToken() {
+        case .success(let token):
+            jwtToken = token
+        case .failure:
+            return request
+        }
+
+        let authHeader = UserPoolsAuthenticationHeader(token: jwtToken, host: host)
+        let base64Auth = AppSyncJSONHelper.base64AuthenticationBlob(authHeader)
+
+        let payloadData = SubscriptionConstants.emptyPayload.data(using: .utf8)
+        let payloadBase64 = payloadData?.base64EncodedString()
+
+        guard var urlComponents = URLComponents(url: request.url, resolvingAgainstBaseURL: false) else {
+            return request
+        }
+        let headerQuery = URLQueryItem(name: RealtimeProviderConstants.header, value: base64Auth)
+        let payloadQuery = URLQueryItem(name: RealtimeProviderConstants.payload, value: payloadBase64)
+        urlComponents.queryItems = [headerQuery, payloadQuery]
+        guard let url = urlComponents.url else {
+            return request
+        }
+        let signedRequest = AppSyncConnectionRequest(url: url)
+        return signedRequest
+    }
+}
+
+/// Authentication header for user pool based auth
+private class UserPoolsAuthenticationHeader: AuthenticationHeader {
+    let authorization: String
+
+    init(token: String, host: String) {
+        self.authorization = token
+        super.init(host: host)
+    }
+
+    private enum CodingKeys: String, CodingKey {
+        case authorization = "Authorization"
+    }
+
+    override func encode(to encoder: Encoder) throws {
+        var container = encoder.container(keyedBy: CodingKeys.self)
+        try container.encode(authorization, forKey: .authorization)
+        try super.encode(to: encoder)
+    }
+}