2013-08 DevSummit Security session

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What do we want for the long term?
What can we do in time for 10.0?
Pawel's attachtimes patch for early entropy gathering
random_adaptor framework
HWRNG support:
- As an entropy source for Yarrow / Fortuna
- As a backend for /dev/random
- Selectable mixer

Walkthrough on actual state of security mitigation in FreeBSD
- ASLR (exprimental patches on people.freebsd.org/~sbz/aslr) ⇒ rewiew + exp-run + security OID
- DEP (nxstack) [data, head and stack OK]
- redzone ⇒ not in production (double allocation for runtime check)
- …

Topics:

Using CPE in VuXML ⇒ no time

Security Testing/Operations
- Security infrastructure (PKI) ⇒ clusteradm not present
- Response to incident quickly (why not having a security operation team) ⇒ clusteradm not present

In total, there were three security-related sessions: one on each day of the summit.

Notes taken by SofianBrabez originally in text/x-zim-wiki syntax, partly moinmoinified by DagErlingSmørgrav

Present

pjd
des
sbz
gavin
markmurray
adrian
rwatson
daviddrysdale
ogoshbo
WarrenHunt

/dev/random session (1h30 min)

ST

des:

we don't change property of the ouput
structural changes only for 10.0

note: “structural changes” means “changes to the framework that the drivers plug into, but no deep rototilling”

LT

Hardware RNG support

Yarrow (WRITE, Keyboard, Mouse, NET, PURE, INTERRUPT)
* hash buffer encryption key
* timestamp class entropy
* Net
* * TSI register buffer timer; need to downgrade number of bit register ⇒ already a fix for that
* * bad entropy because loosing to much in input queue
*
* not identification, sufficient entropy
* * ⇒ pavel patchs (entropy from device attach time)
* * * → no feed the queue
* * * → always feed attach time
* * * → overestimated entropy for some device
* * ⇒ losing something by XORING ?

* quick hashes ?!
* Interrupt
* * software (off by default) + hardware interrupts
* Buffer entropy (circular)
* * store file in DevSummit/201308/Security/entropy
* * pjd: good idea to loader responsible for generation keys (preload entropy in fs)
* * gavin: nextboot project ?!
* * markm:
* * * write general purpose code to bring an API for other case (process, probe temperature, crypto, ect..) (random_adaptor framework)
* * * feed to yarrow
* * * care about DevSummit/201308/Security/dev/random (use DevSummit/201308/Security/dev/zero)
* * * to be done at runtime
* * rwatson:
* * * dealing with ssh keys, probably identical keys in the world because of the entropy?
* * markm when boot and don't have good results or RNG fail :
* * * block (seems the solution ssh-keygen block), crap entropy/pig randomness or panic (not appropriate will be same after next reboot)
* * * pdj: fallback on yarrow but if non yarrow ?!
* * * adrian: on mips can't do pid randomness (base on arc4random())
* * * rc4 vs /dev/random

Embedded
* adrian come up with embedded problem (time attach is low on his board), boot part ?!
* des background noise on wireless device/stack
* markm kill the input queue
* rwatson think we need to focus on desktop and servers to provide good documentation and good pratices by default, provide guidance and clearance
*
Yarrow vs Fortuna
* Y:256 bit hashes into fast and slow buffer, value as a key for encryption function (PRNG + hardware device to change the seed) + 2 pool
* F: 32 pool each event seperatly and evenlty spread each pool from source + bitmaps counter, advantage: counter mode
* * rwatson: queue per cpu core

david miles hash ?!
rwatson: sson did FIPS tests for Apple and MacOS
rwatson: multi socket ?! cpu socket ?! will be a problem high thread…
pjd: Yarrow limited to one CPU ⇒ don't scale because of the LOCK
* reading scalable ⇒ feed directly to the pool and not use queue
* XORING doesn't loose entropy
markm: we need to do the hash in pool !
sbz: test diehards
des: test vritual machine (vbox)

Schema ⇒ take picture

HW: rvy.c + nehemiah.c boot: sysctl yarrow: device driver

Schema propose by pjd

proxy mixer component which take entropy from real rand device and network?

Conclusion

Fix the change NET/PURE/INTERRUPT/?
Fortuna not in 10.0
No new frameworkn bugs ?!
No loose entropy with update to current + adaptar framework
YARROW unconditional
pavel patches includes
* fixes entropy estimation
* by overestimated (des send everything and test the range ⇒ less variation, device prove slowly)
des test regarding attach times:
17:38 <@EvilDES> http://people.freebsd.org/~des/attachtimes-bin.txz
17:38 <@EvilDES> http://people.freebsd.org/~des/attachtimes-text.txz
17:38 <@EvilDES> http://people.freebsd.org/~des/attachtimes-total.txz

mitigation session (25min)

ST

Probably for 11.0

rwatson: Use randomness for ASLR in process and kernel markm : RC4 random (dedicated register) use for mititation and aslr randomness in user mode, DevSummit/201308/Security/dev/random unblock

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