Posts

Showing posts from December, 2016

Word of the day: Rowhammer

Rowhammer is a vulnerability in commodity dynamic random access memory (DRAM) chips that allows an attacker to exploit devices with DRAM memory by repeatedly accessing (hammering) a row of memory until it causes bit flips and transistors in adjacent rows of memory reverse their binary state: ones turn into zeros and vice versa. The flaw, first reported in the paper "Flipping Bits in Memory Without Accessing Them: An Experimental Study of DRAM Disturbance Errors," detailed how, as DRAM processes continues to scale to smaller sizes, it becomes more difficult to prevent individual memory cells from interacting with neighboring cells. The Rowhammer flaw allows memory manipulation to be used by malicious actors to extract data such as passwords from vulnerable systems. The flaw has been detected in DDR3 and DDR4 DRAM chips and, when combined with other attacks, can be used to access the contents of memory on sys

SAP ABAP: Adding leading zero to char or string.

Here are the three ways to add leading zeros to a char or string. 1). Using numeric and character field with the same length. DATA: lv_Belnr(10) TYPE C VALUE '48',             lv_Num(10)   TYPE N. lv_Num =  lv_Belnr. ADD 1 TO  lv_Num. lv_Belnr  = lv_Num . WRITE  lv_Belnr. 2). Using FM CONVERSION_EXIT_ALPHA_INPUT. DATA: lv_Belnr(10) TYPE C VALUE '48'.   ADD 1 TO lv_Belnr.   CALL FUNCTION 'CONVERSION_EXIT_ALPHA_INPUT'            EXPORTING                    INPUT  = lv_Belnr                      IMPORTING                    OUTPUT = lv_Belnr.  3). Using UNPACK.  DATA: lv_Belnr(10) TYPE C VALUE '48'. ADD 1 TO lv_Belnr. UNPACK lv_Belnr TO lv_Belnr. That's all. Mabuhay!