/*
* Copyright (c) 2020, Ali Mohammad Pur <mpfard@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Debug.h>
#include <LibCore/DateTime.h>
#include <LibCore/Timer.h>
#include <LibCrypto/PK/Code/EMSA_PSS.h>
#include <LibTLS/TLSv12.h>
namespace TLS {
Optional<ByteBuffer> TLSv12::read()
{
if (m_context.application_buffer.size()) {
auto buf = move(m_context.application_buffer);
return { move(buf) };
}
return {};
}
ByteBuffer TLSv12::read(size_t max_size)
{
if (m_context.application_buffer.size()) {
auto length = min(m_context.application_buffer.size(), max_size);
auto buf = m_context.application_buffer.slice(0, length);
m_context.application_buffer = m_context.application_buffer.slice(length, m_context.application_buffer.size() - length);
return buf;
}
return {};
}
String TLSv12::read_line(size_t max_size)
{
if (!can_read_line())
return {};
auto* start = m_context.application_buffer.data();
auto* newline = (u8*)memchr(m_context.application_buffer.data(), '\n', m_context.application_buffer.size());
VERIFY(newline);
size_t offset = newline - start;
if (offset > max_size)
return {};
auto buffer_result = ByteBuffer::copy(start, offset);
if (!buffer_result.has_value()) {
dbgln("TLS: Failed to read line, not enough memory");
dbgln("max_size < offset: {} < {} (size = {})", max_size, offset, m_context.application_buffer.size());
dbgln("-> {:32hex-dump}", ReadonlyBytes { start, offset });
return {};
}
String line { bit_cast<char const*>(start), offset, Chomp };
m_context.application_buffer = m_context.application_buffer.slice(offset + 1, m_context.application_buffer.size() - offset - 1);
return line;
}
bool TLSv12::write(ReadonlyBytes buffer)
{
if (m_context.connection_status != ConnectionStatus::Established) {
dbgln_if(TLS_DEBUG, "write request while not connected");
return false;
}
PacketBuilder builder { MessageType::ApplicationData, m_context.options.version, buffer.size() };
builder.append(buffer);
auto packet = builder.build();
update_packet(packet);
write_packet(packet);
return true;
}
bool TLSv12::connect(const String& hostname, int port)
{
set_sni(hostname);
return Core::Socket::connect(hostname, port);
}
bool TLSv12::common_connect(const struct sockaddr* saddr, socklen_t length)
{
if (m_context.critical_error)
return false;
if (Core::Socket::is_connected()) {
if (is_established()) {
VERIFY_NOT_REACHED();
} else {
Core::Socket::close(); // reuse?
}
}
Core::Socket::on_connected = [this] {
Core::Socket::on_ready_to_read = [this] {
read_from_socket();
};
auto packet = build_hello();
write_packet(packet);
deferred_invoke([&] {
m_handshake_timeout_timer = Core::Timer::create_single_shot(
m_max_wait_time_for_handshake_in_seconds * 1000, [&] {
auto timeout_diff = Core::DateTime::now().timestamp() - m_context.handshake_initiation_timestamp;
// If the timeout duration was actually within the max wait time (with a margin of error),
// we're not operating slow, so the server timed out.
// otherwise, it's our fault that the negotiation is taking too long, so extend the timer :P
if (timeout_diff < m_max_wait_time_for_handshake_in_seconds + 1) {
// The server did not respond fast enough,
// time the connection out.
alert(AlertLevel::Critical, AlertDescription::UserCanceled);
m_context.connection_finished = true;
m_context.tls_buffer.clear();
m_context.error_code = Error::TimedOut;
m_context.critical_error = (u8)Error::TimedOut;
check_connection_state(false); // Notify the client.
} else {
// Extend the timer, we are too slow.
m_handshake_timeout_timer->restart(m_max_wait_time_for_handshake_in_seconds * 1000);
}
},
this);
write_into_socket();
m_handshake_timeout_timer->start();
m_context.handshake_initiation_timestamp = Core::DateTime::now().timestamp();
});
m_has_scheduled_write_flush = true;
if (on_tls_connected)
on_tls_connected();
};
bool success = Core::Socket::common_connect(saddr, length);
if (!success)
return false;
return true;
}
void TLSv12::read_from_socket()
{
auto did_schedule_read = false;
auto notify_client_for_app_data = [&] {
if (m_context.application_buffer.size() > 0) {
if (!did_schedule_read) {
deferred_invoke([&] { read_from_socket(); });
did_schedule_read = true;
}
if (on_tls_ready_to_read)
on_tls_ready_to_read(*this);
}
};
// If there's anything before we consume stuff, let the client know
// since we won't be consuming things if the connection is terminated.
notify_client_for_app_data();
if (!check_connection_state(true))
return;
consume(Core::Socket::read(4096));
// If anything new shows up, tell the client about the event.
notify_client_for_app_data();
}
void TLSv12::write_into_socket()
{
dbgln_if(TLS_DEBUG, "Flushing cached records: {} established? {}", m_context.tls_buffer.size(), is_established());
m_has_scheduled_write_flush = false;
if (!check_connection_state(false))
return;
flush();
if (!is_established())
return;
if (!m_context.application_buffer.size()) // hey client, you still have stuff to read...
if (on_tls_ready_to_write)
on_tls_ready_to_write(*this);
}
bool TLSv12::check_connection_state(bool read)
{
if (!Core::Socket::is_open() || !Core::Socket::is_connected() || Core::Socket::eof()) {
// an abrupt closure (the server is a jerk)
dbgln_if(TLS_DEBUG, "Socket not open, assuming abrupt closure");
m_context.connection_finished = true;
}
if (m_context.critical_error) {
dbgln_if(TLS_DEBUG, "CRITICAL ERROR {} :(", m_context.critical_error);
if (on_tls_error)
on_tls_error((AlertDescription)m_context.critical_error);
return false;
}
if (((read && m_context.application_buffer.size() == 0) || !read) && m_context.connection_finished) {
if (m_context.application_buffer.size() == 0 && m_context.connection_status != ConnectionStatus::Disconnected) {
if (on_tls_finished)
on_tls_finished();
}
if (m_context.tls_buffer.size()) {
dbgln_if(TLS_DEBUG, "connection closed without finishing data transfer, {} bytes still in buffer and {} bytes in application buffer",
m_context.tls_buffer.size(),
m_context.application_buffer.size());
} else {
m_context.connection_finished = false;
dbgln_if(TLS_DEBUG, "FINISHED");
}
if (!m_context.application_buffer.size()) {
m_context.connection_status = ConnectionStatus::Disconnected;
return false;
}
}
return true;
}
bool TLSv12::flush()
{
auto out_buffer = write_buffer().data();
size_t out_buffer_index { 0 };
size_t out_buffer_length = write_buffer().size();
if (out_buffer_length == 0)
return true;
if constexpr (TLS_DEBUG) {
dbgln("SENDING...");
print_buffer(out_buffer, out_buffer_length);
}
if (Core::Socket::write(&out_buffer[out_buffer_index], out_buffer_length)) {
write_buffer().clear();
return true;
}
if (m_context.send_retries++ == 10) {
// drop the records, we can't send
dbgln_if(TLS_DEBUG, "Dropping {} bytes worth of TLS records as max retries has been reached", write_buffer().size());
write_buffer().clear();
m_context.send_retries = 0;
}
return false;
}
}