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Ledger Live: A mobile companion app for Ledger hardware wallets

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Re: Ledger Live: A mobile companion app for Ledger hardware wallets

#31

Post by jki275 »

32032141 wrote: post #24
jki275 wrote: post #17

Earlier quoted context omitted.

Let he who has never written software that had a bug throw the first stone...

Hi, I've written bootloaders before.I know that blacklisting addresses doesn't work, as many memory locations will be mapped multiple times. Strangely, most people that have worked with microcontrollers is aware of this, except for the people who wrote the closed source bootloader at ledger.

Well, since you're the expert, why haven't you written a better one? There's a huge market for this...

Re: Ledger Live: A mobile companion app for Ledger hardware wallets

#32

Post by 32032141 »

jki275 wrote: post #31
32032141 wrote: post #24

Earlier quoted context omitted.

Hi, I've written bootloaders before.I know that blacklisting addresses doesn't work, as many memory locations will be mapped multiple times. Strangely, most people that have worked with microcontrollers is aware of this, except for the people who wrote the closed source bootloader at ledger.

Well, since you're the expert, why haven't you written a better one? There's a huge market for this...

I don't think my threat model encompasses the safety of other people's money.

Re: Ledger Live: A mobile companion app for Ledger hardware wallets

#33

Post by otoburb »

YjSe2GMQ wrote: post #30
otoburb wrote: post #26

Earlier quoted context omitted.

>> It could as well be sent via unencrypted http routed through China, then Russia and then an NSA server all while your host device is heavily backdoored. As much as we'd like to believe this is the case, MITM (network or host) allows for replacement of destination addresses that show up on your screen. Redirected/malicious destination addresses showing up on your host screen will be cryptographically verified with…

> but will not prevent you from sending your cryptoassets to the "wrong" endpoint. Can you explain how's that a problem? The only thing you can do with a signed transaction is to either broadcast it or not. MyEtherWallet suffers from the equivalent of supply chain attack here, where the JavaScript gets replaced with malicious code.

I'm treating network & host attacks as a supply chain attack where the authentic/intended destination address is replaced by the attacker with the attacker's address. Hence my air quotes around the word "wrong".

As with MEW, as far as Ledger is concerned, a correct transaction is being signed and will in turn be broadcast. But the final outputs don't actually end up where the sender intended them to be sent because their host or network was compromised.

Re: Ledger Live: A mobile companion app for Ledger hardware wallets

#34

Post by YjSe2GMQ »

otoburb wrote: post #33
YjSe2GMQ wrote: post #30

Earlier quoted context omitted.

> but will not prevent you from sending your cryptoassets to the "wrong" endpoint. Can you explain how's that a problem? The only thing you can do with a signed transaction is to either broadcast it or not. MyEtherWallet suffers from the equivalent of supply chain attack here, where the JavaScript gets replaced with malicious code.

I'm treating network & host attacks as a supply chain attack where the authentic/intended destination address is replaced by the attacker with the attacker's address. Hence my air quotes around the word "wrong". As with MEW, as far as Ledger is concerned, a correct transaction is being signed and will in turn be broadcast. But the final outputs don't actually end up where the sender intended them to be sent because t…

Yeah this is plain wrong. Sorry but you simply don't understand how transactions work in cryptocurrencies.

You cannot edit a transaction (for example by changing it's outputs) after it has been signed. That's how cryptographic signatures work, in general.

And the only way to cause an incorrect transaction to be signed on Ledger/Trezor is by tricking the user, which requires malicious code inside the device.

Re: Ledger Live: A mobile companion app for Ledger hardware wallets

#35

Post by mtgx »

YjSe2GMQ wrote: post #19
topynate wrote: post #3

Good to see Bluetooth in the new hardware. Lack of real mobile support for hardware wallets has been by far the biggest pain point for me. (With regard to the best possible physical security, I would have preferred NFC over Bluetooth, but the latter is alright for everyday use.)

AFAIK given the Ledger's on-screen confirmation process it really doesn't matter what's the medium of communication between the host machine and the device. It could as well be sent via unencrypted http routed through China, then Russia and then an NSA server all while your host device is heavily backdoored. The supply chain attacks/evil maid attacks are a much bigger issue, as pointed out in other comments.

> AFAIK given the Ledger's on-screen confirmation process it really doesn't matter what's the medium of communication

Except for that time when the attacker finds a way to bypass the on-screen confirmation process and make the changes hidden to you, of course, which has happened like only a thousand times on Windows.

Re: Ledger Live: A mobile companion app for Ledger hardware wallets

#37

Post by gapinggasher1 »

ledger is garbage and their software falls over if too many people are using it. Why do I know this? Their customer service literally told me that I cant access my wallet because too many people are trying to use the software. As a silly consequence I was not able to update the firmware.

I switched to a more open source solution for the hardware, and for mobile mycelium.

Ledger can suck a fat one.

Re: Ledger Live: A mobile companion app for Ledger hardware wallets

#38

Post by otoburb »

YjSe2GMQ wrote: post #34
otoburb wrote: post #33

Earlier quoted context omitted.

I'm treating network & host attacks as a supply chain attack where the authentic/intended destination address is replaced by the attacker with the attacker's address. Hence my air quotes around the word "wrong". As with MEW, as far as Ledger is concerned, a correct transaction is being signed and will in turn be broadcast. But the final outputs don't actually end up where the sender intended them to be sent because t…

Yeah this is plain wrong. Sorry but you simply don't understand how transactions work in cryptocurrencies. You cannot edit a transaction (for example by changing it's outputs) after it has been signed. That's how cryptographic signatures work, in general. And the only way to cause an incorrect transaction to be signed on Ledger/Trezor is by tricking the user, which requires malicious code inside the device.

We're in "violent agreement". You seem to be missing my point.

I completely agree with you that you cannot edit a transaction after it's been signed. I was trying to point out above that if the user is tricked, by signing a transaction they think is correct, but is in actuality not the intended destination because we assume the attacker controls what they are seeing, and where they are going.

Ledger signs transactions with a destination address. If the user can't tell (or is tricked) into believing a malicious address is the authentic one, everything will look koshor. This is similar to the level of sophistication and control required in the MEW incident. It's unlikely, but possible.

Re: Ledger Live: A mobile companion app for Ledger hardware wallets

#39

Post by paulsutter »

YjSe2GMQ wrote: post #34
otoburb wrote: post #33

Earlier quoted context omitted.

I'm treating network & host attacks as a supply chain attack where the authentic/intended destination address is replaced by the attacker with the attacker's address. Hence my air quotes around the word "wrong". As with MEW, as far as Ledger is concerned, a correct transaction is being signed and will in turn be broadcast. But the final outputs don't actually end up where the sender intended them to be sent because t…

Yeah this is plain wrong. Sorry but you simply don't understand how transactions work in cryptocurrencies. You cannot edit a transaction (for example by changing it's outputs) after it has been signed. That's how cryptographic signatures work, in general. And the only way to cause an incorrect transaction to be signed on Ledger/Trezor is by tricking the user, which requires malicious code inside the device.

Unless the destination address is changed before it gets to the ledger. Surely you’ve seen the copy/paste malware that changes addresses?

https://techcrunch.com/2018/07/03/new-malware-highjacks-your...

Re: Ledger Live: A mobile companion app for Ledger hardware wallets

#40

Post by sowbug »

YjSe2GMQ wrote: post #34
otoburb wrote: post #33

Earlier quoted context omitted.

I'm treating network & host attacks as a supply chain attack where the authentic/intended destination address is replaced by the attacker with the attacker's address. Hence my air quotes around the word "wrong". As with MEW, as far as Ledger is concerned, a correct transaction is being signed and will in turn be broadcast. But the final outputs don't actually end up where the sender intended them to be sent because t…

Yeah this is plain wrong. Sorry but you simply don't understand how transactions work in cryptocurrencies. You cannot edit a transaction (for example by changing it's outputs) after it has been signed. That's how cryptographic signatures work, in general. And the only way to cause an incorrect transaction to be signed on Ledger/Trezor is by tricking the user, which requires malicious code inside the device.

You're not listening. This is the case that otoburb is describing:

1. Install bad browser extension.

2. Visit coinbase.com.

3. Copy deposit address.

4. Paste into Ledger software.

5. Initiate transfer of funds to Coinbase.

6. Scrutinize transaction details.

7. Approve.

Your funds are now gone, and you'll never see them again.

All cryptography worked as designed in this case. "That's how cryptographic signatures work, in general."

Substitute scenarios with receive addresses triple-notarized with medallion guarantees imprinted in blood if you wish for steps 1-3. It doesn't matter. The deputy is confused.

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