  Certificate Server ġ  Client

  ¼ sskuk@sskuk.cataegu.ac.kr
  V0.1 2000 11 11

     appletΰ Ͽ ̰ ϴٰ,
  OpenSSL̶  ˰ԵǼ, OpenSSL ̿ Certificate
  Server(rootCA) ġϱ    ̴.  OpenSSL
  ġ, apache, mod_ssl, php, mysql ̿Ͽ Certificate Server
  ϱ  а, Netscape, MS Internet Explorer, JDK
  Client   ϴ   ִ.
  ______________________________________________________________________

  

  1. ۱
  2. غ
  3. Certificate Server?
  4. Certificate Server ġ
     4.1 OpenSSL ġ
     4.2 rootCA 
     4.3 Apache + mod_ssl/OpenSSL + PHP4/MySQL ġ
     4.4 Apache Server Ű  

  5. Client 
     5.1 Netscape 
     5.2 MS Internet Explorer 
     5.3 JDK2 

  6. Ÿ
     6.1 ڷ
     6.2 Ҹ..^^
     6.3  

  ______________________________________________________________________

  1.  ۱

     ϻǥ    ڿ ִ.  
   뿡       (Ʋ 뵵
  ϱ..^^;),    ְ,    ٸ
      ִ ˷ֽð,    
   ο  ֽñ ٶ.  (̷ ° ¾ƿ?...^^;)

  2.  غ

  1. OpenSSL <http://www.openssl.org/>

  2. Apache <http://www.apache.org/>

  3. Perl <http://www.perl.com/>

  4. mod_ssl <http://www.modssl.org/>

  5. PHP <http://www.php.net/>

  6. Client Browser(Netscape Explorer)

  7. Java2 SDK

  8.

  9.  ѵΰ   Ŀ(ʼ!)

  10.
     Ǹ ̳ (^^)

     OpenSSL ־ Certificate Service óϴµ 
     ,  ڸ ϰ ҷ  鵵 ִ° .

  3.  Certificate Server?

  Certificate Server ͳݿ ̳ α׷(applet,
  script) ۽ڸ   ´ ִ
  ̴.   ϸ ö ࿡   Sign Ͽ
  ´ٰ ϸ,  忡  ޼  öԼ
  ° Ȯ ʿ䰡 ִ.  ̶ PGP GPGó Ű Ű
  ̿Ͽ ö Ű ϰ ࿡ ö Ű ̿Ͽ,
  ŵ ޼ ö  ´ ȮҼ ִ.   ࿡
  ö   ޼ 쿡  , ΰ Ű
  Ȯϰ  Ǿ Ȯ ʿ䰡 ִ.  ( ̳,
  Ȩ Ͽ ȮҼ ְ,   finger print
  ͼ غ ִ.)

     Ű    ذ
  ̶,  Ű ´ٴ° Ȯϴ   ִµ, 
   Certificate Authority(CA) θ, CAؼ 
  Ű Ǿ , ΰ  Ȯ ʿ Ű 
   ְ Ǵ°̴.

  (OpenSSL ̰ͻӸ ƴϰ      
  ƴ° ξ׿...^^;)  Applet ۼ ź ƽð
    Ǿִ 쿡 Ϻ ý ѵ
  ڿ(, ũ, ) Ҽ ִ Applet Ҽ
  ֽϴ.  (̾е带   Ÿ â غ...^^)

   Ÿ ó, ͳݿ Ư̳   ִ
   CA̸, ̷ Ȱ ϴ  Certificate Server̴.
  VeriSign <http://www.verisign.com/>̳ Thawte Consulting
  <http://www.thawte.com/> ̷ 񽺸 ϰ ְ, ⺻
  Netscape MS Internet Explorer ŷڵ  Ÿ. 
   VeriSign̳ Thawte Consulting  񽺸 OpenSSL
  ̿Ͽ   ִ  Ͽ ϰ ִ.

  OpenSSL Secure Sockets Layer Transport Layer Security
  ϴ Open Source Ŷ̴. OpenSSL Eric A. Young Tim J.
  Hudson  SSLeay ̺귯 ʷϿ  , 
  OpenSSL-0.9.6 밡ϸ, Unix Windows, OpenVMS, MacOS
  ÷ ȴ.

  4.  Certificate Server ġ

  Certificate Server  OpenSSL <http://www.openssl.org/> Apache
  <http://www.apache.org/> ʿϸ,  Ż Web ̿Ͽ
  ۵ Apache  mod_ssl <http://www.modssl.org/> ġϰų
  Apache + SSL · Apache ġϿ Browser Ž
  sniffing ʵ Ͽ  ̴.   ڵȭ 񽺸 ؼ
  Perl <http://www.perl.com/>̳ php <http://www.php.net/>
  ʿϴ.  (Perl̳ PHP module ġص  CGI· ص
      κ غ ġϴ°  .)
   䱸ϴ Client  Ͽ MySQL
  <http://www.mysql.org/> ġϴ ͵  . ׸
  mod_ssl INSTALLȭ 캸  ġϴ ȭ
  ִµ(mm) ̰͵鵵 ʿϸ  ġ  ִ. Perl
  5.6 ʿ Ѵٰ Ǿִ° , 5.6  ġ ʿ
   .

  4.1.  OpenSSL ġ

  OpenSSL ġϱ ؼ Perl 5 <http://www.perl.com> ANSI
  CϷ ʿϴ.  ⺻ ġ  ͳݻ ٸ
  Űó  Ͽ ġҼ ִ.

          $ ./config
          $ make
          $ make test
          $ make install

  config prefix  ʾ  /usr/local/ssl丮 ġ
  Ǵ ٸ 丮 ġ ϰ Ѵٸ   Ѵ.
   $ ./config --prefix=/usr/local --openssldir=/usr/local/openssl ̷
  ϸ OpenSSL ȭ /usr/local/bin ġǰ Certificate
  Service  ȭϵ /usr/local/opensslƷ 丮 ȴ.
   rsaref û ټ ִµ ̰ librsaref.a
  ̺귯 ̺귯 Searchο ־ Ѵ. ( 
  Ǵºκ ƴѰ 𸣰ڳ׿..  Ƽ..-.-; ftp
  search rsaref20 ˻Ͻø ã ֽϴ...׷, ְ
  ϸ  󱸿..)

  make ϸ OpenSSL̺귯(libcrypto.a libssl.a) ȭ
  (openssl) ǰ, ̺귯 make  丮,
  OpenSSLȭ apps丮 ȴ. make ϴ  
  , ޼ 캸ƾ Ѵ. κ OpenSSL  ƴ϶
  ϸ,  OpenSSL  Ǵܵȴٸ make report ̿Ͽ
  µ  openssl-bugs@openssl.org ۽Ѵ.

   make test Ͽ OpenSSL  ϴ ȮѴ.
    ִٸ, CFLAGS ϰ "make clean; make"
  ̿Ͽ ٽ  make test  .

     Ѵٸ, make installɾ ̿Ͽ
  ġ丮(/usr/local/ssl̳ /usr/local/bin,
  /usr/local/openssl) ȭϰ  ȭ, ȯ漳ȭϵ
  ġѴ.      Ǿٸ, Certificate Server
  ϱ  ⺻ غ Ϸ ̴.  OpenSSL ̿
  Certificate Server  Ű ȯ漳 ǽѴ.

  4.2.  rootCA 

  Certificate Server ϴ  Tree · ̷ ִ.
   ó Ÿ CA rootCA ϰ ڱ ڽ 
  䱸 ڱڽ signϿ ̳,  Ѵ.
  rootCAκ    ̶߰ ϸ,
  䱸 rootCA  ޾Ƽ ٸ̳  䱸
  ִ Ȱ Ѵ. ݺʹ տ  OpenSSL
  ȭϵ ̿ؼ ڽŸ rootCA Ѵ.

  (Ʒ ϴ  /path/to/openssldir/misc ø CA.pl
  CA.sh  ֽϴ. CA.xx  ϰ ./CA.xx -newca Ͽ
  rootCA ϼŵ ˴ϴ.  Perl shell script ũ
    ̴ϴ...^^; "CATOP"  Ͻø ˴ϴ.
   Client Sign Request  ϽǼ Ƿ ڼ
  캸ô° ϴ.)

  1. Ű 

     $  openssl genrsa -des3 -out ca.key 1024

     1024Ʈ ȵ  RSAŰ Ѵ.  Certificate
     Serverü Ű  ޵ ٸ  °
     ϰ  Ŀ ϴ° .

  2.  Ű ̿Ͽ Self Sign  ȭ Ѵ.

     $  openssl req -new -x509 -days 365 -key ca.key -out ca.crt

      ɾ ̿ϸ Certificate Server Distinguished Name
     ´.    Ȯϰ Էϰ rootCA
     Certificate Server  ȴ. ׸ ʿ信  days
     ׸ ؼ ϵ Ѵ. (йȣ ؾ ʵ
     ϼ..T.T)

  3. openssl丮 openssl.cnfȭ Ѵ.

     openssl.cnfȭ Certificate Service ϱ  ȯ漳
      ִ ȭϷ make install  sample ڷᰡ ִ.
      ȭ Ͽ   Certificate Service   ֵ
      Ͽ Ѵ.

     a. CA_default κп "dir"   丮
        ´.( "/path/to/openssldir/ڱCA" )

     b. usr_certκ nsCertType  # Ƿ ʿ
          Ǯش.(Netscape Client  ϴ
        κΰ .)

     c. Ca_default dir ʿ 丮 ȭ Ѵ.
        丮 certs, crl, newcerts, privatḛ ȭ "01"
         ִ serial   index.txt̴.  (CA.xx
         openssl.cnf Ͻø ˴ϴ.)

                $ mkdir /usr/local/openssl/MyCA
                $ mkdir /usr/local/openssl/MyCA/certs
                $ mkdir /usr/local/openssl/MyCA/crl
                $ mkdir /usr/local/openssl/MyCA/newcerts
                $ mkdir /usr/local/openssl/MyCA/private
                $ echo "01" > /usr/local/openssl/MyCA/serial
                $ touch /usr/local/openssl/MyCA/index.txt

     d. keyUsageκ # Ǯش.

     e. ʿϴٸ nsComment ϴ° ٲ۴.

  4.  Ű Ű openssl.cnf  丮
     Ѵ.

     ca.key /path/to/openssldir/ڱCA/private/cakey.pem ϰ
     ca.crt /path/to/openssldir/ڱCA/cacert.pem ϸ
     ˴ϴ.

  5. Ű application/x-x509-ca-cert MIME· Client Browser
       , Client "ŷڵ Ʈ" import
      ִ.

      ϼ,  (?) Certificate Service 
      ֽϴ.  ̳ ϰ Service ϱ ؼ
     Apache  ۾ մϴ.(߿ Client ؼ CSR
     Ҷ մϴ.)

  4.3.  Apache + mod_ssl/OpenSSL + PHP4/MySQL ġ

  Ϲ Apache  php ġ  ū ̴ , ⿡
   ϰ Ѿ  Ѵ.    mod_ssl
  INSTALLȭϿ  Ǿ Ƿ װ о  Ȯ ̴.
  mod_ssl  Apache   ڽ ġϴ Apache
  ġϴ mod_ssl ġϿ Ѵ. ̴ mod_ssl ȭϸ  
   ִµ, "mod_ssl-ڽŹ-ġ" · Ǿִ.

          $ tar xvfz apache_1.3.x.tar.gz
          $ tar xvfz mod_ssl-2.7.x-1.3.x.tar.gz
          $ tar xvfz php-4.0.x.tar.gz
          $ cd apache_1.3.x
          $ ./configure
          $ cd ../mod_ssl-2.7.x-1.3.x
          $ ./configure --with-apache=../apache_1.3.x
          $ cd ../apache_1.3.x
          $ .configure --prefix=/path/to/apache
          $ cd ../php-4.0.x
          $ CFLAGS='-O2 -I/path/to/openssl/include' \
            ./configure \
                  --with-apache=../apache_1.3.x \
                  --with-mysql \
                  --enable-memory-limit=yes \
                  --enable-debug=no
          $ make
          $ make install
          $ cd ../apache_1.3.x
          $ SSL_BASE=/path/to/openssl \
            ./configure \
                  --prefix=/path/to/apache \
                  --enable-module=ssl \
                  --activate-module=src/modules/php4/libphp4.a \
                  --enable-module=php4
          $ make
          $ make certificate
          $ make install

       Apache ȯ漳 Ҷ
  SSL_BASE OpenSSL ġҶ prefix ־ 丮 ־
  Ѵ.  (openssldir ƴϴ.)

     ļ  Apache  apachectl start
  ̿Ͽ  ϰ Ǹ Ϲ Apache   ϰ ǰ
  apachectl startssl  ̿ϸ mod_ssl ̿ https
  Ҽ ְ ȴ.  Client  url
  "https://server/path/" ԵǸ, ̶ Server Client ȣȭ
     ̷  ǰ Ŀ Server Client ڷ
  ȣȭ Ǿ  , sniffer ̿ δ ڷḦ ĺ
   ȴ.  ڼѰ kldp.org <http://kldp.org/> mod_ssl
  ˻ ãƺ ٶ.

  4.4.  Apache Server Ű  

  Apache + mod_ssl ġϸ ⺻ 30ϰ Ҽ ִ
  Certificate /path/to/apache/conf/ssl.crt  丮 ġǾ ִ.
  ̰  CA Ѵٸ  ϴ Ⱓ Ҽ
  ִ Certificate ȴ.(1̵ 10̵...^^;) (Ʒ 
  ϴ   ġ OpenSSL 浹ϴ 찡 ֽϴ.
  ̶  ġ OpenSSL  Ͻðų, "-config
  /path/to/openssldir/openssl.cnf" ߰ Էؼ Ͻʽÿ.)
  ġ make certificate TYPE=custom ϴ 쿡
  openssl Ų rootCA key certificateȭ ٽ ġؾ
  Ѵ. ̶  rootCA object sign(S/W ϴ°(?)) 
  Ƿ rootCA ϴ     ִ.

  1. opensslɾ ̿Ͽ Web Server RSAŰ Ѵ.

     $  openssl genrsa -des3 -out server.key 1024

     ̶ Ǵ Ű Web Server ϱ Ű  ݵ
      ޾Ƴ ϴ  .   Ű  
     ̿Ͽ  ȮҼ ִ.

     $  openssl rsa -noout -text -in server.key

  2.  RSAŰ ̿Ͽ Certificate Signing Request(CSR)
     Ѵ.

     $  openssl req -new -days 365 -key server.key -out server.csr

      ɾ ϴ  CommonName  Server
     FQDN(Fully Qualified Domain Name --> host.domain.com )
      Ѵ.  ȭ    Ȯ   ִ.

     $  openssl req -noout -text -in server.csr

  3.  CSRȭ Ἥ񽺸 ϴ VeriSign̳ Thawte rootCA
      server.crtȭ  ִ. OpenSSL ̿  
     Self Sign ó "openssl ca" ̿Ѵ. ̶ ݵ
     /path/to/openssldir/openssl.cnf  nsCertType Server
     سƾ Ѵ.( nsCertType = Server) (  Netscape
     https    ..  -.-)

     $  openssl ca -in server.csr -out server.crt

     (CA.pl̳ CA.sh  Ͽٸ "CA.xx -sign" ̿ص
     ˴ϴ. ׸  OpenSSL 浹 ʴ ȮϽð
     Ͻʽÿ.)

  4.  server.crt server.keyȭ  ġ ϰ
     Ѵ.

     Apache conf/httpd.conf , SSLCertificateFile ׸
     ϴ° server.crtȭ Ÿ ̰ SSLCertificateKeyFile
     ׸ server.keyȭ Ѵ.

  5.  Client 

   ޱؼ DN(Distinguished Name) ϰ ִ
  䱸(CSR) Ͽ CA ۽ؾ Ѵ. DN ̳, ,
   ϱ  ̸, μ, , ּ,  ʵ
  ̷ ְ, CN, OU, O, L, ST, C ʵ ǥȴ.  
  ޱ Client 䱸(CSR)ȭ  ٸ·  ǰ,
  Client  ϴ   ٸ Client 
   Ѵ.

  Client ڽ   , ٸ  ڵ带
    rootCA  ̸ ġǾ ־ Ѵ. 
  տ  rootCA Certificate ̸ ؼ ġؾ Ѵ.
  Netscape MS Explorer application/x-x509-ca-cert MIME ̿ؼ
   ϴ° ϸ ġҼ ְ, JAVA SDK 쿡
  ̸ ٿε Ѵ "keytool -import" ̿ؼ ġؾ Ѵ.
    Netscape MS Interne Explorer 䱸(Certificate
  Signing Request:CSR)     Network ̿Ͽ
  ۵ ݵ https  ̿ϵ Ѵ.

  5.1.  Netscape 

  Netscape CSRȭ ؼ SPKAC ڷḦ Ѵ.
  CSRȭ ϱ ؼ Web Server KEYGEN TAG  Form
  Ͽ Ѵ.  KEYGEN TAG  FORM ̴.

  ______________________________________________________________________
  <FORM name="CSR_request" method="post" action="user_cert.cgi">
  <table border=1>
  <tr><td>    </td><td><input name="CN" type=input></td>
  <tr><td> E-mail </td><td><input name="Email" type=input></td>
  <tr><td> μ   </td><td><input name="OU" type=input></td>
  <tr><td> ȸ   </td><td><input name="O" type=input></td>
  <tr><td>      </td><td><input name="L" type=input></td>
  <tr><td>      </td><td><input name="ST" type=input></td>
  <tr><td>    </td><td><input name="C" type=input></td>
  <tr><td> Ű </td><td><keygen name="SPKAC" type="RSA"></td>
  </table>
  </FORM>
  ______________________________________________________________________

  KEYGEN TAG ⺻  .

   <KEYGEN NAME="name" CHALENGE="challenge string" KEYTYPE="type"
  PQG="pqg-params" >

  NAME׸ ʼ̰(cgi óϿ ) KEYTYPE RSA DSA߿
  ϳ Ҽ ִ. PQG DSA Ѵ. keygen tag form
  tagȿ ȿϸ, Ư  keyũ⸦   ִ.
  ̱ 512, 768, 1024Ʈ Ű   ְ, ׿ 
  512Ʈ Ű   ִ. Form ϸ 512Ʈ ȵ
   Key Pair Ǹ Ű DB ȣȭ Ǿ ǰ
  Ű challengeƮ DER encodeǰ Ű signȴ base64
  encodeǰ  ۵ȴ.  DN SPKACƮ cgi
  ̿Ͽ ȭϷ     ̿Ͽ SignѴ.  (̶
  SPKACƮ 1ٷ Ǿ ־ Ѵ.)

  openssl ca -spkac ȭ -out .crt

    application/x-x509-user-cert MIME· Netscape
  Browser Ͽ importҼ ֵ Ѵ. ̶ Netscape DB
   شϴ Ű   importҼ .

  5.2.  MS Internet Explorer 

  MS Internet Explorer PKCS#10 䱸 ϸ,
  PKCS#7  Ҽ ִ.  Server 忡 
  ణ  ۾ ϳ  Ѵ. ׸ Explorer
  Netscapeó KEYGEN TAG  ʰ Microsoft 
  CryptoAPI(CAPI) ̿Ѵ.( ϴٰ ϴµ...ϱ?..^^;)
  CAPI ⺻ ȣȭ ۾  Լ Ѵ.(Ű , ڷ
  ȣȭ,  ,  䱸)

  CAPI  4ܰ踦 ̿Ͽ 䱸 ϰ 
  Ѵ.

  1. CAPIԼ   Key Pair ϰ  â Ѵ.

  2. DN(Distinguished Name) Ѵ.(?)

  3. CA  ϱ PKCS#10 ڷḦ Ѵ.

  4. CA  ڷḦ  â Ѵ.

     Explorer 
     "HKEY_CURRENT_USER/Software/Microsoft/Cryptography/" ȴ.
     CAPIԼ OBJECT TAG ̿Ͽ õũ ִ DLL
     оĿ    ִ.  CAPI  xenroll.dll
     о̴ ̴.  ( certenr3.dll̶ ȭϿ
     ߾µ   ʰ ְ, 쿡 OpenSSL
     ι Ʋ.)

  ______________________________________________________________________
  <OBJECT classid="clsid:43F8F289-7A20-11D0-8F06-00C04FC295E1"
             codebase="xenroll.dll"
             id=Enroll>
  </OBJECT>
  ______________________________________________________________________

   xenroll.dll ҷ DNƮ  xenroll cre
  atePKCS10Լ ҷ PKCS#10  䱸 .  DNƮ
  ڿ  createPKCS10Լ   Ѵ.

  $szStr="CN=SeungSu KUK; C=KR; ST=KyungBook; L=Kyungsan; O=Catholic
  University of DAEGU; OU=Computer Center";

  $result=Enroll.createPKCS10(szStr, "1.3.6.1.4.1.311.2.1.21");

   $result PKCS#10 ڿ  ְ ̰ CA
  Ѵ. CA ̰Ϳ ϰ PKCS#7 · 
  ش.

  OpenSSL    ̿Ͽ ϰ  Ѵ.
   $result  ڷῡ "BEGIN CERTIFICATE REQUEST"
  ڿ   $result ̿Ͽ    ȭ
  Ѵ.

  -----BEGIN CERTIFICATE REQUEST-----

  $result ^M  

  -----END CERTIFICATE REQUEST-----

   ȭ   ϰ PKCS#7 ȭ Ѵ.

  openssl ca -in ȭ -out certȭ

  openssl crl2pkcs7 -certfile certȭ -in /path/to/crl.pem -out
  pkcs7ȭ

  (crl.pemȭ ̸ Ǿ ־ ϴµ "openssl ca -gencrl"
  ̿Ͽ Ѵ.) pkcs7ȭ Explorer   "BEGIN
  PKCS7" "END PKCS7"̶ ڿ(ùٰ ) · ؾ
  Ѵ.  (ʱ׷  ߻Ѵ.)  ۵ PKCS7ȭ(VBScript
  JavaScript  ) AcceptPKCS7Լ ؼ importǸ 
   Ѵ.

  $szStr="۵ PKCS7ȭ "

  $result=Enroll.AcceptPKCS7(szStr);

  5.3.  JDK2 

  ( 1 Դϴ..-.-   丸 ڽϴ.
  ׸ ð   ϰڽϴ.)

  JDK2 applet̳ javascript ϱ ؼ 
  Ѵ.  Ű Ű  keytool ؼ ̷
  keytool Ͽ import/export Ѵ. keytool ̿
  Ű/Ű    Ѵ.

   keytool -genkey -alias ڸ -keypass شŰǺйȣ

  keytool "-genkey" ̿ϸ Distinguished-Name 䱸ϰ
   ϴ Self-Signed Certificate Ѵ. ̰ ߿
  "import" CA  Ű üȴ.  keytool Ҽ ִ
  ɼ  .

  o  -certreq : CSRȭ Ѵ.

  o  -delete  : keystore شŰ Ѵ.

  o  -export  : Ű Ѵ.

  o  -genkey  : keystore entry Ѵ.

  o  -import  : CA   importѴ.

  o  -list    : keystore  ش.

  o  -keypasswd: Ű ȣ Ѵ.

  o  -storepasswd: (Ǹ?)

     䱸  ؼ "-certreq" Ѵ.  (̶
     genkey Է йȣ ־ Ѵ.)

  keytool -certreq -keystore keystore̸ -alias ڸ -file
  CSRȭϸ

   CSRȭ CA ϰ "-import" ̿ؼ keystore
  Ѵ.
  keytool -import -alias ڸ -file CERTȭϸ -keystore keystore

   Ȯϰ   keytool -printcert -file CERTȭϸ̷
  ԷѴ.

  OpenSSL J2sdk 䱸  ó   Ͽ
   ϰ E-mail ̿Ͽ ָ ȴ.

   openssl ca -in certreqȭ -out certȭ

  6.  Ÿ

  6.1.  ڷ

  1. www.openssl.org <http://www.openssl.org/>

  2. www.modssl.org <http://www.modssl.org/>

  3. www.apache.org <http://www.apache.org/>

  4. Frederick J. Hirsch cookbook
     <http://www.ultranet.com/~fhirsch/Papers/cook/ssl_cook.html>
     (cookbook SSLeay <http://www.ssleay.org/> ѳ ϴٸ
     OpenSSL ssleay ʷϱ    ɰ ϴ.
      ̷ ִ 𸣰 Ƕ صԼ µ...ϸ鼭
     ãƺ ڷᰡ ֳ׿..)

  6.2.  Ҹ..^^

  (1..^^) ڷḦ ⼭ ؼ  ε...
   ڷḦ ã,  ִ  𸣰ڱ.   Ҷ
  ãƳ  ٵ...-.-;

    OpenSSL ̿ Certificate Server ͼ
  ʽϴ. CRL(Certificate Revoke List(?))  CSRȭ
  ڵȭϿ óϴ е     ϰ
  ֽϴ.    ԵǸ鼭 ̻  Ծ ǰڴٴ
   ±...   κе(Client ) 
  غ  Ǹ ̹ (^^) ؼ ٽ ø
  ϰڽϴ.   Ʋ ְų ǻ  
  ȯմϴ.  ֽø   ص ޵ ϵ
  ϰڽϴ.

  6.3.   

     ϴ   Ѻְ  
  ִ ڻԲ ϸ, ǰ   оֽ в
  帳ϴ..^^;

