Add U2F request state machines

device/u2f/u2f_sign.cc

Index: device/u2f/u2f_sign.cc
diff --git a/device/u2f/u2f_sign.cc b/device/u2f/u2f_sign.cc
new file mode 100644
index 0000000000000000000000000000000000000000..76ebbb0ee03e45626a92b1909f666ae20b3f65c3
--- /dev/null
+++ b/device/u2f/u2f_sign.cc
@@ -0,0 +1,94 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "u2f_sign.h"
+
+#include "base/memory/ptr_util.h"
+
+namespace device {
+
+U2fSign::U2fSign(std::vector<std::vector<uint8_t>> registered_keys,
+                 std::vector<uint8_t> challenge_hash,
+                 std::vector<uint8_t> app_param,
+                 const ResponseCallback& cb)
+    : U2fRequest(cb),
+      registered_keys_(registered_keys),
+      challenge_hash_(challenge_hash),
+      app_param_(app_param),
+      weak_factory_(this) {}
+
+U2fSign::~U2fSign() {}
+
+// static
+std::unique_ptr<U2fRequest> U2fSign::TrySign(
+    std::vector<std::vector<uint8_t>> registered_keys,
+    std::vector<uint8_t> challenge_hash,
+    std::vector<uint8_t> app_param,
+    const ResponseCallback& cb) {
+  std::unique_ptr<U2fRequest> request =
+      base::MakeUnique<U2fSign>(registered_keys, challenge_hash, app_param, cb);
+  if (request)

[Reilly Grant (use Gerrit), 2017/04/21 17:19:17]

base::MakeUnique does not fail.

[Casey Piper, 2017/04/21 18:42:26]

Acknowledged.

+    request->Start();
+  return request;
+}
+
+void U2fSign::TryDevice() {
+  if (!current_device_)
+    return;

[Reilly Grant (use Gerrit), 2017/04/21 17:19:16]

DCHECK?

[Casey Piper, 2017/04/21 18:42:26]

Done.

+
+  if (registered_keys_.size() == 0) {
+    // Send registration (Fake enroll) if no keys were provided
+    current_device_->Register(
+        kBogusAppParam, kBogusChallenge,
+        base::Bind(&U2fSign::OnTryDevice, weak_factory_.GetWeakPtr(),
+                   registered_keys_.cbegin()));
+    return;
+  }
+  // Try signing current device with the first registered key
+  auto it = registered_keys_.cbegin();
+  current_device_->Sign(
+      app_param_, challenge_hash_, *it,
+      base::Bind(&U2fSign::OnTryDevice, weak_factory_.GetWeakPtr(), it));
+}
+
+void U2fSign::OnTryDevice(std::vector<std::vector<uint8_t>>::const_iterator it,
+                          U2fDevice::ReturnCode return_code,
+                          std::vector<uint8_t> response_data) {
+  switch (return_code) {
+    case U2fDevice::ReturnCode::SUCCESS:
+      state_ = State::COMPLETE;
+      cb_.Run(static_cast<uint8_t>(return_code), response_data);
+      break;
+    case U2fDevice::ReturnCode::CONDITIONS_NOT_SATISFIED: {
+      // Key handle is accepted by this device, but waiting on user touch. Move
+      // on and try this device again later.
+      state_ = State::IDLE;
+      Transition();
+      break;
+    }
+    case U2fDevice::ReturnCode::INVALID_PARAMS:
+      if (++it != registered_keys_.end()) {
+        // Key is not for this device. Try signing with the next key.
+        current_device_->Sign(
+            app_param_, challenge_hash_, *it,
+            base::Bind(&U2fSign::OnTryDevice, weak_factory_.GetWeakPtr(), it));
+      } else {
+        // No provided key was accepted by this device. Send registration
+        // (Fake enroll) request to device.
+        current_device_->Register(
+            kBogusAppParam, kBogusChallenge,
+            base::Bind(&U2fSign::OnTryDevice, weak_factory_.GetWeakPtr(),
+                       registered_keys_.cbegin()));
+      }
+      break;
+    default:
+      // Some sort of failure occured. Abandon this device and move on.
+      state_ = State::IDLE;
+      current_device_ = nullptr;
+      Transition();
+      break;
+  }
+}
+
+}  // namespace device