--- /dev/null
+/* keysize_descriptor.c */
+/*
+ This file is part of the Crypto-avr-lib/microcrypt-lib.
+ Copyright (C) 2009 Daniel Otte (daniel.otte@rub.de)
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * \file keysize_descriptor.c
+ * \author Daniel Otte
+ * \email daniel.otte@rub.de
+ * \date 2009-01-07
+ * \license GPLv3 or later
+ */
+
+#include <stdint.h>
+#include <avr/pgmspace.h>
+#include "keysize_descriptor.h"
+
+uint8_t is_valid_keysize_P(PGM_VOID_P ks_desc, uint16_t keysize){
+ uint8_t type;
+ type = pgm_read_byte(ks_desc++);
+ if(type==KS_TYPE_TERMINATOR)
+ return 0;
+ if(type==KS_TYPE_LIST){
+ uint8_t items;
+ uint16_t item;
+ items = pgm_read_byte(ks_desc++);
+ while(items--){
+ item = pgm_read_word(ks_desc);
+ ks_desc+=2;
+ if(item==keysize)
+ return 1;
+ }
+ ks_desc -= 2;
+ }
+ if(type==KS_TYPE_RANGE){
+ uint16_t max, min;
+ min = pgm_read_word(ks_desc);
+ ks_desc+=2;
+ max = pgm_read_word(ks_desc);
+ if(min<=keysize && keysize<=max)
+ return 1;
+ }
+ if(type==KS_TYPE_ARG_RANGE){
+ uint16_t max, min, dist, offset;
+ min = pgm_read_word(ks_desc);
+ ks_desc+=2;
+ max = pgm_read_word(ks_desc);
+ ks_desc+=2;
+ dist = pgm_read_word(ks_desc);
+ ks_desc+=2;
+ offset = pgm_read_word(ks_desc);
+ if(min<=keysize && keysize<=max && (keysize%dist==offset))
+ return 1;
+ }
+ if(type>KS_TYPE_ARG_RANGE){
+ /* bad error, you may insert a big warning message here */
+ return 0;
+ }
+ return is_valid_keysize(ks_desc+1, keysize) /* search the next record */
+}
+
+