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 uint8_t is_valid_keysize_P(const void* ks_desc, uint16_t keysize){
  32         uint8_t type;
  33         type = *((uint8_t*)ks_desc);
  34         ks_desc = (uint8_t*)ks_desc + 1;
  35         if(type==KS_TYPE_TERMINATOR)
  36                 return 0;
  37         if(type==KS_TYPE_LIST){
  38                 uint8_t items;
  39                 uint16_t item;
  40                 items = *((uint8_t*)ks_desc);
  41                 ks_desc = (uint8_t*)ks_desc + 1;
  42                 while(items--){
  43                         item = *((uint16_t*)ks_desc);
  44                         ks_desc = (uint8_t*)ks_desc + 2;
  45                         if(item==keysize)
  46                                 return 1;
  47                 }
  48                 ks_desc = (uint8_t*)ks_desc - 2;
  49         }
  50         if(type==KS_TYPE_RANGE){
  51                 uint16_t max, min;
  52                 min = *((uint16_t*)ks_desc);
  53                 ks_desc = (uint8_t*)ks_desc + 2;
  54                 max = *((uint16_t*)ks_desc);
  55                 if(min<=keysize && keysize<=max)
  56                         return 1;
  57         }
  58         if(type==KS_TYPE_ARG_RANGE){
  59                 uint16_t max, min, dist, offset;
  60                 min = *((uint16_t*)ks_desc);
  61                 ks_desc = (uint8_t*)ks_desc + 2;
  62                 max = *((uint16_t*)ks_desc);
  63                 ks_desc = (uint8_t*)ks_desc + 2;
  64                 dist = *((uint16_t*)ks_desc);
  65                 ks_desc = (uint8_t*)ks_desc + 2;
  66                 offset = *((uint16_t*)ks_desc);
  67                 if(min<=keysize && keysize<=max && (keysize%dist==offset))
  68                         return 1;
  69         }
  70         if(type>KS_TYPE_ARG_RANGE){
  71                 /* bad error, you may insert a big warning message here */
  72                 return 0;
  73         }
  74         return is_valid_keysize_P((uint8_t*)ks_desc+1, keysize); /* search the next record */
  75 }
  76
  77 uint16_t get_keysize(const void* ks_desc){
  78         uint8_t type;
  79         uint16_t keysize;
  80         type = *((uint8_t*)ks_desc);
  81         if(type==KS_TYPE_LIST){
  82                 ks_desc = (uint8_t*)ks_desc + 1;
  83         }
  84         ks_desc = (uint8_t*)ks_desc + 1;
  85         keysize = *((uint8_t*)ks_desc);
  86         return keysize;
  87 }
  88
  89 uint16_t get_keysizes(const void* ks_desc, uint16_t** list){
  90         uint8_t type;
  91         uint16_t items;
  92         uint8_t i;
  93         type = *((uint8_t*)ks_desc);
  94         ks_desc = (uint8_t*)ks_desc + 1;
  95         if(type==KS_TYPE_LIST){
  96                 items = *((uint8_t*)ks_desc);
  97                 ks_desc = (uint8_t*)ks_desc + 1;
  98                 if(!*list){
  99                         *list = malloc(items*2);
 100                         if(!*list){
 101                                 return 0;
 102                         }
 103                 }
 104                 for(i=0; i<items; ++i){
 105                         ((uint16_t*)(*list))[i] = *((uint16_t*)ks_desc);
 106                         ks_desc = (uint8_t*)ks_desc + 2;
 107                 }
 108                 return items;
 109         }
 110         if(type==KS_TYPE_ARG_RANGE){
 111                 uint16_t min, max, distance, offset;
 112                 min = *((uint16_t*)ks_desc);
 113                 ks_desc = (uint8_t*)ks_desc + 2;
 114                 max = *((uint16_t*)ks_desc);
 115                 ks_desc = (uint8_t*)ks_desc + 2;
 116                 distance = *((uint16_t*)ks_desc);
 117                 ks_desc = (uint8_t*)ks_desc + 2;
 118                 offset = *((uint16_t*)ks_desc);
 119                 items = (max-min)/distance+1;
 120                 if(min%distance!=offset){
 121                         --items;
 122                         min += (distance-(min%distance-offset))%distance;
 123                 }
 124                 if(!*list){
 125                         *list = malloc(items*2);
 126                         if(!*list){
 127                                 return 0;
 128                         }
 129                 }
 130                 i=0;
 131                 while(min<max){
 132                         ((uint16_t*)*list)[i++] = min;
 133                         min += distance;
 134                 }
 135                 return i;
 136         }
 137         if(type==KS_TYPE_RANGE){
 138                 uint16_t min, max, distance=8, offset=0;
 139                 min = *((uint16_t*)ks_desc);
 140                 ks_desc = (uint8_t*)ks_desc + 2;
 141                 max = *((uint16_t*)ks_desc);
 142                 items = (max-min)/distance+1;
 143                 if(min%distance!=offset){
 144                         --items;
 145                         min += (distance-(min%distance-offset))%distance;
 146                 }
 147                 if(!*list){
 148                         *list = malloc(items*2);
 149                         if(!*list){
 150                                 return 0;
 151                         }
 152                 }
 153                 i=0;
 154                 while(min<max){
 155                         ((uint16_t*)*list)[i++] = min;
 156                         min += distance;
 157                 }
 158                 return i;
 159         }
 160         return 0;
 161 }