bcal/keysize_descriptor.c

   1 /* keysize_descriptor.c */
   2 /*
   3     This file is part of the ARM-Crypto-Lib.
   4     Copyright (C) 2009  Daniel Otte (daniel.otte@rub.de)
   5
   6     This program is free software: you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation, either version 3 of the License, or
   9     (at your option) any later version.
  10
  11     This program is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19 /**
  20  * \file    keysize_descriptor.c
  21  * \author  Daniel Otte
  22  * \email   daniel.otte@rub.de
  23  * \date    2009-01-07
  24  * \license GPLv3 or later
  25  */
  26
  27 #include <stdint.h>
  28 #include <stdlib.h>
  29 #include "keysize_descriptor.h"
  30
  31 #define KS8 ((uint8_t*)ks_desc)
  32 uint8_t is_valid_keysize_P(const void* ks_desc, uint16_t keysize){
  33         uint8_t type;
  34         type = KS8[0];
  35         ks_desc = KS8 + 1;
  36         if(type==KS_TYPE_TERMINATOR)
  37                 return 0;
  38         if(type==KS_TYPE_LIST){
  39                 uint8_t items;
  40                 uint16_t item;
  41                 items = KS8[0];
  42                 ks_desc = KS8 + 1;
  43                 while(items--){
  44                         item = KS8[1] * 256 + KS8[0];
  45                         ks_desc = KS8 + 2;
  46                         if(item==keysize)
  47                                 return 1;
  48                 }
  49                 ks_desc = KS8 - 2;
  50         }
  51         if(type==KS_TYPE_RANGE){
  52                 uint16_t max, min;
  53                 min = KS8[1] * 256 + KS8[0];
  54                 ks_desc = (uint8_t*)ks_desc + 2;
  55                 max = KS8[1] * 256 + KS8[0];
  56                 if(min <= keysize && keysize <= max)
  57                         return 1;
  58         }
  59         if(type==KS_TYPE_ARG_RANGE){
  60                 uint16_t max, min, dist, offset;
  61                 min     = KS8[1] * 256 + KS8[0];
  62                 max     = KS8[3] * 256 + KS8[2];
  63                 dist    = KS8[5] * 256 + KS8[4];
  64                 offset  = KS8[7] * 256 + KS8[6];
  65                 ks_desc = KS8 + 6;
  66                 if(min <= keysize && keysize <= max && (keysize % dist == offset))
  67                         return 1;
  68         }
  69         if(type>KS_TYPE_ARG_RANGE){
  70                 /* bad error, you may insert a big warning message here */
  71                 return 0;
  72         }
  73         return is_valid_keysize_P(KS8+1, keysize); /* search the next record */
  74 }
  75
  76 uint16_t get_keysize(const void* ks_desc){
  77         uint8_t type;
  78         uint16_t keysize;
  79         type = *((uint8_t*)ks_desc);
  80         if(type==KS_TYPE_LIST){
  81                 ks_desc = (uint8_t*)ks_desc + 1;
  82         }
  83         ks_desc = (uint8_t*)ks_desc + 1;
  84         keysize = *((uint8_t*)ks_desc);
  85         return keysize;
  86 }
  87
  88 uint16_t get_keysizes(const void* ks_desc, uint16_t** list){
  89         uint8_t type;
  90         uint16_t items;
  91         uint8_t i;
  92         type = *((uint8_t*)ks_desc);
  93         ks_desc = (uint8_t*)ks_desc + 1;
  94         if(type==KS_TYPE_LIST){
  95                 items = *((uint8_t*)ks_desc);
  96                 ks_desc = (uint8_t*)ks_desc + 1;
  97                 if(!*list){
  98                         *list = malloc(items*2);
  99                         if(!*list){
 100                                 return 0;
 101                         }
 102                 }
 103                 for(i=0; i<items; ++i){
 104                         ((uint16_t*)(*list))[i] = *((uint16_t*)ks_desc);
 105                         ks_desc = (uint8_t*)ks_desc + 2;
 106                 }
 107                 return items;
 108         }
 109         if(type==KS_TYPE_ARG_RANGE){
 110                 uint16_t min, max, distance, offset;
 111                 min = *((uint16_t*)ks_desc);
 112                 ks_desc = (uint8_t*)ks_desc + 2;
 113                 max = *((uint16_t*)ks_desc);
 114                 ks_desc = (uint8_t*)ks_desc + 2;
 115                 distance = *((uint16_t*)ks_desc);
 116                 ks_desc = (uint8_t*)ks_desc + 2;
 117                 offset = *((uint16_t*)ks_desc);
 118                 items = (max-min)/distance+1;
 119                 if(min%distance!=offset){
 120                         --items;
 121                         min += (distance-(min%distance-offset))%distance;
 122                 }
 123                 if(!*list){
 124                         *list = malloc(items*2);
 125                         if(!*list){
 126                                 return 0;
 127                         }
 128                 }
 129                 i=0;
 130                 while(min<max){
 131                         ((uint16_t*)*list)[i++] = min;
 132                         min += distance;
 133                 }
 134                 return i;
 135         }
 136         if(type==KS_TYPE_RANGE){
 137                 uint16_t min, max, distance=8, offset=0;
 138                 min = *((uint16_t*)ks_desc);
 139                 ks_desc = (uint8_t*)ks_desc + 2;
 140                 max = *((uint16_t*)ks_desc);
 141                 items = (max-min)/distance+1;
 142                 if(min%distance!=offset){
 143                         --items;
 144                         min += (distance-(min%distance-offset))%distance;
 145                 }
 146                 if(!*list){
 147                         *list = malloc(items*2);
 148                         if(!*list){
 149                                 return 0;
 150                         }
 151                 }
 152                 i=0;
 153                 while(min<max){
 154                         ((uint16_t*)*list)[i++] = min;
 155                         min += distance;
 156                 }
 157                 return i;
 158         }
 159         return 0;
 160 }