Files
U2FDevice/IO.cpp
2019-08-23 13:27:30 +01:00

140 lines
3.9 KiB
C++

/*
U2FDevice - A program to allow Raspberry Pi Zeros to act as U2F tokens
Copyright (C) 2018 Michael Kuc
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#include "IO.hpp"
#include "Macro.hpp"
#include "Streams.hpp"
#include "U2FDevice.hpp"
#include "u2f.hpp"
#include <android/log.h>
#include <array>
#include <chrono>
#include <cstdio>
#include <ctime>
#include <fcntl.h>
#include <iostream>
#include <memory>
#include <ratio>
#include <stdexcept>
#include <string>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
using namespace std;
bool bytesAvailable(size_t count);
vector<uint8_t>& getBuffer();
string binaryDirectory{};
string cacheDirectory{ DEBUG_STREAMS };
// Thanks to https://stackoverflow.com/a/478960
vector<uint8_t> execOutput(const string& cmd);
void execInput(const string& cmd, const vector<uint8_t>& stdinData);
vector<uint8_t> readNonBlock(const size_t count) {
if (!bytesAvailable(count))
return vector<uint8_t>{};
auto& buffer = getBuffer();
auto buffStart = buffer.begin(), buffEnd = buffer.begin() + count;
vector<uint8_t> bytes{ buffStart, buffEnd };
buffer.erase(buffStart, buffEnd);
errno = 0;
return bytes;
}
void write(const vector<uint8_t>& bytes) {
__android_log_print(ANDROID_LOG_DEBUG, "U2FAndroid", "Writing %zu bytes", bytes.size());
execInput("su -c \"" + binaryDirectory + "/U2FAndroid_Write\"", bytes);
}
bool bytesAvailable(const size_t count) {
auto startTime = std::chrono::high_resolution_clock::now();
const timespec iterDelay{ 0, 10000000 };
chrono::duration<double, milli> delay{ 0 };
while (delay.count() < U2FHID_TRANS_TIMEOUT) {
if (getBuffer().size() >= count) {
#ifdef DEBUG_MSGS
clog << "Requested " << count << " bytes" << endl;
#endif
return true;
}
nanosleep(&iterDelay, nullptr);
delay = chrono::high_resolution_clock::now() - startTime;
}
#ifdef DEBUG_MSGS
cerr << "Failed to obtain " << count << " bytes, having " << getBuffer().size() << endl;
#endif
return false;
}
vector<uint8_t>& bufferVar() {
static vector<uint8_t> buffer{};
return buffer;
}
vector<uint8_t>& getBuffer() {
auto& buff = bufferVar();
vector<uint8_t> bytes = execOutput("su -c \"" + binaryDirectory + "/U2FAndroid_Read\"");
if (!bytes.empty()) {
__android_log_print(ANDROID_LOG_DEBUG, "U2FAndroid", "Reading bytes: got %zu",
bytes.size());
buff.insert(buff.end(), bytes.begin(), bytes.end());
#ifdef DEBUG_STREAMS
fwrite(bytes.data(), 1, bytes.size(), getComHostStream().get());
#endif
}
return buff;
}
vector<uint8_t> execOutput(const string& cmd) {
// NOLINT(hicpp-member-init)
array<char, HID_RPT_SIZE> buffer;
vector<uint8_t> result{};
unique_ptr<FILE, decltype(&pclose)> pipe{ popen(cmd.c_str(), "rb"), pclose };
if (!pipe)
throw std::runtime_error("popen() failed!");
while (size_t readBytes = fread(buffer.data(), 1, buffer.size(), pipe.get()))
copy(buffer.begin(), buffer.begin() + readBytes, back_inserter(result));
return result;
}
void execInput(const string& cmd, const vector<uint8_t>& stdinData) {
assert(stdinData.size() % HID_RPT_SIZE == 0);
size_t writtenBytes = 0;
unique_ptr<FILE, decltype(&pclose)> pipe{ popen(cmd.c_str(), "wb"), pclose };
if (!pipe)
throw std::runtime_error("popen() failed!");
while (writtenBytes < stdinData.size())
writtenBytes += fwrite(stdinData.data(), 1, HID_RPT_SIZE, pipe.get());
}