/*
 * Copyright (c) 2008-2015 Freescale Semiconductor, Inc.
 * Copyright 2016-2018 NXP
 * All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include "stdafx.h"
#include <iostream>
#include <fstream>
#include <sstream>
#include <stdlib.h>
#include <stdexcept>
#include <string>
#include <vector>
#include "options.h"
#include "smart_ptr.h"
#include "Logging.h"
#include "AESKey.h"

//! The tool's name.
const char k_toolName[] = "keygen";

//! Current version number for the tool.
const char k_version[] = "1.0";

//! Copyright string.
const char k_copyright[] = "Copyright (c) 2006-2009 Freescale Semiconductor, Inc.\nAll rights reserved.";

//! Definition of command line options.
static const char *k_optionsDefinition[] = { "?|help", "v|version", "q|quiet", "V|verbose", "n:number <int>", NULL };

//! Help string.
const char k_usageText[] =
    "\nOptions:\n\
  -?/--help                    Show this help\n\
  -v/--version                 Display tool version\n\
  -q/--quiet                   Output only warnings and errors\n\
  -V/--verbose                 Print extra detailed log information\n\
  -n/--number <int>            Number of keys to generate per file (default=1)\n\n";

//! An array of strings.
typedef std::vector<std::string> string_vector_t;

// prototypes
int main(int argc, char *argv[], char *envp[]);

/*!
 * \brief Class that encapsulates the keygen interface.
 *
 * A single global logger instance is created during object construction. It is
 * never freed because we need it up to the last possible minute, when an
 * exception could be thrown.
 */
class keygen
{
protected:
    int m_argc;                       //!< Number of command line arguments.
    char **m_argv;                    //!< String value for each command line argument.
    StdoutLogger *m_logger;           //!< Singleton logger instance.
    string_vector_t m_positionalArgs; //!< Arguments coming after explicit options.
    bool m_isVerbose;                 //!< Whether the verbose flag was turned on.
    int m_keyCount;                   //!< Number of keys to generate.

public:
    /*!
     * Constructor.
     *
     * Creates the singleton logger instance.
     */
    keygen(int argc, char *argv[])
        : m_argc(argc)
        , m_argv(argv)
        , m_logger(0)
        , m_positionalArgs()
        , m_isVerbose(false)
        , m_keyCount(1)
    {
        // create logger instance
        m_logger = new StdoutLogger();
        m_logger->setFilterLevel(Logger::INFO);
        Log::setLogger(m_logger);
    }

    /*!
     * Destructor.
     */
    ~keygen() {}
    /*!
     * Reads the command line options passed into the constructor.
     *
     * This method can return a return code to its caller, which will cause the
     * tool to exit immediately with that return code value. Normally, though, it
     * will return -1 to signal that the tool should continue to execute and
     * all options were processed successfully.
     *
     * The Options class is used to parse command line options. See
     * #k_optionsDefinition for the list of options and #k_usageText for the
     * descriptive help for each option.
     *
     * \retval -1 The options were processed successfully. Let the tool run normally.
     * \return A zero or positive result is a return code value that should be
     *		returned from the tool as it exits immediately.
     */
    int processOptions()
    {
        Options options(*m_argv, k_optionsDefinition);
        OptArgvIter iter(--m_argc, ++m_argv);

        // process command line options
        int optchar;
        const char *optarg;
        while ((optchar = options(iter, optarg)))
        {
            switch (optchar)
            {
                case '?':
                    printUsage(options);
                    return 0;

                case 'v':
                    printf("%s %s\n%s\n", k_toolName, k_version, k_copyright);
                    return 0;

                case 'd':
                    Log::getLogger()->setFilterLevel(Logger::DEBUG);
                    break;

                case 'q':
                    Log::getLogger()->setFilterLevel(Logger::WARNING);
                    break;

                case 'V':
                    m_isVerbose = true;
                    break;

                case 'n':
                    m_keyCount = strtol(optarg, NULL, 0);
                    break;

                default:
                    Log::log(Logger::ERROR, "error: unrecognized option\n\n");
                    printUsage(options);
                    return 1;
            }
        }

        // handle positional args
        if (iter.index() < m_argc)
        {
            //			Log::SetOutputLevel leveler(Logger::DEBUG);
            //			Log::log("positional args:\n");
            int i;
            for (i = iter.index(); i < m_argc; ++i)
            {
                //				Log::log("%d: %s\n", i - iter.index(), m_argv[i]);
                m_positionalArgs.push_back(m_argv[i]);
            }
        }

        // all is well
        return -1;
    }

    /*!
     * Prints help for the tool.
     */
    void printUsage(Options &options)
    {
        options.usage(std::cout, "key-files...");
        printf(k_usageText, k_toolName);
    }

    /*!
     * Core of the tool. Calls processOptions() to handle command line options
     * before performing the real work the tool does.
     */
    int run()
    {
        try
        {
            // read command line options
            int result;
            if ((result = processOptions()) != -1)
            {
                return result;
            }

            // set verbose logging
            setVerboseLogging();

            // make sure a file was provided
            if (m_positionalArgs.size() < 1)
            {
                throw std::runtime_error("no output file path was provided");
            }

            // generate key files
            string_vector_t::const_iterator it = m_positionalArgs.begin();
            for (; it != m_positionalArgs.end(); ++it)
            {
                generateKeyFile(*it);
            }
        }
        catch (std::exception &e)
        {
            Log::log(Logger::ERROR, "error: %s\n", e.what());
            return 1;
        }
        catch (...)
        {
            Log::log(Logger::ERROR, "error: unexpected exception\n");
            return 1;
        }

        return 0;
    }

    /*!
     * \brief Turns on verbose logging.
     */
    void setVerboseLogging()
    {
        if (m_isVerbose)
        {
            // verbose only affects the INFO and DEBUG filter levels
            // if the user has selected quiet mode, it overrides verbose
            switch (Log::getLogger()->getFilterLevel())
            {
                case Logger::INFO:
                    Log::getLogger()->setFilterLevel(Logger::INFO2);
                    break;
                case Logger::DEBUG:
                    Log::getLogger()->setFilterLevel(Logger::DEBUG2);
                    break;
                default:;
            }
        }
    }

    /*!
     * \brief Opens the file at \a path and writes a random key file.
     *
     * Each key file will have #m_keyCount number of keys written into it,
     * each on a line by itself.
     */
    void generateKeyFile(const std::string &path)
    {
        std::ofstream outputStream(path.c_str(), std::ios_base::binary | std::ios_base::out | std::ios_base::trunc);
        if (outputStream.is_open())
        {
            int i;
            for (i = 0; i < m_keyCount; ++i)
            {
                AESKey<128> key;
                key.randomize();
                key.writeToStream(outputStream);

                // put a newline after the key
                outputStream.write("\n", 1);

                // dump it
                dumpKey(key);
            }

            Log::log(Logger::INFO, "wrote key file %s\n", path.c_str());
        }
        else
        {
            throw std::runtime_error("could not open output file");
        }
    }

    /*!
     * \brief Write the value of each byte of the \a key to the log.
     */
    void dumpKey(const AESKey<128> &key)
    {
        // dump key bytes
        Log::log(Logger::INFO2, "key bytes: ");
        AESKey<128>::key_t the_key;
        key.getKey(&the_key);
        int q;
        for (q = 0; q < 16; q++)
        {
            Log::log(Logger::INFO2, "%02x ", the_key[q]);
        }
        Log::log(Logger::INFO2, "\n");
    }

    /*!
     * \brief Log an array of bytes as hex.
     */
    void logHexArray(Logger::log_level_t level, const uint8_t *bytes, unsigned count)
    {
        Log::SetOutputLevel leveler(level);
        //		Log::log("    ");
        unsigned i;
        for (i = 0; i < count; ++i, ++bytes)
        {
            if ((i % 16 == 0) && (i < count - 1))
            {
                if (i != 0)
                {
                    Log::log("\n");
                }
                Log::log("    0x%04x: ", i);
            }
            Log::log("%02x ", *bytes & 0xff);
        }

        Log::log("\n");
    }
};

/*!
 * Main application entry point. Creates an sbtool instance and lets it take over.
 */
int main(int argc, char *argv[], char *envp[])
{
    try
    {
        return keygen(argc, argv).run();
    }
    catch (...)
    {
        Log::log(Logger::ERROR, "error: unexpected exception\n");
        return 1;
    }

    return 0;
}
