diff --git a/include/mbedtls/ssl_internal.h b/include/mbedtls/ssl_internal.h index bd5ad94db..82beea553 100644 --- a/include/mbedtls/ssl_internal.h +++ b/include/mbedtls/ssl_internal.h @@ -236,6 +236,41 @@ #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