Generation of Secure Web Applications from Web Transition Diagrams

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Generation of Secure Web Applications from Web
Transition Diagrams

• K. Jamroendararasame, T. Matsuzaki,
• T. Suzuki, and T. Tokuda
• Dept. of Computer Science,
• Tokyo Inst. of Tech., JAPAN

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Architectures for Web Applications (1)

• Processing on the client side
• scripting languages JavaScript and VBScript
• compiled modules Java applets and ActiveX
  controls
• Processing on the server side
• SSI (Server Side Includes)
• CGI (Common Gateway Interface)
• Java Servlet
• server side scripts JSP, ASP, and PHP
• components EJB and COM

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Architectures for Web Applications (2)

• Processing on client and server sides
• client side scripts with server side programs
• client-server programs communicating by general
  protocols
• RMI (Remote Method Invocation)

We concentrate on CGI architecture.
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Disadvantages of Current Web Application
Construction Approaches

• manual management of consistency and security of
  systems
• ad hoc construction of processing programs
• complex logical structure processing programs
• no graphical view of overall system behavior

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Purposes (1)

• To define a graphical method to describe behavior
  of Web applications

• Web Transition Diagrams
• representation of overall behavior of Web
  applications
• based on pipe/filter software architecture

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Purposes (2)
To generate Web applications from Web transition
diagrams

• A Web application generator T-Web system
• consisting of
• a Web transition diagram editor
• a Web application generator
• based on template method

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Web Transition Diagrams
Links
Nodes
title
title
Page transition link
Fixed Web page node Output Web page node
name
Data-flow link
name
Processing node Database node
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An Example of Web Transition DiagramsA Seminar
Room Booking System
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T-Web Systema Web Application Generator

• We compose a Web transition diagram using the
  editor
• We allow the generator to generate Web pages,
  processing programs, and a script for database
  tables creation
• We optionally revise Web pages using a Web page
  composer
• We place Web pages, processing programs, and the
  script on a Web server and run the script to
  create all database tables

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Composition of Web Transition Diagrams using
T-Web System
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Setting up HTTP cookies

• 4 actions on HTTP cookies set, get, delete, and
  authenticate

delete id
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Web Pages Generating Approach
ltHTMLgt ltTITLEgtRegisterlt/TITLEgt ltBODYgt ltFORM
ACTION "/cgi-bin/ADD1.cgi" METHOD
"POST"gt IDltINPUT TYPE text NAME__IDgt PWltINP
UT TYPE password NAME__PWgt EMltINPUT TYPE
text NAME__EMgt ltINPUT TYPE submit
VALUESubmitgt lt/FORMgt ltA HREF
Top.htmlgthomelt/Agt lt/BODYgt lt/HTMLgt
Register
ID PW EM

Submit
home
an example of Web pages
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Processing Programs and a Script Generating
Approach
dbname ltDB_NAMEgt lt- booking table
ltTABLE_NAMEgt lt- USER_LIST _at_field
(ltFIELD_NAMEgt) lt- ID, PW, EM,
PIN ReadParse(in) ltltPARAMETER_NAME
in'__PARAMETER_NAME'gtgt lt- ID
in'__ID' PW in__PW
EM in__EM if (Blank_check(ltPARAMETER_F
OR_BLANKgt)) lt- ID,EM,PW connect(dbname)
exist_check(table, ltPARAMETER_FOR_MATCHgt,
ltPARAMETER_FOR_MATCHgt) lt- ID, EM
ID,EM if (sth-gtrows 0) ltID_FIELDNAME
PIN_generate(table)gt lt- PIN
PIN_generate(table) ltDATE_FIELDNAME
Date()gt lt- NULL
dbname booking table USER_LIST _at_field
(ID, PW, EM, PIN) ReadParse(in) ID
in__ID PW in__PW EM
in__EM if (Blank_check(ID,EM,PW)) conn
ect(dbname) exist_check(table, ID, EM ,
ID,EM) if (sth-gtrows 0) PIN
PIN_generate(table)
an example of templates
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Consistency management

• Adding some checking codes into templates of
  processing programs which process a side-effect
  on databases
• Checking codes detect inappropriate values of
  input parameters and conclude the process to a
  bad condition.

time
t0
t1
t2
t3
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Security management

• Adding some checking codes in templates and
  predefined CGI libraries
• Examples of codes
• for denying unacceptable amount of form input
• over-maximum-length input data
• for denying unacceptable format of form input
• HTML tags
• abnormal-formatted email addresses

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Evaluation

• T-Web system can generate
• typical small-to-medium scale systems
• a seminar room booking system
• a guest book system
• a shopping cart system
• T-Web system cannot generate
• real-time processing systems
• a real-time chat system
• large-scale systems
• Generalization
• by a reasonable number of predefined templates

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Comparisons (1)
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Comparisons (2)
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Summary Future work

• Web transition diagrams
• T-Web system
• compose Web transition diagrams
• generate Web applications
• Future work
• improvement of the level of systems consistency
  and security
• implementation of a generator for Web
  applications based on other architectures