Tools/Security/RC4.cpp

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#include "RC4.h"

namespace crypt {

  void rc4_removeWarningAndDoNothingFunction() {
    if (RC4_magicbyte == RC4_magicbyte)
      if (RC4_key == RC4_key) {

      }
  }

  void rc4_init(struct rc4_state *s, unsigned char *key, int length)
  {
    int j=0, k=0;

    int *m = s->m;
    s->x = 0;
    s->y = 0;

    for (int i=0; i<256; i++)
      m[i] = i;

    for (int i=0; i<256; i++) {
      int a = m[i];
      j = (unsigned char)(j+a+key[k]);
      m[i] = m[j];
      m[j] = a;

      if (++k >= length)
        k = 0;
    }
  }


  void rc4_crypt(struct rc4_state *s, unsigned char *data, int length)
  {
    int  x = s->x;
    int  y = s->y;
    int *m = s->m;

    for (int i = 0; i < length; i++ ) {
      x = (unsigned char)(x+1);
      int a = m[x];
      y = (unsigned char)(y+a);
      int b = m[y];
      m[x] = b;
      m[y] = a;
      data[i] ^= m[(unsigned char)(a+b)];
    }

    s->x = x;
    s->y = y;
  }
}

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