mirror of
https://github.com/kidfromjupiter/nearby.git
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82 lines
2.6 KiB
C++
82 lines
2.6 KiB
C++
// Copyright 2025 Google LLC
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// https://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include "connections/implementation/mediums/advertisements/advertisement_util.h"
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#include <cstdint>
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#include <optional>
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#include <string>
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#include "absl/strings/string_view.h"
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#include "internal/platform/byte_array.h"
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#include "internal/platform/stream_reader.h"
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namespace nearby::connections::advertisements {
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namespace {
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constexpr uint8_t kFakeEncryptionSize = 16;
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constexpr absl::string_view kFakeEncryptionKey =
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"\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f";
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} // namespace
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// Should always match the protocol implementation to read device name.
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// LINT.IfChange
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std::optional<std::string> ReadDeviceName(const ByteArray& endpoint_info) {
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StreamReader reader(&endpoint_info);
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std::optional<uint8_t> version = reader.ReadBits(3);
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if (!version.has_value() || *version > 1) {
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return std::nullopt;
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}
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std::optional<uint8_t> has_device_name = reader.ReadBits(1);
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if (!has_device_name.has_value() || *has_device_name == 1) {
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return std::nullopt;
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}
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std::optional<uint8_t> device_type = reader.ReadBits(4);
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if (!device_type.has_value()) {
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return std::nullopt;
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}
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if (!reader.ReadBytes(16).has_value()) {
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return std::nullopt;
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}
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std::optional<uint8_t> device_length = reader.ReadUint8();
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if (!device_length.has_value() || *device_length == 0) {
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return std::nullopt;
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}
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std::optional<ByteArray> device_name = reader.ReadBytes(*device_length);
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if (!device_name.has_value()) {
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return std::nullopt;
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}
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return std::string(*device_name);
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}
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std::string BuildEndpointInfo(const std::string& device_name) {
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std::string endpoint_info;
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endpoint_info.reserve(18 + device_name.size());
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// VERSION | HAS_DEVICE_NAME | DEVICE_TYPE
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endpoint_info.push_back(0x22);
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// salt and encrypted_metadata_key
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endpoint_info.append(kFakeEncryptionKey.data(), kFakeEncryptionSize);
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endpoint_info.push_back(device_name.size());
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endpoint_info.append(device_name);
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return endpoint_info;
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}
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// LINT.ThenChange(//depot/google3/third_party/nearby/sharing/advertisement.cc)
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} // namespace nearby::connections::advertisements
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