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
  11 #include <corecrypto/cc.h>
  12
  13 //rdar://problem/26986552
  14
  15 #if ( CC_HAS_MEMSET_S == 1 ) && (defined( __STDC_WANT_LIB_EXT1__ ) && ( __STDC_WANT_LIB_EXT1__ == 1 ) )
  16 void cc_clear(size_t len, void *dst)
  17 {
  18     memset_s(dst,len,0,len);
  19 }
  20 #elif defined(_WIN32) && !defined(__clang__) //Clang with Microsoft CodeGen, doesn't support SecureZeroMemory
  21 #include <windows.h>
  22 static void cc_clear(size_t len, void *dst)
  23 {
  24     SecureZeroMemory(dst, len);
  25 }
  26 #else
  27 void cc_clear(size_t len, void *dst)
  28 {
  29     volatile char *vptr = (volatile char *)dst;
  30     while (len--)
  31         *vptr++ = '\0';
  32 }
  33 #endif
  34
  35 /* This is an altarnative for clang that should work
  36  void cc_clear(size_t len, void *dst) __attribute__ ((optnone))
  37  {
  38  cc_zero(len,dst);
  39  }
  40 */