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/*
* TLS Session Management
* (C) 2011,2012 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include <botan/tls_session_manager.h>
#include <botan/hex.h>
#include <botan/rng.h>
#include <chrono>
namespace Botan {
namespace TLS {
Session_Manager_In_Memory::Session_Manager_In_Memory(
RandomNumberGenerator& rng,
size_t max_sessions,
std::chrono::seconds session_lifetime) :
m_max_sessions(max_sessions),
m_session_lifetime(session_lifetime),
m_rng(rng),
m_session_key(m_rng.random_vec(32))
{}
bool Session_Manager_In_Memory::load_from_session_str(
const std::string& session_str, Session& session)
{
// assert(lock is held)
auto i = m_sessions.find(session_str);
if(i == m_sessions.end())
return false;
try
{
session = Session::decrypt(i->second, m_session_key);
}
catch(...)
{
return false;
}
// if session has expired, remove it
const auto now = std::chrono::system_clock::now();
if(session.start_time() + session_lifetime() < now)
{
m_sessions.erase(i);
return false;
}
return true;
}
bool Session_Manager_In_Memory::load_from_session_id(
const std::vector<uint8_t>& session_id, Session& session)
{
lock_guard_type<mutex_type> lock(m_mutex);
return load_from_session_str(hex_encode(session_id), session);
}
bool Session_Manager_In_Memory::load_from_server_info(
const Server_Information& info, Session& session)
{
lock_guard_type<mutex_type> lock(m_mutex);
auto i = m_info_sessions.find(info);
if(i == m_info_sessions.end())
return false;
if(load_from_session_str(i->second, session))
return true;
/*
* It existed at one point but was removed from the sessions map,
* remove m_info_sessions entry as well
*/
m_info_sessions.erase(i);
return false;
}
void Session_Manager_In_Memory::remove_entry(
const std::vector<uint8_t>& session_id)
{
lock_guard_type<mutex_type> lock(m_mutex);
auto i = m_sessions.find(hex_encode(session_id));
if(i != m_sessions.end())
m_sessions.erase(i);
}
size_t Session_Manager_In_Memory::remove_all()
{
const size_t removed = m_sessions.size();
m_info_sessions.clear();
m_sessions.clear();
m_rng.random_vec(m_session_key, 32);
return removed;
}
void Session_Manager_In_Memory::save(const Session& session)
{
lock_guard_type<mutex_type> lock(m_mutex);
if(m_max_sessions != 0)
{
/*
We generate new session IDs with the first 4 bytes being a
timestamp, so this actually removes the oldest sessions first.
*/
while(m_sessions.size() >= m_max_sessions)
m_sessions.erase(m_sessions.begin());
}
const std::string session_id_str = hex_encode(session.session_id());
m_sessions[session_id_str] = session.encrypt(m_session_key, m_rng);
if(session.side() == CLIENT && !session.server_info().empty())
m_info_sessions[session.server_info()] = session_id_str;
}
}
}