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Feature #406

TNC: Speeding up the Attestation process

Added by Pedro Larbig almost 7 years ago. Updated almost 7 years ago.

Status:
Feedback
Priority:
Low
Category:
-
Target version:
-
Start date:
09.09.2013
Due date:
Estimated time:
Resolution:

Description

Hello again,

when playing around with the TNC Attestation plugins I encountered several IKE_SA timeouts since checking the IMA hashes and rebuilding the PCR took quite a lot of time.
Of course raising the timeout value fixes this error, but still the authentication process is taking a lot of time and sure can be improved.
The first thing that comes to my mind is the database backend that may be slow?

History

#1 Updated by Tobias Brunner almost 7 years ago

  • Assignee set to Andreas Steffen

#2 Updated by Andreas Steffen almost 7 years ago

Yeah, you are right. The current SQLite DB interface is quite slow, especially when inserting new reference values. We are trying to improve the insertion speed by using transactions.

For the time being just increase the charon.half_open_timeout parameter in strongswan.conf from the 30 seconds default value to about 60-90 seconds. Also if you are doing extnensive IMA file measurements, limit the number of Simple Component Evidence Attributes per PA-TNC message via the parameters

charon {
  plugins {
    tnccs-20 {
      max_batch_size = 32754
      max_message_size = 32722
    }
  }
}

which in my setup does not cause IKE message retransmissions by impatient VPN clients.

BTW - with strongswan-5.1.1 the tnccs-20, tnc-imc, and tnc-imv plugins are
going to move to libtnccs, so you have to put any parameters in the libtnccs section:

libtnccs {
  plugins {
    ..
  }
}

This makes the TNC libraries independent of the charon daemon so that they can be used e.g. with our new lean pt-tls-client.

#3 Updated by Andreas Steffen almost 7 years ago

  • Status changed from New to Feedback

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