5 ms·

Just make something like a usb Rubber Ducky with a couple buttons and a screen. Plug it in, scroll to password, hit "type it", and it types it in. Could proba

by Vendan 11y ago

Just make something like a usb Rubber Ducky with a couple buttons and a screen. Plug it in, scroll to password, hit "type it", and it types it in. Could probably make one for about $40. Arduino Leonardo, LCD Shield, and the leonardo keyboard libraries. Could even have it as a full password generator too.

i336_ 11y ago
That actually sounds like a really, really good idea. Although... I just started thinking about the possibility of using a microcontroller that had a tiny bit of internal, non-reprogrammable ROM, so I could implement a secure stage-0 loader... lol
- Vendan 11y ago
  meh, that seems like a protection against physical access, if all else is done correctly, and you are screwed at that point. In other news, I just placed an order for the parts for my prototype, so I'll be putting that together this weekend. Fun thing: If done correctly, it should work with most android phones, as they do understand usb hid keyboards. As a result, final design may end up with a very small lithium battery to allow it to run when connected to a phone that doesn't offer much power. I'll put a blog somewhere and post an update to https://twitter.com/andy_leap https://twitter.com/andy_leap as I work on it.
- Vendan 11y ago
  how about this, as an alternative to going down the route of secure loaders and such. The firmware that's written to the chip is padded out to (sizeof(flash)-X) with cryptographicly secure random bytes, where X is the size of a crypto signature block, which you use to sign the firmware. When you plug the thing into a computer without the sd card inserted(I plan on storing the password vault on an sd card, correctly encrypted), it dumps all of the flash via keyboard. Pipe that into a program that verifies the signature, via whatever means, and you can ensure the firmware has not been tampered short of hardware modification in the form of adding more flash memory/eeprom, as to do so would require compressing the existing code/cryptgraphically secure padding, as you would need to dump the original out to pass the verification. If you want to be even more secure, you can even replace the existing signature with your own, therefore ensuring that people can't change the version without access to your private key.

by Vendan 11y ago

i336_ 11y ago

That actually sounds like a really, really good idea. Although... I just started thinking about the possibility of using a microcontroller that had a tiny bit of internal, non-reprogrammable ROM, so I could implement a secure stage-0 loader... lol

Vendan 11y ago
meh, that seems like a protection against physical access, if all else is done correctly, and you are screwed at that point. In other news, I just placed an order for the parts for my prototype, so I'll be putting that together this weekend. Fun thing: If done correctly, it should work with most android phones, as they do understand usb hid keyboards. As a result, final design may end up with a very small lithium battery to allow it to run when connected to a phone that doesn't offer much power. I'll put a blog somewhere and post an update to https://twitter.com/andy_leap https://twitter.com/andy_leap as I work on it.
Vendan 11y ago
how about this, as an alternative to going down the route of secure loaders and such. The firmware that's written to the chip is padded out to (sizeof(flash)-X) with cryptographicly secure random bytes, where X is the size of a crypto signature block, which you use to sign the firmware. When you plug the thing into a computer without the sd card inserted(I plan on storing the password vault on an sd card, correctly encrypted), it dumps all of the flash via keyboard. Pipe that into a program that verifies the signature, via whatever means, and you can ensure the firmware has not been tampered short of hardware modification in the form of adding more flash memory/eeprom, as to do so would require compressing the existing code/cryptgraphically secure padding, as you would need to dump the original out to pass the verification. If you want to be even more secure, you can even replace the existing signature with your own, therefore ensuring that people can't change the version without access to your private key.