FlowCrypt · tomholub · Nov 3, 2021 · Nov 3, 2021 · Nov 3, 2021 · Nov 3, 2021
@@ -35,8 +35,8 @@ const window = { navigator, crypto, setTimeout, clearTimeout };
 const self = { window, navigator, crypto };
 global.window = window;
 
-var engine_host_cb_value_formatter = function(val) {
-    coreHost.handleCallback(val.json, val.data);
+var engine_host_cb_value_formatter = function(callbackId, val) {
+    coreHost.handleCallback(callbackId, val.json, val.data);
 };
 
 (function() {

@@ -11,17 +11,17 @@ declare const global: any;
 
 const endpoints = new Endpoints();
 
-global.handleRequestFromHost = (endpointName: string, request: string, data: Uint8Array, cb: (response: EndpointRes) => void): void => {
+global.handleRequestFromHost = (endpointName: string, callbackId: string, request: string, data: Uint8Array, cb: (key: string, response: EndpointRes) => void): void => {
   try {
     const handler = endpoints[endpointName];
     if (!handler) {
-      cb(fmtErr(new Error(`Unknown endpoint: ${endpointName}`)));
+      cb(callbackId, fmtErr(new Error(`Unknown endpoint: ${endpointName}`)));
     } else {
       handler(JSON.parse(request), [data])
-        .then(res => cb(res))
-        .catch(err => cb(fmtErr(err)));
+        .then(res => cb(callbackId, res))
+        .catch(err => cb(callbackId, fmtErr(err)));
     }
   } catch (err) {
-    cb(fmtErr(err));
+    cb(callbackId, fmtErr(err));
   }
 };
@@ -53,18 +53,18 @@ protocol KeyParser {
     func parseKeys(armoredOrBinary: Data) async throws -> CoreRes.ParseKeys
 }
 
-final class Core: KeyDecrypter, KeyParser, CoreComposeMessageType {
+actor Core: KeyDecrypter, KeyParser, CoreComposeMessageType {
     static let shared = Core()
 
+    private typealias CallbackResult = (String, [UInt8])
+
     private var jsEndpointListener: JSValue?
     private var cb_catcher: JSValue?
-    private var cb_last_value: (String, [UInt8])?
     private var vm = JSVirtualMachine()!
     private var context: JSContext?
-    private dynamic var started = false
-    private dynamic var ready = false
-
-    private let queue = DispatchQueue(label: "com.flowcrypt.core", qos: .default) // todo - try also with .userInitiated
+
+    private var callbackResults: [String: CallbackResult] = [:]
+    private var ready = false
 
     private lazy var logger = Logger.nested(in: Self.self, with: "Js")
 
@@ -188,32 +188,25 @@ final class Core: KeyDecrypter, KeyParser, CoreComposeMessageType {
         return try r.json.decodeJson(as: CoreRes.ZxcvbnStrengthBar.self)
     }
 
-    func startInBackgroundIfNotAlreadyRunning(_ completion: @escaping (() -> Void)) {
-        if self.ready {
-            completion()
-        }
-        if !started {
-            started = true
-            DispatchQueue.global(qos: .default).async { [weak self] in
-                guard let self = self else { return }
-                let trace = Trace(id: "Start in background")
-                let jsFile = Bundle(for: Core.self).path(forResource: "flowcrypt-ios-prod.js.txt", ofType: nil)!
-                let jsFileSrc = try? String(contentsOfFile: jsFile)
-                self.context = JSContext(virtualMachine: self.vm)!
-                self.context?.setObject(CoreHost(), forKeyedSubscript: "coreHost" as (NSCopying & NSObjectProtocol))
-                self.context!.exceptionHandler = { [weak self] _, exception in
-                    guard let exception = exception else { return }
-                    self?.logger.logWarning("\(exception)")
-                }
-                self.context!.evaluateScript("const APP_VERSION = 'iOS 0.2';")
-                self.context!.evaluateScript(jsFileSrc)
-                self.jsEndpointListener = self.context!.objectForKeyedSubscript("handleRequestFromHost")
-                self.cb_catcher = self.context!.objectForKeyedSubscript("engine_host_cb_value_formatter")
-                self.ready = true
-                self.logger.logInfo("JsContext took \(trace.finish()) to start")
-                completion()
-            }
+    func startIfNotAlreadyRunning() async {
+        guard !ready else { return }
+
+        let trace = Trace(id: "Start in background")
+        let jsFile = Bundle(for: Self.self).path(forResource: "flowcrypt-ios-prod.js.txt", ofType: nil)!
+        let jsFileSrc = try? String(contentsOfFile: jsFile)
+        context = JSContext(virtualMachine: vm)!
+        context?.setObject(CoreHost(), forKeyedSubscript: "coreHost" as (NSCopying & NSObjectProtocol))
+        context!.exceptionHandler = { _, exception in
+            guard let exception = exception else { return }
+            let logger = Logger.nested(in: Self.self, with: "Js")
+            logger.logWarning("\(exception)")
         }
+        context!.evaluateScript("const APP_VERSION = 'iOS 0.2';")
+        context!.evaluateScript(jsFileSrc)
+        jsEndpointListener = context!.objectForKeyedSubscript("handleRequestFromHost")
+        cb_catcher = context!.objectForKeyedSubscript("engine_host_cb_value_formatter")
+        ready = true
+        logger.logInfo("JsContext took \(trace.finish()) to start")
     }
 
     func gmailBackupSearch(for email: String) async throws -> String {
@@ -222,8 +215,8 @@ final class Core: KeyDecrypter, KeyParser, CoreComposeMessageType {
         return result.query
     }
 
-    func handleCallbackResult(json: String, data: [UInt8]) {
-        cb_last_value = (json, data)
+    func handleCallbackResult(callbackId: String, json: String, data: [UInt8]) {
+        callbackResults[callbackId] = (json, data)
     }
 
     // MARK: Private calls
@@ -236,55 +229,45 @@ final class Core: KeyDecrypter, KeyParser, CoreComposeMessageType {
     }
 
     private func call(_ endpoint: String, jsonData: Data, data: Data) async throws -> RawRes {
-        try await sleepUntilReadyOrThrow()
-        return try await withCheckedThrowingContinuation { (continuation: CheckedContinuation<RawRes, Error>) in
-            // tom - todo - currently there is only one callback storage variable "cb_last_value"
-            //   for all JavaScript calls, and so we have to synchronize
-            //   all calls into JavaScript to happen serially, else
-            //   the return values would be undefined when used concurrently
-            //   see https://github.com/FlowCrypt/flowcrypt-ios/issues/852
-            // A possible solution would be to only synchronize returning o fthe callbac values into some dict. But I'm unsure if JavaScript is otherwise safe to call concurrently, so for now we'll do the safer thing.
-            queue.async {
-                self.cb_last_value = nil
-                self.jsEndpointListener!.call(withArguments: [endpoint, String(data: jsonData, encoding: .utf8)!, Array<UInt8>(data), self.cb_catcher!])
-                guard
-                    let resJsonData = self.cb_last_value?.0.data(using: .utf8),
-                    let rawResponse = self.cb_last_value?.1
-                else {
-                    self.logger.logError("could not see callback response, got cb_last_value: \(String(describing: self.cb_last_value))")
-                    continuation.resume(throwing: CoreError.format("JavaScript callback response not available"))
-                    return
-                }
-                let error = try? resJsonData.decodeJson(as: CoreRes.Error.self)
-                if let error = error {
-                    let errMsg = "------ js err -------\nCore \(endpoint):\n\(error.error.message)\n\(error.error.stack ?? "no stack")\n------- end js err -----"
-                    self.logger.logError(errMsg)
-                    continuation.resume(throwing: CoreError(coreError: error))
-                    return
-                }
-                continuation.resume(returning: RawRes(json: resJsonData, data: Data(rawResponse)))
-            }
+        guard ready else {
+            throw CoreError.exception("Core is not ready yet. Most likeyly startIfNotAlreadyRunning wasn't called first")
         }
-    }
-
-    private func sleepUntilReadyOrThrow() async throws {
-        // This will block the task for up to 1000ms if the app was just started and Core method was called before JSContext is ready
-        // It should only affect the user if Core method was called within 500-800ms of starting the app
-        let start = DispatchTime.now()
-        while !ready {
-            if start.millisecondsSince > 1000 { // already waited for 1000 ms, give up
-                throw CoreError.notReady("App Core not ready yet")
-            }
-            await Task.sleep(50 * 1_000_000) // 50ms
+
+        let callbackId = NSUUID().uuidString
+        jsEndpointListener!.call(withArguments: [
+            endpoint,
+            callbackId,
+            String(data: jsonData, encoding: .utf8)!,
+            Array<UInt8>(data), cb_catcher!
+        ])
+
+        while callbackResults[callbackId] == nil {
+            await Task.sleep(1_000_000) // 1ms
         }
-    }
 
-    private struct RawRes {
-        let json: Data
-        let data: Data
+        guard
+            let result = callbackResults.removeValue(forKey: callbackId),
+            let resJsonData = result.0.data(using: .utf8)
+        else {
+            throw CoreError.format("JavaScript callback response not available")
+        }
+
+        let error = try? resJsonData.decodeJson(as: CoreRes.Error.self)
+        if let error = error {
+            let errMsg = "------ js err -------\nCore \(endpoint):\n\(error.error.message)\n\(error.error.stack ?? "no stack")\n------- end js err -----"
+            logger.logError(errMsg)
+            throw CoreError(coreError: error)
+        }
+
+        return RawRes(json: resJsonData, data: Data(result.1))
     }
 }
 
+private struct RawRes {
+    let json: Data
+    let data: Data
+}
+
 private struct GmailBackupSearchResponse: Decodable {
     let query: String
 }
@@ -22,7 +22,7 @@ import SwiftyRSA // for rsa
     func setTimeout(_ callback: JSValue, _ ms: Double) -> String
     func clearTimeout(_ identifier: String)
 
-    func handleCallback(_ string: String, _ data: [UInt8])
+    func handleCallback(_ endpointKey: String, _ string: String, _ data: [UInt8])
 }
 
 var timers = [String: Timer]()
@@ -119,8 +119,10 @@ final class CoreHost: NSObject, CoreHostExports {
         return uuid
     }
 
-    func handleCallback(_ string: String, _ data: [UInt8]) {
-        Core.shared.handleCallbackResult(json: string, data: data)
+    func handleCallback(_ callbackId: String, _ string: String, _ data: [UInt8]) {
+        Task {
+            await Core.shared.handleCallbackResult(callbackId: callbackId, json: string, data: data)
+        }
     }
 
     @objc func callJsCb(_ timer: Timer) {

@@ -26,7 +26,7 @@ struct AppStartup {
 
         Task {
             do {
-                try awaitPromise(setupCore())
+                await setupCore()
                 try setupMigrationIfNeeded()
                 try setupSession()
                 try await getUserOrgRulesIfNeeded()
@@ -37,13 +37,9 @@ struct AppStartup {
         }
     }
 
-    private func setupCore() -> Promise<Void> {
-        Promise { resolve, _ in
-            logger.logInfo("Setup Core")
-            Core.shared.startInBackgroundIfNotAlreadyRunning {
-                resolve(())
-            }
-        }
+    private func setupCore() async {
+        logger.logInfo("Setup Core")
+        await Core.shared.startIfNotAlreadyRunning()
     }
 
     private func setupMigrationIfNeeded() throws {

@@ -40,8 +40,8 @@ const window = { navigator, crypto, setTimeout, clearTimeout };
 const self = { window, navigator, crypto };
 global.window = window;
 
-var engine_host_cb_value_formatter = function(val) {
-    coreHost.handleCallback(val.json, val.data);
+var engine_host_cb_value_formatter = function(callbackId, val) {
+    coreHost.handleCallback(callbackId, val.json, val.data);
 };
 
 (function() {
@@ -86405,20 +86405,20 @@ Object.defineProperty(exports, "__esModule", { value: true });
 const endpoints_1 = __webpack_require__(2);
 const format_output_1 = __webpack_require__(3);
 const endpoints = new endpoints_1.Endpoints();
-global.handleRequestFromHost = (endpointName, request, data, cb) => {
+global.handleRequestFromHost = (endpointName, callbackId, request, data, cb) => {
     try {
         const handler = endpoints[endpointName];
         if (!handler) {
-            cb((0, format_output_1.fmtErr)(new Error(`Unknown endpoint: ${endpointName}`)));
+            cb(callbackId, (0, format_output_1.fmtErr)(new Error(`Unknown endpoint: ${endpointName}`)));
         }
         else {
             handler(JSON.parse(request), [data])
-                .then(res => cb(res))
-                .catch(err => cb((0, format_output_1.fmtErr)(err)));
+                .then(res => cb(callbackId, res))
+                .catch(err => cb(callbackId, (0, format_output_1.fmtErr)(err)));
         }
     }
     catch (err) {
-        cb((0, format_output_1.fmtErr)(err));
+        cb(callbackId, (0, format_output_1.fmtErr)(err));
     }
 };
 
@@ -111770,7 +111770,7 @@ elliptic.eddsa = __webpack_require__(170);
 /* 144 */
 /***/ (function(module) {
 
-module.exports = JSON.parse("{\"_from\":\"elliptic@^6.5.3\",\"_id\":\"elliptic@6.5.4\",\"_inBundle\":false,\"_integrity\":\"sha512-iLhC6ULemrljPZb+QutR5TQGB+pdW6KGD5RSegS+8sorOZT+rdQFbsQFJgvN3eRqNALqJer4oQ16YvJHlU8hzQ==\",\"_location\":\"/elliptic\",\"_phantomChildren\":{},\"_requested\":{\"type\":\"range\",\"registry\":true,\"raw\":\"elliptic@^6.5.3\",\"name\":\"elliptic\",\"escapedName\":\"elliptic\",\"rawSpec\":\"^6.5.3\",\"saveSpec\":null,\"fetchSpec\":\"^6.5.3\"},\"_requiredBy\":[\"/browserify-sign\",\"/create-ecdh\"],\"_resolved\":\"https://registry.npmjs.org/elliptic/-/elliptic-6.5.4.tgz\",\"_shasum\":\"da37cebd31e79a1367e941b592ed1fbebd58abbb\",\"_spec\":\"elliptic@^6.5.3\",\"_where\":\"/home/ivan/pro/flowcrypt/flowcrypt-ios/Core/node_modules/browserify-sign\",\"author\":{\"name\":\"Fedor Indutny\",\"email\":\"fedor@indutny.com\"},\"bugs\":{\"url\":\"https://github.com/indutny/elliptic/issues\"},\"bundleDependencies\":false,\"dependencies\":{\"bn.js\":\"^4.11.9\",\"brorand\":\"^1.1.0\",\"hash.js\":\"^1.0.0\",\"hmac-drbg\":\"^1.0.1\",\"inherits\":\"^2.0.4\",\"minimalistic-assert\":\"^1.0.1\",\"minimalistic-crypto-utils\":\"^1.0.1\"},\"deprecated\":false,\"description\":\"EC cryptography\",\"devDependencies\":{\"brfs\":\"^2.0.2\",\"coveralls\":\"^3.1.0\",\"eslint\":\"^7.6.0\",\"grunt\":\"^1.2.1\",\"grunt-browserify\":\"^5.3.0\",\"grunt-cli\":\"^1.3.2\",\"grunt-contrib-connect\":\"^3.0.0\",\"grunt-contrib-copy\":\"^1.0.0\",\"grunt-contrib-uglify\":\"^5.0.0\",\"grunt-mocha-istanbul\":\"^5.0.2\",\"grunt-saucelabs\":\"^9.0.1\",\"istanbul\":\"^0.4.5\",\"mocha\":\"^8.0.1\"},\"files\":[\"lib\"],\"homepage\":\"https://github.com/indutny/elliptic\",\"keywords\":[\"EC\",\"Elliptic\",\"curve\",\"Cryptography\"],\"license\":\"MIT\",\"main\":\"lib/elliptic.js\",\"name\":\"elliptic\",\"repository\":{\"type\":\"git\",\"url\":\"git+ssh://git@github.com/indutny/elliptic.git\"},\"scripts\":{\"lint\":\"eslint lib test\",\"lint:fix\":\"npm run lint -- --fix\",\"test\":\"npm run lint && npm run unit\",\"unit\":\"istanbul test _mocha --reporter=spec test/index.js\",\"version\":\"grunt dist && git add dist/\"},\"version\":\"6.5.4\"}");
+module.exports = JSON.parse("{\"_args\":[[\"elliptic@6.5.4\",\"/Users/ivan/Documents/Projects/FlowCrypt/flowcrypt-ios/Core\"]],\"_development\":true,\"_from\":\"elliptic@6.5.4\",\"_id\":\"elliptic@6.5.4\",\"_inBundle\":false,\"_integrity\":\"sha512-iLhC6ULemrljPZb+QutR5TQGB+pdW6KGD5RSegS+8sorOZT+rdQFbsQFJgvN3eRqNALqJer4oQ16YvJHlU8hzQ==\",\"_location\":\"/elliptic\",\"_phantomChildren\":{},\"_requested\":{\"type\":\"version\",\"registry\":true,\"raw\":\"elliptic@6.5.4\",\"name\":\"elliptic\",\"escapedName\":\"elliptic\",\"rawSpec\":\"6.5.4\",\"saveSpec\":null,\"fetchSpec\":\"6.5.4\"},\"_requiredBy\":[\"/browserify-sign\",\"/create-ecdh\"],\"_resolved\":\"https://registry.npmjs.org/elliptic/-/elliptic-6.5.4.tgz\",\"_spec\":\"6.5.4\",\"_where\":\"/Users/ivan/Documents/Projects/FlowCrypt/flowcrypt-ios/Core\",\"author\":{\"name\":\"Fedor Indutny\",\"email\":\"fedor@indutny.com\"},\"bugs\":{\"url\":\"https://github.com/indutny/elliptic/issues\"},\"dependencies\":{\"bn.js\":\"^4.11.9\",\"brorand\":\"^1.1.0\",\"hash.js\":\"^1.0.0\",\"hmac-drbg\":\"^1.0.1\",\"inherits\":\"^2.0.4\",\"minimalistic-assert\":\"^1.0.1\",\"minimalistic-crypto-utils\":\"^1.0.1\"},\"description\":\"EC cryptography\",\"devDependencies\":{\"brfs\":\"^2.0.2\",\"coveralls\":\"^3.1.0\",\"eslint\":\"^7.6.0\",\"grunt\":\"^1.2.1\",\"grunt-browserify\":\"^5.3.0\",\"grunt-cli\":\"^1.3.2\",\"grunt-contrib-connect\":\"^3.0.0\",\"grunt-contrib-copy\":\"^1.0.0\",\"grunt-contrib-uglify\":\"^5.0.0\",\"grunt-mocha-istanbul\":\"^5.0.2\",\"grunt-saucelabs\":\"^9.0.1\",\"istanbul\":\"^0.4.5\",\"mocha\":\"^8.0.1\"},\"files\":[\"lib\"],\"homepage\":\"https://github.com/indutny/elliptic\",\"keywords\":[\"EC\",\"Elliptic\",\"curve\",\"Cryptography\"],\"license\":\"MIT\",\"main\":\"lib/elliptic.js\",\"name\":\"elliptic\",\"repository\":{\"type\":\"git\",\"url\":\"git+ssh://git@github.com/indutny/elliptic.git\"},\"scripts\":{\"lint\":\"eslint lib test\",\"lint:fix\":\"npm run lint -- --fix\",\"test\":\"npm run lint && npm run unit\",\"unit\":\"istanbul test _mocha --reporter=spec test/index.js\",\"version\":\"grunt dist && git add dist/\"},\"version\":\"6.5.4\"}");
 
 /***/ }),
 /* 145 */

@@ -15,7 +15,8 @@ final class FlowCryptCoreTests: XCTestCase {
 
     override func setUp() {
         let expectation = XCTestExpectation()
-        core.startInBackgroundIfNotAlreadyRunning {
+        Task {
+            await core.startIfNotAlreadyRunning()
             expectation.fulfill()
         }
         wait(for: [expectation], timeout: 20)
@@ -387,9 +388,8 @@ final class FlowCryptCoreTests: XCTestCase {
         }
     }
 
-    // this test is only meaningful on a real device
-    // it passes on simulator even if implementation is broken
-    // maybe there's a way to run simulator with more cores? (on a mac that has them) which would simulate real device better
+    // This test always passes, even wrongly, on simulators running on a mac with 2 or fewer cores.
+    // Behaves meaningfully on real iPhone or simulator on a mac with many cores
     func testCoreResponseCorrectnessUnderConcurrency() async throws {
         // given: a bunch of keys
         let pp = "this particular pass phrase is long enough"

@@ -15,7 +15,8 @@ final class KeyServiceTests: XCTestCase {
         super.setUp()
 
         let expectation = XCTestExpectation()
-        Core.shared.startInBackgroundIfNotAlreadyRunning {
+        Task {
+            await Core.shared.startIfNotAlreadyRunning()
             expectation.fulfill()
         }
         wait(for: [expectation], timeout: 10)