X-Git-Url: https://git.cryptolib.org/?p=avr-crypto-lib.git;a=blobdiff_plain;f=keysize_descriptor.c;fp=keysize_descriptor.c;h=5b148f659961a2c371a434cef31483b8213caa6d;hp=0000000000000000000000000000000000000000;hb=017345097a7e5e05d7751816d2c8e29af3bacadc;hpb=3caccd2034e682222162e24c256d20bf65d7c649

diff --git a/keysize_descriptor.c b/keysize_descriptor.c
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+++ b/keysize_descriptor.c
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+/* 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 */
+}
+
+