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Show HN: The SC4-HSM, a fully open USB hardware secure module

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Re: Show HN: The SC4-HSM, a fully open USB hardware secure module

#31

Post by kosma »

mkj wrote: post #27
kosma wrote: post #26

Earlier quoted context omitted.

> there is readout protection built into the SoC I have managed to bypass readout protection on STM32F1 with just a few nights of hacking and $2 in parts; I suspect F4 isn't much different. I wouldn't trust any general purpose MCU in this regard.

Nice, I'd wondered how hard that would be. Could you share details?

The FPB (flash patch and breakpoint) peripheral on Cortex-M3 allows live-patching the flash contents; this allows you to temporarily change the reset vector. That, plus careful supply voltage glitching to reset some peripherals but not other, and the device is pwned.

Re: Show HN: The SC4-HSM, a fully open USB hardware secure module

#32

Post by lisper »

ComodoHacker wrote: post #28

>The display and user buttons protect against an attack launched from the host machine. Before the unit performs a cryptographic operation it can display information about what it is about to do on the display and wait for the user to confirm the operation by pushing one of the user input buttons on the unit. As the author is here, I'd suggest adding a beeper as a way to alert about potentially unsolicited access to…

There is a tri-color LED that is intended to be used for that purpose. Red means something bad has happened :-)

Re: Show HN: The SC4-HSM, a fully open USB hardware secure module

#33

Post by lisper »

kosma wrote: post #31
mkj wrote: post #27

Earlier quoted context omitted.

Nice, I'd wondered how hard that would be. Could you share details?

The FPB (flash patch and breakpoint) peripheral on Cortex-M3 allows live-patching the flash contents; this allows you to temporarily change the reset vector. That, plus careful supply voltage glitching to reset some peripherals but not other, and the device is pwned.

Nice! But it sounds like it would not be effective against RDP level 2.

Re: Show HN: The SC4-HSM, a fully open USB hardware secure module

#35

Post by pjc50 »

jaekwon wrote: post #8

Awesome. One question... why STM/ARM? I'm not an expert in the available choices, but I'm generally curious about RiskV devices because they're fully open. Are the designs of this chip at least available, and audit-able, or could it contain something like Intel's HM?

Are RISCV devices actually available at all?

I'm not too worried about backdoors in microcontrollers, they're too small to hide much.

Are the designs of this chip at least available, and audit-able

I'm not aware of any processors you can buy from current production that meet this criterion (because it would involve complete exposure of that company's IP). I suppose the fully reverse-engineered 6502 meets it.

Re: Show HN: The SC4-HSM, a fully open USB hardware secure module

#36

Post by frederikvs »

pjc50 wrote: post #35
jaekwon wrote: post #8

Awesome. One question... why STM/ARM? I'm not an expert in the available choices, but I'm generally curious about RiskV devices because they're fully open. Are the designs of this chip at least available, and audit-able, or could it contain something like Intel's HM?

Are RISCV devices actually available at all? I'm not too worried about backdoors in microcontrollers, they're too small to hide much. Are the designs of this chip at least available, and audit-able I'm not aware of any processors you can buy from current production that meet this criterion (because it would involve complete exposure of that company's IP). I suppose the fully reverse-engineered 6502 meets it.

> I'm not too worried about backdoors in microcontrollers, they're too small to hide much.

Have you read the article "A2: Analog Malicious Hardware" [1]? You really don't need much space to insert a backdoor in silicon.

[1] http://ieee-security.org/TC/SP2016/papers/0824a018.pdf

Re: Show HN: The SC4-HSM, a fully open USB hardware secure module

#37

Post by mSparks »

lisper wrote: post #29
mSparks wrote: post #22

Earlier quoted context omitted.

just thinking out loud. definately not disagreeing with your hardware choice. a good idea for a pi zero?

You could certainly do something like this with a pi. But it would be bulkier and probably less secure. But my initial prototyping was done with a Teensy3. It all depends on your threat model.

its great that we are getting access to so many tiny sweet tiny boards. just in case - pi zero: https://www.raspberrypi.org/products/pi-zero/

i was thinking more feature set than threat model. Namely Secure at rest storage and password generator for secure comms. i believe the pi has a hwrnd which is probably the most essential thing for such devices.

Re: Show HN: The SC4-HSM, a fully open USB hardware secure module

#38

Post by e12e »

lisper wrote: post #14
e12e wrote: post #13

Earlier quoted context omitted.

It looks like a very nice piece of kit - I just might have to get one :-) But speaking of hardware, I was recently reminded of the new BBC:Micro[m] project thanks to an email by the PythonAnywhere[p]-team. I wonder how much of the features could be implemented on that? I'm guessing that while the micro-usb might allow for power and data connection to the host - there'd probably not be a way to prevent compromise when…

> I just might have to get one Better hurry. My stock of prototypes is very nearly sold out. > BBC:Micro[m] project I have no idea about that particular device. But very few things end up being secure by accident. But if it's not designed for security like the STM32F415 is, then I'd say odds are good it's not secure.

Sorry (happy :) to hear that you're running out. Might actually be in a situation soon where it will make more sense to hold a workshop and build a good handful of the things.

Agreed on the "accidentally secure" part. Then again, if you could drench a full x86 pc in epoxy, it might be possible to make "reasonably secure" blob if all you left open was a serial port. Might.

Re: Show HN: The SC4-HSM, a fully open USB hardware secure module

#39

Post by captainmuon »

mcpherrinm wrote: post #2

Calling this an HSM is somewhat disingenuous, as it seems to contain none of the usual defenses found in a "real" hardware security module, like tamper self-destruction of key material, and likely no side-channel protection. This is essentially just putting your keys on a dedicated computer, connected over USB. That does have value, mind you. Keeping your keys isolated definitely makes it harder for malware to exfilt…

At least for me, this "HSM" makes the right trade-offs. I don't need tamper self-destruction, for example. My adversaries are either: 1) thieves of opportunity, or 2) the "world conspiracy" / nation state intelligence agencies who suddenly might decide to spy on me if the world takes a dystopian turn.

For 1) tamper-proofness is total overkill. For 2), I doubt that any civilian technology would withstand a hardware attack e.g. by the NSA. If I just look at the equipment we have at our lowly, underfunded physics laboratory - probe stations, decapping facilities, wirebonders, an expert can already defeat many older hardware countermeasures with that. And I know there are much more sophisticated techniques out there, e.g. to image chips and extract secrets. Also, a variation of the "wrench" argument: Who says that the vendors of closed HSMs have not all been just forced to place backdoors?

The biggest realistic threat to me (by probability times possible damage) is by far that I might catch a Trojan. This device provides at least partial protection, in that it makes it hard for a remote attacker to sign messages or log on in my name.

Re: Show HN: The SC4-HSM, a fully open USB hardware secure module

#40

Post by technion »

captainmuon wrote: post #39
mcpherrinm wrote: post #2

Calling this an HSM is somewhat disingenuous, as it seems to contain none of the usual defenses found in a "real" hardware security module, like tamper self-destruction of key material, and likely no side-channel protection. This is essentially just putting your keys on a dedicated computer, connected over USB. That does have value, mind you. Keeping your keys isolated definitely makes it harder for malware to exfilt…

At least for me, this "HSM" makes the right trade-offs. I don't need tamper self-destruction, for example. My adversaries are either: 1) thieves of opportunity, or 2) the "world conspiracy" / nation state intelligence agencies who suddenly might decide to spy on me if the world takes a dystopian turn. For 1) tamper-proofness is total overkill. For 2), I doubt that any civilian technology would withstand a hardware at…

I see this as a lot like the "GPG is very secure but no one uses it" scenario. People who have certain needs can open up their wallets for certain products.

The adversary for the vast majority of practical scenarios is some remote attacker exploiting some unpatched vulnerability.

How much less of an issue would all the recent password dumps be if the hash algorithm was a simple HMAC on a device like this?

And surely a bitcoin wallet has a better chance on this device, than sitting in a file on my desktop just hoping the password never gets key logged.

And, moreso than any other point, at the current price point, this device is actually plausible to experiment with.

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