LCOV - code coverage report
Current view: top level - shishi/gl - arcfour.c (source / functions) Hit Total Coverage
Test: GNU Shishi Lines: 28 28 100.0 %
Date: 2010-05-20 Functions: 2 2 100.0 %
Legend: Lines: hit not hit | Branches: + taken - not taken # not executed Branches: 8 8 100.0 %

           Branch data     Line data    Source code
       1                 :            : /* arcfour.c --- The arcfour stream cipher
       2                 :            :  * Copyright (C) 2000, 2001, 2002, 2003, 2005, 2006, 2009, 2010 Free Software
       3                 :            :  * Foundation, Inc.
       4                 :            :  *
       5                 :            :  * This file is free software; you can redistribute it and/or modify
       6                 :            :  * it under the terms of the GNU General Public License as published
       7                 :            :  * by the Free Software Foundation; either version 3, or (at your
       8                 :            :  * option) any later version.
       9                 :            :  *
      10                 :            :  * This file is distributed in the hope that it will be useful, but
      11                 :            :  * WITHOUT ANY WARRANTY; without even the implied warranty of
      12                 :            :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13                 :            :  * General Public License for more details.
      14                 :            :  *
      15                 :            :  * You should have received a copy of the GNU General Public License
      16                 :            :  * along with this file; if not, write to the Free Software
      17                 :            :  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
      18                 :            :  * 02110-1301, USA.
      19                 :            :  *
      20                 :            :  */
      21                 :            : 
      22                 :            : /* Code from Libgcrypt adapted for gnulib by Simon Josefsson. */
      23                 :            : 
      24                 :            : /*
      25                 :            :  * For a description of the algorithm, see:
      26                 :            :  *   Bruce Schneier: Applied Cryptography. John Wiley & Sons, 1996.
      27                 :            :  *   ISBN 0-471-11709-9. Pages 397 ff.
      28                 :            :  */
      29                 :            : 
      30                 :            : #include <config.h>
      31                 :            : 
      32                 :            : #include "arcfour.h"
      33                 :            : 
      34                 :            : void
      35                 :        290 : arcfour_stream (arcfour_context * context, const char *inbuf, char *outbuf,
      36                 :            :                 size_t length)
      37                 :            : {
      38                 :        290 :   uint8_t i = context->idx_i;
      39                 :        290 :   uint8_t j = context->idx_j;
      40                 :        290 :   char *sbox = context->sbox;
      41                 :            : 
      42         [ +  + ]:      12835 :   for (; length > 0; length--)
      43                 :            :     {
      44                 :            :       char t;
      45                 :            : 
      46                 :      12545 :       i++;
      47                 :      12545 :       j += sbox[i];
      48                 :      12545 :       t = sbox[i];
      49                 :      12545 :       sbox[i] = sbox[j];
      50                 :      12545 :       sbox[j] = t;
      51                 :      25090 :       *outbuf++ = (*inbuf++
      52                 :      12545 :                    ^ sbox[(0U + sbox[i] + sbox[j]) % ARCFOUR_SBOX_SIZE]);
      53                 :            :     }
      54                 :            : 
      55                 :        290 :   context->idx_i = i;
      56                 :        290 :   context->idx_j = j;
      57                 :        290 : }
      58                 :            : 
      59                 :            : void
      60                 :          6 : arcfour_setkey (arcfour_context * context, const char *key, size_t keylen)
      61                 :            : {
      62                 :            :   size_t i, j, k;
      63                 :          6 :   char *sbox = context->sbox;
      64                 :            : 
      65                 :          6 :   context->idx_i = context->idx_j = 0;
      66         [ +  + ]:       1542 :   for (i = 0; i < ARCFOUR_SBOX_SIZE; i++)
      67                 :       1536 :     sbox[i] = i;
      68         [ +  + ]:       1542 :   for (i = j = k = 0; i < ARCFOUR_SBOX_SIZE; i++)
      69                 :            :     {
      70                 :            :       char t;
      71                 :       1536 :       j = (j + sbox[i] + key[k]) % ARCFOUR_SBOX_SIZE;
      72                 :       1536 :       t = sbox[i];
      73                 :       1536 :       sbox[i] = sbox[j];
      74                 :       1536 :       sbox[j] = t;
      75         [ +  + ]:       1536 :       if (++k == keylen)
      76                 :        124 :         k = 0;
      77                 :            :     }
      78                 :          6 : }

Generated by: LCOV version 1.8