utils/sbinfo/sha1.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2010 Amaury Pouly
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21 /* Based on http://en.wikipedia.org/wiki/SHA-1 */
  22 #include "crypto.h"
  23
  24 static uint32_t rot_left(uint32_t val, int rot)
  25 {
  26     return (val << rot) | (val >> (32 - rot));
  27 }
  28
  29 static inline void byte_swapxx(byte *ptr, int size)
  30 {
  31     for(int i = 0; i < size / 2; i++)
  32     {
  33         byte c = ptr[i];
  34         ptr[i] = ptr[size - i - 1];
  35         ptr[size - i - 1] = c;
  36     }
  37 }
  38
  39 static void byte_swap32(uint32_t *v)
  40 {
  41     byte_swapxx((byte *)v, 4);
  42 }
  43
  44 void sha_1_init(struct sha_1_params_t *params)
  45 {
  46     params->hash[0] = 0x67452301;
  47     params->hash[1] = 0xEFCDAB89;
  48     params->hash[2] = 0x98BADCFE;
  49     params->hash[3] = 0x10325476;
  50     params->hash[4] = 0xC3D2E1F0;
  51     params->buffer_nr_bits = 0;
  52 }
  53
  54 void sha_1_update(struct sha_1_params_t *params, byte *buffer, int size)
  55 {
  56     int buffer_nr_bytes = (params->buffer_nr_bits / 8) % 64;
  57     params->buffer_nr_bits += 8 * size;
  58     int pos = 0;
  59     if(buffer_nr_bytes + size >= 64)
  60     {
  61         pos = 64 - buffer_nr_bytes;
  62         memcpy((byte *)(params->w) + buffer_nr_bytes, buffer, 64 - buffer_nr_bytes);
  63         sha_1_block(params, params->hash, (byte *)params->w);
  64         for(; pos + 64 <= size; pos += 64)
  65             sha_1_block(params, params->hash, buffer + pos);
  66         buffer_nr_bytes = 0;
  67     }
  68     memcpy((byte *)(params->w) + buffer_nr_bytes, buffer + pos, size - pos);
  69 }
  70
  71 void sha_1_finish(struct sha_1_params_t *params)
  72 {
  73     /* length (in bits) in big endian BEFORE preprocessing */
  74     byte length_big_endian[8];
  75     memcpy(length_big_endian, &params->buffer_nr_bits, 8);
  76     byte_swapxx(length_big_endian, 8);
  77     /* append '1' and then '0's to the message to get 448 bit length for the last block */
  78     byte b = 0x80;
  79     sha_1_update(params, &b, 1);
  80     b = 0;
  81     while((params->buffer_nr_bits % 512) != 448)
  82         sha_1_update(params, &b, 1);
  83     /* append length */
  84     sha_1_update(params, length_big_endian, 8);
  85     /* go back to big endian */
  86     for(int i = 0; i < 5; i++)
  87         byte_swap32(&params->hash[i]);
  88 }
  89
  90 void sha_1_output(struct sha_1_params_t *params, byte *out)
  91 {
  92     memcpy(out, params->hash, 20);
  93 }
  94
  95 void sha_1_block(struct sha_1_params_t *params, uint32_t cur_hash[5], byte *data)
  96 {
  97     uint32_t a, b, c, d, e;
  98     a = cur_hash[0];
  99     b = cur_hash[1];
 100     c = cur_hash[2];
 101     d = cur_hash[3];
 102     e = cur_hash[4];
 103
 104     #define w params->w
 105
 106     memcpy(w, data, 64);
 107     for(int i = 0; i < 16; i++)
 108         byte_swap32(&w[i]);
 109
 110     for(int i = 16; i <= 79; i++)
 111         w[i] = rot_left(w[i - 3] ^ w[i - 8] ^ w[i - 14] ^ w[i - 16], 1);
 112
 113     for(int i = 0; i<= 79; i++)
 114     {
 115         uint32_t f, k;
 116         if(i <= 19)
 117         {
 118             f = (b & c) | ((~b) & d);
 119             k = 0x5A827999;
 120         }
 121         else if(i <= 39)
 122         {
 123             f = b ^ c ^ d;
 124             k = 0x6ED9EBA1;
 125         }
 126         else if(i <= 59)
 127         {
 128             f = (b & c) | (b & d) | (c & d);
 129             k = 0x8F1BBCDC;
 130         }
 131         else
 132         {
 133             f = b ^ c ^ d;
 134             k = 0xCA62C1D6;
 135         }
 136         uint32_t temp = rot_left(a, 5) + f + e + k + w[i];
 137         e = d;
 138         d = c;
 139         c = rot_left(b, 30);
 140         b = a;
 141         a = temp;
 142     }
 143     #undef w
 144
 145     cur_hash[0] += a;
 146     cur_hash[1] += b;
 147     cur_hash[2] += c;
 148     cur_hash[3] += d;
 149     cur_hash[4] += e;
 150 }