#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int ordered[256];
int reversed[256];
int streamout[256];

int encrypt();
int decrypt();

void printout()
{
        printf("\n**************************************************************************");
        printf("\n*                                                   *");
        printf("\n*  STREAMBUDDY a cipher by JT [Turbo C 2.01]               *");
        printf("\n*  (The code looks funny i know but it works mainthing?;)  *");
        printf("\n*  Buddy variable sized cipher, key 1>-256 bytes, int state 4096-bits    *");
        printf("\n*  Key is expand into two streams, each run a keybased shuffle 256bytes  *");
        printf("\n*  Every round the shuffle are dowmmixed to 1 stream with a saved state  *");
        printf("\n*  Stream A xor B-> xor mixpad ->xor streamout[savedstate]->xor plaintxt *");
        printf("\n*  A zero filled 102 MB file called plain.txt is created at start +-1min *");
        printf("\n*                                                          *");
        printf("\n* The encoded file cipher.txt, and the decoded file decipher.txt +-1min  *");
        printf("\n*                                                          *");
        printf("\n**************************************************************************");
        printf("\n\n\n");

}

/*PRNG*/
int streambuddy()
{
        int mixpad[256];
        int slot_1,slot_2,slot_3,slot_4;
        int i;

        for(i=0;i<255;i++)
        {
                slot_1 = ordered[i+1];
                slot_2 = ordered[slot_1];
                ordered[slot_1] = ordered[i];
                ordered[i] = slot_2;
                slot_3 = reversed[i+1];
                slot_4 = reversed[slot_3];
                reversed[slot_3] = reversed[i];
                reversed[i] = slot_4;
        }

        for(i=0;i<256;i++)
        {
                mixpad[i] = reversed[i] ^ ordered[i];
        }

        for(i=0;i<256;i++)
        {
                streamout[i] ^= mixpad[i];
        }
        return 0;
}

/*KEYXPAND*/
int keyexpander(int key[], int keysize)
{
        int serie[256];
        int i=0,j=0,k=0;
        int stop=0;
        int found=0;

        for(i=0;i<256;i++)
        {
                stop=0;
                while(!stop)
                {
                        found = 0;
                        for(k=0;k<i;k++)
                        {
                                if(key[j]==serie[k]){found=1;}
                        }
                        if(!found)
                        {
                                serie[i]=key[j];stop=1;
                        } else
                        {
                                key[j] = key[j]+1;
                        }
                        if(key[j] > 255) {
                                key[j]=0;
                        }
                }
                j++;
                if(j > keysize-1) {j=0;}
        }

        for(k=0;k<42;k++)
        {
                for(i=0;i<255;i++)
                {
                        int slot_1,slot_2;
                        slot_1 = serie[i+1];
                        slot_2 = serie[slot_1];
                        serie[slot_1] = serie[i];
                        serie[i] = slot_2;

                }
        }

        for(i=0;i<256;i++)
        {
        ordered[i]=serie[i];
        }
        return 0;
}

int ireverse()
{
        int i;int j=0;
        for(i=255;i>-1;i--)
        {
                reversed[j] = ordered[i];
                j++;
        }
        for(i=1;i<255;i++){
        }
        return 0;
}

int main(void){
        printout();
        encrypt();
        decrypt();
        return 0;
}

int saltIV(int keyread[]){
        int i;
        srand(clock());
        for (i=0;i<4;i++){
                keyread[i]=rand()%256;
        }
        return 0;
}

int decrypt()
{
        int keyread[256];
        int text[256];
        int keysize=0;
        int i,j,k;
        FILE* in;
        FILE* out;
        printf("\n\n\nInput password for decode: ");
        keysize=4;
        in=fopen("cipher.txt","rb");
        /*GET KEY SALTIV+PASSWD*/
        for(i=0;i<4;i++){keyread[i]=getc(in);}
        while ((keyread[keysize]=getchar())!=10){keysize++;}
        printf("\n\nIV+password:");
        for(i=0;i<keysize;i++){printf("%d",keyread[i]);printf(",");}
        /*EXPAND KEY AND CREATE REVERSED SHADOW*/
        keyexpander(keyread,keysize);
        ireverse();
        /*MAKE SURE ARRAY DONT GET FUCKED UP*/
        for(i=0;i<256;i++){
                streamout[i]=0;
        }
        printf("\n\n\nWait while decrypt 102 MB to disk...+-1min");
        /*DECRYPT FILE*/
        out=fopen("decipher.txt","wb");
        for(k=0;k<20;k++){
                for(j=0;j<20000;j++){
                        streambuddy();
                                for(i=0;i<256;i++){
                                        text[i]=getc(in);
                                        text[i]^=streamout[i];
                                        fputc(text[i],out);
                                }
                }
        }
        fclose(in);
        fclose(out);
        printf("\n\n\nFINISHED!!");
        return 0;
}

int encrypt()
{
        int keyread[256];
        int text[256];
        int keysize=0;
        int i,j,k;
        FILE* in;
        FILE* out;
        /*CREATE ZEROFILLED PLAINTEXT*/
        printf("\n\n\nWait!! while 102 MB zerofilled plaintext created +-1min");
        out=fopen("plain.txt","wb");
        for(k=0;k<20;k++){
        for(j=0;j<20000;j++)
        {
                for(i=0;i<256;i++)
                {
                        fputc('0',out);
                }
        }
        }
        fclose(out);
        out=fopen("cipher.txt","wb");
        keysize=4;
        /*CREATE KEY ->IV+PASSWORD*/
        saltIV(keyread);
        printf("\n\n\nInput password for encode:");
        for(i=0;i<4;i++){fputc(keyread[i],out);}
        while ((keyread[keysize]=getchar())!=10){keysize++;}
        printf("\n\nIV+password:");
        for(i=0;i<keysize;i++){printf("%d",keyread[i]);printf(",");}
        /*EXPAND KEY AND CREATE REVERSED SHADOW*/
        keyexpander(keyread,keysize);
        ireverse();
        for(i=0;i<256;i++){streamout[i]=0;}
        /*ENCRYPT FILE*/
        in=fopen("plain.txt","rb");
        printf("\n\n\nWait while encrypt 102 MB to disk...+-1 min");
        for(k=0;k<20;k++){
                for(j=0;j<20000;j++){
                        streambuddy();
                        for(i=0;i<256;i++){
                                text[i]=getc(in);
                                text[i]^=streamout[i];
                                fputc(text[i],out);
                        }
                }
        }
        fclose(in);
        fclose(out);
        return 0;
}