crypto.h

/*
 * Copyright (c) 2017, Matias Fontanini
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following disclaimer
 *   in the documentation and/or other materials provided with the
 *   distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include <tins/config.h>

#if !defined(TINS_CRYPTO_H) && defined(TINS_HAVE_DOT11)
#define TINS_CRYPTO_H

#include <map>
#include <string>
#include <vector>
#ifdef TINS_HAVE_WPA2_CALLBACKS
    #include <functional>
#endif // TINS_HAVE_WPA2_CALLBACKS
#include <tins/macros.h>
#include <tins/handshake_capturer.h>

namespace Tins {

class PDU;
class Dot11;
class Dot11Data;
class SNAP;
class RawPDU;

namespace Crypto {

#ifdef TINS_HAVE_WPA2_DECRYPTION
namespace WPA2 {

class TINS_API SessionKeys {
public:
    static const size_t PMK_SIZE;

    static const size_t PTK_SIZE;

    typedef std::vector<uint8_t> ptk_type;

    typedef std::vector<uint8_t> pmk_type;
    
    SessionKeys();

    SessionKeys(const ptk_type& ptk, bool is_ccmp);

    SessionKeys(const RSNHandshake& hs, const pmk_type& pmk);

    SNAP* decrypt_unicast(const Dot11Data& dot11, RawPDU& raw) const;

    const ptk_type& get_ptk() const;

    bool uses_ccmp() const;
private:
    SNAP* ccmp_decrypt_unicast(const Dot11Data& dot11, RawPDU& raw) const;
    SNAP* tkip_decrypt_unicast(const Dot11Data& dot11, RawPDU& raw) const;

    ptk_type ptk_;
    bool is_ccmp_;
};

class TINS_API SupplicantData {
public:
    typedef SessionKeys::pmk_type pmk_type;
    
    SupplicantData(const std::string& psk, const std::string& ssid);
    
    const pmk_type& pmk() const;

    const std::string& ssid() const;
private:
    pmk_type pmk_;
    std::string ssid_;
};

} // WPA2
#endif // TINS_HAVE_WPA2_DECRYPTION

class TINS_API WEPDecrypter {
public:
    typedef HWAddress<6> address_type;

    WEPDecrypter();
    
    void add_password(const address_type& addr, const std::string& password);
    
    void remove_password(const address_type& addr);
    
    bool decrypt(PDU& pdu);
private:
    typedef std::map<address_type, std::string> passwords_type;

    PDU* decrypt(RawPDU& raw, const std::string& password);

    passwords_type passwords_;
    std::vector<uint8_t> key_buffer_;
};

#ifdef TINS_HAVE_WPA2_DECRYPTION

class TINS_API WPA2Decrypter {
public:
    /*
     * \brief The type used to store Dot11 addresses.
     */
    typedef HWAddress<6> address_type;
    
    typedef std::pair<address_type, address_type> addr_pair;

    typedef std::map<addr_pair, WPA2::SessionKeys> keys_map;

    #ifdef TINS_HAVE_WPA2_CALLBACKS

    typedef std::function<void(const std::string&,
                               const address_type&)> ap_found_callback_type;

    typedef std::function<void(const std::string&,
                               const address_type&,
                               const address_type&)> handshake_captured_callback_type;
    
    #endif // TINS_HAVE_WPA2_CALLBACKS

    void add_ap_data(const std::string& psk, const std::string& ssid);

    void add_ap_data(const std::string& psk,
                     const std::string& ssid,
                     const address_type& addr);
    
    void add_decryption_keys(const addr_pair& addresses, 
                             const WPA2::SessionKeys& session_keys);

    bool decrypt(PDU& pdu);

    #ifdef TINS_HAVE_WPA2_CALLBACKS

    void handshake_captured_callback(const handshake_captured_callback_type& callback);

    void ap_found_callback(const ap_found_callback_type& callback);

    #endif // TINS_HAVE_WPA2_CALLBACKS

    const keys_map& get_keys() const;
private:
    typedef std::map<std::string, WPA2::SupplicantData> pmks_map;
    typedef std::map<address_type, WPA2::SupplicantData> bssids_map;
    
    void try_add_keys(const Dot11Data& dot11, const RSNHandshake& hs);
    addr_pair make_addr_pair(const address_type& addr1, const address_type& addr2) {
        return (addr1 < addr2) ? 
            std::make_pair(addr1, addr2) :
            std::make_pair(addr2, addr1);
    }
    addr_pair extract_addr_pair(const Dot11Data& dot11);
    addr_pair extract_addr_pair_dst(const Dot11Data& dot11);
    bssids_map::const_iterator find_ap(const Dot11Data& dot11);
    void add_access_point(const std::string& ssid, const address_type& addr);

    RSNHandshakeCapturer capturer_;
    pmks_map pmks_;
    bssids_map aps_;
    keys_map keys_;
    #ifdef TINS_HAVE_WPA2_CALLBACKS
        handshake_captured_callback_type handshake_captured_callback_;
        ap_found_callback_type ap_found_callback_;
    #endif // TINS_HAVE_WPA2_CALLBACKS
};
#endif // TINS_HAVE_WPA2_DECRYPTION

template<typename Functor, typename Decrypter>
class DecrypterProxy {
public:
    typedef Functor functor_type;

    typedef Decrypter decrypter_type;
    
    DecrypterProxy(const functor_type& func, 
      const decrypter_type& decr = decrypter_type());
    
    decrypter_type& decrypter();
    
    const decrypter_type& decrypter() const;
    
    bool operator() (PDU& pdu);
private:
    Functor functor_;
    decrypter_type decrypter_;
};

template<typename Functor>
DecrypterProxy<Functor, WEPDecrypter> make_wep_decrypter_proxy(const Functor& functor);

#ifdef TINS_HAVE_WPA2_DECRYPTION

template<typename Functor>
DecrypterProxy<Functor, WPA2Decrypter> make_wpa2_decrypter_proxy(const Functor& functor) {
    return DecrypterProxy<Functor, WPA2Decrypter>(functor);
}
#endif // TINS_HAVE_WPA2_DECRYPTION

// Implementation section

// DecrypterProxy

template<typename Functor, typename Decrypter>
DecrypterProxy<Functor, Decrypter>::DecrypterProxy(const functor_type& func,
                                                   const decrypter_type& decr) 
: functor_(func), decrypter_(decr) {
    
}

template<typename Functor, typename Decrypter>
typename DecrypterProxy<Functor, Decrypter>::decrypter_type &
  DecrypterProxy<Functor, Decrypter>::decrypter() {
    return decrypter_;
}

template<typename Functor, typename Decrypter>
const typename DecrypterProxy<Functor, Decrypter>::decrypter_type &
  DecrypterProxy<Functor, Decrypter>::decrypter() const {
    return decrypter_;
}

template<typename Functor, typename Decrypter>
bool DecrypterProxy<Functor, Decrypter>::operator() (PDU& pdu) {
    return decrypter_.decrypt(pdu) ? functor_(pdu) : true;
}

template<typename Functor>
DecrypterProxy<Functor, WEPDecrypter> make_wep_decrypter_proxy(const Functor& functor) {
    return DecrypterProxy<Functor, WEPDecrypter>(functor);
}

} // Crypto
} // Tins

#endif // TINS_CRYPTO_H