ibrdtn/ibrdtn/security/SecurityBlock.cpp

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/*
 * SecurityBlock.cpp
 *
 *  Created on: 08.03.2010
 *      Author: morgenro
 */

#include "ibrdtn/security/SecurityBlock.h"
#include "ibrdtn/security/MutualSerializer.h"
#include "ibrdtn/data/Bundle.h"
#include "ibrdtn/data/PayloadBlock.h"
#include "ibrdtn/data/ExtensionBlock.h"

#include <ibrcommon/Logger.h>
#include <cstdlib>
#include <openssl/rand.h>
#include <openssl/err.h>
#include <openssl/rsa.h>

#ifdef __DEVELOPMENT_ASSERTIONS__
#include <cassert>
#endif

namespace dtn
{
        namespace security
        {
                const std::string SecurityBlock::TLVList::toString() const
                {
                        std::stringstream ss;

                        for (std::set<TLV>::const_iterator iter = begin(); iter != end(); iter++)
                        {
                                ss << (*iter);
                        }

                        return ss.str();
                }

                size_t SecurityBlock::TLVList::getLength() const
                {
                        size_t len = getPayloadLength();
                        return len;
                }

                size_t SecurityBlock::TLVList::getPayloadLength() const
                {
                        size_t len = 0;

                        for (std::set<SecurityBlock::TLV>::const_iterator iter = begin(); iter != end(); iter++)
                        {
                                len += (*iter).getLength();
                        }

                        return len;
                }

                const std::string SecurityBlock::TLVList::get(SecurityBlock::TLV_TYPES type) const
                {
                        for (std::set<SecurityBlock::TLV>::const_iterator iter = begin(); iter != end(); iter++)
                        {
                                if ((*iter).getType() == type)
                                {
                                        return (*iter).getValue();
                                }
                        }

                        throw ibrcommon::Exception("element not found");
                }

                void SecurityBlock::TLVList::get(TLV_TYPES type, unsigned char *value, size_t length) const
                {
                        const std::string data = get(type);

                        if (length < data.size())
                        {
                                ::memcpy(value, data.c_str(), length);
                        }
                        else
                        {
                                ::memcpy(value, data.c_str(), data.size());
                        }
                }

                void SecurityBlock::TLVList::set(SecurityBlock::TLV_TYPES type, std::string value)
                {
                        SecurityBlock::TLV tlv(type, value);

                        erase(tlv);
                        insert(tlv);
                }

                void SecurityBlock::TLVList::set(TLV_TYPES type, const unsigned char *value, size_t length)
                {
                        const std::string data(reinterpret_cast<const char *>(value), length);
                        set(type, data);
                }

                void SecurityBlock::TLVList::remove(SecurityBlock::TLV_TYPES type)
                {
                        erase(SecurityBlock::TLV(type, ""));
                }

                const std::string SecurityBlock::TLV::getValue() const
                {
                        return _value;
                }

                SecurityBlock::TLV_TYPES SecurityBlock::TLV::getType() const
                {
                        return _type;
                }

                size_t SecurityBlock::TLV::getLength() const
                {
                        return _value.getLength() + sizeof(char);
                }

                std::ostream& operator<<(std::ostream &stream, const SecurityBlock::TLVList &tlvlist)
                {
                        dtn::data::SDNV length(tlvlist.getPayloadLength());
                        stream << length;

                        for (std::set<SecurityBlock::TLV>::const_iterator iter = tlvlist.begin(); iter != tlvlist.end(); iter++)
                        {
                                stream << (*iter);
                        }
                        return stream;
                }

                std::istream& operator>>(std::istream &stream, SecurityBlock::TLVList &tlvlist)
                {
                        dtn::data::SDNV length;
                        stream >> length;
                        size_t read_length = 0;

                        while (read_length < length.getValue())
                        {
                                SecurityBlock::TLV tlv;
                                stream >> tlv;
                                tlvlist.insert(tlv);
                                read_length += tlv.getLength();
                        }

                        return stream;
                }

                bool SecurityBlock::TLV::operator<(const SecurityBlock::TLV &tlv) const
                {
                        return (_type < tlv._type);
                }

                bool SecurityBlock::TLV::operator==(const SecurityBlock::TLV &tlv) const
                {
                        return (_type == tlv._type);
                }

                std::ostream& operator<<(std::ostream &stream, const SecurityBlock::TLV &tlv)
                {
                        stream.put((char)tlv._type);
                        stream << tlv._value;
                        return stream;
                }

                std::istream& operator>>(std::istream &stream, SecurityBlock::TLV &tlv)
                {
                        char tlv_type;
                        stream.get(tlv_type); tlv._type = SecurityBlock::TLV_TYPES(tlv_type);
                        stream >> tlv._value;
                        return stream;
                }

                SecurityBlock::SecurityBlock(const dtn::security::SecurityBlock::BLOCK_TYPES type, const dtn::security::SecurityBlock::CIPHERSUITE_IDS id)
                : Block(type), _ciphersuite_id(id), _ciphersuite_flags(0), _correlator(0)
                {

                }

                SecurityBlock::SecurityBlock(const dtn::security::SecurityBlock::BLOCK_TYPES type)
                : Block(type), _ciphersuite_flags(0), _correlator(0)
                {

                }

                SecurityBlock::~SecurityBlock()
                {
                }

                void SecurityBlock::store_security_references()
                {
                        // clear the EID list
                        _eids.clear();

                        // first the security source
                        if (_security_source == dtn::data::EID())
                        {
                                _ciphersuite_flags &= ~(SecurityBlock::CONTAINS_SECURITY_SOURCE);
                        }
                        else
                        {
                                _ciphersuite_flags |= SecurityBlock::CONTAINS_SECURITY_SOURCE;
                                _eids.push_back(_security_source);
                        }

                        // then the destination
                        if (_security_destination == dtn::data::EID())
                        {
                                _ciphersuite_flags &= ~(SecurityBlock::CONTAINS_SECURITY_DESTINATION);
                        }
                        else
                        {
                                _ciphersuite_flags |= SecurityBlock::CONTAINS_SECURITY_DESTINATION;
                                _eids.push_back(_security_destination);
                        }

                        if (_eids.size() > 0)
                        {
                                set(Block::BLOCK_CONTAINS_EIDS, true);
                        }
                        else
                        {
                                set(Block::BLOCK_CONTAINS_EIDS, false);
                        }
                }

                const dtn::data::EID SecurityBlock::getSecuritySource() const
                {
                        return _security_source;
                }

                const dtn::data::EID SecurityBlock::getSecurityDestination() const
                {
                        return _security_destination;
                }

                void SecurityBlock::setSecuritySource(const dtn::data::EID &source)
                {
                        _security_source = source;
                        store_security_references();
                }

                void SecurityBlock::setSecurityDestination(const dtn::data::EID &destination)
                {
                        _security_destination = destination;
                        store_security_references();
                }

                void SecurityBlock::setCiphersuiteId(const CIPHERSUITE_IDS id)
                {
                        _ciphersuite_id = static_cast<u_int64_t>(id);
                }

                void SecurityBlock::setCorrelator(const u_int64_t corr)
                {
                        _correlator = corr;
                        _ciphersuite_flags |= SecurityBlock::CONTAINS_CORRELATOR;
                }

                bool SecurityBlock::isCorrelatorPresent(const dtn::data::Bundle& bundle, const u_int64_t correlator)
                {
                        std::list<const dtn::data::Block *> blocks = bundle.getBlocks();
                        bool return_val = false;
                        for (std::list<const dtn::data::Block *>::const_iterator it = blocks.begin(); it != blocks.end() && !return_val; it++)
                        {
                                char type = (*it)->getType();
                                if (type == BUNDLE_AUTHENTICATION_BLOCK
                                        || type == PAYLOAD_INTEGRITY_BLOCK
                                        || type == PAYLOAD_CONFIDENTIAL_BLOCK
                                        || type == EXTENSION_SECURITY_BLOCK)
                                return_val = static_cast<const SecurityBlock*>(*it)->_correlator == correlator;
                        }
                        return return_val;
                }

                u_int64_t SecurityBlock::createCorrelatorValue(const dtn::data::Bundle& bundle)
                {
                        u_int64_t corr = random();
                        while (isCorrelatorPresent(bundle, corr))
                                corr = random();
                        return corr;
                }

                size_t SecurityBlock::getLength() const
                {
                        size_t length = dtn::data::SDNV::getLength(_ciphersuite_id)
                                + dtn::data::SDNV::getLength(_ciphersuite_flags);

                        if (_ciphersuite_flags & CONTAINS_CORRELATOR)
                        {
                                length += dtn::data::SDNV::getLength(_correlator);
                        }

                        if (_ciphersuite_flags & CONTAINS_CIPHERSUITE_PARAMS)
                        {
                                const dtn::data::SDNV size(_ciphersuite_params.getLength());
                                length += size.getLength() + size.getValue();
                        }

                        if (_ciphersuite_flags & CONTAINS_SECURITY_RESULT)
                        {
                                const dtn::data::SDNV size(getSecurityResultSize());
                                length += size.getLength() + size.getValue();
                        }

                        return length;
                }

                size_t SecurityBlock::getLength_mutable() const
                {
                        // ciphersuite_id
                        size_t length = MutualSerializer::sdnv_size;

                        // ciphersuite_flags
                        length += MutualSerializer::sdnv_size;

                        // correlator
                        if (_ciphersuite_flags & CONTAINS_CORRELATOR)
                        {
                                length += MutualSerializer::sdnv_size;
                        }

                        // ciphersuite parameters
                        if (_ciphersuite_flags & CONTAINS_CIPHERSUITE_PARAMS)
                        {
                                length += MutualSerializer::sdnv_size;
                                length += _ciphersuite_params.getLength();
                        }
                        // security result
                        if (_ciphersuite_flags & CONTAINS_SECURITY_RESULT)
                        {
                                length += MutualSerializer::sdnv_size + getSecurityResultSize();
                        }

                        return length;
                }

                std::ostream& SecurityBlock::serialize(std::ostream &stream, size_t &length) const
                {
                        stream << dtn::data::SDNV(_ciphersuite_id) << dtn::data::SDNV(_ciphersuite_flags);

                        if (_ciphersuite_flags & CONTAINS_CORRELATOR)
                        {
                                stream << dtn::data::SDNV(_correlator);
                        }

                        if (_ciphersuite_flags & CONTAINS_CIPHERSUITE_PARAMS)
                        {
                                stream << _ciphersuite_params;
                        }

                        if (_ciphersuite_flags & CONTAINS_SECURITY_RESULT)
                        {
                                stream << _security_result;
                        }

                        return stream;
                }

                std::ostream& SecurityBlock::serialize_strict(std::ostream &stream, size_t &length) const
                {
                        stream << dtn::data::SDNV(_ciphersuite_id) << dtn::data::SDNV(_ciphersuite_flags);

                        if (_ciphersuite_flags & CONTAINS_CORRELATOR)
                        {
                                stream << dtn::data::SDNV(_correlator);
                        }

                        if (_ciphersuite_flags & CONTAINS_CIPHERSUITE_PARAMS)
                        {
                                stream << _ciphersuite_params;
                        }

                        if (_ciphersuite_flags & CONTAINS_SECURITY_RESULT)
                        {
                                stream << dtn::data::SDNV(getSecurityResultSize());
                        }

                        return stream;
                }

                std::istream& SecurityBlock::deserialize(std::istream &stream, const size_t length)
                {
#ifdef __DEVELOPMENT_ASSERTIONS__
                        // recheck blocktype. if blocktype is set wrong, this will be a huge fail
                        assert(_blocktype == BUNDLE_AUTHENTICATION_BLOCK || _blocktype == PAYLOAD_INTEGRITY_BLOCK || _blocktype == PAYLOAD_CONFIDENTIAL_BLOCK || _blocktype == EXTENSION_SECURITY_BLOCK);
#endif

                        dtn::data::SDNV ciphersuite_id, ciphersuite_flags;
                        stream >> ciphersuite_id >> ciphersuite_flags;
                        _ciphersuite_id = ciphersuite_id.getValue();
                        _ciphersuite_flags = ciphersuite_flags.getValue();

#ifdef __DEVELOPMENT_ASSERTIONS__
                        // recheck ciphersuite_id
                        assert(_ciphersuite_id == BAB_HMAC || _ciphersuite_id == PIB_RSA_SHA256 || _ciphersuite_id == PCB_RSA_AES128_PAYLOAD_PIB_PCB || _ciphersuite_id == ESB_RSA_AES128_EXT);
                        // recheck ciphersuite_flags, could be more exhaustive
                        assert(_ciphersuite_flags < 32);
#endif

                        // copy security source and destination
                        if (_ciphersuite_flags & SecurityBlock::CONTAINS_SECURITY_SOURCE)
                        {
                                if (_eids.size() == 0)
                                        throw dtn::SerializationFailedException("ciphersuite flags indicate a security source, but it is not present");

                                _security_source = _eids.front();
                        }

                        if (_ciphersuite_flags & SecurityBlock::CONTAINS_SECURITY_DESTINATION)
                        {
                                if (_ciphersuite_flags & SecurityBlock::CONTAINS_SECURITY_SOURCE)
                                {
                                        if (_eids.size() < 2)
                                                throw dtn::SerializationFailedException("ciphersuite flags indicate a security destination, but it is not present");

                                        _security_destination = (*(_eids.begin())++);
                                }
                                else
                                {
                                        if (_eids.size() == 0)
                                                throw dtn::SerializationFailedException("ciphersuite flags indicate a security destination, but it is not present");

                                        _security_destination = _eids.front();
                                }
                        }

                        if (_ciphersuite_flags & CONTAINS_CORRELATOR)
                        {
                                dtn::data::SDNV correlator;
                                stream >> correlator;
                                _correlator = correlator.getValue();
                        }
                        if (_ciphersuite_flags & CONTAINS_CIPHERSUITE_PARAMS)
                        {
                                stream >> _ciphersuite_params;
#ifdef __DEVELOPMENT_ASSERTIONS__
                                assert(_ciphersuite_params.getLength() > 0);
#endif
                        }

                        if (_ciphersuite_flags & CONTAINS_SECURITY_RESULT)
                        {
                                stream >> _security_result;
#ifdef __DEVELOPMENT_ASSERTIONS__
                                assert(_security_result.getLength() > 0);
#endif
                        }

                        return stream;
                }

                dtn::security::MutualSerializer& SecurityBlock::serialize_mutable(dtn::security::MutualSerializer &serializer) const
                {
                        serializer << dtn::data::SDNV(_ciphersuite_id);
                        serializer << dtn::data::SDNV(_ciphersuite_flags);

                        if (_ciphersuite_flags & CONTAINS_CORRELATOR)
                                serializer << dtn::data::SDNV(_ciphersuite_flags);

                        if (_ciphersuite_flags & CONTAINS_CIPHERSUITE_PARAMS)
                        {
                                serializer << _ciphersuite_params;
                        }

                        if (_ciphersuite_flags & CONTAINS_SECURITY_RESULT)
                        {
                                serializer << _security_result;
                        }

                        return serializer;
                }

                dtn::security::MutualSerializer& SecurityBlock::serialize_mutable_without_security_result(dtn::security::MutualSerializer &serializer) const
                {
                        serializer << dtn::data::SDNV(_ciphersuite_id);
                        serializer << dtn::data::SDNV(_ciphersuite_flags);

                        if (_ciphersuite_flags & CONTAINS_CORRELATOR)
                                serializer << dtn::data::SDNV(_ciphersuite_flags);

                        if (_ciphersuite_flags & CONTAINS_CIPHERSUITE_PARAMS)
                        {
                                serializer << _ciphersuite_params;
                        }

                        if (_ciphersuite_flags & CONTAINS_SECURITY_RESULT)
                        {
                                serializer << dtn::data::SDNV(getSecurityResultSize());
                        }

                        return serializer;
                }

                size_t SecurityBlock::getSecurityResultSize() const
                {
#ifdef __DEVELOPMENT_ASSERTIONS__
                        assert(_security_result.getLength() != 0);
#endif
                        return _security_result.getLength();
                }

                void SecurityBlock::createSaltAndKey(u_int32_t& salt, unsigned char* key, size_t key_size)
                {

                        if (!RAND_bytes(reinterpret_cast<unsigned char *>(&salt), sizeof(u_int32_t)))
                        {
                                IBRCOMMON_LOGGER_ex(critical) << "failed to generate salt. maybe /dev/urandom is missing for seeding the PRNG" << IBRCOMMON_LOGGER_ENDL;
                                ERR_print_errors_fp(stderr);
                        }
                        if (!RAND_bytes(key, key_size))
                        {
                                IBRCOMMON_LOGGER_ex(critical) << "failed to generate key. maybe /dev/urandom is missing for seeding the PRNG" << IBRCOMMON_LOGGER_ENDL;
                                ERR_print_errors_fp(stderr);
                        }
                }

                void SecurityBlock::addKey(TLVList& security_parameter, unsigned char const * const key, size_t key_size, RSA * rsa)
                {
                        // encrypt the ephemeral key and place it in _ciphersuite_params
#ifdef __DEVELOPMENT_ASSERTIONS__
                        assert(key_size < RSA_size(rsa)-41);
#endif
                        unsigned char encrypted_key[RSA_size(rsa)];
                        int encrypted_key_len = RSA_public_encrypt(key_size, key, encrypted_key, rsa, RSA_PKCS1_OAEP_PADDING);
                        if (encrypted_key_len == -1)
                        {
                                IBRCOMMON_LOGGER_ex(critical) << "failed to encrypt the symmetric AES key" << IBRCOMMON_LOGGER_ENDL;
                                ERR_print_errors_fp(stderr);
                        }
                        security_parameter.set(SecurityBlock::key_information, std::string(reinterpret_cast<char *>(encrypted_key), encrypted_key_len));
                }

                bool SecurityBlock::getKey(const TLVList& security_parameter, unsigned char * key, size_t key_size, RSA * rsa)
                {
                        std::string key_string = security_parameter.get(SecurityBlock::key_information);
                        // get key, convert with reinterpret_cast
                        unsigned char const * encrypted_key = reinterpret_cast<const unsigned char*>(key_string.c_str());
                        unsigned char the_key[RSA_size(rsa)];
                        RSA_blinding_on(rsa, NULL);
                        int plaintext_key_len = RSA_private_decrypt(key_string.size(), encrypted_key, the_key, rsa, RSA_PKCS1_OAEP_PADDING);
                        RSA_blinding_off(rsa);
                        if (plaintext_key_len == -1)
                        {
                                IBRCOMMON_LOGGER_ex(critical) << "failed to decrypt the symmetric AES key" << IBRCOMMON_LOGGER_ENDL;
                                ERR_print_errors_fp(stderr);
                                return false;
                        }
#ifdef __DEVELOPMENT_ASSERTIONS__
                        assert(plaintext_key_len == key_size);
#endif
                        std::copy(the_key, the_key+key_size, key);
                        return true;
                }

                void SecurityBlock::copyEID(const Block& from, Block& to, size_t skip)
                {
                        // take eid list, getEIDList() is broken
                        std::list<dtn::data::EID> their_eids = from.getEIDList();
                        std::list<dtn::data::EID>::iterator it = their_eids.begin();

                        while (it != their_eids.end() && skip > 0)
                        {
                                skip--;
                                it++;
                        }

                        for (; it != their_eids.end(); it++)
                                to.addEID(*it);
                }

                void SecurityBlock::addSalt(TLVList& security_parameters, u_int32_t salt)
                {
                        std::stringstream salt_stream;
                        salt_stream << salt;
                        security_parameters.set(SecurityBlock::salt, salt_stream.str());
                }

                u_int32_t SecurityBlock::getSalt(const TLVList& security_parameters)
                {
                        // get salt, convert with stringstream
                        std::string salt_string = security_parameters.get(SecurityBlock::salt);
                        std::stringstream salt_stream;
                        salt_stream << salt_string;
                        u_int32_t salt;
                        salt_stream >> salt;
                        return salt;
                }

                void SecurityBlock::decryptBlock(dtn::data::Bundle& bundle, const dtn::security::SecurityBlock &block, u_int32_t salt, const unsigned char key[ibrcommon::AES128Stream::key_size_in_bytes])
                {
                        // the array for the extracted tag
                        unsigned char tag[ibrcommon::AES128Stream::tag_len];

                        // the array for the extracted iv
                        unsigned char iv[ibrcommon::AES128Stream::iv_len];

                        // get iv, convert with reinterpret_cast
                        block._ciphersuite_params.get(SecurityBlock::initialization_vector, iv, ibrcommon::AES128Stream::iv_len);

                        // get data and tag, the last tag_len bytes are the tag. cut them of and reinterpret_cast
                        std::string block_data = block._security_result.get(SecurityBlock::encapsulated_block);

                        // create a pointer to the tag begin
                        const char *tag_p = block_data.c_str() + (block_data.size() - ibrcommon::AES128Stream::tag_len);

                        // copy the tag
                        ::memcpy(tag, tag_p, ibrcommon::AES128Stream::tag_len);

                        // strip off the tag from block data
                        block_data.resize(block_data.size() - ibrcommon::AES128Stream::tag_len);

                        // decrypt block
                        std::stringstream plaintext;
                        ibrcommon::AES128Stream decrypt(ibrcommon::CipherStream::CIPHER_DECRYPT, plaintext, key, salt, iv);
                        decrypt << block_data << std::flush;

                        // verify the decrypt tag
                        if (!decrypt.verify(tag))
                        {
                                throw ibrcommon::Exception("decryption of block failed - tag is bad");
                        }

                        // deserialize block
                        dtn::data::DefaultDeserializer ddser(plaintext);

                        // peek the block type
                        char block_type = plaintext.peek();

                        if (block_type == dtn::data::PayloadBlock::BLOCK_TYPE)
                        {
                                dtn::data::PayloadBlock &plaintext_block = bundle.insert<dtn::data::PayloadBlock>(block);
                                ddser >> plaintext_block;
                        }
                        else
                        {
                                try {
                                        dtn::data::ExtensionBlock::Factory &f = dtn::data::ExtensionBlock::Factory::get(block_type);
                                        dtn::data::Block &plaintext_block = bundle.insert(f, block);
                                        ddser >> plaintext_block;

                                        plaintext_block.getEIDList().clear();

                                        // copy eids
                                        // remove security_source and destination
                                        size_t skip = 0;
                                        if (block._ciphersuite_flags & SecurityBlock::CONTAINS_SECURITY_DESTINATION)
                                                skip++;
                                        if (block._ciphersuite_flags & SecurityBlock::CONTAINS_SECURITY_SOURCE)
                                                skip++;
                                        copyEID(plaintext_block, plaintext_block, skip);

                                } catch (const ibrcommon::Exception &ex) {
                                        dtn::data::ExtensionBlock &plaintext_block = bundle.insert<dtn::data::ExtensionBlock>(block);
                                        ddser >> plaintext_block;

                                        plaintext_block.getEIDList().clear();

                                        // copy eids
                                        // remove security_source and destination
                                        size_t skip = 0;
                                        if (block._ciphersuite_flags & SecurityBlock::CONTAINS_SECURITY_DESTINATION)
                                                skip++;
                                        if (block._ciphersuite_flags & SecurityBlock::CONTAINS_SECURITY_SOURCE)
                                                skip++;
                                        copyEID(plaintext_block, plaintext_block, skip);
                                }
                        }

                        bundle.remove(block);
                }

                void SecurityBlock::addFragmentRange(TLVList& ciphersuite_params, size_t fragmentoffset, size_t payload_length)
                {
                        dtn::data::SDNV offset(fragmentoffset);
                        dtn::data::SDNV range_sdnv(payload_length);

                        std::stringstream ss;
                        ss << offset << range_sdnv;

                        ciphersuite_params.set(SecurityBlock::fragment_range, ss.str());
                }

                bool SecurityBlock::isSecuritySource(const dtn::data::Bundle& bundle, const dtn::data::EID& eid) const
                {
                        IBRCOMMON_LOGGER_DEBUG(30) << "check security source: " << getSecuritySource(bundle).getString() << " == " << eid.getNode().getString() << IBRCOMMON_LOGGER_ENDL;
                        return getSecuritySource(bundle) == eid.getNode();
                }

                bool SecurityBlock::isSecurityDestination(const dtn::data::Bundle& bundle, const dtn::data::EID& eid) const
                {
                        IBRCOMMON_LOGGER_DEBUG(30) << "check security destination: " << getSecurityDestination(bundle).getString() << " == " << eid.getNode().getString() << IBRCOMMON_LOGGER_ENDL;
                        return getSecurityDestination(bundle) == eid.getNode();
                }
                
                const dtn::data::EID SecurityBlock::getSecuritySource(const dtn::data::Bundle& bundle) const
                {
                        dtn::data::EID source = getSecuritySource();
                        if (source == dtn::data::EID())
                                source = bundle._source.getNode();
                        return source;
                }

                const dtn::data::EID SecurityBlock::getSecurityDestination(const dtn::data::Bundle& bundle) const
                {
                        dtn::data::EID destination = getSecurityDestination();
                        if (destination == dtn::data::EID())
                                destination = bundle._destination.getNode();
                        return destination;
                }
        }
}