http://www.hackerschool.org/HS_Boards/zboard.php?id=Free_Lectures&no=1728 [º¹»ç]
[¡Ø °¡µ¶¼ºÀ» Áß¿ä½ÃÇÏ´Â ºÐÀº http://white-hacker.wo.tc/60128678142 ¿¡¼ º¸½Ã´Â °ÍÀ» ±ÇÇص帳´Ï´ç ]
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Ã¥µµ µÚÁ®º¸°í ³×À̹ö¿¡ µÚÁ®º¸°í ±¸±Û¿¡ µÚÁ®º¸°í ¿Â°® ´Ù µÚÁ®ºÁ¼ ³ª¿Â º°°Å¾ø´Â °á°ú¹°ÀÌ¿¡¿ä..¤»
¿ì¼± À§¿¡²« ´Ù Àá½Ã ½ºÅµÇÏ°í ÇÁ·¹ÀÓ ÄÁÆ®·Ñ(FC : Frame Control) ºÎÅÍ º¼°Ô¿ä
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ÇÁ·¹ÀÓ ÄÁÆ®·ÑÀº ÃÑ 2byteÀÇ °ø°£À» °®°í, ±× ³»ºÎ °ªµéÀº ´ÙÀ½°ú °°½À´Ï´Ù.
1. Protocol Version.............2 bit
2. Frame Type....................2 bit
3. Frame Subtype................4 bit
4. To DS ..........................1 bit
5. From DS .......................1 bit
6. More Fragment...............1 bit
7. Retry............................1 bit
8. Power Management.........1 bit
9. More Data.....................1 bit
10. WEP ..........................1 bit
11. Order .........................1 bit
ÇϳªÇϳª ¤¾îº¾½Ã´Ù ^-^;;
1. Protocol Version.............2 bit
=> ¸» ±×´ë·Î 802.11 MACÇÁ·ÎÅäÄÝÀÇ ¹öÁ¯À» ÀǹÌÇÕ´Ï´Ù.
ÀÌ´Â Ç×»ó..0À¸·Î ÃʱâȵǾîÀÖ´ä´Ï´Ù. ¿Ö³ÄÇϸé 0 Çϳª¹Û¿¡ ¾øÀ¸´Ï±î¿ä ¤»_¤»
2. Frame Type....................2 bit
=> À̰Ž¼.. ÇÁ·¹ÀÓÀÇ À¯ÇüÀÌ Á¤ÀǵǾî ÀÖ½À´Ï´Ù.
ÃÑ 2ºñÆ®·Î ±¸¼ºµÇ¾îÀÖÀ¸¸ç,
°ü¸® ÇÁ·¹ÀÓÀ» ÀǹÌÇÏ´Â 00(0)
Á¦¾î ÇÁ·¹ÀÓÀ» ÀǹÌÇÏ´Â 01(1)
µ¥ÀÌÅÍ ÇÁ·¹ÀÓÀ» ÀǹÌÇÏ´Â 10(2)
¿¹¾àµÈ ÇÁ·¹ÀÓÀ» ÀǹÌÇÏ´Â 11(3)
ÀÌ·¸°Ô ³× °¡Áö·Î ±¸¼ºµÇ¾î ÀÖ½À´Ï´Ù.
°¢°¢¿¡ ´ëÇÑ ¼³¸íÀº °Ë»öÀ» ÅëÇؼ ÀÚ¼¼ÇÑ ÀÌÇظ¦ ÇÏ½Ã±æ ¹Ù¶ø´Ï´Ù.
3. Frame Subtype................4 bit
ºÎ À¯ÇüÀº À¯ÇüÀÇ Á¾·ù¿¡ µû¶ó ´Þ¶óÁý´Ï´Ù.
°ü¸®ÇÁ·¹ÀÓ
0000(0) - Association Request (°áÇÕ ¿äû)
0001(1) - Association Response (°áÇÕ ÀÀ´ä)
0010(2)- Reassociation Request (Àç°áÇÕ ¿äû)
0011(3) - Reassociation Response (Àç°áÇÕ ÀÀ´ä)
0100(4) - Probe Request (ÇÁ·Îºê ¿äû)
0101(5) - Probe Response (ÇÁ·Îºê ÀÀ´ä)
1000(8) - Beacon (ºñÄÜ)
1001(9) - ATIM (Announcement Traffic Indication Message)
1010(10) - Association Clear (°áÇÕ ÇØÁ¦)
1011(11) - Authentication (ÀÎÁõ)
1100 (12)- Authentication Clear (ÀÎÁõ ÇØÁ¦)
Á¦¾î ÇÁ·¹ÀÓ
1010(10) - Power Management Mode (Àü·Â Àý¾à ¸ðµå)
1011(11) - RTS (Request to Send)
1100(12) - CTS (Clear to Send)
1101(13) - ACK (Acknowledgement)
µ¥ÀÌÅÍ ÇÁ·¹ÀÓ
0000(0) - µ¥ÀÌÅÍ
0001(1) - µ¥ÀÌÅÍ + CF ACK
0010(2) - µ¥ÀÌÅÍ + CF Poll
0011(3) - µ¥ÀÌÅÍ + CF ACK + CF Poll
0100(4)- NULL
0101(5) - CF ACK
0110(6) - CF Poll
0111(7) - CF ACK + CF Poll
4. To DS ..........................1 bit
5. From DS .......................1 bit
to DS¶û from DS´Â ±×°Ô ±×°Å´Ï±î Çϳª·Î ¹¾î¼ ¼³¸íÇÒ°Ô¿ä ¤»_¤»
to DS¶õ? ¸» ±×´ë·Î DS·Î º¸³»´Â°ÅÁö¿ä^
stationÀÌ AP¸¦ ÅëÇØ ´Ù¸¥ station¿¡°Ô º¸³»°íÀÚ ÇÒ ¶§ DS¸¦ ¹Ýµå½Ã °ÅÄ¡°Ô µË´Ï´Ù. °í·Î, ¹ß¼ÛÇÒ ¶§ to DS°¡ È°¼ºÈ µË´Ï´Ù.
to DS´Â 10(2) ÀÔ´Ï´Ù.
from DS´Â? ¿ªÀ¸·Î Infrastructure ³×Æ®¿öÅ©»ó¿¡ Á¸ÀçÇÏ´Â AP·ÎºÎÅÍ station¿¡°Ô º¸³»´Â°Ì´Ï´Ù. ÀÌ°Ç 01(1)ÀÔ´Ï´Ù.
ÀÎÇÁ¶ó ½ºÆ®·°ÃÄ ³×Æ®¿öÅ©°¡ ¾Æ´Ñ Ad-hoc(IBSS)Åë½ÅÀÏ °æ¿ì¿£ 00(0)ÀÌ È°¼ºÈ°¡ µË´Ï´Ù.
ÀÌ ¿Ü¿¡ 11(3)Àº ¹«¼± ºê¸´Áö¸¦ ÀǹÌÇÕ´Ï´Ù.
6. More Fragment...............1 bit
µ¥ÀÌÅ͸¦ ºÐÇÒÇÒ°Ô ´õ ÀÖ´ÂÁö È®ÀÎÇÏ´Â ºÎºÐÀÔ´Ï´Ù.
¿¹¸¦ µé¾î, 3000byteÀÇ µ¥ÀÌÅÍ ÇÁ·¹ÀÓÀ» Çѹø¿¡ Àü¼ÛÇÏ·Á°íÇϸé MTU(Maximum Transfer Unit) ¼öÄ¡¿¡ ¹þ¾î³ª±â ¶§¹®¿¡ ÀÌ µ¥ÀÌÅ͸¦ ºÐÇÒÇÕ´Ï´Ù.
¹«¼±¿¡¼ÀÇ MTU´Â ÃÖ´ë 2304byte(2312byte¶ó°í Á¤ÀǵǾîÀÖ´Â ÀÌÀ¯´Â, ½ÇÁ¦·Ð WEPÀÇ ¿À¹öÇìµå¸¦ ¼ö¿ëÇϱ⠶§¹®¿¡ 8byte°¡ Ãß°¡µÇ±â ¶§¹®ÀÌ´Ù.
Àε¥, ÀÌ·¸°ÔµÇ¸é 2304byte¿Í 696byte ÀÌ·¸°Ô 2¹ø ºÐÇÒÀÌ µË´Ï´Ù.
ÀÚ½ÅÀÇ µ¥ÀÌÅÍ ÇÁ·¹ÀÓ µÚ¿¡ ºÐÇÒµÈ ÇÁ·¹ÀÓÀÌ Á¸ÀçÇÒ °æ¿ì¿£ 1(1)ÀÌ È°¼ºÈ°¡ µÇ°í, Á¸ÀçÇÏÁö ¾ÊÀ» ¶© 0(0)ÀÌ È°¼ºÈ µË´Ï´Ù.
7. Retry............................1 bit
ACK¸¦ ¹ÞÁö ¸øÇÏ¿© Àç Àü¼ÛÀÌ ÇÊ¿äÇÒ ½Ã »ç¿ëµË´Ï´Ù.
¶Ç, ¼ö½Å ½ºÅ×À̼ÇÀÌ Áߺ¹µÇ´Â ÇÁ·¹ÀÓÀÌ Á¸ÀçÇÒ °æ¿ì Àç Àü¼ÛÀ» ÇÏ¿© Á¦°ÅÇÏ´Â °æ¿ì¿¡µµ »ç¿ëÀÌ µË´Ï´Ù.
8. Power Management.........1 bit
Àü¿ø Àý¾à ¸ðµå¿¡ ºüÁ³´ÂÁö, ±× ¿©ºÎ¸¦ ³ªÅ¸³»´Â ÇʵåÀÔ´Ï´Ù.
power management ¸ðµå¶ó¸é 1(1)·Î Ç¥½ÃµÇ°í, ¾Æ´Ï¶ó¸é 0(0)À¸·Î Ç¥½ÃµË´Ï´Ù.
stationÀÇ °æ¿ì ÀÌ ÇÊµå °ªÀÌ °¡º¯ÀûÀÏ ¼öµµ ÀÖÁö¸¸, APÀÇ °æ¿ì Ç×»ó ÄÑÁ®ÀÖ¾î¾ß ÇϹǷΠ±× °ªÀÌ Ç×»ó 0(0)À¸·Î ¼ÂÆõǾî ÀÖ¾î¾ß ÇÕ´Ï´Ù.
9. More Data.....................1 bit
Èì..ÀÌ°ÍÀº..Àü¿ø Àý¾à ¸ðµåÀÏ ¶§ »ç¿ëµÇ¾îÁý´Ï´Ù.
½ºÅ×À̼ÇÀÌ Àü¿ø Àý¾à¸ðµå À϶© ÇØ´ç ½ºÅ×À̼ÇÀ» ¸ñÀûÁö·ÎÇÏ´Â µ¥ÀÌÅÍ ÇÁ·¹ÀÓÀ» AP´Â ¹öÆÛ¸µ(buffering)ÇÏ¿©¾ß ÇÕ´Ï´Ù.
¿©±â¼ ¹öÆÛ¸µÀ̶õ, ÀϽÃÀûÀ¸·Î ÀúÀåÇÏ¿© ³õ´Â´Ù´Â Àǹ̷Π¹Þ¾ÆµéÀÌ½Ã¸é µË´Ï´Ù.
AP´Â ÀÌ ºñÆ®¸¦ ¼³Á¤Çؼ Àü¿ø Àý¾à ¸ðµå¿¡ ºüÁø ½ºÅ×À̼ÇÀ» È®ÀÎÇÏ¿© ÇÁ·¹ÀÓÀ» Àü¼ÛÇؾßÇÑ´Ù´Â °ÍÀ» Áö½ÃÇÏ°Ô µË´Ï´Ù.
ÀÌ ºñÆ®´Â °ü¸® ÇÁ·¹ÀÓ°ú µ¥ÀÌÅÍÇÁ·¹ÀÓ¿¡¼´Â 1(1)·Î ¼³Á¤ÀÌ °¡´ÉÇϸç, Á¦¾îÇÁ·¹ÀÓÀÏ °æ¿ì¿£ »ç¿ëÀÌ ºÒ°¡´ÉÇϱ⠶§¹®¿¡ 0(0)À¸·Î ¼¼ÆÃÇÕ´Ï´Ù.
10. WEP ..........................1 bit
WEP(Wired Equivalent Privacy : À¯¼± µ¿µî ÇÁ¶óÀ̹ö½Ã) ¾Ïȣȸ¦ ÀǹÌÇÕ´Ï´Ù.
WEP¾ÏȣȰ¡ Àû¿ëµÈ ÇÁ·¹ÀÓÀÎ °æ¿ì, 1(1)·Î ¼³Á¤µÇ¾îÀÖ½À´Ï´Ù.
´ç¿¬È÷ Àû¿ëµÇÁö ¾ÊÀº °æ¿ì¿£ 0(0)ÀÌ°ÚÁÒ?
11. Order .........................1 bit
µ¥ÀÌÅÍ°¡ ³Ê¹« Ä¿¼ ºÐÇÒµÈ µ¥ÀÌÅÍÀÎ °æ¿ì, ¼ø¼°¡ ¾Ë¸ÂÁö ¾Ê°Ô Àü¼ÛÀÌ µÉ ¼ö ÀÖ½À´Ï´Ù.
À̸¦ º¸¿ÏÇϱâ À§ÇØ ÀÌ Çʵ带 ¼³Á¤ÇÒ ¼ö ÀÖ½À´Ï´Ù.
Order Çʵå´Â ¼ø¼¸¦ ÁöÁ¤ÇÏ¿© ¼ø¼´ë·Î Àü¼ÛÀ» ÇÒ ¼ö ÀÖ°Ô ÇÏ´Â ÀÏÁ¾ÀÇ '¼ø¹ø' ¿ªÇÒÀ» ÇÕ´Ï´Ù.
ÇÏ..Áö±Ý±îÁö 802.11ÀÇ ÇÁ·¹ÀÓ¿¡¼!! MAC ÇÁ·¹ÀÓ Çì´õÀÇ!! ÇÁ·¹ÀÓ ÄÁÆ®·Ñ¿¡ ´ëÇØ ¾Ë¾ÆºÃ½À´Ï´Ù.
µÇ°Ô...¤»...¾çÀÌ ¸¸¸¸Ä¡¾Ê³×¿ä...................¤»¤»¤»¤»¤»¤»¤»¤»¤»¤»¤»¤»¤»¤»¤»¤»¤»
»õº®¿¡ ¾´ ±ÛÀÌ¶ó ¸»ÀÌ Ç곪¿Ô´Ù°Å³ª ¾î»öÇÑ°Ô ÀÖÀ» ¼ö ÀÖ½À´Ï´Ù ¤Ð¤Ð ÀÖÀ¸¸é ÁöÀûÁ» ºÎŹµå¸³´Ï´Ù~¤Ì¤Ì
Âü°íÅ°¿öµå-802.11 frame, 802.11 MAC frame, 802.11 Frame Control
Âü°í¹®Çå- 802.11 Wireless Networks: The Definitive Guide
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Hit : 10701 Date : 2011/04/27 07:04
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