osfmk/corecrypto/cc/src/cc_clear.c

   1 /*
   2  *  cc_clear.c
   3  *  corecrypto
   4  *
   5  *  Created on 05/21/2014
   6  *
   7  *  Copyright (c) 2014,2015 Apple Inc. All rights reserved.
   8  *
   9  *
  10  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  11  *
  12  * This file contains Original Code and/or Modifications of Original Code
  13  * as defined in and that are subject to the Apple Public Source License
  14  * Version 2.0 (the 'License'). You may not use this file except in
  15  * compliance with the License. The rights granted to you under the License
  16  * may not be used to create, or enable the creation or redistribution of,
  17  * unlawful or unlicensed copies of an Apple operating system, or to
  18  * circumvent, violate, or enable the circumvention or violation of, any
  19  * terms of an Apple operating system software license agreement.
  20  *
  21  * Please obtain a copy of the License at
  22  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  23  *
  24  * The Original Code and all software distributed under the License are
  25  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  26  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  27  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  28  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  29  * Please see the License for the specific language governing rights and
  30  * limitations under the License.
  31  *
  32  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  33  */
  34
  35 #include <corecrypto/cc.h>
  36 #include "corecrypto/fipspost_trace.h"
  37
  38 //rdar://problem/26986552
  39
  40 #if (CC_HAS_MEMSET_S == 1) && (defined(__STDC_WANT_LIB_EXT1__) && (__STDC_WANT_LIB_EXT1__ == 1))
  41 void
  42 cc_clear(size_t len, void *dst)
  43 {
  44         FIPSPOST_TRACE_EVENT;
  45         memset_s(dst, len, 0, len);
  46 }
  47 #elif defined(_WIN32) && !defined(__clang__) //Clang with Microsoft CodeGen, doesn't support SecureZeroMemory
  48 #include <windows.h>
  49 static void
  50 cc_clear(size_t len, void *dst)
  51 {
  52         SecureZeroMemory(dst, len);
  53 }
  54 #else
  55 void
  56 cc_clear(size_t len, void *dst)
  57 {
  58         FIPSPOST_TRACE_EVENT;
  59         volatile char *vptr = (volatile char *)dst;
  60         while (len--) {
  61                 *vptr++ = '\0';
  62         }
  63 }
  64 #endif
  65
  66 /* This is an altarnative for clang that should work
  67  *  void cc_clear(size_t len, void *dst) __attribute__ ((optnone))
  68  *  {
  69  *  cc_clear(len,dst);
  70  *  }
  71  */