Posts
4825
Following
321
Followers
488
Linux kernel hacker and maintainer etc.

OpenPGP: 3AB05486C7752FE1
jarkko

Jarkko Sakkinen

Learned a cool trick in Python, if need to have more deterministic latency for a thread: shutdown the gc as prologue and do collection once as epilogue.

I.e.

gc.disable()
# Do stuff that does not cause CPU
# exceptions or interrupts.
gc.collect()

I also noticed that MicroPython has pretty usable inline assembler.

This makes me wonder if you could implement Python version of https://rtic.rs/2/book/en/ running hard real-time tasks on bare metal.

This is more like learning thing than challenging thing… I.e. by doing the similar thing perhaps in limited scope in other language it is easier to get grip of the original target…

#python #rustlang

1
1
3
jarkko

Jarkko Sakkinen

Reply to @jarkko
@briankrebs right, and to add, if you have a criminal court case ongoing shut f*ck up until it is done and finished. you might end up saying stupid things on internet that can be potentially used against you as evidence. no wonder the security was flawed...
0
0
0
jarkko

Jarkko Sakkinen

Reply to @briankrebs@infosec.exchange
Edited 1 year ago
@briankrebs apparently that ceo has yet to find mastodon ;-) social suicide commentary in every other possible social media. he should author a book called "how to f*ck up your life and beyond"
1
0
1
jarkko
repeated
briankrebs@infosec.exchange

BrianKrebs

Edited 1 year ago

A 26-year-old Finnish man was sentenced to more than six years in prison today after being convicted of hacking into an online psychotherapy clinic, leaking tens of thousands of patient therapy records, and attempting to extort the clinic and patients.

https://krebsonsecurity.com/2024/04/man-who-mass-extorted-psychotherapy-patients-gets-six-years/

Even though Julius "Zeekill" Kivimaki has a cybercrime rap sheet thicker than a dictionary, he will end up serving roughly half that time, because all that stuff he did before he turned 18 doesn't count toward first-time offender status.

BTW, the CEO of the now-bankrupt psychotherapy practice was prosecuted as well (database credentials "root/root") but received a suspended sentence.

2
2
1
jarkko

Jarkko Sakkinen

Reply to @jarkko
@signalapp in linux. (once we add x509 support for TPM2, probably 6.11) the CPU certificate delivery could be even delivered with a public key coming from TPM (private key non-existent in the machine). So you could hardware-to-hardware pipeline.
0
0
1
jarkko

Jarkko Sakkinen

hmm... https://www.phoronix.com/news/Linux-610-TPM-Encrypt-Integrity. so it is not yet pulled so no need to announce in the current state "unfinished work" (by definition, given that it is not pulled) ;-)

I'll try to get asymmetric keys soon out which cleans this stack up further as a side-effect. If this did not make into 6.10 then I'll just add it on top of that patch set.
0
0
0
jarkko

Jarkko Sakkinen

Reply to @jarkko
@signalapp also e.g. signal would benefit in qa if there was emulated infrastructure in place (my previous post). not that well tested except field tested ofc.
0
0
0
jarkko

Jarkko Sakkinen

Reply to @jarkko
Edited 1 year ago
@signalapp like for instance: https://signal.org/blog/building-faster-oram/. none of this applies unless proven otherwise for every single running instance of the client. or if you have a belief system applied.
1
0
0
jarkko

Jarkko Sakkinen

The single biggest issue in confidential computing is still. that there is no legit way to deliver cryptographic proof to client/browser inherited from CPU attestation. i.e. a x509 certificate. and so that it is vendor-neutral. not sure if even @signalapp can do this. who cares what you run in the backend if you cannot prove it.
2
0
0
jarkko

Jarkko Sakkinen

this is still somewhat solid reference: https://www.decentriq.com/article/swiss-cheese-to-cheddar-securing-amd-sev-snp-early-boot
0
0
1
jarkko

Jarkko Sakkinen

I wonder if it would make sense to elf stamp kernel images with some sort of. identifier to check where the image is at in the mainline reflecting to the latest of https://docs.kernel.org/process/cve.html. Or maybe this already exist. It would make in the mainline perhaps because then you could detect "too old" when running multiple distributions.
0
0
0
jarkko

Jarkko Sakkinen

Reply to @jarkko
Edited 1 year ago
Which gives you an infrastructure to differentiate emulated attested from production attested. So even attestation is technically possible but at minimum unattested version which is just upgrading qemu would help a lot.
0
0
0
jarkko

Jarkko Sakkinen

Reply to @jarkko
I.e. it cannot force you from not setting "fake stamp" but it can refuse to give attestation to it if you don't set it. Intel won't sign it for you plain and simple.
1
0
0
jarkko

Jarkko Sakkinen

Reply to @jarkko
In SGX attestation, which mostly applies also to TDX, you could possibly use e.g. enclave attribute for this defined by the ISA spec (Intel SDM). I mean for the "fake stamp". Attestation can refuse to attest if the provision matches to some list inside archiectural enclave (aka Intell signed) but that "fake stamp" attribute is not set.
1
0
0
jarkko

Jarkko Sakkinen

Reply to @jarkko
because of the hard-bound bare metal depeendency quality assurance in the real sense of that word like super-transparent does not exist in this world for confidential computing no wonder it is confidential when it is not even measured by most of the qa infrastructure existing. totally fights against the marketing promise.
1
0
0
jarkko

Jarkko Sakkinen

Reply to @jarkko
heck maybe it would be even possible to fixup "knowingly known cryptographic material" that would be fixed up also to the qemu code base to which Intel's and AMD's servers would respond as legitimately.or maybe salt somehow to stamp the fake stamp. like just for infrasturcuture QA type of stuff use.

this is not an issue in the CA part as e.g. AMD already today has a rate-limited attestation paradigm. so yeah i think really would make sense for companies to spend money for fixing up this.
1
0
0
jarkko

Jarkko Sakkinen

Reply to @jarkko
for instance you could run CI test in Gitlab/Github runner running kselftest with confidential computing part just emulated and "unattested".
1
0
0
jarkko

Jarkko Sakkinen

Reply to @jarkko
there is only one thing actually that will fail and it is remote attestion because no legit cryptographic material but remote attestation is irrelevant for kernel testing (for the most part at least).
1
0
0
jarkko

Jarkko Sakkinen

Reply to @jarkko
95% of KVM and 5% qemu emulation in non-performance sensitive task (which neither is in kernel patch or patch set scale when tested as part of review process)
1
0
0
jarkko

Jarkko Sakkinen

imho at least qemu would need snp and tdx emulation in upstream for like testing patches. i mean most have x86 so even rigged emulation would do the job for trivial patch testing
1
0
0
Show older
About social.kernel.org

Terms of service

  1. Please do not use this service in violation of the Linux Kernel Code of Conduct. Doing so will result in your account suspension with the referral of the matter to the CoC committee.

  2. "Repeating"/"boosting" someone else's status on this platform will be treated as endorsement and will fall under rule #1.

  3. You are encouraged to use this platform to promote your work on the Linux Kernel, but there is no restriction on permitted topics (with the exception of anything covered by #1 above).

  4. There is no requirement to post in English, but it should be considered the primary language of communication on this platform.

Privacy notice

The admins of this service have access to all posted statuses. They aren't looking, but if it's something they shouldn't know about, then you should not post it on this platform.

Please see the Linux Foundation Privacy Policy, which applies to this platform as well.

Getting your own account

If you would like an account on this instance, please check that the following applies to you:

  • You are listed in MAINTAINERS or CREDITS

  • OR: You have a kernel.org account or email address

  • OR: You have a long and established history of involvement with the Linux Kernel

If the above is true and you agree with the Terms of Service and Privacy Notice listed above, please use these instructions to request an account: