Intonga yamandulo kwintonga endala

Ndiza kuqala ngaphandle kwe-hitch, ndakuba ndibe nesityhilelo (kakuhle, singenamandla kakhulu, ukunyaniseka) kwaye kwavela ingcamango yokuprinta inkqubo ehambisa umfanekiso ukusuka kumxhasi ukuya kumncedisi. Lula ngokwaneleyo akunjalo? Ewe, kumdwelisi onamava, kuya kuba njalo. Iimeko zilula - musa ukusebenzisa amathala eencwadi yomntu wesithathu. Ngokomgaqo, inzima ngakumbi, kodwa ngenxa yokuba kufuneka uyiqikelele kwaye ukhangele imizekelo, kakuhle, umsebenzi onjalo. Ndagqiba kwelokuba lo msebenzi uxhomekeke kum. Ngaphezu koko, kunqweneleka ukuba kubekho ikhowudi eyaneleyo ukuze ifakwe kwiforum xa ufuna uncedo. Okokuqala, amehlo am awela kwi-FTP, ngendlela, i-OS apho iWindows iphuhliswa. Inzuzo yeFTP kukuba awukwazi ukudlulisa umfanekiso kuphela, kodwa nayiphi na ifayile ngayo. Emva kokukhuphela i-Filezilla Server, ukwabelana ngesikhokelo sokufunda / ukubhala kunye nokudala umsebenzisi ngegama eliyimfihlo, ndazama ukudibanisa i-Filezilla Client, yonke into yasebenza. Ndenze umzekelo olula wekhowudi kwiC/C++:

#include <iostream>
void main()
{
	FILE* fs;
	fopen_s(&fs, "1.txt", "w");
	if (fs)
	{
    fwrite("userrnpasswordrnsend D:\share.txtrnbye", 1, sizeof("userrnpasswordrnsend D:\share.txtrnbye"), fs);
    fwrite("00", 1, sizeof("00"), fs);
    fclose(fs);
	}
	system("ftp -s:1.txt 127.0.0.1");
}

Ukuba inkumbulo yam iyandikhonza, ngoko yonke into yasebenza kwi-localhost, kwaye xa ihambisa phezu kwenethiwekhi, kwenzeke impazamo kumgca wokuthumela. Eyona nto iluncedo apha kuku a) ngokufutshane b) awudingi kufakela umxhasi, kodwa sebenzisa isixhobo esele sakhelwe ngaphakathi se-ftp esivela kuMicrosoft. Nangona ngokombono wam kufuneka isebenze ngeenkqubo kunye namacandelo. Ukuba ufumanisa ukuba yintoni ingxaki yale ndlela kwaye ubhale kumazwana, kuya kuba kuhle.

Ndingakhange ndifumane mpendulo kwiqela leeforamu, ndishiye le khowudi kwaye ndagqiba ekubeni ndisebenzise ujongano lweenethiwekhi zesokhethi. Ndandisele ndinamava okudlulisa uluhlu lwe chars kwenye inkqubo. Ngendlela, unokufunda kwi-Tanenbaum, iinethiwekhi zeKhompyutha, kwisahluko malunga noluhlu lwezothutho. Kukho umzekelo womxhasi kunye nomncedisi, nangona kungekhona "kubathengi abaninzi - umncedisi omnye", kodwa kuphela "umthengi omnye - umncedisi omnye". Kuba ukuhanjiswa kungaphaya kwe-Intanethi, kufuneka uguqulele idatha ngandlela thile. Kule nto, i-block cipher isetyenziswa - inethiwekhi ye-Feistel. Ukongeza kwiseva kuyimfuneko ukwenza abathengi abaninzi (ngaphezu kwesinye). Ukwenza oku, siza kusebenzisa Imisonto, umfanekiso wothumelo uzakuthatha umfanekiso wekhusi wekhusi kumxhasi, uguqulelwe ngokuntsonkothileyo kwaye udluliselwe kumncedisi, apho uya kucinywa kwaye ngoko nangoko iboniswe kwiscreen ngenkqubo engagqibekanga yokuvula * .tga imifanekiso.

Ikhowudi yeseva:

#include <iostream>
#include <WinSock.h>
#pragma comment (lib,"WS2_32.lib")

#include <fstream>
#include <algorithm>
#include <string>
#include <iterator>
#include <vector>
void error(const char* msg)
{
    //perror(msg);
    std::cout<<'n'<<WSAGetLastError();
    WSACleanup();
    std::cin.ignore();
    exit(1);
}
void bzero(char*buf, int l)
{
    for (int i = 0; i < l; i++)
        buf[i] = '';
}
struct arg_s
{
    unsigned char* buffer2;
    bool exit;
};
char** buffer;
struct arg_sa
{
    struct arg_s* lalk;
    int current;
};
#define type struct arg_sa
int sockfd, * newsockfd;//слушающий и массив клиентских сокетов
int buflen2 = 10292000;//максимальный размер изображения в байтах для RGBA*Width*Height
struct sockaddr_in *cli_addr;
int* clilen;
int currentclient,cc;//сс-клиент по счету(для записи инкремента имени файла клиента изображения)

typedef unsigned long long uint64_t;
typedef unsigned int uint32_t;
#define N 8//размер блока
#define F32 0xFFFFFFFF
uint32_t RK[N];//раундовые ключи
#define size64 sizeof(uint64_t)
#define ROR(x,n,xsize)((x>>n)|(x<<(xsize-n)))
#define ROL(x,n,xsize)((x<<n)|(x>>(xsize-n)))
#define RKEY(r)((ROR(K,r*3,size64*8))&F32)
const uint64_t K = 0x96EA704CFB1CF671;//ключ шифрования
struct hostent* server;
uint32_t F(uint32_t subblk, uint32_t key)
{
    return subblk + key;//функция шифрования
}
void createRoundKeys()
{
    for (int i = 0; i < N; i++)
        RK[i] = (ROR(K, i * 8, size64 * 8)) & F32;
}
uint64_t decrypt(uint64_t c_block)//расшифровка блоков сетью фейстеля
{
    //select subblocks
    uint32_t left = (c_block >> 32) & F32;
    uint32_t right = c_block & F32;
    uint32_t left_, right_;//subblock in the end of round
    for (int r = N - 1; r >= 0; r--)
    {
        uint32_t fk = F(left, RK[r]);
        left_ = left;
        right_ = right ^ fk;
        if (r > 0)//swap places to next round
        {
            left = right_;
            right = left_;
        }
        else //last round not swap
        {
            left = left_;
            right = right_;
        }
    }
    //collect subblock in block
    uint64_t block = left;
    block = (block << 32) | (right & F32);
    return block;
}
void session_(LPVOID args)//функция потока ля каждого клиента
{
    int current = currentclient++;
    bzero((char*)&(cli_addr[current]), sizeof(&(cli_addr[current])));
    newsockfd[current] = accept(sockfd, (struct sockaddr*)&(cli_addr[current]), &(clilen[current]));
    if (newsockfd[current] < 0)
    {
        error("Error on acceptn");
    }
    char* s = new char[100];
    int n = recv(newsockfd[current], s, 100, 0);
    int buflen2 = atoi(s);//получаем число байтов изображения
    FILE* f;
    std::string name = "Screen";
    cc++;
    _itoa_s(cc, s, 100, 10);
    name += s;
    name += ".tga";
    fopen_s(&f,name.c_str(), "wb");//создаем файл изображения с увеличиваещимся на 1 именем, чтобы не перезаписать
    if (f != NULL)
    {
        unsigned char tgaHeader[12] = { 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
        unsigned char header[6];
        n = recv(newsockfd[current], buffer[current], sizeof(tgaHeader), 0);
        fwrite((unsigned char*)buffer[current], 1, sizeof(tgaHeader), f);
        bzero(buffer[current], buflen2);
        n = recv(newsockfd[current], buffer[current],sizeof(header), 0);
        fwrite((unsigned char*)buffer[current], 1, sizeof(header), f);//записали хидеры
        bzero(buffer[current], buflen2);
        n = recv(newsockfd[current], buffer[current], buflen2, 0);//получили байты самого изображения
        //
        //расшифровка байтов
        createRoundKeys();
        unsigned long long id;
        std::vector<uint64_t>* plaintext = new std::vector<uint64_t>();
        int i = 0;
        while (i<buflen2)
        {
            memcpy(&id, (buffer[current]) + i, N);
            plaintext->push_back(decrypt(id));
            i += 8;
        }
        std::cout << "i=" << i << std::endl;
        i = 0;
        char str_[N + 1];
        memset(str_, 0, N);
        str_[N] = '';
        for (std::vector<uint64_t>::iterator it = plaintext->begin(); it != plaintext->end(); ++it)
        {
            memcpy(str_, &*it, N);
            fwrite((unsigned char*)str_, sizeof(unsigned char), N/*strlen(str_)*/, f);
            i += 8;
        }
        std::cout << "i=" << i << std::endl;
        //конец рашифровки байтов
        //fwrite((unsigned char*)buffer[current], sizeof(char), buflen2, f);
        fclose(f);
    }
    system(name.c_str());//открываем изображение *.tga встроенным редактором
}
int main()
{
    cc = 0;
    WSADATA ws = { 0 };
    if (WSAStartup(MAKEWORD(2, 2), &ws) == 0)
    {
        currentclient = 0;
        int maxclients = 2;//максимальное число клиентов
        cli_addr = new struct sockaddr_in[maxclients];
        clilen = new int[maxclients];
        buffer = new char* [maxclients];
        for (int i = 0; i < maxclients; i++)
        {
            clilen[i] = sizeof(cli_addr[i]);
        }
        sockfd = socket(AF_INET, SOCK_STREAM, 0);//tcp сокет
        if (sockfd < 0)
            error("ERROR opening socket");
        struct sockaddr_in serv_addr;
        bzero((char*)&serv_addr, sizeof(serv_addr));
        serv_addr.sin_family = AF_INET;
        serv_addr.sin_addr.s_addr = INADDR_ANY;
        int port = 30000;//порт
        serv_addr.sin_port = htons(port);
        if (bind(sockfd, (struct sockaddr*)&serv_addr, sizeof(serv_addr)) < 0)
            error("ERROR on binding");
        if (listen(sockfd, 10) < 0)
            error("ERROR listen");
        HANDLE* thread;//массив потоков для каждого клиента отдельный
        struct arg_sa* args;
        while (true)
        {
            newsockfd = new int[maxclients];
            thread = (HANDLE*)malloc(sizeof(HANDLE) * maxclients);
            args = new struct arg_sa[maxclients];
            for (int i = 0; i < maxclients; i++)
            {
                args[i].lalk = new struct arg_s();
                buffer[i] = new char[buflen2];
            }
            int i = -1;
            while (++i < maxclients)
            {
                Sleep(1);
                args[i].current = i;
                args[i].lalk->exit = false;
                thread[i] = CreateThread(0, 0, (LPTHREAD_START_ROUTINE)(session_), args, 0, 0);
            }
                for (int i = 0; i < maxclients; i++)
                    WaitForSingleObject(thread[i], INFINITE);//ждем завершения всех потоков
            i = -1;
            while (++i < maxclients)
            {
                shutdown(newsockfd[i], 0);
                TerminateThread(thread[i], 0);
            }
            //delete[] newsockfd;
            //free(thread);
            currentclient = 0;
            for (int i = 0; i < maxclients; i++)
            {
                //delete args[i].lalk;
                //delete[] args[i].lalk->buffer;
            }
            //delete[] args;
        }
        shutdown(sockfd, 0);
        WSACleanup();
        return 0;
    }
    std::cin.ignore();
}

Ngamafutshane, kwi-loop engunaphakade, iintambo zenziwe kumxhasi ngamnye kwaye zilinde ukwamkelwa de abathengi badibanise. Emva koko, i-WaitForSingleObject ilinda de zidlule zonke. Umxhasi ngamnye unesokethi yakhe kunye ne-buffer yakhe yokuthumela. Oko kukuthi, kukho iisokethi ze-M+1 kumncedisi, apho uM inani labathengi. Emva kokugqiba konke ukudluliselwa, yonke into iyaphinda.

Ngoku qwalasela umxhasi:

#include <iostream>
#include <WinSock.h>
#include <vector>
#pragma comment (lib,"WS2_32.lib")
void error(const char* msg)
{
    //perror(msg);
    std::cout << 'n' << WSAGetLastError();
    WSACleanup();
    std::cin.ignore();
    exit(1);
}
void bzero(char* buf, int l)
{
    for (int i = 0; i < l; i++)
        buf[i] = '';
}
typedef unsigned long long uint64_t;
typedef unsigned int uint32_t;
#define N 8
#define F32 0xFFFFFFFF
uint32_t RK[N];//раундовые ключи
#define size64 sizeof(uint64_t)
#define ROR(x,n,xsize)((x>>n)|(x<<(xsize-n)))
#define ROL(x,n,xsize)((x<<n)|(x>>(xsize-n)))
#define RKEY(r)((ROR(K,r*3,size64*8))&F32)
const uint64_t K = 0x96EA704CFB1CF671;//ключ шифрования
void createRoundKeys()
{
    for (int i = 0; i < N; i++)
        RK[i] = (ROR(K, i * 8, size64 * 8)) & F32;
}
uint32_t F(uint32_t subblk, uint32_t key)
{
    return subblk + key;//функция шифрования
}
uint64_t encrypt(uint64_t block)//зашифровка блоков сетью Фейстеля
{
    //select subblocks
    uint32_t left = (block >> 32) & F32;
    uint32_t right = block & F32;
    uint32_t left_, right_;//subblock in the end of round
    for (int r = 0; r < N; r++)
    {
        uint32_t fk = F(left, RK[r]);
        left_ = left;
        right_ = right ^ fk;
        if (r < N - 1)//swap places to next round
        {
            left = right_;
            right = left_;
        }
        else//last round not swap
        {
            left = left_;
            right = right_;
        }
    }
    //collect subblock in block
    uint64_t c_block = left;
    c_block = (c_block << 32) | (right & F32);
    return c_block;
}
int main()
{
    keybd_event(VK_LWIN, 0, 0, 0);
    keybd_event('M', 0, 0, 0);
    keybd_event('M', 0, KEYEVENTF_KEYUP, 0);
    keybd_event(VK_LWIN, 0, KEYEVENTF_KEYUP, 0);//эти строки сворачивают все приложения
    Sleep(1000);//чтобы сделать скриншот рабочего стола
    WSADATA ws = { 0 };
    if (WSAStartup(MAKEWORD(2, 2), &ws) == 0)
    {
        int sockfd;
        sockfd = socket(AF_INET, SOCK_STREAM, 0);
        struct sockaddr_in serv_addr, cli_addr;
        bzero((char*)&serv_addr, sizeof(serv_addr));
        bzero((char*)&cli_addr, sizeof(cli_addr));
        serv_addr.sin_family = AF_INET;

        const char* add = "127.0.0.1";//адрес сервера
        serv_addr.sin_addr.s_addr = inet_addr(add);
        int port = 30000;//порт
        serv_addr.sin_port = htons(port);
        int servlen = sizeof(serv_addr);
        int n = connect(sockfd, (struct sockaddr*)&serv_addr, servlen);
        
        //ниже код делает скриншот
        HDC ScreenDC = GetDC(0);
        HDC MemoryDC = CreateCompatibleDC(ScreenDC);
        int ScreenHeight = GetSystemMetrics(SM_CYSCREEN);
        int ScreenWidth = GetSystemMetrics(SM_CXSCREEN);
        ScreenWidth = ((ScreenWidth - 1) / 4 + 1) * 4;
        BITMAPINFO BMI;
        BMI.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
        BMI.bmiHeader.biWidth = ScreenWidth;
        BMI.bmiHeader.biHeight = ScreenHeight;
        BMI.bmiHeader.biSizeImage = ScreenWidth * ScreenHeight * 3;
        BMI.bmiHeader.biCompression = BI_RGB;
        BMI.bmiHeader.biBitCount = 24;
        BMI.bmiHeader.biPlanes = 1;
        DWORD ScreenshotSize;
        ScreenshotSize = BMI.bmiHeader.biSizeImage;
        unsigned char* ImageBuffer;
        HBITMAP hBitmap = CreateDIBSection(ScreenDC, &BMI, DIB_RGB_COLORS, (void**)&ImageBuffer, 0, 0);
        SelectObject(MemoryDC, hBitmap);
        BitBlt(MemoryDC, 0, 0, ScreenWidth, ScreenHeight, ScreenDC, 0, 0, SRCCOPY);
        DeleteDC(MemoryDC);
        ReleaseDC(NULL, ScreenDC);
        FILE* sFile = 0;
        unsigned char tgaHeader[12] = { 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
        unsigned char header[6];
        unsigned char tempColors = 0;
        fopen_s(&sFile, "S.tga", "wb");
        if (!sFile) {
            exit(1);
        }
        header[0] = ScreenWidth % 256;
        header[1] = ScreenWidth / 256;
        header[2] = ScreenHeight % 256;
        header[3] = ScreenHeight / 256;
        header[4] = BMI.bmiHeader.biBitCount;
        header[5] = 0;
        fwrite(tgaHeader, 1, sizeof(tgaHeader), sFile);
        fwrite(header, sizeof(header), 1, sFile);
        //конец записали изображение в файл
        
        //шифруем блоками полезную нагрузку изображения кроме хидеров
        createRoundKeys();
        std::vector<uint64_t>* msg = new std::vector<uint64_t>(),*crpt = new std::vector<uint64_t>();
        unsigned long long id;
        int i = 0;
        while (i < BMI.bmiHeader.biSizeImage)
        {
            memcpy(&id, (ImageBuffer + i), N);
            msg->push_back(id);
            i += 8;
        }
        std::cout << "i=" << i << std::endl; 
        uint64_t cipher;
        i = 0;
        char str_[N + 1];
        memset(str_, 0, N);
        str_[N] = '';
        for (std::vector<uint64_t>::iterator it = msg->begin(); it != msg->end(); ++it)
        {
            cipher = encrypt(*it);
            memcpy(str_, &cipher, N);
            fwrite((unsigned char*)str_, sizeof(unsigned char), N, sFile);
            i += 8;
        }
        std::cout << "i=" << i << std::endl;
        //
        //fwrite(ImageBuffer, BMI.bmiHeader.biSizeImage, 1, sFile);
        std::cout << BMI.bmiHeader.biSizeImage << std::endl;
        fclose(sFile);
        DeleteObject(hBitmap);
        FILE* f;
        fopen_s(&f, "S.tga", "rb");
        int count = 0;
        if (f != NULL)
        {
            while (getc(f) != EOF)
                count++;//считаем байты изображения в счетчик чтобы потом передать
            fclose(f);
        }
        count -= 18;
        std::cout << count<< std::endl;
        char* s = new char[100];
        _itoa_s(count, s, 100, 10);
        n = send(sockfd, s, 100, 0);//передаем счетчик
        char* buffer = new char[count];
        fopen_s(&f, "S.tga", "rb");
        size_t bytes;
        if (f != NULL)
        {
            memcpy(buffer, tgaHeader, sizeof(tgaHeader));
            n = send(sockfd, buffer, sizeof(tgaHeader), 0);
            bzero(buffer, count);
            memcpy(buffer, header, sizeof(header));
            n = send(sockfd, buffer, sizeof(header), 0);
            bzero(buffer, count);//передаем хидеры
            for(int i=0;i<18;i++)
                fgetc(f);
            bzero(buffer, count);
            bytes = fread(buffer, sizeof(unsigned char), count, f);
            n = send(sockfd,buffer, count, 0);//передаем шифрованные байты изображения
            fclose(f);
        }
        Sleep(1000);
        shutdown(sockfd, 0);
        WSACleanup();
        //system("del S.tga");
        delete[] buffer,s;
        return 0;
    }
    //std::cin.ignore();
}

Nasi isiphumo somsebenzi womxhasi, ifayile yesikrini ye-S.tga, efihliweyo

Kubonakala ngathi yidesktop.

Kwaye nantsi isiphumo esiye sakhutshelwa kwiseva kwaye yacocwa yiScreen.tga

Njengoko ubona, inethiwekhi ye-Feistel eqhelekileyo ayifanelekanga ukubethelwa, kodwa ungasebenzisa iindlela ze-CBC kunye ne-CFB, mhlawumbi iya kube iguqulelwe kakuhle, ukunyaniseka, andizange ndiyihlolisise.

Спасиalu

umthombo: www.habr.com