====== Unattended encrypted kernel crash dumps ======
  * Student: [[/KonradWitaszczyk|KonradWitaszczyk]]
  * Mentor: [[/GlebKurtsou|GlebKurtsou]]

===== Project description =====

Kernel dump may contain a backtrace of function calls, information about processes or even device data. These information should not be seen by a person trying to attack our OS because it might help to hack it. The main goal of the project is to implement encrypted crash dumps. It means that a user will have to decrypt a dump before analysing it. Crash dumps will be encrypted with an one-time AES key which will be shared with a user using an asymmetric key encryption.

===== Approach to solving the problem =====

In order to finish this feature it is required to modify crash dump routines, [[http://www.freebsd.org/cgi/man.cgi?query=savecore&sektion=8|savecore(8)]] and [[http://www.freebsd.org/cgi/man.cgi?query=crashinfo&sektion=8|crashinfo(8)]]. Our solution will use a random symmetric key to encrypt data with AES using XTS mode which will be encrypted with an asymmetric key chosen by a user. We will start with constant keys to implement encryption and then we will make it more user-friendly.
After reboot caused by a panic, [[http://www.freebsd.org/cgi/man.cgi?query=savecore&sektion=8|savecore(8)]] will copy the dump and its key to dumpdir and make it able to decrypt with [[/PEFS]].

During my work I will be sending reports every Monday to the soc-status@%%FreeBSD%%.org mailing list:
  * [[http://lists.freebsd.org/pipermail/soc-status/2013-June/000633.html|Report #1]]
  * [[http://lists.freebsd.org/pipermail/soc-status/2013-July/000665.html|Report #4]]
  * [[http://lists.freebsd.org/pipermail/soc-status/2013-July/000684.html|Report #5]]
  * [[http://lists.freebsd.org/pipermail/soc-status/2013-July/000692.html|Report #6]]

===== Deliverables =====

  * Write a rc.d script to generate a symmetric key and encrypt it with an asymmetric key.
  * Change crash dump routines to write an encrypted data in a dump device.
  * Change [[http://www.freebsd.org/cgi/man.cgi?query=savecore&sektion=8|savecore(8)]] to store the encrypted dump and its encrypted symmetric key in dumpdir.
  * Change [[http://www.freebsd.org/cgi/man.cgi?query=crashinfo&sektion=8|crashinfo(8)]] to save an encrypted crash summary along with a crash dump.

===== Milestones =====

  * **June 17: Start of coding**
  * June 24: Define a new format of a crash dump header and change [[http://www.freebsd.org/cgi/man.cgi?query=savecore&sektion=8|savecore(8)]] to support it
  * July 1: Import and change [[/PEFS]] library to encrypt crash dumps
  * July 8: Encrypt a crash dump with a constant AES key
  * July 15: Change [[http://www.freebsd.org/cgi/man.cgi?query=savecore&sektion=8|savecore(8)]] to save encrypted crash dumps with its key
  * July 22: Change [[http://www.freebsd.org/cgi/man.cgi?query=savecore&sektion=8|savecore(8)]] to support PEFS
  * **July 29-August 2: Mid-term Evaluations**
  * August 5: Generate a random one-time symmetric key
  * August 12: Encrypt a crash dump with the random symmetric key
  * August 19: Decrypt a crash dump with the encrypted random symmetric key ([[http://www.freebsd.org/cgi/man.cgi?query=savecore&sektion=8|savecore(8)]])
  * August 26: Decrypt a crash dump with the encrypted random symmetric key (PEFS)
  * September 2: Encrypt a crash summary
  * September 9: Tests and documentation
  * **September 16: End of coding (soft)**
  * **September 23: End of coding (hard)**

===== Test Plan =====

I would like to test my project in the following stages:
  * Encrypting with a constant AES key.
  * Decrypting with [[/PEFS]] after [[http://www.freebsd.org/cgi/man.cgi?query=savecore&sektion=8|savecore(8)]] changes.
  * Exchanging an one-time AES key.
  * Encrypting/decrypting with the one-time AES key.
  * Encrypting/decrypting crash summaries.
In order to test the project I will use [[http://blog.eitanadler.com/2012/10/nfs-mount-network-booting-virtualbox.html|a diskless virtual machine]] with a memory disk on a host machine as a dump device. Panics will be forced with the special sysctl variable: //sysctl debug.kdb.panic=1//.

===== The Code =====

Modified %%FreeBSD%%-HEAD: https://svnweb.freebsd.org/socsvn/soc2013/def/crashdump-head/

===== Presentation =====

The project was presented at [[DevSummit/201309|FreeBSD Developer Summit during EuroBSDcon 2013]]. You can find the presentation [[DevSummit/201309#Presentations|here]].

===== Useful links =====

Project in Melange: http://www.google-melange.com/gsoc/project/google/gsoc2013/def/25001

Kernel Debugging: http://www.freebsd.org/doc/en/books/developers-handbook/kerneldebug.html

The XTS-AES Mode for Confidentiality on Storage Devices: http://csrc.nist.gov/publications/nistpubs/800-38E/nist-sp-800-38E.pdf

Efficient Instantiations of Tweakable Blockciphers and Refinements to Modes OCB and PMAC: http://www.cs.ucdavis.edu/~rogaway/papers/offsets.pdf

PEFS: [[/PEFS]]

savecore(8): http://www.freebsd.org/cgi/man.cgi?query=savecore&sektion=8

NFS Mount Network Booting [[/VirtualBox|VirtualBox]]: http://blog.eitanadler.com/2012/10/nfs-mount-network-booting-virtualbox.html

%%FreeBSD%% Development for Smarties. The quest for a better kernel development environment: https://www.bsdcan.org/2010/schedule/attachments/144_bsdcan2010_lstewart_smarties.pdf