// SPDX-License-Identifier: GPL-2.0+

  /*
   * (C) Copyright 2015 Google, Inc
   *
   * (C) Copyright 2008-2014 Rockchip Electronics
   *
   * Rivest Cipher 4 (RC4) implementation

   */
  
  #ifndef USE_HOSTCC
  #include <common.h>
  #endif
  #include <rc4.h>
  
  void rc4_encode(unsigned char *buf, unsigned int len, unsigned char key[16])
  {
  	unsigned char s[256], k[256], temp;
  	unsigned short i, j, t;
  	int ptr;
  
  	j = 0;
  	for (i = 0; i < 256; i++) {
  		s[i] = (unsigned char)i;
  		j &= 0x0f;
  		k[i] = key[j];
  		j++;
  	}
  
  	j = 0;
  	for (i = 0; i < 256; i++) {
  		j = (j + s[i] + k[i]) % 256;
  		temp = s[i];
  		s[i] = s[j];
  		s[j] = temp;
  	}
  
  	i = 0;
  	j = 0;
  	for (ptr = 0; ptr < len; ptr++) {
  		i = (i + 1) % 256;
  		j = (j + s[i]) % 256;
  		temp = s[i];
  		s[i] = s[j];
  		s[j] = temp;
  		t = (s[i] + (s[j] % 256)) % 256;
  		buf[ptr] = buf[ptr] ^ s[t];
  	}
  }