PRSONA/prsona/src/serverMain.cpp

#include <mutex>
#include <condition_variable>
#include <chrono>
#include <iostream>
#include <fstream>
#include <cstring>
#include <cstdlib>
#include <vector>
#include <string>

#include "networkServer.hpp"

#define EXIT_URI "/exit"
#define BEGIN_URI "/begin"
#define READY_URI "/ready"
#define EPOCH_URI "/epoch"
#define BGN_URI "/ws?p"
#define GET_FRESH_GEN_URI "/ws?q"
#define GIVE_FRESH_GEN_URI "/ws?r"
#define GET_BLIND_GEN_URI "/ws?s"
#define GIVE_BLIND_GEN_URI "/ws?t"
#define EPOCH_BUILD_UP_URI "/ws?u"
#define EPOCH_BREAK_DOWN_URI "/ws?v"
#define GIVE_BLIND_GEN_URI "/ws?t"
#define GET_DECRYPTION_URI "/ws?y"
#define GIVE_DECRYPTION_URI "/ws?z"
#define BGN_TMP_FILE "~/tmp/bgn"
#define GEN_TMP_FILE "~/tmp/generator"
#define EPOCH_GEN_TMP_FILE "~/tmp/epoch"

using namespace std;

struct synchronization_tool exitSync, bgnSync, generatorSync, readySync, updateSync, epochSync, tallySync;
mutex updateMtx;

size_t epochNum = 0;

// Initialize the classes we use
void initialize_prsona_classes()
{
    Scalar::init();
    PrsonaBase::init();
    PrsonaBase::set_client_malicious();
}

PrsonaServer *create_server_from_bgn_file(size_t numServers)
{
    unique_lock<mutex> lck(bgnSync.mtx);
    ifstream bgnFile(BGN_TMP_FILE);
    BGN privateKey;
    bgnFile >> privateKey;

    return new PrsonaServer(numServers, privateKey);
}

static int bgn_websocket_data_handler(
    struct mg_connection *conn,
    int bits,
    char *data,
    size_t data_len,
    void *user_data)
{
    if ((bits & 0xf) == MG_WEBSOCKET_OPCODE_CONNECTION_CLOSE)
        return false;

    if ((bits & 0xf) != MG_WEBSOCKET_OPCODE_BINARY && (bits & 0xf) != MG_WEBSOCKET_OPCODE_CONTINUATION)
    {
        std::cerr << "Unknown opcode: failing." << std::endl;
        return false;
    }

    unique_lock<mutex> lck(bgnSync.mtx);
    FILE *currFile = fopen(BGN_TMP_FILE, "ab");
    fwrite(data, sizeof(char), data_len, currFile);
    fclose(currFile);

    return true;
}

static void bgn_websocket_close_handler(
    const struct mg_connection *conn,
    void *user_data)
{
    unique_lock<mutex> lck(bgnSync.mtx);
    bgnSync.val = 1;
    bgnSync.cv.notify_all();
}

Twistpoint update_generator_from_gen_file(Proof& pi)
{
    unique_lock<mutex> lck(generatorSync.mtx);
    ifstream genFile(GEN_TMP_FILE);
    Twistpoint retval;

    genFile >> pi;
    genFile >> retval;

    return retval;
}

Twistpoint update_data_from_epoch_gen_file(vector<Proof>& pi)
{
    unique_lock<mutex> lck(epochSync.mtx);
    ifstream epochFile(EPOCH_GEN_TMP_FILE);
    
    Twistpoint retval;
    size_t piSize;
    pi.clear();

    epochFile >> piSize;
    for (size_t i = 0; i < piSize; i++)
    {
        Proof currProof;
        epochFile >> currProof;
        pi.push_back(currProof);
    }
    epochFile >> retval;

    return retval;
}

static int generator_websocket_data_handler(
    struct mg_connection *conn,
    int bits,
    char *data,
    size_t data_len,
    void *user_data)
{
    struct synchronization_tool *synch = (struct synchronization_tool *) user_data;

    if ((bits & 0xf) == MG_WEBSOCKET_OPCODE_CONNECTION_CLOSE || (bits & 0xf) == MG_WEBSOCKET_OPCODE_DATACOMPLETE)
        return false;

    if ((bits & 0xf) != MG_WEBSOCKET_OPCODE_BINARY && (bits & 0xf) != MG_WEBSOCKET_OPCODE_CONTINUATION)
    {
        std::cerr << "Unknown opcode: failing." << std::endl;
        return false;
    }

    unique_lock<mutex> lck(generatorSync.mtx);
    FILE *currFile = fopen(GEN_TMP_FILE, "ab");
    fwrite(data, sizeof(char), data_len, currFile);
    fclose(currFile);

    return true;
}

static void generator_websocket_close_handler(
    const struct mg_connection *conn,
    void *user_data)
{
    unique_lock<mutex> lck(generatorSync.mtx);
    generatorSync.val = 1;
    generatorSync.cv.notify_all();
}

static int epoch_websocket_data_handler(
    struct mg_connection *conn,
    int bits,
    char *data,
    size_t data_len,
    void *user_data)
{
    if ((bits & 0xf) == MG_WEBSOCKET_OPCODE_CONNECTION_CLOSE)
        return false
    if ((bits & 0xf) == MG_WEBSOCKET_OPCODE_DATACOMPLETE)
    {
        unique_lock<mutex> lck(epochSync.mtx);
        epochSync.val++;

        return false;
    }

    if ((bits & 0xf) != MG_WEBSOCKET_OPCODE_BINARY && (bits & 0xf) != MG_WEBSOCKET_OPCODE_CONTINUATION)
    {
        std::cerr << "Unknown opcode: failing." << std::endl;
        return false;
    }

    unique_lock<mutex> lck(epochSync.mtx);
    FILE *currFile = fopen(EPOCH_GEN_TMP_FILE, "ab");
    fwrite(data, sizeof(char), data_len, currFile);
    fclose(currFile);

    return true;
}

static void epoch_websocket_close_handler(
    const struct mg_connection *conn,
    void *user_data)
{
    unique_lock<mutex> lck(epochSync.mtx);
    epochSync.val2 = 0;
    epochSync.cv.notify_all();
}

static int tally_websocket_data_handler(
    struct mg_connection *conn,
    int bits,
    char *data,
    size_t data_len,
    void *user_data)
{
    if ((bits & 0xf) == MG_WEBSOCKET_OPCODE_CONNECTION_CLOSE)
        return false;

    if ((bits & 0xf) == MG_WEBSOCKET_OPCODE_DATACOMPLETE)
    {
        unique_lock<mutex> lck(tallySync.mtx);
        tallySync.val++;

        tallySync.cv.notify_all();

        return false;
    }

    if ((bits & 0xf) != MG_WEBSOCKET_OPCODE_BINARY && (bits & 0xf) != MG_WEBSOCKET_OPCODE_CONTINUATION)
    {
        std::cerr << "Unknown opcode: failing." << std::endl;
        return false;
    }

    return true;
}

Twistpoint get_generator(
    vector<Proof>& pi,
    PrsonaServer *prsonaServer,
    const vector<string>& serverIPs,
    const string& selfIP,
    bool fresh)
{
    Twistpoint retval = PrsonaServer::EL_GAMAL_GENERATOR;
    pi.clear();

    if (fresh)
        retval = prsonaServer->add_curr_seed_to_generator(pi, retval);
    else
        retval = prsonaServer->add_rand_seed_to_generator(pi, retval);

    for (size_t i = 0; i < serverIPs.size(); i++)
    {
        if (serverIPs[i] == selfIP)
            continue;

        char* which;
        if (fresh)
            which = GET_FRESH_GEN_URI;
        else
            which = GET_BLIND_GEN_URI;

        Proof currProof;

        struct mg_connection *conn =
            mg_connect_websocket_client(
                serverIPs[i].c_str(),
                PRSONA_PORT,
                USE_SSL,
                NULL,
                0,
                which,
                "null",
                generator_websocket_data_handler,
                generator_websocket_close_handler,
                NULL);

        if (!conn)
        {
            cerr << "Couldn't get server " << i << "'s update on generator" << endl;
            return 1;
        }

        stringstream buffer;
        string data;
        buffer << retval;
        data = buffer.str();

        mg_websocket_client_write(
            conn,
            MG_WEBSOCKET_OPCODE_BINARY,
            data.c_str(),
            data.length());

        unique_lock<mutex> lck(generatorSync.mtx);
        remove(GEN_TMP_FILE);
        generatorSync.val = 0;
        mg_websocket_client_write(
            conn,
            MG_WEBSOCKET_OPCODE_DATACOMPLETE,
            "",
            0);

        while (!generatorSync.val)
            generatorSync.cv.wait(lck);

        retval = update_generator_from_gen_file(currProof);
        pi.push_back(currProof);
    }

    return retval;
}

void handout_generator(
    const vector<Proof>& pi,
    const Twistpoint generator,
    PrsonaServer *prsonaServer,
    const vector<string> serverIPs,
    string selfIP,
    bool fresh)
{
    if (fresh)
        prsonaServer->initialize_fresh_generator(pi, generator);
    else
        prsonaServer->set_EG_blind_generator(pi, generator);

    stringstream buffer;
    string data;
    
    buffer << pi.size();
    for (size_t i = 0; i < pi.size(); i++)
        buffer << pi[i];

    buffer << generator;
    data = buffer.str();

    for (size_t i = 0; i < serverIPs.size(); i++)
    {
        if (serverIPs[i] == selfIP)
            continue;

        char* which;
        if (fresh)
            which = GIVE_FRESH_GEN_URI;
        else
            which = GIVE_BLIND_GEN_URI;

        struct mg_connection *conn =
            mg_connect_websocket_client(
                serverIPs[i].c_str(),
                PRSONA_PORT,
                USE_SSL,
                NULL,
                0,
                which,
                "null",
                empty_websocket_data_handler,
                empty_websocket_close_handler,
                NULL);

        if (!conn)
        {
            cerr << "Couldn't give " << (fresh ? "fresh" : "blind") << " generator to server " << i << endl;
            return 1;
        }

        mg_websocket_client_write(
            conn,
            MG_WEBSOCKET_OPCODE_BINARY,
            data.c_str(),
            data.length());

        mg_websocket_client_write(
            conn,
            MG_WEBSOCKET_OPCODE_DATACOMPLETE,
            "",
            0);
    }
}

Twistpoint initiate_epoch_updates(
    const string& recipient,
    const string& data,
    vector<vector<Proof>>& generatorProofHolder,
    bool isBreakdown)
{
    Twistpoint retval;
    struct synchronization_tool epochSync;

    bool flag = false;
    while (!flag)
    {
        char* which;
        if (isBreakdown)
            which = EPOCH_BREAK_DOWN_URI;
        else
            which = EPOCH_BUILD_UP_URI;

        struct mg_connection *conn =
            mg_connect_websocket_client(
                serverIPs[i].c_str(),
                PRSONA_PORT,
                USE_SSL,
                NULL,
                0,
                which,
                "null",
                epoch_websocket_data_handler,
                epoch_websocket_close_handler,
                NULL);

        if (!conn)
        {
            std::cerr << "Trouble initiating epoch update with server at " << recipient << std::endl;
            continue;
        }
        
        unique_lock<mutex> lck(epochSync.mtx);
        remove(EPOCH_GEN_TMP_FILE);
        epochSync.val = 0;
        epochSync.val2 = 1;

        mg_websocket_client_write(
            conn,
            MG_WEBSOCKET_OPCODE_BINARY,
            data.c_str(),
            data.length());

        mg_websocket_client_write(
            conn,
            MG_WEBSOCKET_OPCODE_DATACOMPLETE,
            "",
            0);

        while (epochSync.val2)
            epochSync.cv.wait(lck);

        if (!epochSync.val)
            flag = true;
    }

    if (isBreakdown)
        return retval;

    vector<Proof> generatorProof;
    generatorProofHolder.clear();

    retval = update_data_from_epoch_gen_file(generatorProof);

    generatorProofHolder.push_back(generatorProof);



    return retval;
}

vector<Proof> epoch_build_up(
    PrsonaServer *prsonaServer,
    const vector<string>& serverIPs,
    const string& selfIP,
    Twistpoint& nextGenerator)
{
    std::vector<std::vector<std::vector<Proof>>> pi;
    std::vector<std::vector<std::vector<Twistpoint>>> permutationCommits;
    std::vector<std::vector<std::vector<Twistpoint>>> freshPseudonymCommits;
    std::vector<std::vector<std::vector<Twistpoint>>> freshPseudonymSeedCommits;
    std::vector<std::vector<std::vector<CurveBipoint>>> serverTallyCommits;
    std::vector<std::vector<std::vector<std::vector<TwistBipoint>>>> partwayVoteMatrixCommits;
    std::vector<std::vector<std::vector<std::vector<TwistBipoint>>>> finalVoteMatrixCommits;

    std::vector<std::vector<Proof>> generatorProofHolder(1);

    for (size_t i = 0; i < serverIPs.size(); i++)
    {
        if (serverIPs[i] == selfIP)
        {
            pi.clear();
            permutationCommits.clear();
            freshPseudonymCommits.clear();
            freshPseudonymSeedCommits.clear();
            serverTallyCommits.clear();
            partwayVoteMatrixCommits.clear();
            finalVoteMatrixCommits.clear();

            pi.push_back(generatorProofHolder);

            prsonaServer->build_up_midway_pseudonyms(
                pi,
                permutationCommits,
                freshPseudonymCommits,
                freshPseudonymSeedCommits,
                serverTallyCommits,
                partwayVoteMatrixCommits,
                finalVoteMatrixCommits,
                nextGenerator);

            vector<vector<Twistpoint>> currUserTallyMaskCommits;
            vector<vector<Twistpoint>> currUserTallyMessageCommits;
            vector<vector<Twistpoint>> currUserTallySeedCommits;

            string data = make_epoch_update_string(
                pi[1],
                permutationCommits[0],
                freshPseudonymCommits[0],
                freshPseudonymSeedCommits[0],
                serverTallyCommits[0],
                partwayVoteMatrixCommits[0],
                finalVoteMatrixCommits[0],
                nextGenerator[0],
                currUserTallyMaskCommits,
                currUserTallyMessageCommits,
                currUserTallySeedCommits,
                nextGenerator,
                false);

            struct synchronization_tool epochSync;
            epochSync->val = 1;
            for (size_t j = 0; j < serverIPs.size(); j++)
            {
                if (i == j)
                    continue;

                distribute_epoch_updates(
                    serverIPs[j],
                    data,
                    &epochSync);
            }
            unique_lock<mutex> lck(epochSync);
            while (epochSync.val < serverIPs.size())
                epochSync.cv.wait(lck);

            generatorProofHolder = pi[0];
        }
        else
        {
            string data = make_epoch_initiator_string(
                generatorProofHolder[0],
                nextGenerator);
            nextGenerator = initiate_epoch_updates(
                serverIPs[j],
                data,
                generatorProofHolder,
                false);
        }
    }

    return generatorProofHolder[0];
}

void epoch_break_down(
    PrsonaServer *prsonaServer,
    const vector<string>& serverIPs,
    const string& selfIP,
    const vector<Proof>& generatorProof,
    const Twistpoint& nextGenerator)
{
    std::vector<std::vector<std::vector<Proof>>> pi;
    std::vector<std::vector<std::vector<Twistpoint>>> permutationCommits;
    std::vector<std::vector<std::vector<Twistpoint>>> freshPseudonymCommits;
    std::vector<std::vector<std::vector<Twistpoint>>> freshPseudonymSeedCommits;
    std::vector<std::vector<std::vector<CurveBipoint>>> serverTallyCommits;
    std::vector<std::vector<std::vector<std::vector<TwistBipoint>>>> partwayVoteMatrixCommits;
    std::vector<std::vector<std::vector<std::vector<TwistBipoint>>>> finalVoteMatrixCommits;
    std::vector<std::vector<std::vector<Twistpoint>>> userTallyMaskCommits;
    std::vector<std::vector<std::vector<Twistpoint>>> userTallyMessageCommits;
    std::vector<std::vector<std::vector<Twistpoint>>> userTallySeedCommits;

    for (size_t i = 0; i < serverIPs.size(); i++)
    {
        pi.clear();
        permutationCommits.clear();
        freshPseudonymCommits.clear();
        freshPseudonymSeedCommits.clear();
        serverTallyCommits.clear();
        partwayVoteMatrixCommits.clear();
        finalVoteMatrixCommits.clear();
        userTallyMaskCommits.clear();
        userTallyMessageCommits.clear();
        userTallySeedCommits.clear();

        if (serverIPs[i] == selfIP)
        {
            prsonaServer->break_down_midway_pseudonyms(
                generatorProof,
                pi,
                permutationCommits,
                freshPseudonymCommits,
                freshPseudonymSeedCommits,
                serverTallyCommits,
                partwayVoteMatrixCommits,
                finalVoteMatrixCommits,
                userTallyMaskCommits,
                userTallyMessageCommits,
                userTallySeedCommits,
                nextGenerator);

            string data = make_epoch_update_string(
                pi[0],
                permutationCommits[0],
                freshPseudonymCommits[0],
                freshPseudonymSeedCommits[0],
                serverTallyCommits[0],
                partwayVoteMatrixCommits[0],
                finalVoteMatrixCommits[0],
                nextGenerator[0],
                userTallyMaskCommits[0],
                userTallyMessageCommits[0],
                userTallySeedCommits[0],
                nextGenerator,
                true);

            struct synchronization_tool epochSync;
            epochSync->val = 1;
            for (size_t j = 0; j < serverIPs.size(); j++)
            {
                if (i == j)
                    continue;

                distribute_epoch_updates(
                    serverIPs[j],
                    data,
                    &epochSync);
            }
            unique_lock<mutex> lck(epochSync.mtx);
            while (epochSync.val < serverIPs.size())
                epochSync.cv.wait(lck);

            epochNum++;
        }
        else
        {
            vector<vector<Proof>> unused;
            string data = make_epoch_initiator_string(
                generatorProof,
                nextGenerator);
            initiate_epoch_updates(
                serverIPs[j],
                data,
                unused,
                true);
        }
    }
}

void tally_scores(
    PrsonaServer *prsonaServer,
    const vector<string>& serverIPs,
    const string& selfIP,
    const Twistpoint& nextGenerator,
    std::vector<EGCiphertext>& userTallyScores,
    std::vector<CurveBipoint>& serverTallyScores)
{
    tallySync.val = 0;
    for (size_t i = 0; i < serverIPs.size(); i++)
    {
        if (serverIPs[i] == selfIP)
        {
            unique_lock<mutex> lck(tallySync.mtx);
            tallySync.val++;
            continue;
        }
        else
        {
            bool flag = false;
            while (!flag)
            {
                struct mg_connection *conn =
                    mg_connect_websocket_client(
                        serverIPs[i].c_str(),
                        PRSONA_PORT,
                        USE_SSL,
                        NULL,
                        0,
                        GET_DECRYPTION_URI,
                        "null",
                        tally_websocket_data_handler,
                        empty_websocket_close_handler,
                        NULL);

                if (!conn)
                {
                    std::cerr << "Trouble initiating epoch update with server at " << recipient << std::endl;
                    continue;
                }

                mg_websocket_client_write(
                    conn,
                    MG_WEBSOCKET_OPCODE_DATACOMPLETE,
                    "",
                    0);
            }
        }
    }

    unique_lock<mutex> lck(tallySync.mtx)
    while (tallySync.val < serverIPs.size())
        tallySync.cv.wait(lck);

    std::vector<EGCiphertext> retval;
    std::vector<Scalar> decryptedTalliedScores = prsonaServer->tally_scores();
    mpz_class maxScorePossibleThisRound =
        prsonaServer->get_max_possible_score().toInt() *
        PrsonaBase::get_max_allowed_vote();
    mpz_class topOfScoreRange =
        decryptedTalliedScores.size() * PrsonaBase::get_max_allowed_vote();

    userTallyScores.clear();
    serverTallyScores.clear();
    for (size_t i = 0; i < decryptedTalliedScores.size(); i++)
    {
        decryptedTalliedScores[i] =
            Scalar(
                (decryptedTalliedScores[i].toInt() * topOfScoreRange) /
                maxScorePossibleThisRound
            );

        EGCiphertext currCiphertext;
        userTallyScores.push_back(currCiphertext);
        CurveBipoint currServerScore;
        serverTallyScores.push_back(currServerScore);
        Scalar currMask;
        currMask.set_random();

        // Give the server the new weights,
        // to get passed around to the other servers
        prsonaServer->bgnSystem.encrypt(
            serverTallyScores[i], decryptedTalliedScores[i]);

        userTallyScores[i].mask = prsonaServer->currentPseudonyms[i] * currMask;
        userTallyScores[i].encryptedMessage =
            (nextGenerator * currMask) +
            (prsonaServer->get_blinding_generator() * decryptedTalliedScores[i]);
    }
}

void distribute_tallied_scores(
    PrsonaServer *prsonaServer,
    const vector<string>& serverIPs,
    const string& selfIP,
    const Twistpoint& nextGenerator,
    const std::vector<EGCiphertext>& userTallyScores,
    const std::vector<CurveBipoint>& serverTallyScores)
{
    stringstream buffer;
    string data;
    
    buffer << userTallyScores.size();
    for (size_t i = 0; i < userTallyScores.size(); i++)
        buffer << userTallyScores[i];
    for (size_t i = 0; i < serverTallyScores.size(); i++)
        buffer << serverTallyScores[i];

    data = buffer.str();

    tallySync.val = 0;
    for (size_t i = 0; i < serverIPs.size(); i++)
    {
        if (serverIPs[i] == selfIP)
        {
            prsonaServer->receive_tallied_scores(userTallyScores, serverTallyScores);
            unique_lock<mutex> lck(tallySync.mtx);
            tallySync.val++;
            continue;
        }
        else
        {
            bool flag = false;
            while (!flag)
            {
                struct mg_connection *conn =
                    mg_connect_websocket_client(
                        serverIPs[i].c_str(),
                        PRSONA_PORT,
                        USE_SSL,
                        NULL,
                        0,
                        GIVE_DECRYPTION_URI,
                        "null",
                        tally_websocket_data_handler,
                        empty_websocket_close_handler,
                        NULL);

                if (!conn)
                {
                    std::cerr << "Trouble initiating epoch update with server at " << recipient << std::endl;
                    continue;
                }

                mg_websocket_client_write(
                    conn,
                    MG_WEBSOCKET_OPCODE_BINARY,
                    data.c_str(),
                    data.length());

                mg_websocket_client_write(
                    conn,
                    MG_WEBSOCKET_OPCODE_DATACOMPLETE,
                    "",
                    0);
            }
        }
    }

    unique_lock<mutex> lck(tallySync.mtx)
    while (tallySync.val < serverIPs.size())
        tallySync.cv.wait(lck);
}

void epoch(
    PrsonaServer *prsonaServer,
    const vector<string>& serverIPs,
    const string& selfIP)
{
    Twistpoint nextGenerator = PrsonaServer::EL_GAMAL_GENERATOR;
    
    unique_lock<mutex> lck(updateMtx, defer_lock);
    obtain_update_locks(
        lck,
        serverIPs,
        selfIP,
        updateSync);

    vector<Proof> generatorProof =
        epoch_build_up(
            prsonaServer,
            serverIPs,
            selfIP,
            nextGenerator);

    std::vector<EGCiphertext> currentUserEncryptedTallies;
    std::vector<CurveBipoint> currentServerEncryptedTallies;

    tally_scores(
        prsonaServer,
        serverIPs,
        selfIP,
        nextGenerator,
        currentUserEncryptedTallies,
        currentServerEncryptedTallies);

    distribute_tallied_scores(
        prsonaServer,
        serverIPs,
        selfIP,
        nextGenerator,
        currentUserEncryptedTallies,
        currentServerEncryptedTallies);

    epoch_break_down(
        prsonaServer,
        serverIPs,
        selfIP,
        generatorProof,
        nextGenerator);

    release_update_locks(
        lck,
        serverIPs,
        selfIP,
        updateSync);
}

class ExitHandler : public CivetHandler
{
    public:
        bool handleGet(CivetServer *server, struct mg_connection *conn)
        {
            unique_lock<mutex> lck(exitSync.mtx);

            mg_printf(conn,
                      "HTTP/1.1 200 OK\r\nContent-Type: "
                      "text/plain\r\nConnection: close\r\n\r\n");
            mg_printf(conn, "Server coming down!\n");

            exitSync.val = 1;
            exitSync.cv.notify_all();

            return true;
        }
};

class BeginHandler : public CivetHandler
{
    public:
        bool handleGet(CivetServer *server, struct mg_connection *conn)
        {
            unique_lock<mutex> lck(exitSync.mtx);

            mg_printf(conn,
                      "HTTP/1.1 200 OK\r\nContent-Type: "
                      "text/plain\r\nConnection: close\r\n\r\n");
            mg_printf(conn, "Server will begin periodically initiating epochs!\n");

            exitSync.val2 = 1;
            exitSync.cv.notify_all();

            return true;
        }
};

class ReadyHandler : public CivetHandler
{
    public:
        bool handleGet(CivetServer *server, struct mg_connection *conn)
        {
            unique_lock<mutex> lck(readySync.mtx);

            mg_printf(conn,
                      "HTTP/1.1 200 OK\r\nContent-Type: "
                      "text/plain\r\nConnection: close\r\n\r\n");
            mg_printf(conn, "ACK\n");

            readySync.val++;
            readySync.cv.notify_all();

            return true;
        }
};

class EpochHandler : public CivetHandler
{
    public:
        bool handleGet(CivetServer *server, struct mg_connection *conn)
        {
            mg_printf(conn,
                      "HTTP/1.1 200 OK\r\nContent-Type: "
                      "text/plain\r\nConnection: close\r\n\r\n");
            mg_printf(conn, "%lu\n", epochNum);

            return true;
        }
};

int main(int argc, char *argv[])
{
    initialize_prsona_classes();

#if USE_SSL
    mg_init_library(0);
#else
    mg_init_library(MG_FEATURES_SSL);
#endif
    
    const char *options[] = {"listening_ports", PRSONA_PORT, 0};

    vector<string> serverIPs;
    string selfIP, dealerIP;

    char buffer[40];
    ifstream serverConfig("serverIPs.cfg");
    while (!serverConfig.eof())
    {
        serverConfig.getline(buffer, 40);
        if (strlen(buffer) > 0)
            serverIPs.push_back(string(buffer));
    }

    ifstream selfConfig("selfIP.cfg");
    while (!selfConfig.eof())
    {
        selfConfig.getline(buffer, 40);
        if (strlen(buffer) > 0)
            selfIP = buffer;
    }

    ifstream dealerConfig("dealerIP.cfg");
    while (!dealerConfig.eof())
    {
        dealerConfig.getline(buffer, 40);
        if (strlen(buffer) > 0)
            dealerIP = buffer;
    }

    // Defaults
    size_t numServers = serverIPs.size();
    bool bgnDealer = selfIP == dealerIP;
    size_t timeToEpoch = 600;
    bool maliciousServers = true;

    if (argc > 1)
        timeToEpoch = atoi(argv[1]);
    if (argc > 2)
    {
        bool setting = argv[2][0] == 't' || argv[2][0] == 'T';
        maliciousServers = setting;
    }

    cout << "Establishing PRSONA server with the following parameters: " << endl;
    cout << numServers << " PRSONA servers" << endl;
    if (bgnDealer)
    {
        cout << "This server IS the trusted BGN dealer" << endl;
        cout << "The time between epochs is " << timeToEpoch << " seconds" << endl;
    }
    else
    {
        cout << "This server is NOT the trusted BGN dealer" << endl;
    }
    cout << "Servers are set to " << (maliciousServers ? "MALICIOUS" : "HBC") << " security" << endl;
    cout << "This server is at IP address: " << selfIP << endl;
    cout << "The BGN dealer is at IP address: " << dealerIP << endl;
    cout << endl;

    // Set malicious flags where necessary
    if (maliciousServers)
        PrsonaBase::set_server_malicious();

    // Entities we operate with
    PrsonaServer *prsonaServer;
    if (bgnDealer)
        prsonaServer = new PrsonaServer(numServers);
    else
    {
        struct mg_connection *conn =
            mg_connect_websocket_client(
                dealerIP.c_str(),
                PRSONA_PORT,
                USE_SSL,
                NULL,
                0,
                BGN_URI,
                "null",
                bgn_websocket_data_handler,
                bgn_websocket_close_handler,
                NULL);

        if (!conn)
        {
            cerr << "Couldn't obtain BGN details" << endl;
            return 1;
        }

        unique_lock<mutex> lck(bgnSync.mtx);
        remove(BGN_TMP_FILE);
        bgnSync.val = 0;
        mg_websocket_client_write(
            conn,
            MG_WEBSOCKET_OPCODE_DATACOMPLETE,
            "",
            0);

        while (!bgnSync.val)
            bgnSync.cv.wait(lck);

        prsonaServer = create_server_from_bgn_file(numServers);
    }

    CivetServer server(options);

    PrsonaServerWebSocketHandler wsHandler(prsonaServer, &updateMtx, &epochNum, serverIPs, selfIP);
    server.addWebSocketHandler("/ws", wsHandler);

    ReadyHandler readyHandler;
    server.addHandler(READY_URI, readyHandler);

    if (bgnDealer)
    {
        unique_lock<mutex> lck(readySync.mtx);
        readySync.val++;
        while (readySync.val < numServers)
            readySync.cv.wait(lck);

        vector<Proof> pi;
        Twistpoint freshGenerator =
            get_generator(pi, prsonaServer, serverIPs, true);

        handout_generator(pi, freshGenerator, prsonaServer, serverIPs, true);

        Twistpoint blindGenerator =
            get_generator(pi, prsonaServer, serverIPs, false);

        handout_generator(pi, freshGenerator, prsonaServer, serverIPs, false);
    }
    else
    {
        stringstream sysString;
        string data;

        struct mg_connection *conn =
            mg_connect_client(
                dealerIP, 
                PRSONA_PORT,
                USE_SSL, 
                NULL,
                0);

        sysString << "GET " << READY_URI << " HTTP/1.1\r\n";
        sysString << "Host: " << dealerIP << "\r\n\r\n";
        data = sysString.str();

        mg_write(conn, data.c_str(), data.length());
        mg_close_connection(conn);
    }

    ExitHandler exitHandler;
    server.addHandler(EXIT_URI, exitHandler);

    if (bgnDealer)
    {
        BeginHandler beginHandler;
        server.addHandler(BEGIN_URI, beginHandler);

        unique_lock<mutex> lck(exitSync.mtx);
        while (!exitSync.val && !exitSync.val2)
            exitSync.cv.wait(lck);

        while (!exitSync.val)
        {
            epoch(prsonaServer);
            exitSync.cv.waitFor(lck, chrono::seconds(timeToEpoch));
        }
    }
    else
    {
        unique_lock<mutex> lck(exitSync.mtx);
        while (!exitSync.val)
            exitSync.cv.wait(lck)
    }

    mg_exit_library();

    delete prsonaServer;

    if (bgnDealer)
    {
        for (size_t i = 0; i < serverIPs.size(); i++)
        {
            if (serverIPs[i] == selfIP)
                continue;

            stringstream sysString;
            string data;

            struct mg_connection *conn =
                mg_connect_client(
                    serverIPs[i], 
                    PRSONA_PORT,
                    USE_SSL, 
                    NULL,
                    0);

            sysString << "GET " << EXIT_URI << " HTTP/1.1\r\n";
            sysString << "Host: " << serverIPs[i] << "\r\n\r\n";
            data = sysString.str();

            mg_write(conn, data.c_str(), data.length());
            mg_close_connection(conn);
        }
    }

    return 0;
}