blowfish.c

/*
 * Author     :  Paul Kocher
 * E-mail     :  pck@netcom.com
 * Date       :  1997
 * Description:  C implementation of the Blowfish algorithm.
 */

#include "includes.h"
#include "defines.h"
#include "blowfish.h"
#define N               16/* Exchange Xl and Xr */
    temp = Xl;
    Xl = Xr;
    Xr = temp;
  }

  /* Exchange Xl and Xr */
  temp = Xl;
  Xl = Xr;
  Xr = temp;
  Xr = Xr ^ ctx->P[1];
  Xl = Xl ^ ctx->P[0];
  *xl = Xl;
  *xr = Xr;
}

void Blowfish_Init(BLOWFISH_CTX *ctx, unsigned char *key, int keyLen) {
  int i, j, k;
  uInt32 data, datal, datar;

  for (i = 0; i < 4; i++) {

    for (j = 0; j < 256; j++)
      ctx->S[i][j] = ORIG_S[i][j];
  }

  j = 0;

  for (i = 0; i < N + 2; ++i) {
    data = 0x00000000;

    for (k = 0; k < 4; ++k) {
      data = (data << 8) | key[j];
      j = j + 1;
      if (j >= keyLen)
        j = 0;
    }

    ctx->P[i] = ORIG_P[i] ^ data;
  }

  datal = 0x00000000;
  datar = 0x00000000;

  for (i = 0; i < N + 2; i += 2) {
    Blowfish_Encrypt(ctx, &datal, &datar);
    ctx->P[i] = datal;
    ctx->P[i + 1] = datar;
  }

  for (i = 0; i < 4; ++i) {

    for (j = 0; j < 256; j += 2) {
      Blowfish_Encrypt(ctx, &datal, &datar);
      ctx->S[i][j] = datal;
      ctx->S[i][j + 1] = datar;
    }
  }
}