Graduate School of Information Security

MIN CHUL, KIM

HACKING – THE ART OF EXPLOITATIONOx28O BUILDING ON BASIC - ANALYSIS SOURCE CODE

CONTENTS• Simplenote.c• Bitwise.c• Functioncontrol_flags.c• UserID_demo.c• Notetaker.c• Notesearch.c • Time_example.c• Functionponter_example.c• Rand_example.c• Game_of_chance.c

SIMPLENOTE.C

Permission part

IMPLEMENT SIMPLENOTE.C

IMPLEMENT SIMPLENOTE.C

BUFFER OVER-FLOW

memory

File save location

Buffer destination

Buffer start

IMPLEMENT SIMPLENOTE.C

BITWISE.C

i 1 2 a=i&2 b=i&1

0 00 01 10 0 0

1 01 01 10 0 1

2 10 01 10 1 0

3 11 01 10 1 1

IMPLEMENT BITWISE.C

FUNCTIONCONTROL_FLAGS.C

♧

mask shift

♧

value=0

IMPLEMENT FCNTL_FLAGS.C

FILE PERMISSIONS

-rw-r-r-- 1 nare nare 1872 2014-09-17 12:57simplenote.

c

permission link user group file size date time file nameDe-tail

FILE PERMISSIONS

ownership group othersr

readw

writex

operate r w x r w x

4 2 1 4 - 1 - 2 -7 5 2

Change ownership chown [ownership][.group] [file name]

Change permission chmod [number or symbol] [file name]

-rw-r-r-- 1 nare nare 1872 2014-09-17 12:57simplenote.

c

permission link user group file size date time file name

Symbol u ownership + add permission

g group - del permission

o others = only permission

a all s file owned user

USER IDs

Change shell user login shell

USER IDs

Locked

HACKING.h

Making header file

Easy to use function

NOTETAKER.c

IMPLEMENT NOTETAKER.c

User id

NOTESEARCH.c

NOTESEARCH.c

NOTESEARCH.c

IMPLEMENT NOTESEARCH.c

Independent

TIME_EXAMPLE.C

TIME_EXAMPLE2.C

IMPLEMENT TIME_EXAMPLE2.C

FUNCTION POINTER.C

RAND_EXAMPLE.C

RAND_EXAMPLE.C

Different

GAME OF CHANCE.C

GAME OF CHANCE.C

GAME OF CHANCE.C

GAME OF CHANCE.C

GAME OF CHANCE.C

GAME OF CHANCE.C

GAME OF CHANCE.C

GAME OF CHANCE.C

GAME OF CHANCE.C

GAME OF CHANCE.C

GAME OF CHANCE.C

PLAY‘GAME OF CHANCE’

I didn’t win the game. T_T