ModSecurity/src/assay.cc

/**
 * ModSecurity, http://www.modsecurity.org/
 * Copyright (c) 2015 Trustwave Holdings, Inc. (http://www.trustwave.com/)
 *
 * You may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * If any of the files related to licensing are missing or if you have any
 * other questions related to licensing please contact Trustwave Holdings, Inc.
 * directly using the email address security@modsecurity.org.
 *
 */

#include "modsecurity/assay.h"

#include <yajl/yajl_tree.h>
#include <yajl/yajl_gen.h>
#include <stdio.h>
#include <string.h>

#include <ctime>
#include <iostream>
#include <unordered_map>
#include <fstream>
#include <vector>
#include <iomanip>
#include <set>

#include "modsecurity/modsecurity.h"
#include "modsecurity/intervention.h"
#include "actions/action.h"
#include "src/utils.h"
#include "src/audit_log.h"
#include "src/unique_id.h"

using ModSecurity::actions::Action;

namespace ModSecurity {

/**
 * @name    Assay
 * @brief   Represents the inspection on an entire request.
 *
 * An instance of the Assay class represents an entire request, on its
 * different phases.
 *
 * @note Remember to cleanup the assay when the transaction is complete.
 *
 * @param ms ModSecurity core pointer.
 * @param rules Rules pointer.
 *
 * Example Usage:
 * @code
 *
 * using ModSecurity::ModSecurity;
 * using ModSecurity::Rules;
 * using ModSecurity::Assay;
 *
 * ModSecurity *modsec;
 * ModSecurity::Rules *rules;
 *
 * modsec = new ModSecurity();
 * rules = new Rules();
 * rules->loadFromUri(rules_file);
 *
 * Assay *modsecAssay = new Assay(modsec, rules);
 * modsecAssay->processConnection("127.0.0.1", 33333, "127.0.0.1", 8080);
 *
 * if (modsecAssay->intervention()) {
 *     std::cout << "There is an intervention" << std::endl;
 * }
 *
 * ...      
 *
 * @endcode
 *
 */
Assay::Assay(ModSecurity *ms, Rules *rules)
    : m_clientIpAddress(""),
    m_serverIpAddress(""),
    m_clientPort(0),
    m_serverPort(0),
    m_uri(""),
    m_protocol(""),
    m_httpVersion(""),
    m_rules(rules),
    save_in_auditlog(false),
    do_not_save_in_auditlog(false),
    timeStamp(std::time(NULL)),
    httpCodeReturned(200),
    m_ARGScombinedSize(0),
    m_ARGScombinedSizeStr(NULL),
    m_namesArgs(NULL),
    m_ms(ms) {
    id = std::to_string(this->timeStamp) + \
        std::to_string(generate_assay_unique_id());
    m_rules->incrementReferenceCount();

    store_variable("ARGS_COMBINED_SIZE", std::string("0"));
    this->m_ARGScombinedSizeStr = resolve_variable_first("ARGS_COMBINED_SIZE");
    store_variable("ARGS_NAMES", std::string(""));
    this->m_namesArgs = resolve_variable_first("ARGS_NAMES");

    this->debug(4, "Initialising transaction");
}


Assay::~Assay() {
    m_rules->decrementReferenceCount();
}


/**
 * @name    debug
 * @brief   Prints a message on the debug logs.
 *
 * Debug logs are important during the rules creation phase, this method can be
 * used to print message on this debug log.
 * 
 * @param level Debug level, current supported from 0 to 9.
 * @param message Message to be logged.
 *
 */
void Assay::debug(int level, std::string message) {
    m_rules->debug(level, message);
}


/**
 * @name    processConnection
 * @brief   Perform the analysis on the connection.
 *
 * This method should be called at very beginning of a request process, it is
 * expected to be executed prior to the virtual host resolution, when the
 * connection arrives on the server.
 *
 * @note Remember to check for a possible intervention.
 *
 * @param assay ModSecurity assay.
 * @param client Client's IP address in text format.
 * @param cPort Client's port
 * @param server Server's IP address in text format.
 * @param sPort Server's port
 *
 * @returns If the operation was successful or not.
 * @retval true Operation was successful.
 * @retval false Operation failed.
 *
 */
int Assay::processConnection(const char *client, int cPort, const char *server,
    int sPort) {
    this->m_clientIpAddress = client;
    this->m_serverIpAddress = server;
    this->m_clientPort = cPort;
    this->m_serverPort = sPort;
    debug(4, "Transaction context created (blah blah)");
    debug(4, "Starting phase CONNECTION. (SecRules 0)");

    this->store_variable("REMOTE_ADDR", m_clientIpAddress);
    this->m_rules->evaluate(ModSecurity::ConnectionPhase, this);
    return true;
}


/**
 * @name    processURI
 * @brief   Perform the analysis on the URI and all the query string variables.
 *
 * This method should be called at very beginning of a request process, it is
 * expected to be executed prior to the virtual host resolution, when the
 * connection arrives on the server.
 *
 * @note There is no direct connection between this function and any phase of
 *       the SecLanguage's phases. It is something that may occur between the
 *       SecLanguage phase 1 and 2.
 * @note Remember to check for a possible intervention.
 *
 * @param assay ModSecurity assay.
 * @param uri   Uri.
 * @param protocol   Protocol (GET, POST, PUT).
 * @param http_version   Http version (1.0, 1.2, 2.0).
 *
 * @returns If the operation was successful or not.
 * @retval true Operation was successful.
 * @retval false Operation failed.
 *
 */
int Assay::processURI(const char *uri, const char *protocol,
    const char *http_version) {
    debug(4, "Starting phase URI. (SecRules 0 + 1/2)");

    m_protocol = protocol;
    m_httpVersion = http_version;
    m_uri = uri;
    m_uri_decoded = uri_decode(uri);

    const char *pos = strchr(m_uri_decoded.c_str(), '?');

    if (pos != NULL && strlen(pos) > 2) {
        /**
         * FIXME:
         *
         * This is configurable by secrules, we should respect whatever
         * the secrules said about it.
         *
         */
        char sep1 = '&';

        std::vector<std::string> key_value = split(pos+1, sep1);

        for (std::string t : key_value) {
            /**
             * FIXME:
             *
             * Mimic modsecurity when there are multiple keys with the same name.
             *
             */
            char sep2 = '=';

            std::vector<std::string> key_value = split(t, sep2);
            store_variable("ARGS:" + key_value[0], key_value[1]);
            store_variable("ARGS_GET:" + key_value[0], key_value[1]);

            if (m_namesArgs->empty()) {
                m_namesArgs->assign(key_value[0]);
            } else {
                m_namesArgs->assign(*m_namesArgs + " " + key_value[0]);
            }

            this->m_ARGScombinedSize = this->m_ARGScombinedSize + \
                key_value[0].length() + key_value[1].length();
            this->m_ARGScombinedSizeStr->assign(
                std::to_string(this->m_ARGScombinedSize));

            debug(4, "Adding request argument (QUERY_STRING): name \"" + \
                key_value[0] + "\", value \"" + key_value[1] + "\"");
            store_variable("QUERY_STRING:" + key_value[0], key_value[1]);
        }
    }
    return true;
}


/**
 * @name    processRequestHeaders
 * @brief   Perform the analysis on the request readers.
 *
 * This method perform the analysis on the request headers, notice however
 * that the headers should be added prior to the execution of this function.
 *
 * @note Remember to check for a possible intervention.
 *
 * @returns If the operation was successful or not.
 * @retval true Operation was successful.
 * @retval false Operation failed.
 *
 */
int Assay::processRequestHeaders() {
    debug(4, "Starting phase REQUEST_HEADERS.  (SecRules 1)");
    this->m_rules->evaluate(ModSecurity::RequestHeadersPhase, this);
    return 0;
}


/**
 * @name    addRequestHeader
 * @brief   Adds a request header
 *
 * With this method it is possible to feed ModSecurity with a request header.
 *
 * @note This function expects a NULL terminated string, for both: key and
 *       value.
 *
 * @param key   header name.
 * @param value header value.
 *
 * @returns If the operation was successful or not.
 * @retval true Operation was successful.
 * @retval false Operation failed.
 *
 */
int Assay::addRequestHeader(const std::string& key,
    const std::string& value) {
    std::string *names = resolve_variable_first("REQUEST_HEADERS_NAMES");

    if (names == NULL) {
        this->store_variable("REQUEST_HEADERS_NAMES", m_namesRequest);
        m_namesRequest = key;
    } else {
        m_namesRequest = m_namesRequest + " " + key;
    }

    this->store_variable("REQUEST_HEADERS:" + key, value);

    return 1;
}


/**
 * @name    addRequestHeader
 * @brief   Adds a request header
 *
 * With this method it is possible to feed ModSecurity with a request header.
 *
 * @note This function expects a NULL terminated string, for both: key and
 *       value.
 *
 * @param key   header name.
 * @param value header value.
 *
 * @returns If the operation was successful or not.
 * @retval true Operation was successful.
 * @retval false Operation failed.
 *
 */
int Assay::addRequestHeader(const unsigned char *key,
    const unsigned char *value) {
    return this->addRequestHeader(key,
        strlen(reinterpret_cast<const char *>(key)),
        value,
        strlen(reinterpret_cast<const char *>(value)));
}


/**
 * @name    addRequestHeader
 * @brief   Adds a request header
 *
 * Do not expect a NULL terminated string, instead it expect the string and the
 * string size, for the value and key.
 *
 * @param assay   ModSecurity assay.
 * @param key     header name.
 * @param key_n   header name size.
 * @param value   header value.
 * @param value_n header value size.
 *
 * @returns If the operation was successful or not.
 * @retval 1 Operation was successful.
 * @retval 0 Operation failed.
 *
 */
int Assay::addRequestHeader(const unsigned char *key, size_t key_n,
    const unsigned char *value, size_t value_n) {
    std::string keys;
    std::string values;

    keys.assign(reinterpret_cast<const char *>(key), key_n);
    values.assign(reinterpret_cast<const char *>(value), value_n);

    return this->addRequestHeader(keys, values);
}


/**
 * @name    processRequestBody
 * @brief   Perform the request body (if any)
 *
 * This method perform the analysis on the request body. It is optional to
 * call that function. If this API consumer already know that there isn't a
 * body for inspect it is recommended to skip this step.
 *
 * @note It is necessary to "append" the request body prior to the execution
 *       of this function.
 * @note Remember to check for a possible intervention.
 * 
 * @returns If the operation was successful or not.
 * @retval true Operation was successful.
 * @retval false Operation failed.
 *
 */
int Assay::processRequestBody() {
    debug(4, "Starting phase REQUEST_BODY. (SecRules 2)");

    if (m_requestBody.tellp() > 0) {
        /**
         * FIXME:
         *
         * This is configurable by secrules, we should respect whatever
         * the secrules said about it.
         *
         */
        std::string content = uri_decode(m_requestBody.str());
        content.erase(content.length()-1, 1);

        char sep1 = '&';
        const char *pos = strchr(content.c_str(), '?');

        std::vector<std::string> key_value = split(content.c_str(), sep1);

        for (std::string t : key_value) {
            /**
             * FIXME:
             *
             * Mimic modsecurity when there are multiple keys with the same name.
             *
             */
            char sep2 = '=';

            std::vector<std::string> key_value = split(t, sep2);
            store_variable("ARGS:" + key_value[0], key_value[1]);
            store_variable("ARGS_POST:" + key_value[0], key_value[1]);

            if (m_namesArgs->empty()) {
                m_namesArgs->assign(key_value[0]);
            } else {
                m_namesArgs->assign(*m_namesArgs + " " + key_value[0]);
            }

            this->m_ARGScombinedSize = this->m_ARGScombinedSize + \
                key_value[0].length() + key_value[1].length();
            this->m_ARGScombinedSizeStr->assign(
                std::to_string(this->m_ARGScombinedSize));
        }
    }

    this->m_rules->evaluate(ModSecurity::RequestBodyPhase, this);
    return 0;
}


/**
 * @name    appendRequestBody
 * @brief   Adds request body to be inspected.
 *
 * With this method it is possible to feed ModSecurity with data for
 * inspection regarding the request body. There are two possibilities here:
 * 
 * 1 - Adds the buffer in a row;
 * 2 - Adds it in chunks;
 *
 * A third option should be developed which is share your application buffer.
 * In any case, remember that the utilization of this function may reduce your
 * server throughput, as this buffer creations is computationally expensive.
 *
 * @note While feeding ModSecurity remember to keep checking if there is an
 *       intervention, Sec Language has the capability to set the maximum
 *       inspection size which may be reached, and the decision on what to do
 *       in this case is upon the rules.
 *
 * @returns If the operation was successful or not.
 * @retval true Operation was successful.
 * @retval false Operation failed.
 *
 */
int Assay::appendRequestBody(const unsigned char *buf, size_t len) {
    /**
     * as part of the confiurations or rules it is expected to 
     * set a higher value for this. Will not handle it for now.
     */
    this->m_requestBody.write(reinterpret_cast<const char*>(buf), len);

    return 0;
}


/**
 * @name    processResponseHeaders
 * @brief   Perform the analysis on the response readers.
 *
 * This method perform the analysis on the response headers, notice however
 * that the headers should be added prior to the execution of this function.
 *
 * @note Remember to check for a possible intervention.
 *
 * @returns If the operation was successful or not.
 * @retval true Operation was successful.
 * @retval false Operation failed.
 *
 */
int Assay::processResponseHeaders() {
    debug(4, "Starting phase RESPONSE_HEADERS. (SecRules 3)");
    this->m_rules->evaluate(ModSecurity::ResponseHeadersPhase, this);
    return 0;
}


/**
 * @name    addResponseHeader
 * @brief   Adds a response header
 *
 * With this method it is possible to feed ModSecurity with a response
 * header.
 *
 * @note This method expects a NULL terminated string, for both: key and
 *       value.
 *
 * @param key     header name.
 * @param value   header value.
 *
 * @returns If the operation was successful or not.
 * @retval true Operation was successful.
 * @retval false Operation failed.
 *
 */
int Assay::addResponseHeader(const std::string& key,
    const std::string& value) {
    std::string *names = resolve_variable_first("RESPONSE_HEADERS_NAMES");

    if (names == NULL) {
        this->store_variable("RESPONSE_HEADERS_NAMES", m_namesResponse);
        m_namesRequest = key;
    } else {
        m_namesRequest = m_namesRequest + " " + key;
    }

    this->store_variable("RESPONSE_HEADERS:" + key, value);

    return 1;
}


/**
 * @name    addResponseHeader
 * @brief   Adds a response header
 *
 * With this method it is possible to feed ModSecurity with a response
 * header.
 *
 * @note This method expects a NULL terminated string, for both: key and
 *       value.
 *
 * @param key     header name.
 * @param value   header value.
 *
 * @returns If the operation was successful or not.
 * @retval true Operation was successful.
 * @retval false Operation failed.
 *
 */
int Assay::addResponseHeader(const unsigned char *key,
    const unsigned char *value) {
    return this->addResponseHeader(key,
        strlen(reinterpret_cast<const char *>(key)),
        value,
        strlen(reinterpret_cast<const char *>(value)));
}


/**
 * @name    msc_add_n_response_header
 * @brief   Adds a response header
 *
 * Do not expect a NULL terminated string, instead it expect the string and the
 * string size, for the value and key.
 *
 * @param key     header name.
 * @param key_n   header name size.
 * @param value   header value.
 * @param value_n header value size.
 * 
 * @returns If the operation was successful or not.
 * @retval true Operation was successful.
 * @retval false Operation failed.
 *
 */
int Assay::addResponseHeader(const unsigned char *key, size_t key_n,
    const unsigned char *value, size_t value_n) {
    std::string keys;
    std::string values;

    keys.assign(reinterpret_cast<const char *>(key), key_n);
    values.assign(reinterpret_cast<const char *>(value), value_n);

    return this->addResponseHeader(keys, values);
}


/**
 * @name    processResponseBody
 * @brief   Perform the request body (if any)
 *
 * This method perform the analysis on the request body. It is optional to
 * call that method. If this API consumer already know that there isn't a
 * body for inspect it is recommended to skip this step.
 *
 * @note It is necessary to "append" the request body prior to the execution
 *       of this method.
 * @note Remember to check for a possible intervention.
 *
 * @returns If the operation was successful or not.
 * @retval true Operation was successful.
 * @retval false Operation failed.
 *
 */
int Assay::processResponseBody() {
    debug(4, "Starting phase RESPONSE_BODY. (SecRules 4)");
    this->m_rules->evaluate(ModSecurity::ResponseBodyPhase, this);
    return 0;
}


/**
 * @name    appendResponseBody
 * @brief   Adds reponse body to be inspected.
 *
 * With this method it is possible to feed ModSecurity with data for
 * inspection regarding the response body. ModSecurity can also update the
 * contents of the response body, this is not quite ready yet on this version
 * of the API. 
 *
 * @note If the content is updated, the client cannot receive the content
 *       length header filled, at least not with the old values. Otherwise
 *       unexpected behavior may happens.
 *
 * @returns If the operation was successful or not.
 * @retval true Operation was successful.
 * @retval false Operation failed.
 *
 */
int Assay::appendResponseBody(const unsigned char *buf, size_t len) {
    /**
     * as part of the confiurations or rules it is expected to 
     * set a higher value for this. Will not handle it for now.
     */
    this->m_responseBody.write(reinterpret_cast<const char*>(buf), len);

    return 0;
}


/**
 * @name    getResponseBody
 * @brief   Retrieve a buffer with the updated response body.
 *
 * This method is needed to be called whenever ModSecurity update the
 * contents of the response body, otherwise there is no need to call this
 * method.
 *
 * @return It returns a buffer (const char *)
 * @retval >0   body was update and available.
 * @retval NULL Nothing was updated.
 *
 */
const char *Assay::getResponseBody() {
    // int there_is_update = this->rules->loadResponseBodyFromJS(this);
    return this->m_responseBody.str().c_str();
}


/**
 * @name    getResponseBodyLenth
 * @brief   Retrieve the length of the updated response body.
 *
 * This method returns the size of the update response body buffer, notice
 * however, that most likely there isn't an update. Thus, this method will
 * return 0.
 *
 *
 * @return Size of the update response body.
 * @retval ==0 there is no update.
 * @retval >0  the size of the updated buffer.
 *
 */
int Assay::getResponseBodyLenth() {
    int size = 0;
#if 0
    int there_is_update = this->rules->loadResponseBodyFromJS(this);
    if (there_is_update == -1) {
        return -1;
    }
#endif
    this->m_responseBody.seekp(0, std::ios::end);
    size = this->m_responseBody.tellp();

    return size;
}


/**
 * @name    processLogging
 * @brief   Logging all information relative to this assay.
 *
 * At this point there is not need to hold the connection, the response can be
 * delivered prior to the execution of this method.
 *
 * @returns If the operation was successful or not.
 * @retval true Operation was successful.
 * @retval false Operation failed.
 *
 */
int Assay::processLogging(int returned_code) {
    debug(4, "Starting phase LOGGING. (SecRules 5)");
    this->httpCodeReturned = returned_code;
    this->m_rules->evaluate(ModSecurity::LoggingPhase, this);

    /* If relevant, save this assay information at the audit_logs */
    this->m_rules->audit_log->saveIfRelevant(this);

    return 0;
}


/**
 * @name    cleanup
 * @brief   Removes all the resources allocated by a given Assay.
 *
 * It is mandatory to call this function after every request being finished,
 * otherwise it may end up in a huge memory leak.
 *
 * @returns If the operation was successful or not.
 * @retval true Operation was successful.
 * @retval false Operation failed.
 *
 */
void Assay::cleanup() {
    m_responseBody.str("");
    m_responseBody.clear();

    m_requestBody.str("");
    m_requestBody.clear();

    delete this;
}


/**
 * @name    intervention
 * @brief   Check if ModSecurity has anything to ask to the server.
 *
 * Intervention can generate a log event and/or perform a disruptive action.
 *
 * @return Pointer to ModSecurityIntervention structure
 * @retval >0   A intervention should be made.
 * @retval NULL Nothing to be done.
 *
 */
ModSecurityIntervention *Assay::intervention() {
    ModSecurityIntervention *ret = NULL;

    /**
     * FIXME: Implement this.
     * 
     */
    if (actions.size() > 0) {
        for (Action *a : actions) {
            if (a->action_kind == Action::Kind::RunTimeOnlyIfMatchKind) {
                if (ret == NULL) {
                    ret = static_cast<ModSecurityIntervention *>(calloc( \
                        1, sizeof(struct ModSecurityIntervention_t)));
                    ret->status = 200;
                }
                a->fill_intervention(ret);
            }
        }
        actions.clear();
    }

    return ret;
}


std::string Assay::toOldAuditLogFormatIndex(const std::string &filename,
    double size, const std::string &md5) {
    std::stringstream ss;
    struct tm timeinfo;
    char tstr[300];

    memset(tstr, '\0', 300);
    localtime_r(&this->timeStamp, &timeinfo);

    strftime(tstr, 299, "[%d/%b/%Y:%H:%M:%S %z]", &timeinfo);

    ss << dash_if_empty(
        *this->resolve_variable_first("REQUEST_HEADERS:Host")) << " ";
    ss << dash_if_empty(this->m_clientIpAddress) << " ";
    /** TODO: Check variable */
    ss << dash_if_empty(*this->resolve_variable_first("REMOTE_USER")) << " ";
    /** TODO: Check variable */
    ss << dash_if_empty(*this->resolve_variable_first("LOCAL_USER")) << " ";
    ss << tstr << " ";

    ss << "\"";
    ss << this->m_protocol << " ";
    ss << this->m_uri << " ";
    ss << "HTTP/" << m_httpVersion;
    ss << "\" ";

    ss << this->httpCodeReturned << " ";
    ss << this->m_responseBody.tellp();
    /** TODO: Check variable */
    ss << dash_if_empty(*this->resolve_variable_first("REFERER")) << " ";
    ss << "\"";
    ss << dash_if_empty(
        *this->resolve_variable_first("REQUEST_HEADERS:User-Agent"));
    ss << "\" ";
    ss << this->id << " ";
    /** TODO: Check variable */
    ss << dash_if_empty(*this->resolve_variable_first("REFERER")) << " ";

    ss << filename << " ";
    ss << "0" << " ";
    ss << std::to_string(size) << " ";
    ss << "md5:" << md5 << std::endl;

    return ss.str();
}


std::string Assay::toOldAuditLogFormat(int parts, const std::string &trailer) {
    std::stringstream audit_log;
    struct tm timeinfo;
    char tstr[300];

    memset(tstr, '\0', 300);
    localtime_r(&this->timeStamp, &timeinfo);

    audit_log << "--" << trailer << "-" << "A--" << std::endl;
    strftime(tstr, 299, "[%d/%b/%Y:%H:%M:%S %z]", &timeinfo);
    audit_log << tstr;
    audit_log << " " << this->id.c_str();
    audit_log << " " << this->m_clientIpAddress;
    audit_log << " " << this->m_clientPort;
    audit_log << " " << this->m_serverIpAddress;
    audit_log << " " << this->m_serverPort;
    audit_log << std::endl;

    if (parts & AuditLog::BAuditLogPart) {
        audit_log << "--" << trailer << "-" << "B--" << std::endl;
        audit_log << this->m_protocol << " " << this->m_uri << " " << "HTTP/";
        audit_log << this->m_httpVersion << std::endl;

        for (auto h : this->m_variables_strings) {
            std::string filter = "REQUEST_HEADERS:";
            std::string a = h.first;
            std::string b = h.second;

            if (a.compare(0, filter.length(), filter) == 0) {
                if (a.length() > filter.length()) {
                    audit_log << a.c_str() + filter.length() << ": ";
                    audit_log << b.c_str() << std::endl;
                }
            }
        }
    }
    if (parts & AuditLog::CAuditLogPart) {
        audit_log << "--" << trailer << "-" << "C--" << std::endl;
        /** TODO: write audit_log C part. */
    }
    if (parts & AuditLog::DAuditLogPart) {
        audit_log << "--" << trailer << "-" << "D--" << std::endl;
        /** TODO: write audit_log D part. */
    }
    if (parts & AuditLog::EAuditLogPart) {
        audit_log << "--" << trailer << "-" << "E--" << std::endl;
        /** TODO: write audit_log E part. */
    }
    if (parts & AuditLog::FAuditLogPart) {
        audit_log << "--" << trailer << "-" << "F--" << std::endl;
        for (auto h : this->m_variables_strings) {
            std::string filter = "RESPONSE_HEADERS:";
            std::string a = h.first;
            std::string b = h.second;

            if (a.compare(0, filter.length(), filter) == 0) {
                if (a.length() > filter.length()) {
                    audit_log << a.c_str() + filter.length() << ": ";
                    audit_log << b.c_str() << std::endl;
                }
            }
        }
    }
    if (parts & AuditLog::GAuditLogPart) {
        audit_log << "--" << trailer << "-" << "G--" << std::endl;
        /** TODO: write audit_log G part. */
    }
    if (parts & AuditLog::HAuditLogPart) {
        audit_log << "--" << trailer << "-" << "H--" << std::endl;
        /** TODO: write audit_log H part. */
    }
    if (parts & AuditLog::IAuditLogPart) {
        audit_log << "--" << trailer << "-" << "I--" << std::endl;
        /** TODO: write audit_log I part. */
    }
    if (parts & AuditLog::JAuditLogPart) {
        audit_log << "--" << trailer << "-" << "J--" << std::endl;
        /** TODO: write audit_log J part. */
    }
    if (parts & AuditLog::KAuditLogPart) {
        audit_log << "--" << trailer << "-" << "K--" << std::endl;
        /** TODO: write audit_log K part. */
    }
    audit_log << "--" << trailer << "-" << "Z--" << std::endl << std::endl;

    return audit_log.str();
}


std::string Assay::to_json(int parts) {
    const unsigned char *buf;
    size_t len;
    yajl_gen g = NULL;
    std::string ts = ascTime(&timeStamp).c_str();
    std::string uniqueId = UniqueId::uniqueId();

    parts = 0;
    g = yajl_gen_alloc(NULL);
    if (g == NULL) {
      return "";
    }
    yajl_gen_config(g, yajl_gen_beautify, 1);

    /* main */
    yajl_gen_map_open(g);

    /* trasaction */
    yajl_gen_string(g, reinterpret_cast<const unsigned char*>("transaction"),
        strlen("transaction"));

    yajl_gen_map_open(g);
    /* Part: A (header mandatory) */
    LOGFY_ADD("client_ip", this->m_clientIpAddress);
    LOGFY_ADD("time_stamp", ts.c_str());
    LOGFY_ADD("server_id", uniqueId.c_str());
    LOGFY_ADD_NUM("client_port", m_clientPort);
    LOGFY_ADD("host_ip", m_serverIpAddress);
    LOGFY_ADD_NUM("host_port", m_serverPort);
    LOGFY_ADD("id", this->id.c_str());

    /* request */
    yajl_gen_string(g, reinterpret_cast<const unsigned char*>("request"),
        strlen("request"));
    yajl_gen_map_open(g);

    LOGFY_ADD("protocol", m_protocol);
    LOGFY_ADD_INT("http_version", m_httpVersion);
    LOGFY_ADD("uri", this->m_uri);

    if (parts & AuditLog::CAuditLogPart) {
        LOGFY_ADD("body", this->m_requestBody.str().c_str());
    }

    /* request headers */
    if (parts & AuditLog::BAuditLogPart) {
        yajl_gen_string(g, reinterpret_cast<const unsigned char*>("headers"),
            strlen("headers"));
        yajl_gen_map_open(g);

        for (auto h : this->m_variables_strings) {
            std::string filter = "REQUEST_HEADERS:";
            std::string a = h.first;
            std::string b = h.second;

            if (a.compare(0, filter.length(), filter) == 0) {
                if (a.length() > filter.length()) {
                    LOGFY_ADD(a.c_str() + filter.length(), b.c_str());
                }
            }
        }

        /* end: request headers */
        yajl_gen_map_close(g);
    }

    /* end: request */
    yajl_gen_map_close(g);

    /* response */
    yajl_gen_string(g, reinterpret_cast<const unsigned char*>("response"),
        strlen("response"));
    yajl_gen_map_open(g);

    if (parts & AuditLog::GAuditLogPart) {
        LOGFY_ADD("body", this->m_responseBody.str().c_str());
    }
    LOGFY_ADD_NUM("http_code", httpCodeReturned);

    /* response headers */
    if (parts & AuditLog::FAuditLogPart) {
        yajl_gen_string(g, reinterpret_cast<const unsigned char*>("headers"),
            strlen("headers"));
        yajl_gen_map_open(g);

        for (auto h : this->m_variables_strings) {
            std::string filter = "RESPONSE_HEADERS:";
            std::string a = h.first;
            std::string b = h.second;

            if (a.compare(0, filter.length(), filter) == 0) {
                if (a.length() > filter.length()) {
                    LOGFY_ADD(a.c_str() + filter.length(), b.c_str());
                }
            }
        }
        /* end: response headers */
        yajl_gen_map_close(g);
    }
    /* end: response */
    yajl_gen_map_close(g);

    /* producer */
    if (parts & AuditLog::HAuditLogPart) {
        yajl_gen_string(g, reinterpret_cast<const unsigned char*>("producer"),
            strlen("producer"));
        yajl_gen_map_open(g);

        /* producer > libmodsecurity */
        LOGFY_ADD("modsecurity", ModSecurity::whoAmI().c_str());

        /* producer > connector */
        LOGFY_ADD("connector", m_ms->getConnectorInformation().c_str());

        /* producer > engine state */
        LOGFY_ADD("secrules_engine",
            Rules::ruleEngineStateString(m_rules->secRuleEngine));

        /* producer > components */
        yajl_gen_string(g,
            reinterpret_cast<const unsigned char*>("components"),
            strlen("components"));

        yajl_gen_array_open(g);
        for (auto a : m_rules->components) {
            yajl_gen_string(g,
                reinterpret_cast<const unsigned char*>
                    (a.c_str()), a.length());
        }
        yajl_gen_array_close(g);

        /* end: producer */
        yajl_gen_map_close(g);
    }
    /* end: transaction */
    yajl_gen_map_close(g);

    /* end: main */
    yajl_gen_map_close(g);

    yajl_gen_get_buf(g, &buf, &len);

    std::string log(reinterpret_cast<const char*>(buf), len);

    yajl_gen_free(g);

    return log;
}


void Assay::store_variable(std::string key, const std::string &value) {
    this->m_variables_strings.emplace(key, value);
}


std::list<std::string> Assay::resolve_variable(std::string var) {
    std::list<std::string> l;
    auto range = m_variables_strings.equal_range(var);

    for (auto it = range.first; it != range.second; ++it) {
        std::cout << it->first << ' ' << it->second << '\n';
        l.push_back(it->second);
    }

    return l;
}


std::string* Assay::resolve_variable_first(std::string var) {
    auto range = m_variables_strings.equal_range(var);

    for (auto it = range.first; it != range.second; ++it) {
        return &it->second;
    }

    return NULL;
}


/**
 * @name    msc_new_assay
 * @brief   Create a new assay for a given configuration and ModSecurity core.
 *
 * The assay is the unit that will be used the inspect every request. It holds
 * all the information for a given request.
 * 
 * @note Remember to cleanup the assay when the transaction is complete.
 *
 * @param ms ModSecurity core pointer.
 * @param rules Rules pointer.
 *
 * @return Pointer to Assay structure
 * @retval >0   Assay structure was initialized correctly
 * @retval NULL Assay cannot be initialized, either by problems with the rules,
 *              problems with the ModSecurity core or missing memory to
 *              allocate the resources needed by the assay.
 *
 */
extern "C" Assay *msc_new_assay(ModSecurity *ms,
    Rules *rules) {
    return new Assay(ms, rules);
}


/**
 * @name    msc_process_connection
 * @brief   Perform the analysis on the connection.
 *
 * This function should be called at very beginning of a request process, it is
 * expected to be executed prior to the virtual host resolution, when the
 * connection arrives on the server.
 *
 * @note Remember to check for a possible intervention.
 *
 * @param assay ModSecurity assay.
 * @param client Client's IP address in text format.
 * @param cPort Client's port
 * @param server Server's IP address in text format.
 * @param sPort Server's port
 *
 * @returns If the operation was successful or not.
 * @retval 1 Operation was successful.
 * @retval 0 Operation failed.
 *
 */
extern "C" int msc_process_connection(Assay *assay, const char *client,
    int cPort, const char *server, int sPort) {
    return assay->processConnection(client, cPort, server, sPort);
}


/**
 * @name    msc_process_uri
 * @brief   Perform the analysis on the URI and all the query string variables.
 *
 * This function should be called at very beginning of a request process, it is
 * expected to be executed prior to the virtual host resolution, when the
 * connection arrives on the server.
 *
 * @note There is no direct connection between this function and any phase of
 *       the SecLanguage's phases. It is something that may occur between the
 *       SecLanguage phase 1 and 2.
 * @note Remember to check for a possible intervention.
 *
 * @param assay ModSecurity assay.
 * @param uri   Uri.
 * @param protocol   Protocol (GET, POST, PUT).
 * @param http_version   Http version (1.0, 1.2, 2.0).
 *
 * @returns If the operation was successful or not.
 * @retval 1 Operation was successful.
 * @retval 0 Operation failed.
 *
 */
extern "C" int msc_process_uri(Assay *assay, const char *uri,
    const char *protocol, const char *http_version) {
    return assay->processURI(uri, protocol, http_version);
}


/**
 * @name    msc_process_request_headers
 * @brief   Perform the analysis on the request readers.
 *
 * This function perform the analysis on the request headers, notice however
 * that the headers should be added prior to the execution of this function.
 *
 * @note Remember to check for a possible intervention.
 *
 * @param assay ModSecurity assay.
 *
 * @returns If the operation was successful or not.
 * @retval 1 Operation was successful.
 * @retval 0 Operation failed.
 *
 */
extern "C" int msc_process_request_headers(Assay *assay) {
    return assay->processRequestHeaders();
}


/**
 * @name    msc_process_request_body
 * @brief   Perform the request body (if any)
 *
 * This function perform the analysis on the request body. It is optional to
 * call that function. If this API consumer already know that there isn't a
 * body for inspect it is recommended to skip this step.
 *
 * @note It is necessary to "append" the request body prior to the execution
 *       of this function.
 * @note Remember to check for a possible intervention.
 *
 * @param assay ModSecurity assay.
 * 
 * @returns If the operation was successful or not.
 * @retval 1 Operation was successful.
 * @retval 0 Operation failed.
 *
 */
extern "C" int msc_process_request_body(Assay *assay) {
    return assay->processRequestBody();
}


/**
 * @name    msc_append_request_body
 * @brief   Adds request body to be inspected.
 *
 * With this function it is possible to feed ModSecurity with data for
 * inspection regarding the request body. There are two possibilities here:
 * 
 * 1 - Adds the buffer in a row;
 * 2 - Adds it in chunks;
 *
 * A third option should be developed which is share your application buffer.
 * In any case, remember that the utilization of this function may reduce your
 * server throughput, as this buffer creations is computationally expensive.
 *
 * @note While feeding ModSecurity remember to keep checking if there is an
 *       intervention, Sec Language has the capability to set the maximum
 *       inspection size which may be reached, and the decision on what to do
 *       in this case is upon the rules.
 *
 * @param assay ModSecurity assay.
 * 
 * @returns If the operation was successful or not.
 * @retval 1 Operation was successful.
 * @retval 0 Operation failed.
 *
 */
extern "C" int msc_append_request_body(Assay *assay,
    const unsigned char *buf, size_t len) {
    return assay->appendRequestBody(buf, len);
}


/**
 * @name    msc_process_response_headers
 * @brief   Perform the analysis on the response readers.
 *
 * This function perform the analysis on the response headers, notice however
 * that the headers should be added prior to the execution of this function.
 *
 * @note Remember to check for a possible intervention.
 *
 * @param assay ModSecurity assay.
 *
 * @returns If the operation was successful or not.
 * @retval 1 Operation was successful.
 * @retval 0 Operation failed.
 *
 */
extern "C" int msc_process_response_headers(Assay *assay) {
    return assay->processResponseHeaders();
}


/**
 * @name    msc_process_response_body
 * @brief   Perform the request body (if any)
 *
 * This function perform the analysis on the request body. It is optional to
 * call that function. If this API consumer already know that there isn't a
 * body for inspect it is recommended to skip this step.
 *
 * @note It is necessary to "append" the request body prior to the execution
 *       of this function.
 * @note Remember to check for a possible intervention.
 *
 * @param assay ModSecurity assay.
 *
 * @returns If the operation was successful or not.
 * @retval 1 Operation was successful.
 * @retval 0 Operation failed.
 *
 */
extern "C" int msc_process_response_body(Assay *assay) {
    return assay->processResponseBody();
}


/**
 * @name    msc_append_response_body
 * @brief   Adds reponse body to be inspected.
 *
 * With this function it is possible to feed ModSecurity with data for
 * inspection regarding the response body. ModSecurity can also update the
 * contents of the response body, this is not quite ready yet on this version
 * of the API. 
 *
 * @note If the content is updated, the client cannot receive the content
 *       length header filled, at least not with the old values. Otherwise
 *       unexpected behavior may happens.
 *
 * @param assay ModSecurity assay.
 *
 * @returns If the operation was successful or not.
 * @retval 1 Operation was successful.
 * @retval 0 Operation failed.
 *
 */
extern "C" int msc_append_response_body(Assay *assay,
    const unsigned char *buf, size_t len) {
    return assay->appendResponseBody(buf, len);
}


/**
 * @name    msc_add_request_header
 * @brief   Adds a request header
 *
 * With this function it is possible to feed ModSecurity with a request header.
 *
 * @note This function expects a NULL terminated string, for both: key and
 *       value.
 *
 * @param assay ModSecurity assay.
 * @param key   header name.
 * @param value header value.
 *
 * @returns If the operation was successful or not.
 * @retval 1 Operation was successful.
 * @retval 0 Operation failed.
 *
 */
extern "C" int msc_add_request_header(Assay *assay, const unsigned char *key,
    const unsigned char *value) {
    return assay->addRequestHeader(key, value);
}


/**
 * @name    msc_add_n_request_header
 * @brief   Adds a request header
 *
 * Same as msc_add_request_header, do not expect a NULL terminated string,
 * instead it expect the string and the string size, for the value and key.
 *
 * @param assay   ModSecurity assay.
 * @param key     header name.
 * @param key_len header name size.
 * @param value   header value.
 * @param val_len header value size.
 *
 * @returns If the operation was successful or not.
 * @retval 1 Operation was successful.
 * @retval 0 Operation failed.
 *
 */
extern "C" int msc_add_n_request_header(Assay *assay, const unsigned char *key,
    size_t key_len, const unsigned char *value, size_t value_len) {
    return assay->addRequestHeader(key, key_len, value, value_len);
}


/**
 * @name    msc_add_response_header
 * @brief   Adds a response header
 *
 * With this function it is possible to feed ModSecurity with a response
 * header.
 *
 * @note This function expects a NULL terminated string, for both: key and
 *       value.
 *
 * @param assay   ModSecurity assay.
 * @param key     header name.
 * @param value   header value.
 *
 * @returns If the operation was successful or not.
 * @retval 1 Operation was successful.
 * @retval 0 Operation failed.
 *
 */
extern "C" int msc_add_response_header(Assay *assay, const unsigned char *key,
    const unsigned char *value) {
    return assay->addResponseHeader(key, value);
}


/**
 * @name    msc_add_n_response_header
 * @brief   Adds a response header
 *
 * Same as msc_add_response_header, do not expect a NULL terminated string,
 * instead it expect the string and the string size, for the value and key.
 *
 * @param assay   ModSecurity assay.
 * @param key     header name.
 * @param key_len header name size.
 * @param value   header value.
 * @param val_len header value size.
 * 
 * @returns If the operation was successful or not.
 * @retval 1 Operation was successful.
 * @retval 0 Operation failed.
 *
 */
extern "C" int msc_add_n_response_header(Assay *assay,
    const unsigned char *key, size_t key_len, const unsigned char *value,
    size_t value_len) {
    return assay->addResponseHeader(key, key_len, value, value_len);
}


/**
 * @name    msc_assay_cleanup
 * @brief   Removes all the resources allocated by a given Assay.
 *
 * It is mandatory to call this function after every request being finished,
 * otherwise it may end up in a huge memory leak.
 *
 * @param assay ModSecurity assay.
 *
 * @returns If the operation was successful or not.
 * @retval 1 Operation was successful.
 * @retval 0 Operation failed.
 *
 */
extern "C" void msc_assay_cleanup(Assay *assay) {
    assay->cleanup();
}


/**
 * @name    msc_intervention
 * @brief   Check if ModSecurity has anything to ask to the server.
 *
 * Intervention can generate a log event and/or perform a disruptive action.
 *
 * @param assay ModSecurity assay.
 *
 * @return Pointer to ModSecurityIntervention structure
 * @retval >0   A intervention should be made.
 * @retval NULL Nothing to be done.
 *
 */
extern "C" ModSecurityIntervention *msc_intervention(Assay *assay) {
    return assay->intervention();
}


/**
 * @name    msc_get_response_body
 * @brief   Retrieve a buffer with the updated response body.
 *
 * This function is needed to be called whenever ModSecurity update the
 * contents of the response body, otherwise there is no need to call this
 * function.
 *
 * @param assay ModSecurity assay.
 *
 * @return It returns a buffer (const char *)
 * @retval >0   body was update and available.
 * @retval NULL Nothing was updated.
 *
 */
extern "C" const char *msc_get_response_body(Assay *assay) {
    return assay->getResponseBody();
}


/**
 * @name    msc_get_response_body_length
 * @brief   Retrieve the length of the updated response body.
 *
 * This function returns the size of the update response body buffer, notice
 * however, that most likely there isn't an update. Thus, this function will
 * return 0.
 *
 * @param assay ModSecurity assay.
 *
 * @return Size of the update response body.
 * @retval ==0 there is no update.
 * @retval >0  the size of the updated buffer.
 *
 */
extern "C" int msc_get_response_body_length(Assay *assay) {
    return assay->getResponseBodyLenth();
}

/**
 * @name    msc_process_logging
 * @brief   Logging all information relative to this assay.
 *
 * At this point there is not need to hold the connection, the response can be
 * delivered prior to the execution of this function.
 *
 * @param assay ModSecurity assay.
 * @param code  HTTP code returned to the user.
 *
 * @returns If the operation was successful or not.
 * @retval 1 Operation was successful.
 * @retval 0 Operation failed.
 *
 */
extern "C" int msc_process_logging(Assay *assay, int code) {
    return assay->processLogging(code);
}

}  // namespace ModSecurity