Add FIDO U2F message and packet classes

device/u2f/u2f_packet.cc

+// Copyright 2016 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 "device/u2f/u2f_packet.h"
+
+namespace device {
+
+U2fPacket::U2fPacket(const std::vector<uint8_t> data, const uint32_t channel_id)
+    : data_(data), channel_id_(channel_id) {}
+
+U2fPacket::U2fPacket() : data_(), channel_id_() {}
+
+U2fPacket::~U2fPacket() {}
+
+scoped_refptr<net::IOBufferWithSize> U2fPacket::GetSerializedBuffer() {
+  if (serialized_)
+    return serialized_;
+  else
+    return make_scoped_refptr(new net::IOBufferWithSize(0));
+}
+
+const std::vector<uint8_t> U2fPacket::GetPacketPayload() {
+  return data_;
+}
+
+uint32_t U2fPacket::GetChannelId() {
+  return channel_id_;
+}
+
+uint16_t U2fInitPacket::GetPayloadLength() {
+  return payload_length_;
+}
+
+// U2F Initialization packet is defined as:
+// Offset Length
+// 0      4       Channel ID
+// 4      1       Command ID
+// 5      1       High order packet payload size
+// 6      1       Low order packet payload size
+// 7      (s-7)   Payload data
+U2fInitPacket::U2fInitPacket(const uint32_t channel_id,
+                             const uint8_t cmd,
+                             const std::vector<uint8_t> data,
+                             const uint16_t payload_length)
+    : U2fPacket(data, channel_id), command_(cmd), payload_length_() {
+  serialized_ = new net::IOBufferWithSize(kPacketSize);
+  size_t index = 0;
+  serialized_->data()[index++] = 0;

[Reilly Grant (use Gerrit), 2016/12/09 01:19:43]

Add a comment about why the byte at offset 0 is always 0 (report ID).

[Casey Piper, 2016/12/09 18:56:50]

Done.

+
+  serialized_->data()[index++] = (channel_id_ >> 24) & 0xff;
+  serialized_->data()[index++] = (channel_id_ >> 16) & 0xff;
+  serialized_->data()[index++] = (channel_id_ >> 8) & 0xff;
+  serialized_->data()[index++] = channel_id_ & 0xff;
+
+  serialized_->data()[index++] = command_;
+  payload_length_ = payload_length;
+  serialized_->data()[index++] = (payload_length >> 8) & 0xff;
+  serialized_->data()[index++] = payload_length & 0xff;
+  for (size_t data_idx = 0; data_idx < data_.size(); ++data_idx)
+    serialized_->data()[index++] = data_.at(data_idx);
+  while (static_cast<int>(index) < serialized_->size())
+    serialized_->data()[index++] = 0;
+}
+
+// static
+scoped_refptr<U2fInitPacket> U2fInitPacket::CreateFromSerializedData(
+    scoped_refptr<net::IOBufferWithSize> buf,
+    size_t* remaining_size) {
+  if (buf == nullptr || remaining_size == nullptr || buf->size() != kPacketSize)
+    return nullptr;
+
+  return make_scoped_refptr(new U2fInitPacket(buf, remaining_size));
+}
+
+U2fInitPacket::U2fInitPacket(scoped_refptr<net::IOBufferWithSize> buf,
+                             size_t* remaining_size)
+    : U2fPacket(), command_(), payload_length_() {
+  size_t index = 1;

[Reilly Grant (use Gerrit), 2016/12/09 01:19:43]

Again, note about the report ID.

[Casey Piper, 2016/12/09 18:56:50]

Done.

+  uint16_t payload_size = 0;
+  uint16_t data_size = 0;
+
+  channel_id_ = (buf->data()[index++] & 0xff) << 24;
+  channel_id_ |= (buf->data()[index++] & 0xff) << 16;
+  channel_id_ |= (buf->data()[index++] & 0xff) << 8;
+  channel_id_ |= buf->data()[index++] & 0xff;
+  command_ = buf->data()[index++];
+  payload_size = buf->data()[index++] << 8;
+  payload_size |= static_cast<uint8_t>(buf->data()[index++]);
+  payload_length_ = payload_size;
+
+  // Check to see if payload is less than maximum size and padded with 0s
+  data_size =
+      std::min(payload_size, static_cast<uint16_t>(kPacketSize - index));
+  // Update remaining size to determine the payload size of follow on packets
+  *remaining_size = payload_size - data_size;
+
+  data_.insert(data_.end(), &buf->data()[index],
+               &buf->data()[index + data_size]);
+
+  for (int i = index + data_size; i < buf->size(); ++i)
+    buf->data()[i] = 0;
+  serialized_ = buf;
+}
+
+uint8_t U2fInitPacket::GetCommand() {
+  return command_;
+}
+
+U2fInitPacket::~U2fInitPacket() {}
+
+// U2F Continuation packet is defined as:
+// Offset Length
+// 0      4       Channel ID
+// 4      1       Packet sequence 0x00..0x7f
+// 5      (s-5)   Payload data
+U2fContinuationPacket::U2fContinuationPacket(const uint32_t channel_id,
+                                             const uint8_t sequence,
+                                             std::vector<uint8_t> data)
+    : U2fPacket(data, channel_id), sequence_(sequence) {
+  serialized_ = new net::IOBufferWithSize(kPacketSize);
+  size_t index = 0;
+  serialized_->data()[index++] = 0;
+
+  serialized_->data()[index++] = (channel_id_ >> 24) & 0xff;
+  serialized_->data()[index++] = (channel_id_ >> 16) & 0xff;
+  serialized_->data()[index++] = (channel_id_ >> 8) & 0xff;
+  serialized_->data()[index++] = channel_id_ & 0xff;
+
+  serialized_->data()[index++] = sequence_;
+  for (size_t idx = 0; idx < data_.size(); ++idx)
+    serialized_->data()[index++] = data_.at(idx);
+
+  while (static_cast<int>(index) < serialized_->size())
+    serialized_->data()[index++] = 0;
+}
+
+// static
+scoped_refptr<U2fContinuationPacket>
+U2fContinuationPacket::CreateFromSerializedData(
+    scoped_refptr<net::IOBufferWithSize> buf,
+    size_t* remaining_size) {
+  if (buf == nullptr || remaining_size == nullptr || buf->size() != kPacketSize)
+    return nullptr;
+
+  return make_scoped_refptr(new U2fContinuationPacket(buf, remaining_size));
+}
+
+U2fContinuationPacket::U2fContinuationPacket(
+    scoped_refptr<net::IOBufferWithSize> buf,
+    size_t* remaining_size)
+    : U2fPacket() {
+  size_t index = 1, data_size;
+
+  channel_id_ = (buf->data()[index++] & 0xff) << 24;
+  channel_id_ |= (buf->data()[index++] & 0xff) << 16;
+  channel_id_ |= (buf->data()[index++] & 0xff) << 8;
+  channel_id_ |= buf->data()[index++] & 0xff;
+  sequence_ = buf->data()[index++];
+
+  data_size = std::min(*remaining_size, kPacketSize - index);
+  *remaining_size -= data_size;
+  data_.insert(std::end(data_), &buf->data()[index],
+               &buf->data()[index + data_size]);
+
+  // Incoming buffer may not be padded with 0's, so manually update buffer
+  for (int i = index + data_size; i < buf->size(); ++i)
+    buf->data()[i] = 0;
+  serialized_ = buf;
+}
+
+uint8_t U2fContinuationPacket::GetSequence() {
+  return sequence_;
+}
+
+U2fContinuationPacket::~U2fContinuationPacket() {}
+}  // namespace device