%% options copyright owner = Dirk Krause copyright year = 2015-xxxx SPDX-License-Identifier: BSD-3-Clause %% header /** @file dk4memrs.h Secure memory reset. Securely reset byte buffer to 0x00 bytes. */ #ifdef __cplusplus extern "C" { #endif /** Secure memory reset. CRT on Windows: Not used. @param ptr Start address of memory range. @param sz Size of memory range in bytes. @param erp Error report, may be NULL. @return 1 on success, 0 on error. You should not ignore the return value. Error codes: - DK4_E_INVALID_ARGUMENTS
if ptr is NULL or sz is 0, - DK4_E_BUG
if one of the bytes in the buffer is not 0 during check. */ int dk4mem_reset_secure(void *ptr, size_t sz, dk4_er_t *erp); #ifdef __cplusplus } #endif %% module #include "dk4conf.h" #ifndef STDIO_H_INCLUDED #include #define STDIO_H_INCLUDED 1 #endif #ifndef STDLIB_H_INCLUDED #include #define STDLIB_H_INCLUDED 1 #endif #if DK4_ON_WINDOWS #ifndef WINDOWS_H_INCLUDED #include #define WINDOWS_H_INCLUDED 1 #endif #endif #if DK4_HAVE_ASSERT_H #ifndef ASSERT_H_INCLUDED #include #define ASSERT_H_INCLUDED 1 #endif #endif #include "dk4mem.h" #include "dk4memrs.h" $!trace-include #ifndef DK4MEMRS_PARANOID_CHECK #define DK4MEMRS_PARANOID_CHECK 0 #endif int dk4mem_reset_secure(void *ptr, size_t sz, dk4_er_t *erp) { #if (!DK4_ON_WINDOWS) && (DK4MEMRS_PARANOID_CHECK) unsigned char *p1; #endif int back = 0; #if DK4_USE_ASSERT assert(NULL != ptr); assert(0 < sz); #endif if ((NULL != ptr) && (0 < sz)) { #if DK4_ON_WINDOWS SecureZeroMemory(ptr, sz); back = 1; #else DK4_MEMRES(ptr, sz); back = 1; #if DK4MEMRS_PARANOID_CHECK p1 = (unsigned char *)ptr; while((0 != back) && (sz--)) { if ('\0' != *(p1++)) { back = 0; dk4error_set_simple_error_code(erp, DK4_E_BUG); } } #endif #endif } else { dk4error_set_simple_error_code(erp, DK4_E_INVALID_ARGUMENTS); } return back; }