hallock.c

开发源代码的CPU卡的COS源程序。

/* ============================================================================
   Project Name : jayaCard
   Module Name  : proto/hal/avr/hallock.c
   Version : $Id: hallock.c,v 1.4 2004/01/11 09:56:32 dgil Exp $

	Description: Locks

    The Original Code is jayaCard code.

    The Initial Developer of the Original Code is Gilles Dumortier.

    Portions created by the Initial Developer are Copyright (C) 2002-2004 the
    Initial Developer. All Rights Reserved.

    Contributor(s):

    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 2 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; see http://www.gnu.org/licenses/gpl.html

   History Rev	Description
   073103 dgil	wrote it from scratch
   ============================================================================
*/

#include "precomp.h"

/* =========================================================================
	__hal_lock()

	returns a lock (LOCK_UNSET == unset; other value set). By design, the
 	lock cell must have the 0x00 value to be unset; otherwise the cell
 	should be considered as locked.

	secure: use the global semaphore
   ========================================================================= */

jbyte __hal_lock(jbyte LockNum)
{
	LOCAL(jbyte,byLock);

	/* should be done by the caller: gGlobalSem = JSEC_OK; */

	/* read the first cell of the lock */
	gGlobalSem++;
	byLock = HAL_EEPROM_READ_BYTE(BASE_OTP+LockNum);

	/* read the second cell of the lock and be sure it has the same value */
	byLock = byLock - HAL_EEPROM_READ_BYTE(BASE_OTP+LockNum+8);
	gGlobalSem++;

	/* returns the byLock */
	if (byLock==0x00) {
		/* re-read the lock :
		 		validate it is the same value +
				validate that cell1 != cell2 if cell1 != 0x00
		*/
		byLock = LOCK_UNSET + HAL_EEPROM_READ_BYTE(BASE_OTP+LockNum);
	}

	return byLock;
}

/* =========================================================================
	__hal_setlock()

	Set a lock. Default implementation is to replace the 0x00 cell value
 	with a JSEC_FAIL cell value.

	secure: use the global semaphore
   ========================================================================= */

void __hal_setlock(jbyte LockNum)
{
	/* should be done by the caller: gGlobalSem = JSEC_OK; */

	/* set the lock in the first cell */
	HAL_EEPROM_WRITE_BYTE(BASE_OTP+LockNum,JSEC_FAIL);
	/* flash detection */
	gGlobalSem++;
	/* set the lock in the second cell */
	HAL_EEPROM_WRITE_BYTE(BASE_OTP+LockNum+8,JSEC_FAIL);

	/* re-read the lock to be sure it is NO MORE unset */
	if (HAL_LOCK(LockNum)==LOCK_UNSET) {
		/* __x under attack */
		HAL_HALT();
		return;
	}

	/* flash detection */
	gGlobalSem--;
}

/* =========================================================================
	That's all folks !
   ========================================================================= */