Question

Fingerprint for session did not match error while trying to login

0

When we try to login with a certain user with correct credentials the user is logged out immediately with "Fingerprint not match error" given by the Runtime. From another PC login works fine, just on the clients PC it will not work. Dec 7 14:40:05 127.0.0.1 offectip: INFO - Core: Login OK: user 'User252' (Number of concurrent users: 5). Dec 7 14:40:06 127.0.0.1 offectip: WARNING - Connector: Fingerprint for session '72992a15-0226-4c39-a15c-14677b1fe814' (user: User252, request info: 127.0.0.1,94.210.170.57,Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Win64; x64; Trident/5.0),*/*,nl,gzip, deflate) did not match, sending 401.

asked 2012-12-07

Herbert Vuijk

4 answers

Hans van Kranenburg · Answer 1 · 2012-12-08

In Mendix 4.1.0 a configuration item was added that allows you to disable this fingerprinting check:

EnableSessionFingerprinting: false

When running a server using m2ee-tools, you can add this configuration item at the runtime: section of the yaml configuration file.

Sebastiaan van den Broek · Answer 2 · 2012-12-07

It could be the user's browser or some plugin in the browser that's modifying the fingerprint. Perhaps the user can use a different browser or reinstall his current one?

This is a safety mechanism so sessions can not easily be taken over, a fingerprint is basically a collection of identifiable aspects of a certain browser. However, it's expected to remain constant for a certain client so if this isn't the case then you will get problems like these.

Arjan van IJzendoorn · Answer 3 · 2012-12-07

This will definitely be fixed in 4.3.0 because we are replacing the fingerprint system with something that is a) more secure and b) not dependent on browser (plugin) quirks.

And as Bas says, it probably has to do with the browser on that particular computer. Maybe they have a toolbar installed?

Herbert Vuijk · Answer 4 · 2012-12-07

Thanks for the replys. I never had this issue reported when using Mendix < 4. Now just a few days live with a major 4.2.2 application and already five users reported this, the same, issue. Seems to be a serious problem!

Just today the fingerprint error count is 66 in the m2ee logging with just a few users online.

I will file a ticket because this becomes a high prio issue..

Can it have anything to do with using anonymous and users? For example: in one tab visiting a anonymous form an then logging in in another tab?

UPDATE 08-12-2012: I tried disabling anonymous users in a test environment but didn't help. Just had a call with one of the users He had Google Toolbar enabled. After disabling logging in works just fine. Since a lot of people use the Google toolbar you should think that more projects has this issue..