Add macro for bounds checking

This commit adds a macro for buffer bounds checks in the SSL
module. It takes the buffer's current and end position as the
first argument(s), followed by the needed space; if the
available space is too small, it returns an SSL_BUFFER_TOO_SMALL
error.

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
This commit is contained in:
Hanno Becker 2017-04-12 14:54:42 +01:00 committed by Ronald Cron
parent 4c7bbe289a
commit 51018aab56

View file

@ -299,6 +299,41 @@ static inline uint32_t mbedtls_ssl_get_input_buflen( const mbedtls_ssl_context *
#define MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS_PRESENT (1 << 0)
#define MBEDTLS_TLS_EXT_ECJPAKE_KKPP_OK (1 << 1)
/**
* \brief This function checks if the remaining size in a buffer is
* greater or equal than a needed space.
*
* \param cur Pointer to the current position in the buffer.
* \param end Pointer to one past the end of the buffer.
* \param need Needed space in bytes.
*
* \return Non-zero if the needed space is available in the buffer, 0
* otherwise.
*/
static inline int mbedtls_ssl_chk_buf_ptr( const uint8_t *cur,
const uint8_t *end, size_t need )
{
return( cur <= end && need <= (size_t)( end - cur ) );
}
/**
* \brief This macro checks if the remaining size in a buffer is
* greater or equal than a needed space. If it is not the case,
* it returns an SSL_BUFFER_TOO_SMALL error.
*
* \param cur Pointer to the current position in the buffer.
* \param end Pointer to one past the end of the buffer.
* \param need Needed space in bytes.
*
*/
#define MBEDTLS_SSL_CHK_BUF_PTR( cur, end, need ) \
do { \
if( mbedtls_ssl_chk_buf_ptr( ( cur ), ( end ), ( need ) ) == 0 ) \
{ \
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL ); \
} \
} while( 0 )
#ifdef __cplusplus
extern "C" {
#endif