platform_util.h File Reference

User supplied callback function for parameter validation failure.

See MBEDTLS_CHECK_PARAMS for context.

This function will be called unless an alternative treatement is defined through the MBEDTLS_PARAM_FAILED macro.

This function can return, and the operation will be aborted, or alternatively, through use of setjmp()/longjmp() can resume execution in the application code.

Parameters:

failure_condition	The assertion that didn't hold.
file	The file where the assertion failed.
line	The line in the file where the assertion failed.

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:

tt	Pointer to an object containing time (in seconds) since the epoch to be converted
tm_buf	Pointer to an object where the results will be stored

Returns:

Pointer to an object of type struct tm on success, otherwise NULL

Definition at line 109 of file platform_util.c.

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:

buf	Buffer to be zeroized
len	Length of the buffer in bytes

Definition at line 73 of file platform_util.c.