OS???????

1
?????????????????????????????

• ???? ????
• ???? ???

2
???????????

• ??????????????????
• OS???????
• ???????????????????????????????????

3
?????VPN

• ?????????Virtual Private Network

kourai
process
VPN
kourai
kourai
process
firewall
?????? ???????? ftp, web, ...
chiba
process
hosting service
chiba
4
???VPN????
???????

• ?????????????????????????
• IPsec
• ?????????
• PPTP????????port forwarding
• ?????????????VPN??????????VPN???????

5
??????????
???????

• IP?????????????
• ???????????????
• 130.158.85. ?????????
• TCP Wrapper
• 130.158.85. ??pop????????
• VPN?????????????????
• ????port forwarding???????????????????????????????
  ??

6
??????
???????

• ??????????VPN???
• SSL (Secure Socket Layer)
• ???
• ???????????????????????
• ???????????????????????????????????
• ????????

7
OS?????????(1)
??

• ???????????
• VPN???????
• ???OS????????
• ???ID???VPN??????

kourai
chiba
kourai
OS
OS
virtual private network
8
OS?????????(2)
??

• VPN??????
• ????OS?????????
• ????????????DHCP
• ????????????VPN??????

kourai
chiba
kourai
OS
OS
virtual private network
9
????????????
????????

• TCP??????????TCP???????3-way handshake?????????
• ????????????????????????
• ??????????????????????

10
??????????
????????

• ???????SYN?????????????????????
• ??????IP?????????????????????????????????
• ??????????????????????????????????????

11
????????
????????

• ????SYNACK?????????????
• ?????????????????????????(??)??????
• TCP????????????????????????

12
????????
????????

• ?????????????ACK???????
• ??????????????????? ??????????????????????
• ??????????????????????
• ???????????????

13
?????????????
????????

• ?????????????????
• ???????????????????????????????????
• ?????????????????????
• ?????????
• ????????????????
• ??????????????

14
?????????
????????

• ???????SSL Wrapper?????
• ????????????????SSL????????????
• ????????????????????????
• OpenSSL?????????

15
SSL Wrapper
????????

• ???????????????????SSL????????????
• LD_PRELOAD??????????????????libc????????????
• connect ? connect SSLconnect
• accept ? accept SSLaccept
• read, write ? SSLread, SSLwrite
• ...

16
SSL Wrapper?????
????????

• SSLaccept?????????????????
• accept??????????????????????(ftp)
• SSLaccept???????listen?????select???
• accept??????????????
• non-blocking??????connect????
• connect?????SSL??????????????????????

17
????

• ssh X11 forwarding
• X??????????????????
• IPsec
• Security Association(SA)??????????????????????
• Ident
• TCP?????????????????????????

18
?????????

• ?????VPN?????
• OS????????????????
• ??????????????????????