release/src-rt-6.x.4708/bcmcrypto/rc4.c

   1 /*
   2  * rc4.c
   3  * RC4 stream cipher
   4  *
   5  * Copyright (C) 2012, Broadcom Corporation
   6  * All Rights Reserved.
   7  *
   8  * This is UNPUBLISHED PROPRIETARY SOURCE CODE of Broadcom Corporation;
   9  * the contents of this file may not be disclosed to third parties, copied
  10  * or duplicated in any form, in whole or in part, without the prior
  11  * written permission of Broadcom Corporation.
  12  *
  13  * $Id: rc4.c 241182 2011-02-17 21:50:03Z $
  14  */
  15
  16 #include <typedefs.h>
  17 #include <bcmcrypto/rc4.h>
  18
  19 void
  20 BCMROMFN(prepare_key)(uint8 *key_data, int key_data_len, rc4_ks_t *ks)
  21 {
  22         unsigned int counter, index1 = 0, index2 = 0;
  23         uint8 key_byte, temp;
  24         uint8 *key_state = ks->state;
  25
  26         for (counter = 0; counter < RC4_STATE_NBYTES; counter++) {
  27                 key_state[counter] = (uint8) counter;
  28         }
  29
  30         for (counter = 0; counter < RC4_STATE_NBYTES; counter++) {
  31                 key_byte = key_data[index1];
  32                 index2 = (key_byte + key_state[counter] + index2) % RC4_STATE_NBYTES;
  33                 temp = key_state[counter];
  34                 key_state[counter] = key_state[index2];
  35                 key_state[index2] = temp;
  36                 index1 = (index1 + 1) % key_data_len;
  37         }
  38
  39         ks->x = 0;
  40         ks->y = 0;
  41 }
  42
  43 /* encrypt or decrypt using RC4 */
  44 void
  45 BCMROMFN(rc4)(uint8 *buf, int data_len, rc4_ks_t *ks)
  46 {
  47         uint8 tmp;
  48         uint8 xor_ind, x = ks->x, y = ks->y, *key_state = ks->state;
  49         int i;
  50
  51         for (i = 0; i < data_len; i++) {
  52                 y += key_state[++x]; /* mod RC4_STATE_NBYTES */
  53                 tmp = key_state[x];
  54                 key_state[x] = key_state[y];
  55                 key_state[y] = tmp;
  56                 xor_ind = key_state[x] + key_state[y];
  57                 buf[i] ^= key_state[xor_ind];
  58         }
  59
  60         ks->x = x;
  61         ks->y = y;
  62 }
  63
  64 #ifdef BCMRC4_TEST
  65 #include <stdio.h>
  66 #include <string.h>
  67
  68 #include "rc4_vectors.h"
  69
  70 #define NUM_VECTORS  (sizeof(rc4_vec) / sizeof(rc4_vec[0]))
  71
  72 int
  73 main(int argc, char **argv)
  74 {
  75         int k, fail = 0;
  76         uint8 data[RC4_STATE_NBYTES];
  77         rc4_ks_t ks;
  78         for (k = 0; k < NUM_VECTORS; k++) {
  79                 memset(data, 0, RC4_STATE_NBYTES);
  80                 memcpy(data, rc4_vec[k].input, rc4_vec[k].il);
  81
  82                 prepare_key(rc4_vec[k].key, rc4_vec[k].kl, &ks);
  83                 rc4(data, rc4_vec[k].il, &ks);
  84                 if (memcmp(data, rc4_vec[k].ref, rc4_vec[k].il) != 0) {
  85                         printf("%s: rc4 encrypt failed\n", *argv);
  86                         fail++;
  87                 } else {
  88                         printf("%s: rc4 encrypt %d passed\n", *argv, k);
  89                 }
  90
  91                 memset(data, 0, RC4_STATE_NBYTES);
  92                 memcpy(data, rc4_vec[k].ref, rc4_vec[k].il);
  93
  94                 prepare_key(rc4_vec[k].key, rc4_vec[k].kl, &ks);
  95                 rc4(data, rc4_vec[k].il, &ks);
  96                 if (memcmp(data, rc4_vec[k].input, rc4_vec[k].il) != 0) {
  97                         printf("%s: rc4 decrypt failed\n", *argv);
  98                         fail++;
  99                 } else {
 100                         printf("%s: rc4 decrypt %d passed\n", *argv, k);
 101                 }
 102         }
 103
 104         printf("%s: %s\n", *argv, fail?"FAILED":"PASSED");
 105         return (fail);
 106 }
 107 #endif /* BCMRC4_TEST */