Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Ledger Live: A mobile companion app for Ledger hardware wallets

github.com

Post reply on HN
Print view View original

41–50 of 58 posts

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

#41

Post by DennisP »

otoburb wrote: post #26
YjSe2GMQ wrote: post #19

Earlier quoted context omitted.

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.

>> 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…

Yes but the Ledger has its own screen that shows what you're actually signing. If you verify that, you're good.

There are a couple caveats. First, the Ledger Nano's screen is too small to display the entire address at once, so an attacker who knows where you might send money could generate an address that appears that same on the characters that display. (The Ledger Blue shows the full address but is getting discontinued.)

Secondly, if you're on Ethereum and using a multisig contract, the destination address is just the contract and the ETH amount is zero. The function parameters which define your actual request are just displayed by the Ledger as a warning that they exist.

I've suggested to Ledger that they come up with a way to import the json.abi and display the actual parameters on device, which is what desktop clients do. They thought it was doable but I haven't seen any suggestion of it happening.

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

#42

Post by YjSe2GMQ »

sowbug wrote: post #40
YjSe2GMQ wrote: post #34

Earlier quoted context omitted.

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,…

I'll reply here to the three comments: I admit that you're right guys. I have to concede my point about backdoors. If you modify user's view of Coinbase DOM then no security in the Ledger/Trezor is going to help with that.

But also it's independent of the discussion around whether NFC or Bluetooth is a better choice for host device comms.

PS. I love the term "violent agreement".

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

#43

Post by DennisP »

mtgx wrote: post #35
YjSe2GMQ wrote: post #19

Earlier quoted context omitted.

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.

To do that they would have to hack the Ledger's secure chip, which is quite a bit harder than hacking Windows.

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

#44

Post by YjSe2GMQ »

DennisP wrote: post #41
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…

Yes but the Ledger has its own screen that shows what you're actually signing. If you verify that, you're good. There are a couple caveats. First, the Ledger Nano's screen is too small to display the entire address at once, so an attacker who knows where you might send money could generate an address that appears that same on the characters that display. (The Ledger Blue shows the full address but is getting disconti…

It is already implemented for ERC20 token transfers which are probably >90% of smart contract invocations.

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

#46

Post by YjSe2GMQ »

paulsutter wrote: post #39
YjSe2GMQ wrote: post #34

Earlier quoted context omitted.

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...

Technically, only copy-paste mutations are not enough as you confirm addresses on the screen. But, for example, DOM edits from a malicious extension are enough.

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

#47

Post by kybernetikos »

jillesvangurp wrote: post #16
mr_sturd wrote: post #8

I'm still very much in favour of managing my own private keys in an encrypted database on my desktop/laptop. I feel like everyone is blindly trusting these devices, having been scared in to it by horror stories of malware lifting keys off machines. I will eat my paper wallets if my meagre holdings are stolen from me like that.

I sort of agree with this. One caveat is that laptops are commonly compromised and your security would depend on nobody stealing keys/passwords needed to access your database/password manager/whatever. Having hardware token with paper backup, makes this harder. Having a lot of tokens creates a huge incentive for getting hacked. If you have non trivial amounts of tokens under your control, you need to consider all the…

My Ledger Nano supports fido u2f and manages blockchain wallets, so I presume you're just asking for an open version of that?

Maybe the ease of use isn't quite where it could be.

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

#48

Post by kirushik »

mr_sturd wrote: post #8

I'm still very much in favour of managing my own private keys in an encrypted database on my desktop/laptop. I feel like everyone is blindly trusting these devices, having been scared in to it by horror stories of malware lifting keys off machines. I will eat my paper wallets if my meagre holdings are stolen from me like that.

Another possible take on this would be Parity Signer (https://www.parity.io/signer/), which is an opensource app turning your (full-disk encrypted and put into an airplane mode) old phone into an improvised hardware wallet.

Very narrow attack surface (no USB or Bluetooth, only QR codes are used for communication), and more safety against the supply chain attacks make it a viable alternative for some particular threat models.

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

#49

Post by jki275 »

doomslice wrote: post #29
jillesvangurp wrote: post #16

Earlier quoted context omitted.

I sort of agree with this. One caveat is that laptops are commonly compromised and your security would depend on nobody stealing keys/passwords needed to access your database/password manager/whatever. Having hardware token with paper backup, makes this harder. Having a lot of tokens creates a huge incentive for getting hacked. If you have non trivial amounts of tokens under your control, you need to consider all the…

Founder of StellarGuard here, so sort of in the same realm. Just wondering what additional features you'd want out of such a hardware token. Would it need to do the actual signing of transactions on the device for you to feel secure with it, or would generic U2F (Yubikey) + signing on the software be sufficient, assuming we could do it securely?

Signing on the hardware is pretty much the only way to safeguard the keys. PCs and phones have an attack surface much too large to properly secure.

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

#50

Post by jki275 »

DennisP wrote: post #41
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…

Yes but the Ledger has its own screen that shows what you're actually signing. If you verify that, you're good. There are a couple caveats. First, the Ledger Nano's screen is too small to display the entire address at once, so an attacker who knows where you might send money could generate an address that appears that same on the characters that display. (The Ledger Blue shows the full address but is getting disconti…

Just for the record, the entire address for the transaction is displayed on the screen, it just scrolls side to side. Generating another address that's similar enough to be confused easily would be prohibitively difficult at best.
Post reply on HN