NimbUx
Posts: 151
Joined: Fri Jan 03, 2020 10:33 am

Of canaries and backdoors

Fri Feb 21, 2020 10:39 am

Hello ! Unless it be disallowed to discuss such matters, I'd like to learn more about what is - and what is not - inside the proprietary, non-open, blocks of firm/software embarked in the RPI4 SoC. Questions such as :

° What level of access our great Engineers at RPF/RPT have to that material (under NDA, I imagine) : full view of the sources ? On demand, on an "need to know" only ?

° To the best of their knowledge, can the RaspberryPi team declare that there is no intentional "backdoor" included in the closed-ware, for (legal or otherwise) interception by the Powers-that-be ? If they cannot make such a statement, could be say why they cannot (f/example: not enough access / gag order...)

° If - as is hopefully the case - it can be asserted that no "spying" device is hidden in the firmware/closed software at the moment, could some kind of "warning canari" be setup and regularly renewed on the Foundation's website to signal that, at the moment, no "backdoor" is known or suspected to exist and no "gag order" has been received ?

Thank you. Please no pointless comments on this question being "paranoïd" - just ignore me if you think it is :=)

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 26379
Joined: Sat Jul 30, 2011 7:41 pm

Re: Of canaries and backdoors

Fri Feb 21, 2020 11:10 am

I thought all this had been discussed before but...

Yes, we have access to all the GPU firmware source - in fact it's been much modified by us. We woudl not be able to do the work required without full access to it.

There are no backdoors in the GPU firmware.

We've never been approached to add anything like a backdoor AFAIK, and never had any 'gag' orders. And I have no idea what you mean by canaries.

Note, I am discussing the GPU firmware. There is also firmware on the Wireless chip (Cypress) and the VLI USB hub chip. We do NOT have access to the source code of those, so cannot comment on them in this regard.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed.
I've been saying "Mucho" to my Spanish friend a lot more lately. It means a lot to him.

gordon77
Posts: 4969
Joined: Sun Aug 05, 2012 3:12 pm

Re: Of canaries and backdoors

Fri Feb 21, 2020 11:13 am

"And I have no idea what you mean by canaries."

i thought from the title it was someone who had canaries who wanted a detector to know if the backdoor was open , allowing them to escape ;)
Last edited by gordon77 on Fri Feb 21, 2020 11:15 am, edited 1 time in total.

User avatar
PeterO
Posts: 5820
Joined: Sun Jul 22, 2012 4:14 pm

Re: Of canaries and backdoors

Fri Feb 21, 2020 11:14 am

jamesh wrote:
Fri Feb 21, 2020 11:10 am
, and never had any 'gag' orders.
That's assuming they don't contain a "Do not admit to having received this gagging order" clause :lol:
PeterO
Discoverer of the PI2 XENON DEATH FLASH!
Interests: C,Python,PIC,Electronics,Ham Radio (G0DZB),1960s British Computers.
"The primary requirement (as we've always seen in your examples) is that the code is readable. " Dougie Lawson

User avatar
PeterO
Posts: 5820
Joined: Sun Jul 22, 2012 4:14 pm

Re: Of canaries and backdoors

Fri Feb 21, 2020 11:15 am

gordon77 wrote:
Fri Feb 21, 2020 11:13 am
i thought from the title it was someone who had canaries who wanted a detector to know if the backdoor was open ;)
Which ironically would have been much more "On topic" :lol:
PeterO
Discoverer of the PI2 XENON DEATH FLASH!
Interests: C,Python,PIC,Electronics,Ham Radio (G0DZB),1960s British Computers.
"The primary requirement (as we've always seen in your examples) is that the code is readable. " Dougie Lawson

fruitoftheloom
Posts: 23032
Joined: Tue Mar 25, 2014 12:40 pm
Location: Delightful Dorset

Re: Of canaries and backdoors

Fri Feb 21, 2020 11:20 am

NimbUx wrote:
Fri Feb 21, 2020 10:39 am
Hello ! Unless it be disallowed to discuss such matters, I'd like to learn more about what is - and what is not - inside the proprietary, non-open, blocks of firm/software embarked in the RPI4 SoC. Questions such as :

° What level of access our great Engineers at RPF/RPT have to that material (under NDA, I imagine) : full view of the sources ? On demand, on an "need to know" only ?

° To the best of their knowledge, can the RaspberryPi team declare that there is no intentional "backdoor" included in the closed-ware, for (legal or otherwise) interception by the Powers-that-be ? If they cannot make such a statement, could be say why they cannot (f/example: not enough access / gag order...)

° If - as is hopefully the case - it can be asserted that no "spying" device is hidden in the firmware/closed software at the moment, could some kind of "warning canari" be setup and regularly renewed on the Foundation's website to signal that, at the moment, no "backdoor" is known or suspected to exist and no "gag order" has been received ?

Thank you. Please no pointless comments on this question being "paranoïd" - just ignore me if you think it is :=)

Poppycock, Balderdash and FUD :roll: :roll: :roll: :roll: :roll:
Rather than negativity think outside the box !
RPi 4B 4GB (SSD Boot)..
Asus ChromeBox 3 Celeron is my other computer...

NimbUx
Posts: 151
Joined: Fri Jan 03, 2020 10:33 am

Re: Of canaries and backdoors

Fri Feb 21, 2020 11:30 am

jamesh wrote:
Fri Feb 21, 2020 11:10 am
I thought all this had been discussed before but...
Sincere apologies if it was so. I swear did attempt to search before posting, but obviously wasn't successful.
Yes, we have access to all the GPU firmware source - in fact it's been much modified by us. We woudl not be able to do the work required without full access to it.
understood...
There are no backdoors in the GPU firmware.
We've never been approached to add anything like a backdoor AFAIK, and never had any 'gag' orders
Sweet !
Note, I am discussing the GPU firmware. There is also firmware on the Wireless chip (Cypress) and the VLI USB hub chip. We do NOT have access to the source code of those, so cannot comment on them in this regard.
Not so sweet...
. And I have no idea what you mean by canaries.
A reference to caged birds were used by coal miners as living indicators, early warning against asphyxiating and/or inflamable gaz emanations. In online sites, a Canary is a conspicuous, dated, signed and oft renewed affirmation that the security has not been breached at the date of last posting, and that the posting itself shall be removed if ever the affirmation came to be no more trustable. (I know my English is terrible, but still hope one gets the idea...)

paulie
Posts: 275
Joined: Thu Jan 19, 2012 6:51 pm

Re: Of canaries and backdoors

Fri Feb 21, 2020 11:34 am

The expression derived from the practice of miners carrying caged birds (such as canaries) underground with them. When the air became noxious, the birds fell from their perches.

https://en.m.wikipedia.org/wiki/Sentine ... l_examples
It has been my custom to use Xeyes

PhatFil
Posts: 1665
Joined: Thu Apr 13, 2017 3:55 pm
Location: Oxford UK

Re: Of canaries and backdoors

Fri Feb 21, 2020 11:55 am

Not paranoid, just rude, what makes you think any backdoors exist? have you monitored suspicious traffic? if so where is the evidence.. Thats how a rational person would start such a conversation. "Hey I found this suspicious traffic from my pi any ideas??"

for example if i asked loudly "how many children did your puppy murder?" anyone within earshot would be wary of your puppy dog regardless of its true nature.

without qualification your questions only serves as an unfounded slur and assumes an evil organisation which if the case could not be trusted to respond with any honesty anyway.. SO why ask in the first place?

pica200
Posts: 216
Joined: Tue Aug 06, 2019 10:27 am

Re: Of canaries and backdoors

Fri Feb 21, 2020 12:17 pm

Don't you think someone who wants access to your Pi would go the easy route exploiting some Linux vulnerability to escalate privileges and then installing spyware? Not saying a backdoor in for example the WiFi module firmware doesn't have advantages but there are so many other ways not involving secret NDAs so i think this is extremely unlikely.

epoch1970
Posts: 4979
Joined: Thu May 05, 2016 9:33 am
Location: Paris, France

Re: Of canaries and backdoors

Fri Feb 21, 2020 12:26 pm

paulie wrote:
Fri Feb 21, 2020 11:34 am
The expression derived from the practice of miners carrying caged birds (such as canaries) underground with them.
And the proposition here is for the mine owner to put a canary in a cage at the entrance of the pit. Makes excellent sense, especially if next you want to question the allegiances of the poor creature ...
"S'il n'y a pas de solution, c'est qu'il n'y a pas de problème." Les Shadoks, J. Rouxel

Heater
Posts: 15778
Joined: Tue Jul 17, 2012 3:02 pm

Re: Of canaries and backdoors

Fri Feb 21, 2020 12:33 pm

The term "canaries" does indeed date back to the time of miners taking birds underground to detect toxic/explosive gasses. Before Humphry Davy invented his famous Davy Lamp which did the job much better: https://en.wikipedia.org/wiki/Davy_lamp

In recent times the term has been applied to a rather different situation:

Social media and other companies, in fact anyone, in the USA have to provide details of their internet service users to the government when it is requested. They can be required to install "back doors" to enable the government to spy on people.

At the same time they are not allowed to say that they have received such requests.

Enter the idea of the "canary". Such companies can put up notice that they have never received such a request to aid government spying. Then if they do get such a request they can take that notice down, thus indicating to everyone that something is up.

I have no idea if any net service has ever done this.

As for the firmware: As Bryan Cantrill says: "There is a war going on, firmware vs humanity, choose your side."

We could vainly hope the Pi Foundation would set a good example here but I would not hold my breath.

And as jamesh says we have closed source firmware in everything everywhere now a days. Much of which is far more critical positions in our systems. It's kind of hopeless.
Memory in C++ is a leaky abstraction .

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 26379
Joined: Sat Jul 30, 2011 7:41 pm

Re: Of canaries and backdoors

Fri Feb 21, 2020 7:38 pm

Heater wrote:
Fri Feb 21, 2020 12:33 pm
The term "canaries" does indeed date back to the time of miners taking birds underground to detect toxic/explosive gasses. Before Humphry Davy invented his famous Davy Lamp which did the job much better: https://en.wikipedia.org/wiki/Davy_lamp

In recent times the term has been applied to a rather different situation:

Social media and other companies, in fact anyone, in the USA have to provide details of their internet service users to the government when it is requested. They can be required to install "back doors" to enable the government to spy on people.

At the same time they are not allowed to say that they have received such requests.

Enter the idea of the "canary". Such companies can put up notice that they have never received such a request to aid government spying. Then if they do get such a request they can take that notice down, thus indicating to everyone that something is up.

I have no idea if any net service has ever done this.

As for the firmware: As Bryan Cantrill says: "There is a war going on, firmware vs humanity, choose your side."

We could vainly hope the Pi Foundation would set a good example here but I would not hold my breath.

And as jamesh says we have closed source firmware in everything everywhere now a days. Much of which is far more critical positions in our systems. It's kind of hopeless.
Thanks - someone who understood what my question about canaries actually meant (I am perfectly familiar with the historical use of canaries in coal mines)
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed.
I've been saying "Mucho" to my Spanish friend a lot more lately. It means a lot to him.

cleverca22
Posts: 486
Joined: Sat Aug 18, 2012 2:33 pm

Re: Of canaries and backdoors

Fri Feb 21, 2020 8:30 pm

i have heard of an OTP setting to make the rom boot from 0x60008000 instead, but i dont know of any ram or rom at said address

my best guess would be to side-load things via jtag, but it would also have the side-effect of making the chip entirely reliant on vpu-jtag to even boot


User avatar
HermannSW
Posts: 2524
Joined: Fri Jul 22, 2016 9:09 pm
Location: Eberbach, Germany
Contact: Website Twitter YouTube

Re: Of canaries and backdoors

Sat Feb 22, 2020 10:31 am

NimbUx wrote:
Fri Feb 21, 2020 11:30 am
Note, I am discussing the GPU firmware. There is also firmware on the Wireless chip (Cypress) and the VLI USB hub chip. We do NOT have access to the source code of those, so cannot comment on them in this regard.
Not so sweet...
Until recently I would have said:
You can capture ethernet and Wifi traffic with Wireshark, and then analyze.
Even if traffic is encrypted, you can at least identify suspicous traffic.

Recently I learned that my smartphone talks to smart plug via a Wifi morse protocol for providing Wifi password to the plug, so that plug can connect to Wifi and register itself to internet server via MQTT:
viewtopic.php?f=37&t=264577&p=1612002#p1612002
I have no idea how to capture that kind of traffic.

Not sure how to capture Bluetooth traffic as well.

For both types of access attacker would need to be close to your Pi4B though ...
https://stamm-wilbrandt.de/en/Raspberry_camera.html
https://stamm-wilbrandt.de/en#raspcatbot
https://github.com/Hermann-SW/raspiraw
https://github.com/Hermann-SW/Raspberry_v1_camera_global_external_shutter
https://stamm-wilbrandt.de/github_repo_i420toh264

Return to “General discussion”