mbed TLS v2.24.0
Macros | Functions
platform_util.h File Reference

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

#include "mbedtls/config.h"
#include <stddef.h>
#include "mbedtls/platform_time.h"
#include <time.h>
#include <assert.h>
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Macros

#define MBEDTLS_PARAM_FAILED(cond)   assert( cond )
 
#define MBEDTLS_PARAM_FAILED_ALT
 
#define MBEDTLS_INTERNAL_VALIDATE_RET(cond, ret)
 
#define MBEDTLS_INTERNAL_VALIDATE(cond)
 

Functions

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

#define MBEDTLS_INTERNAL_VALIDATE (   cond)
Value:
do { \
if( !(cond) ) \
{ \
return; \
} \
} while( 0 )
#define MBEDTLS_PARAM_FAILED(cond)
Definition: platform_util.h:59

Definition at line 97 of file platform_util.h.

#define MBEDTLS_INTERNAL_VALIDATE_RET (   cond,
  ret 
)
Value:
do { \
if( !(cond) ) \
{ \
return( ret ); \
} \
} while( 0 )
#define MBEDTLS_PARAM_FAILED(cond)
Definition: platform_util.h:59

Definition at line 87 of file platform_util.h.

Referenced by mbedtls_cipher_get_block_size(), mbedtls_cipher_get_cipher_mode(), mbedtls_cipher_get_iv_size(), mbedtls_cipher_get_key_bitlen(), mbedtls_cipher_get_name(), mbedtls_cipher_get_operation(), and mbedtls_cipher_get_type().

#define MBEDTLS_PARAM_FAILED (   cond)    assert( cond )

Definition at line 59 of file platform_util.h.

#define MBEDTLS_PARAM_FAILED_ALT

Definition at line 60 of file platform_util.h.

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.

Parameters
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
Returns
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

Parameters
bufBuffer to be zeroized
lenLength of the buffer in bytes