Add signer action extension with shared keychain and data store

Yeti.xcodeproj/project.pbxproj

@@ -8,6 +8,9 @@
 
 /* Begin PBXBuildFile section */
 		3AA481172D3ECDFD0052A05C /* NostrSDK in Frameworks */ = {isa = PBXBuildFile; productRef = 3AA481162D3ECDFD0052A05C /* NostrSDK */; };
+		3AC2CDAA2D4683AD00A6DEDB /* UniformTypeIdentifiers.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 3AC2CDA92D4683AD00A6DEDB /* UniformTypeIdentifiers.framework */; };
+		3AC2CDB62D4683AD00A6DEDB /* YetiSignerAction.appex in Embed Foundation Extensions */ = {isa = PBXBuildFile; fileRef = 3AC2CDA72D4683AD00A6DEDB /* YetiSignerAction.appex */; settings = {ATTRIBUTES = (RemoveHeadersOnCopy, ); }; };
+		3AC2CDC32D468B7800A6DEDB /* NostrSDK in Frameworks */ = {isa = PBXBuildFile; productRef = 3AC2CDC22D468B7800A6DEDB /* NostrSDK */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -25,12 +28,35 @@
 			remoteGlobalIDString = 3AA480B72D3DECF10052A05C;
 			remoteInfo = Yeti;
 		};
+		3AC2CDB42D4683AD00A6DEDB /* PBXContainerItemProxy */ = {
+			isa = PBXContainerItemProxy;
+			containerPortal = 3AA480B02D3DECF10052A05C /* Project object */;
+			proxyType = 1;
+			remoteGlobalIDString = 3AC2CDA62D4683AD00A6DEDB;
+			remoteInfo = YetiSignerAction;
+		};
 /* End PBXContainerItemProxy section */
 
+/* Begin PBXCopyFilesBuildPhase section */
+		3AC2CDB72D4683AD00A6DEDB /* Embed Foundation Extensions */ = {
+			isa = PBXCopyFilesBuildPhase;
+			buildActionMask = 2147483647;
+			dstPath = "";
+			dstSubfolderSpec = 13;
+			files = (
+				3AC2CDB62D4683AD00A6DEDB /* YetiSignerAction.appex in Embed Foundation Extensions */,
+			);
+			name = "Embed Foundation Extensions";
+			runOnlyForDeploymentPostprocessing = 0;
+		};
+/* End PBXCopyFilesBuildPhase section */
+
 /* Begin PBXFileReference section */
 		3AA480B82D3DECF10052A05C /* Yeti.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = Yeti.app; sourceTree = BUILT_PRODUCTS_DIR; };
 		3AA480CA2D3DECF20052A05C /* YetiTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = YetiTests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
 		3AA480D42D3DECF20052A05C /* YetiUITests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = YetiUITests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
+		3AC2CDA72D4683AD00A6DEDB /* YetiSignerAction.appex */ = {isa = PBXFileReference; explicitFileType = "wrapper.app-extension"; includeInIndex = 0; path = YetiSignerAction.appex; sourceTree = BUILT_PRODUCTS_DIR; };
+		3AC2CDA92D4683AD00A6DEDB /* UniformTypeIdentifiers.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = UniformTypeIdentifiers.framework; path = System/Library/Frameworks/UniformTypeIdentifiers.framework; sourceTree = SDKROOT; };
 /* End PBXFileReference section */
 
 /* Begin PBXFileSystemSynchronizedBuildFileExceptionSet section */
@@ -41,6 +67,27 @@
 			);
 			target = 3AA480B72D3DECF10052A05C /* Yeti */;
 		};
+		3AAAFACC2D47C0180065A065 /* Exceptions for "Yeti" folder in "YetiSignerAction" target */ = {
+			isa = PBXFileSystemSynchronizedBuildFileExceptionSet;
+			membershipExceptions = (
+				Models/GeneralSettingsModel.swift,
+				Models/NostrClientModel.swift,
+				Models/ProfileSettingsModel.swift,
+				Models/SignerRequestModel.swift,
+				Models/SignEventPermissionModel.swift,
+				Models/SigningPolicy.swift,
+				Models/YetiModelContainer.swift,
+				Utilities/PrivateKeySecureStorage.swift,
+			);
+			target = 3AC2CDA62D4683AD00A6DEDB /* YetiSignerAction */;
+		};
+		3AC2CDBB2D4683AD00A6DEDB /* Exceptions for "YetiSignerAction" folder in "YetiSignerAction" target */ = {
+			isa = PBXFileSystemSynchronizedBuildFileExceptionSet;
+			membershipExceptions = (
+				Info.plist,
+			);
+			target = 3AC2CDA62D4683AD00A6DEDB /* YetiSignerAction */;
+		};
 /* End PBXFileSystemSynchronizedBuildFileExceptionSet section */
 
 /* Begin PBXFileSystemSynchronizedRootGroup section */
@@ -48,6 +95,7 @@
 			isa = PBXFileSystemSynchronizedRootGroup;
 			exceptions = (
 				3AA481082D3DF3E40052A05C /* Exceptions for "Yeti" folder in "Yeti" target */,
+				3AAAFACC2D47C0180065A065 /* Exceptions for "Yeti" folder in "YetiSignerAction" target */,
 			);
 			path = Yeti;
 			sourceTree = "<group>";
@@ -62,6 +110,14 @@
 			path = YetiUITests;
 			sourceTree = "<group>";
 		};
+		3AC2CDAB2D4683AD00A6DEDB /* YetiSignerAction */ = {
+			isa = PBXFileSystemSynchronizedRootGroup;
+			exceptions = (
+				3AC2CDBB2D4683AD00A6DEDB /* Exceptions for "YetiSignerAction" folder in "YetiSignerAction" target */,
+			);
+			path = YetiSignerAction;
+			sourceTree = "<group>";
+		};
 /* End PBXFileSystemSynchronizedRootGroup section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -87,6 +143,15 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
+		3AC2CDA42D4683AD00A6DEDB /* Frameworks */ = {
+			isa = PBXFrameworksBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+				3AC2CDC32D468B7800A6DEDB /* NostrSDK in Frameworks */,
+				3AC2CDAA2D4683AD00A6DEDB /* UniformTypeIdentifiers.framework in Frameworks */,
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
 /* End PBXFrameworksBuildPhase section */
 
 /* Begin PBXGroup section */
@@ -96,6 +161,8 @@
 				3AA480BA2D3DECF10052A05C /* Yeti */,
 				3AA480CD2D3DECF20052A05C /* YetiTests */,
 				3AA480D72D3DECF20052A05C /* YetiUITests */,
+				3AC2CDAB2D4683AD00A6DEDB /* YetiSignerAction */,
+				3AC2CDA82D4683AD00A6DEDB /* Frameworks */,
 				3AA480B92D3DECF10052A05C /* Products */,
 			);
 			sourceTree = "<group>";
@@ -106,10 +173,19 @@
 				3AA480B82D3DECF10052A05C /* Yeti.app */,
 				3AA480CA2D3DECF20052A05C /* YetiTests.xctest */,
 				3AA480D42D3DECF20052A05C /* YetiUITests.xctest */,
+				3AC2CDA72D4683AD00A6DEDB /* YetiSignerAction.appex */,
 			);
 			name = Products;
 			sourceTree = "<group>";
 		};
+		3AC2CDA82D4683AD00A6DEDB /* Frameworks */ = {
+			isa = PBXGroup;
+			children = (
+				3AC2CDA92D4683AD00A6DEDB /* UniformTypeIdentifiers.framework */,
+			);
+			name = Frameworks;
+			sourceTree = "<group>";
+		};
 /* End PBXGroup section */
 
 /* Begin PBXNativeTarget section */
@@ -120,11 +196,13 @@
 				3AA480B42D3DECF10052A05C /* Sources */,
 				3AA480B52D3DECF10052A05C /* Frameworks */,
 				3AA480B62D3DECF10052A05C /* Resources */,
+				3AC2CDB72D4683AD00A6DEDB /* Embed Foundation Extensions */,
 			);
 			buildRules = (
 			);
 			dependencies = (
 				3AA480FA2D3DF10E0052A05C /* PBXTargetDependency */,
+				3AC2CDB52D4683AD00A6DEDB /* PBXTargetDependency */,
 			);
 			fileSystemSynchronizedGroups = (
 				3AA480BA2D3DECF10052A05C /* Yeti */,
@@ -185,6 +263,29 @@
 			productReference = 3AA480D42D3DECF20052A05C /* YetiUITests.xctest */;
 			productType = "com.apple.product-type.bundle.ui-testing";
 		};
+		3AC2CDA62D4683AD00A6DEDB /* YetiSignerAction */ = {
+			isa = PBXNativeTarget;
+			buildConfigurationList = 3AC2CDBA2D4683AD00A6DEDB /* Build configuration list for PBXNativeTarget "YetiSignerAction" */;
+			buildPhases = (
+				3AC2CDA32D4683AD00A6DEDB /* Sources */,
+				3AC2CDA42D4683AD00A6DEDB /* Frameworks */,
+				3AC2CDA52D4683AD00A6DEDB /* Resources */,
+			);
+			buildRules = (
+			);
+			dependencies = (
+			);
+			fileSystemSynchronizedGroups = (
+				3AC2CDAB2D4683AD00A6DEDB /* YetiSignerAction */,
+			);
+			name = YetiSignerAction;
+			packageProductDependencies = (
+				3AC2CDC22D468B7800A6DEDB /* NostrSDK */,
+			);
+			productName = YetiSignerAction;
+			productReference = 3AC2CDA72D4683AD00A6DEDB /* YetiSignerAction.appex */;
+			productType = "com.apple.product-type.app-extension";
+		};
 /* End PBXNativeTarget section */
 
 /* Begin PBXProject section */
@@ -206,6 +307,9 @@
 						CreatedOnToolsVersion = 16.2;
 						TestTargetID = 3AA480B72D3DECF10052A05C;
 					};
+					3AC2CDA62D4683AD00A6DEDB = {
+						CreatedOnToolsVersion = 16.2;
+					};
 				};
 			};
 			buildConfigurationList = 3AA480B32D3DECF10052A05C /* Build configuration list for PBXProject "Yeti" */;
@@ -229,6 +333,7 @@
 				3AA480B72D3DECF10052A05C /* Yeti */,
 				3AA480C92D3DECF20052A05C /* YetiTests */,
 				3AA480D32D3DECF20052A05C /* YetiUITests */,
+				3AC2CDA62D4683AD00A6DEDB /* YetiSignerAction */,
 			);
 		};
 /* End PBXProject section */
@@ -255,6 +360,13 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
+		3AC2CDA52D4683AD00A6DEDB /* Resources */ = {
+			isa = PBXResourcesBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
 /* End PBXResourcesBuildPhase section */
 
 /* Begin PBXSourcesBuildPhase section */
@@ -279,6 +391,13 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
+		3AC2CDA32D4683AD00A6DEDB /* Sources */ = {
+			isa = PBXSourcesBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
 /* End PBXSourcesBuildPhase section */
 
 /* Begin PBXTargetDependency section */
@@ -304,6 +423,11 @@
 			isa = PBXTargetDependency;
 			productRef = 3AA481012D3DF20D0052A05C /* SwiftLintBuildToolPlugin */;
 		};
+		3AC2CDB52D4683AD00A6DEDB /* PBXTargetDependency */ = {
+			isa = PBXTargetDependency;
+			target = 3AC2CDA62D4683AD00A6DEDB /* YetiSignerAction */;
+			targetProxy = 3AC2CDB42D4683AD00A6DEDB /* PBXContainerItemProxy */;
+		};
 /* End PBXTargetDependency section */
 
 /* Begin XCBuildConfiguration section */
@@ -433,6 +557,7 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = AccentColor;
+				CODE_SIGN_ENTITLEMENTS = Yeti/Yeti.entitlements;
 				CODE_SIGN_STYLE = Automatic;
 				CURRENT_PROJECT_VERSION = 1;
 				DEVELOPMENT_ASSET_PATHS = "\"Yeti/Preview Content\"";
@@ -464,6 +589,7 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = AccentColor;
+				CODE_SIGN_ENTITLEMENTS = Yeti/Yeti.entitlements;
 				CODE_SIGN_STYLE = Automatic;
 				CURRENT_PROJECT_VERSION = 1;
 				DEVELOPMENT_ASSET_PATHS = "\"Yeti/Preview Content\"";
@@ -558,6 +684,58 @@
 			};
 			name = Release;
 		};
+		3AC2CDB82D4683AD00A6DEDB /* Debug */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				CODE_SIGN_ENTITLEMENTS = YetiSignerAction/YetiSignerAction.entitlements;
+				CODE_SIGN_STYLE = Automatic;
+				CURRENT_PROJECT_VERSION = 1;
+				DEVELOPMENT_TEAM = S99A5B637C;
+				GENERATE_INFOPLIST_FILE = YES;
+				INFOPLIST_FILE = YetiSignerAction/Info.plist;
+				INFOPLIST_KEY_CFBundleDisplayName = "Sign Nostr Event";
+				INFOPLIST_KEY_NSHumanReadableCopyright = "";
+				LD_RUNPATH_SEARCH_PATHS = (
+					"$(inherited)",
+					"@executable_path/Frameworks",
+					"@executable_path/../../Frameworks",
+				);
+				MARKETING_VERSION = 1.0;
+				PRODUCT_BUNDLE_IDENTIFIER = xyz.tyiu.Yeti.YetiSignerAction;
+				PRODUCT_NAME = "$(TARGET_NAME)";
+				SKIP_INSTALL = YES;
+				SWIFT_EMIT_LOC_STRINGS = YES;
+				SWIFT_VERSION = 5.0;
+				TARGETED_DEVICE_FAMILY = "1,2";
+			};
+			name = Debug;
+		};
+		3AC2CDB92D4683AD00A6DEDB /* Release */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				CODE_SIGN_ENTITLEMENTS = YetiSignerAction/YetiSignerAction.entitlements;
+				CODE_SIGN_STYLE = Automatic;
+				CURRENT_PROJECT_VERSION = 1;
+				DEVELOPMENT_TEAM = S99A5B637C;
+				GENERATE_INFOPLIST_FILE = YES;
+				INFOPLIST_FILE = YetiSignerAction/Info.plist;
+				INFOPLIST_KEY_CFBundleDisplayName = "Sign Nostr Event";
+				INFOPLIST_KEY_NSHumanReadableCopyright = "";
+				LD_RUNPATH_SEARCH_PATHS = (
+					"$(inherited)",
+					"@executable_path/Frameworks",
+					"@executable_path/../../Frameworks",
+				);
+				MARKETING_VERSION = 1.0;
+				PRODUCT_BUNDLE_IDENTIFIER = xyz.tyiu.Yeti.YetiSignerAction;
+				PRODUCT_NAME = "$(TARGET_NAME)";
+				SKIP_INSTALL = YES;
+				SWIFT_EMIT_LOC_STRINGS = YES;
+				SWIFT_VERSION = 5.0;
+				TARGETED_DEVICE_FAMILY = "1,2";
+			};
+			name = Release;
+		};
 /* End XCBuildConfiguration section */
 
 /* Begin XCConfigurationList section */
@@ -597,6 +775,15 @@
 			defaultConfigurationIsVisible = 0;
 			defaultConfigurationName = Release;
 		};
+		3AC2CDBA2D4683AD00A6DEDB /* Build configuration list for PBXNativeTarget "YetiSignerAction" */ = {
+			isa = XCConfigurationList;
+			buildConfigurations = (
+				3AC2CDB82D4683AD00A6DEDB /* Debug */,
+				3AC2CDB92D4683AD00A6DEDB /* Release */,
+			);
+			defaultConfigurationIsVisible = 0;
+			defaultConfigurationName = Release;
+		};
 /* End XCConfigurationList section */
 
 /* Begin XCRemoteSwiftPackageReference section */
@@ -639,6 +826,11 @@
 			package = 3AA481152D3ECDFD0052A05C /* XCRemoteSwiftPackageReference "nostr-sdk-ios" */;
 			productName = NostrSDK;
 		};
+		3AC2CDC22D468B7800A6DEDB /* NostrSDK */ = {
+			isa = XCSwiftPackageProductDependency;
+			package = 3AA481152D3ECDFD0052A05C /* XCRemoteSwiftPackageReference "nostr-sdk-ios" */;
+			productName = NostrSDK;
+		};
 /* End XCSwiftPackageProductDependency section */
 	};
 	rootObject = 3AA480B02D3DECF10052A05C /* Project object */;

Yeti/Models/YetiModelContainer.swift

@@ -0,0 +1,28 @@
+//
+//  YetiModelContainer.swift
+//  Yeti
+//
+//  Created by Terry Yiu on 1/27/25.
+//
+
+import SwiftData
+
+public func createYetiModelContainer() -> ModelContainer {
+    let schema = Schema([
+        GeneralSettingsModel.self,
+        ProfileSettingsModel.self,
+        SignerRequestModel.self
+    ])
+
+    let modelConfiguration = ModelConfiguration(
+        schema: schema,
+        isStoredInMemoryOnly: false,
+        cloudKitDatabase: .none
+    )
+
+    do {
+        return try ModelContainer(for: schema, configurations: [modelConfiguration])
+    } catch {
+        fatalError("Could not create ModelContainer: \(error.localizedDescription)")
+    }
+}

Yeti/SceneDelegate.swift

@@ -15,18 +15,7 @@ class SceneDelegate: NSObject, UIWindowSceneDelegate, ObservableObject {
     private let modelContainer: ModelContainer
 
     override init() {
-        let schema = Schema([
+        modelContainer = createYetiModelContainer()
-            GeneralSettingsModel.self,
-            ProfileSettingsModel.self,
-            SignerRequestModel.self
-        ])
-        let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false)
-
-        do {
-            modelContainer = try ModelContainer(for: schema, configurations: [modelConfiguration])
-        } catch {
-            fatalError("Could not create ModelContainer: \(error)")
-        }
     }
 
     func scene(

Yeti/Utilities/PrivateKeySecureStorage.swift

@@ -13,6 +13,7 @@ class PrivateKeySecureStorage {
     static let shared = PrivateKeySecureStorage()
 
     private let service = "yeti-private-keys"
+    private let accessGroup = "S99A5B637C.xyz.tyiu.Yeti.SharedKeychain"
 
     func keypair(for publicKey: PublicKey) -> Keypair? {
         let query = [
@@ -20,7 +21,8 @@ class PrivateKeySecureStorage {
             kSecAttrAccount: publicKey.hex,
             kSecClass: kSecClassGenericPassword,
             kSecReturnData: true,
-            kSecMatchLimit: kSecMatchLimitOne
+            kSecMatchLimit: kSecMatchLimitOne,
+            kSecAttrAccessGroup: accessGroup
         ] as [CFString: Any] as CFDictionary
 
         var result: AnyObject?
@@ -40,16 +42,19 @@ class PrivateKeySecureStorage {
             kSecAttrService: service,
             kSecAttrAccount: keypair.publicKey.hex,
             kSecClass: kSecClassGenericPassword,
-            kSecValueData: keypair.privateKey.hex.data(using: .utf8) as Any
+            kSecValueData: keypair.privateKey.hex.data(using: .utf8) as Any,
+            kSecAttrAccessGroup: accessGroup
         ] as [CFString: Any] as CFDictionary
 
         var status = SecItemAdd(query, nil)
 
-        if status == errSecDuplicateItem {
+        switch status {
+        case errSecDuplicateItem:
             let query = [
                 kSecAttrService: service,
                 kSecAttrAccount: keypair.publicKey.hex,
-                kSecClass: kSecClassGenericPassword
+                kSecClass: kSecClassGenericPassword,
+                kSecAttrAccessGroup: accessGroup
             ] as [CFString: Any] as CFDictionary
 
             let updates = [
@@ -57,6 +62,12 @@ class PrivateKeySecureStorage {
             ] as CFDictionary
 
             status = SecItemUpdate(query, updates)
+        case errSecSuccess:
+            print("Successfully stored keypair.")
+        case errSecMissingEntitlement:
+            print("Missing entitlement error while storing keypair.")
+        default:
+            print("Error storing keypair: \(status)")
         }
     }
 
@@ -64,7 +75,8 @@ class PrivateKeySecureStorage {
         let query = [
             kSecAttrService: service,
             kSecAttrAccount: publicKey.hex,
-            kSecClass: kSecClassGenericPassword
+            kSecClass: kSecClassGenericPassword,
+            kSecAttrAccessGroup: accessGroup
         ] as [CFString: Any] as CFDictionary
 
         _ = SecItemDelete(query)

Yeti/Yeti.entitlements

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>com.apple.security.application-groups</key>
+	<array>
+		<string>group.xyz.tyiu.Yeti</string>
+	</array>
+	<key>keychain-access-groups</key>
+	<array>
+		<string>$(AppIdentifierPrefix)xyz.tyiu.Yeti.SharedKeychain</string>
+	</array>
+</dict>
+</plist>

Yeti/YetiApp.swift

@@ -5,6 +5,7 @@
 //  Created by Terry Yiu on 1/19/25.
 //
 
+import NostrSDK
 import SwiftUI
 import SwiftData
 
@@ -15,23 +16,16 @@ struct YetiApp: App {
     private let modelContainer: ModelContainer
 
     init() {
-        let schema = Schema([
+        modelContainer = createYetiModelContainer()
-            GeneralSettingsModel.self,
-            ProfileSettingsModel.self,
-            SignerRequestModel.self
-        ])
-        let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false)
-
-        do {
-            modelContainer = try ModelContainer(for: schema, configurations: [modelConfiguration])
-        } catch {
-            fatalError("Could not create ModelContainer: \(error)")
-        }
 
         var descriptor = FetchDescriptor<GeneralSettingsModel>()
         descriptor.fetchLimit = 1
 
-        if (try? modelContainer.mainContext.fetch(descriptor))?.first == nil {
+        if let generalSettingsModel = (try? modelContainer.mainContext.fetch(descriptor))?.first,
+           let activePublicKey = generalSettingsModel.activePublicKey,
+           let publicKey = PublicKey(hex: activePublicKey) {
+            print("Found pubkey=\(PrivateKeySecureStorage.shared.keypair(for: publicKey)?.publicKey.npub ?? "")")
+        } else {
             let newGeneralSettingsModel = GeneralSettingsModel()
             modelContainer.mainContext.insert(newGeneralSettingsModel)
             do {

YetiSignerAction/Info.plist

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>NSExtension</key>
+	<dict>
+		<key>NSExtensionAttributes</key>
+		<dict>
+			<key>NSExtensionActivationRule</key>
+			<dict>
+				<key>NSExtensionActivationSupportsText</key>
+				<true/>
+			</dict>
+			<key>NSExtensionServiceAllowsFinderPreviewItem</key>
+			<true/>
+			<key>NSExtensionServiceAllowsTouchBarItem</key>
+			<true/>
+			<key>NSExtensionServiceFinderPreviewIconName</key>
+			<string>NSActionTemplate</string>
+			<key>NSExtensionServiceTouchBarBezelColorName</key>
+			<string>TouchBarBezel</string>
+			<key>NSExtensionServiceTouchBarIconName</key>
+			<string>NSActionTemplate</string>
+		</dict>
+		<key>NSExtensionPrincipalClass</key>
+		<string>YetiSignerAction.YetiSignerActionViewController</string>
+		<key>NSExtensionPointIdentifier</key>
+		<string>com.apple.ui-services</string>
+	</dict>
+</dict>
+</plist>

YetiSignerAction/Media.xcassets/Contents.json

@@ -0,0 +1,6 @@
+{
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

YetiSignerAction/Media.xcassets/TouchBarBezel.colorset/Contents.json

@@ -0,0 +1,14 @@
+{
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  },
+  "colors" : [
+    {
+      "idiom" : "mac",
+      "color" : {
+        "reference" : "systemPurpleColor"
+      }
+    }
+  ]
+}

YetiSignerAction/YetiSignerAction.entitlements

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>com.apple.security.application-groups</key>
+	<array>
+		<string>group.xyz.tyiu.Yeti</string>
+	</array>
+	<key>keychain-access-groups</key>
+	<array>
+		<string>$(AppIdentifierPrefix)xyz.tyiu.Yeti.SharedKeychain</string>
+	</array>
+</dict>
+</plist>

YetiSignerAction/YetiSignerActionView.swift

@@ -0,0 +1,54 @@
+//
+//  YetiSignerActionView.swift
+//  YetiSignerAction
+//
+//  Created by Terry Yiu on 1/26/25.
+//
+
+import NostrSDK
+import SwiftUI
+
+struct YetiSignerActionView: View {
+    @State private var text: String
+    @State private var result: String = ""
+
+    init(text: String) {
+        self.text = text
+    }
+
+    var body: some View {
+        EmptyView()
+            .onAppear {
+                do {
+                    try sign()
+                    done()
+                } catch {
+                    result = error.localizedDescription
+                }
+            }
+    }
+
+    func sign() throws {
+        let data = Data(text.utf8)
+        let unsignedNostrEvent = try JSONDecoder().decode(NostrEvent.self, from: data)
+        let pubkey = unsignedNostrEvent.pubkey
+        if let publicKey = PublicKey(hex: pubkey),
+           let keypair = PrivateKeySecureStorage.shared.keypair(for: publicKey) {
+            let signedNostrEvent = try NostrEvent.Builder(nostrEvent: unsignedNostrEvent)
+                .build(signedBy: keypair)
+
+            let encodedSignedEvent = try JSONEncoder().encode(signedNostrEvent)
+            let encodedSignedEventString = String(data: encodedSignedEvent, encoding: .utf8)!
+
+            self.result = encodedSignedEventString
+        }
+    }
+
+    func done() {
+        NotificationCenter.default.post(name: NSNotification.Name("done"), object: result)
+    }
+}
+
+#Preview {
+    YetiSignerActionView(text: "Hello, world!")
+}

YetiSignerAction/YetiSignerActionViewController.swift

@@ -0,0 +1,81 @@
+//
+//  YetiSignerActionViewController.swift
+//  YetiSignerAction
+//
+//  Created by Terry Yiu on 1/26/25.
+//
+
+//import MobileCoreServices
+import SwiftUI
+import UIKit
+import UniformTypeIdentifiers
+
+class YetiSignerActionViewController: UIViewController {
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+
+        guard
+            let extensionItem = extensionContext?.inputItems.first as? NSExtensionItem,
+            let itemProvider = extensionItem.attachments?.first
+        else {
+            done()
+            return
+        }
+
+
+        let textDataType = UTType.plainText.identifier
+        guard itemProvider.hasItemConformingToTypeIdentifier(textDataType) else {
+            done()
+            return
+        }
+
+        itemProvider.loadItem(forTypeIdentifier: textDataType , options: nil) { (providedText, error) in
+            if let error {
+                self.done(signedEvent: error.localizedDescription)
+                return
+            }
+
+            if let text = providedText as? String {
+                DispatchQueue.main.async {
+                    let contentView = UIHostingController(rootView: YetiSignerActionView(text: text))
+                    self.addChild(contentView)
+                    self.view.addSubview(contentView.view)
+
+                    // set up constraints
+                    contentView.view.translatesAutoresizingMaskIntoConstraints = false
+                    contentView.view.topAnchor.constraint(equalTo: self.view.topAnchor).isActive = true
+                    contentView.view.bottomAnchor.constraint (equalTo: self.view.bottomAnchor).isActive = true
+                    contentView.view.leftAnchor.constraint(equalTo: self.view.leftAnchor).isActive = true
+                    contentView.view.rightAnchor.constraint (equalTo: self.view.rightAnchor).isActive = true
+                }
+            } else {
+                self.done()
+                return
+            }
+        }
+
+        NotificationCenter.default.addObserver(forName: NSNotification.Name("done"), object: nil, queue: nil) { notification in
+            DispatchQueue.main.async {
+                self.done(signedEvent: notification.object as? String)
+            }
+        }
+    }
+
+    func done(signedEvent: String? = nil) {
+        if let extensionContext = self.extensionContext {
+            if let signedEvent {
+                let itemProvider = NSItemProvider(
+                    item: signedEvent as NSSecureCoding?,
+                    typeIdentifier: UTType.text.identifier
+                )
+                let extensionItem = NSExtensionItem()
+                extensionItem.attachments = [itemProvider]
+                extensionContext.completeRequest(returningItems: [extensionItem], completionHandler: nil)
+            } else {
+                extensionContext.completeRequest(returningItems: [], completionHandler: nil)
+            }
+        }
+    }
+
+}