Hi Allen,
ÐÐ Thursday 10 January 2008 22:02:01 Brokken, Allen P. ÐÐÐÐÑÐ:
Somebody here is developing a Web application that requires user logins,
but that is unable to store session information on the server (don't ask
me why, it's a long story). So here's what they propose: to take the
username, hash of the password, and date the user logged in, encrypt
them with a strong encryption algorithm, and store them in a cookie
(along with a hash to ensure integrity).
I am currently in a simiral position. I have to write an
authentication/authorization program and to present my work J have to make a
few example pages...
My question is, assuming a proper encryption algorithm/eky are chosen,
can anybody think of a problem that this will create that sessions don't
already have (namely, replay attacks)?
I have always loved taking a different angle. Having a cryptographic cookie...
means that we are having a token, which can be used for authentication for a
specific domain and time. Doesn't that mean that we have a key for a specific
domain and time? (the replay attacks are based somewhat on that logic,
right?) So is an approach that creates a static token a real security
sollution? May be a more dynamic "cookie" can be the solution. A cookie that
works with a CHAP based sollution (what I think) somewhat more secure.
Offcourse there is the productivity problem...
Search in google for: session security with coockies. It will help you a lot.
A nice link as well:
http://www.technicalinfo.net/papers/WebBasedSessionManagement.html
Regards,
Orlin
-------------------------------------------------------------------------
Sponsored by: Watchfire
Methodologies & Tools for Web Application Security Assessment
With the rapid rise in the number and types of security threats, web
application security assessments should be considered a crucial phase in the
development of any web application. What methodology should be followed? What
tools can accelerate the assessment process? Download this Whitepaper today!
https://www.watchfire.com/securearea/whitepapers.aspx?id=70170000000940F
-------------------------------------------------------------------------
