PolarSSL is now part of ARM Official announcement and rebranded as mbed TLS.

API Documentation (Doxygen generated)

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platform_util.h File Reference

Common and shared functions used by multiple modules in the Mbed TLS library. More...

#include "config.h"
#include <stddef.h>
#include "platform_time.h"
#include <time.h>
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#define MBEDTLS_INTERNAL_VALIDATE_RET(cond, ret)   do { } while( 0 )
#define MBEDTLS_INTERNAL_VALIDATE(cond)   do { } while( 0 )


void mbedtls_platform_zeroize (void *buf, size_t len)
 Securely zeroize a buffer. More...
struct tm * mbedtls_platform_gmtime_r (const mbedtls_time_t *tt, struct tm *tm_buf)
 Platform-specific implementation of gmtime_r() More...

Detailed Description

Common and shared functions used by multiple modules in the Mbed TLS library.

Definition in file platform_util.h.

Macro Definition Documentation


Definition at line 122 of file platform_util.h.


Definition at line 121 of file platform_util.h.

#define MBEDTLS_INTERNAL_VALIDATE (   cond)    do { } while( 0 )

Definition at line 101 of file platform_util.h.

)    do { } while( 0 )

Function Documentation

struct tm* mbedtls_platform_gmtime_r ( const mbedtls_time_t tt,
struct tm *  tm_buf 

Platform-specific implementation of gmtime_r()

The function is a thread-safe abstraction that behaves similarly to the gmtime_r() function from Unix/POSIX.

Mbed TLS will try to identify the underlying platform and make use of an appropriate underlying implementation (e.g. gmtime_r() for POSIX and gmtime_s() for Windows). If this is not possible, then gmtime() will be used. In this case, calls from the library to gmtime() will be guarded by the mutex mbedtls_threading_gmtime_mutex if MBEDTLS_THREADING_C is enabled. It is recommended that calls from outside the library are also guarded by this mutex.

If MBEDTLS_PLATFORM_GMTIME_R_ALT is defined, then Mbed TLS will unconditionally use the alternative implementation for mbedtls_platform_gmtime_r() supplied by the user at compile time.

ttPointer to an object containing time (in seconds) since the epoch to be converted
tm_bufPointer to an object where the results will be stored
Pointer to an object of type struct tm on success, otherwise NULL
void mbedtls_platform_zeroize ( void *  buf,
size_t  len 

Securely zeroize a buffer.

The function is meant to wipe the data contained in a buffer so that it can no longer be recovered even if the program memory is later compromised. Call this function on sensitive data stored on the stack before returning from a function, and on sensitive data stored on the heap before freeing the heap object.

It is extremely difficult to guarantee that calls to mbedtls_platform_zeroize() are not removed by aggressive compiler optimizations in a portable way. For this reason, Mbed TLS provides the configuration option MBEDTLS_PLATFORM_ZEROIZE_ALT, which allows users to configure mbedtls_platform_zeroize() to use a suitable implementation for their platform and needs

bufBuffer to be zeroized
lenLength of the buffer in bytes