szyfry

#include "stdafx.h"
#include<iostream>
#include <fstream>
#include<cstring>
#include <string>

using namespace std;

void kodowanie(char *napis)
{
    int dl = strlen(napis); //wyznaczenie liczby znaków

    for(int i=0; i<dl-1; i+=2) //przesuwamy się o dwa znaki
    //zamiana sąsiadujących znaków
    {
        char pom = napis[i];
        napis[i] = napis[i+1]; //dlatego w pętli i<dl-1
        napis[i+1] = pom;
    }
}

int main()
{
    char napis[100];

    cout<<"Podaj napis do zaszyfrowania: ";
    cin.getline(napis, 100);

    cout<<"Przed szyfrowaniem: ";
    cout<<napis<<endl;

    //szyfrujemy
    kodowanie(napis);

    cout<<"Szyfrogram: ";
    cout<<napis<<endl;

    //deszyfrujemy
    kodowanie(napis);

    cout<<"Tekst jawny: ";
    cout<<napis<<endl;

    cin.get();
    return 0;
}

 //This function receives text and shift and
// returns the encrypted text

//CEZAR
string encrypt(string text, int s)
{
    string result = "";

    // traverse text
    for (int i=0;i<text.length();i++)
    {
        // apply transformation to each character
        // Encrypt Uppercase letters
        if (isupper(text[i]))
            result += char(int(text[i]+s-65)%26 +65);

    // Encrypt Lowercase letters
    else
        result += char(int(text[i]+s-97)%26 +97);
    }

    // Return the resulting string
    return result;
}

// Driver program to test the above function
int main()
{
    string text="ATTACKATONCE";
    int s = 4;
    cout << "Text : " << text;
    cout << "\nShift: " << s;
    cout << "\nCipher: " << encrypt(text, s);
    system("pause");
    return 0;
}
////////XOR
void encryptDecrypt(char inpString[])
{
    // Define XOR key
    // Any character value will work
    char xorKey = 'P';

    // calculate length of input string
    int len = strlen(inpString);

    // perform XOR operation of key
    // with every caracter in string
    for (int i = 0; i < len; i++)
    {
        inpString[i] = inpString[i] ^ xorKey;
        printf("%c",inpString[i]);
    }
}

 Driver program to test above function
int main()
{
    char sampleString[] = "GeeksforGeeks";

    // Encrypt the string
    printf("Encrypted String: ");
    encryptDecrypt(sampleString);
    printf("\n");

    // Decrypt the string
    printf("Decrypted String: ");
    encryptDecrypt(sampleString);
  system("pause");
    return 0;
}
string GetFilePathFromUser() {
    string path;
    cout << "Please enter the full file path: ";
    cin >> path;
    return path;
}
string GetFileData() {

    string filePath = GetFilePathFromUser();

    string txt;
    string resultTxt;


    ifstream inFile("a.txt", std::ios_base::binary);
    inFile.open(filePath);
    if (!inFile) {
        cout << "Unable to open file \n";
        exit(1); // terminate with error
    }

    inFile >> resultTxt;

    while (inFile >> txt) {
        resultTxt += txt;
    }

    inFile.close();
    return resultTxt;
}
string encrypt(string text, int s)
{
    string result = "";

     traverse text
    for (int i=0;i<text.length();i++)
    {
         apply transformation to each character
         Encrypt Uppercase letters
        if (isupper(text[i]))
            result += char(int(text[i]+s-65)%26 +65);

     Encrypt Lowercase letters
    else
        result += char(int(text[i]+s-97)%26 +97);
    }

     Return the resulting string
    return result; }

int main()
{ string txt = GetFileData();
cout<<txt<<endl;
  cout<<encrypt(txt,2);
  system("pause");
  return 0;}

rc4
    #include <stdio.h>
#include <string.h>
#include <stdlib.h>

#define N 256   // 2^8

void swap(unsigned char *a, unsigned char *b) {
    int tmp = *a;
    *a = *b;
    *b = tmp;
}

int KSA(char *key, unsigned char *S) {

    int len = strlen(key);
    int j = 0;

    for(int i = 0; i < N; i++)
        S[i] = i;

    for(int i = 0; i < N; i++) {
        j = (j + S[i] + key[i % len]) % N;

        swap(&S[i], &S[j]);
    }

    return 0;
}

int PRGA(unsigned char *S, char *plaintext, unsigned char *ciphertext) {

    int i = 0;
    int j = 0;

    for(size_t n = 0, len = strlen(plaintext); n < len; n++) {
        i = (i + 1) % N;
        j = (j + S[i]) % N;

        swap(&S[i], &S[j]);
        int rnd = S[(S[i] + S[j]) % N];

        ciphertext[n] = rnd ^ plaintext[n];

    }

    return 0;
}

int RC4(char *key, char *plaintext, unsigned char *ciphertext) {

    unsigned char S[N];
    KSA(key, S);

    PRGA(S, plaintext, ciphertext);

    return 0;
}

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

    if(argc < 3) {
        printf("Usage: %s <key> <plaintext>", argv[0]);
        return -1;
    }

    unsigned char *ciphertext = malloc(sizeof(int) * strlen(argv[2]));

    RC4(argv[1], argv[2], ciphertext);

    for(size_t i = 0, len = strlen(argv[2]); i < len; i++)
        printf("%02hhX", ciphertext[i]);

    return 0;
}