6 ms·

I think the YK5's biggest problem is that the YK Neo and 4, which have been out for years, were already so good. Unless you really care about NFC at the same ti

by lvh 8y ago

I think the YK5's biggest problem is that the YK Neo and 4, which have been out for years, were already so good. Unless you really care about NFC at the same time as RSA-4096, I'm not sure I see a big impetus to upgrade. Hopefully the USB-C line won't be plagued with supply issues. WebAuthn is mostly boring and I think that's mostly a good thing. I'm glad that there's a way to evolve the spec. Some of the changes are arguably improvements; I could see how Direct Anonymous Attestation is better than the old certificate method. On the other hand, that's more exciting crypto than I want to see in W3C specs. But the vast majority of deployments don't care about attestation at all: they just care that you can register a specific U2F key once (say, during employee onboarding), and then you never have to care about attestation again. So other than crypto-nerdery, I'm going to choose not to care much about (EC)DAA. U2F keys already do WebAuthn (individual sites doing bogus feature detection notwithstanding). Despite the name, at the end of the day U2F is just a way to sign some stuff so that it can't be replayed and you can't get phished. If you really wanted to use it as a single factor, you could. I'm not sold that the integration of e.g. the browser's password manager into WebAuthn is super valuable, but I'm still happily monitoring what they come up with. That is not a criticism, and certainly not a deprecation. The bottom line is U2F was great, and WebAuthn not convincing me yet is not a good reason to shy away from WebAuthn. WebAuthn is still the best authentication mechanism we (realistically) have by far. Go use it.

toomuchtodo 8y ago
Just wanted to say thanks for these analysis blubs on HN. Whenever something security related pops up, I rest assured that you or tptacek are going to pop in and tell it how it is.
bonestamp2 8y ago
> Unless you really care about NFC at the same time as RSA-4096, I'm not sure I see a big impetus to upgrade Agreed, it looks more like the new keys main draw is feature consistency across the whole YK5 line. You can now select the form factor you want and, aside from NFC, it has the same features as the other form factors. With YK4, there was not nearly the same feature parity across form factors.
Snawoot 8y ago
> you really care about NFC at the same time as RSA-4096 It is exactly my case. Also my dongle is already old and its body has abrasion marks due to heavy usage. So, it's a great reason for upgrade and I think I'm not alone in it. Looking forward for available shipping in my country.
jolmg 8y ago
> the YK Neo and 4, which have been out for years, were already so good I agree that the keys themselves are good; I just wish that configuring Linux systems to take advantage of them would be easier. I've been working on setting my systems up in bits of my free time for more than a month now. I'm in my last stretch, but I have to do some weird things. Maybe I'm just trying to squeeze more out of the key than most would. For example, when I'm in my laptop and I ssh to my desktop and use sudo, I want it to use the key connected to the laptop to authenticate me. At the same time, if I walk over to the desktop and use sudo, I want it to seek the key in the desktop. Same if I use gpg or anything else that wants to use the key. As part of this, to make use of the key as transparent to me as possible, I'm finding myself making a compiled executable to override gpg and gpgconf to unshare the mount namespace and bind mount a socket specified by environment variable over the default gpg-agent socket, because there seems to be no easier way to override the gpg-agent socket path via environment variable. gnupg seems to have no such environment variable, and while other utilities query the socket path via gpgconf, gpg itself seems to just know what it is... You know what... I'm starting to realize that's not going to work... Programs that query gpgconf would connect to the wrong agent. I gotta figure out how gpg knows the gpg-agent socket path... Since it doesn't call gpgconf, I wonder if it shares an .o file with it...
- xienze 8y ago
  >For example, when I'm in my laptop and I ssh to my desktop and use sudo, I want it to use the key connected to the laptop to authenticate me. At the same time, if I walk over to the desktop and use sudo, I want it to seek the key in the desktop. Same if I use gpg or anything else that wants to use the key. This can easily be done, I do it all the time. You have to set up both YKs to have the same PGP keys and then use gpg as your SSH agent.
  - jolmg 8y ago
    That would be enough, if I would compromise to forego use of sudo and relogin with ssh as root. I really would preper to keep the ability to only sudo the parts of composed commands that need it in my non-root shell session, though, which is why I'm still looking into this. This effort will also allow me to use gpg and the programs that depend on it like my password manager, pass, to use the correct agent.
tomatocracy 8y ago
The feature the 4 has which the Neo doesn't which matters most to me is 'touch to confirm key operation' when used via USB. I'm quite surprised how little this seems to be known - a hardware key which will sign anything a potential piece of malware or malicious actor asks for without question (assuming said malware is able to steal the PIN or get access to the appropriate agent socket which is not too much of a stretch) is a lesser improvement over pure software keys (sure, you can get the same effect by plugging and unplugging but thats a pain). On the other hand, NFC is pretty much essential to me for use on an android phone. If this has both then I will look carefully at upgrading.
- lvh 8y ago
  Wait, seriously? Not even the OpenPGP applet/with ykman configuration? In what modes does it do that? That’s send-it-back bad.
  - tomatocracy 8y ago
    Certainly for the OpenPGP applet, require touch to sign/auth/enc was introduced with the Yubikey 4. For U2F touch is always required and you do get an option on the NEO to require touch for Yubico challenge/response. Not sure about the PIV or TOTP applets.
    - lvh 8y ago
      Dang, TIL; I could've sworn I've made that work on a NEO. PIV mode presumably also has forced touch/reauth for signing?
- patcheudor 8y ago
  This makes sense for enterprise uses where an organization wants to keep private key material off a server, but don't want to spend the money for a enterprise security key manager.
  - tomatocracy 8y ago
    Yes - I'm not saying it shouldn't be possible to configure it that way but it is not great that (at least for OpenPGP) there's no way to set it to require physical interaction to gain access to key functions on the NEO.
piotrkubisa 8y ago
> I think the YK5's biggest problem is that the YK Neo and 4, which have been out for years, were already so good. I'd say YK5 is in "mature"/"stability" product cycle, what means it is good time to buy it whether you haven't yet purchased any MFA key.

by lvh 8y ago

toomuchtodo 8y ago

Just wanted to say thanks for these analysis blubs on HN. Whenever something security related pops up, I rest assured that you or tptacek are going to pop in and tell it how it is.

bonestamp2 8y ago

> Unless you really care about NFC at the same time as RSA-4096, I'm not sure I see a big impetus to upgrade Agreed, it looks more like the new keys main draw is feature consistency across the whole YK5 line. You can now select the form factor you want and, aside from NFC, it has the same features as the other form factors. With YK4, there was not nearly the same feature parity across form factors.

Snawoot 8y ago

> you really care about NFC at the same time as RSA-4096 It is exactly my case. Also my dongle is already old and its body has abrasion marks due to heavy usage. So, it's a great reason for upgrade and I think I'm not alone in it. Looking forward for available shipping in my country.

jolmg 8y ago

> the YK Neo and 4, which have been out for years, were already so good I agree that the keys themselves are good; I just wish that configuring Linux systems to take advantage of them would be easier. I've been working on setting my systems up in bits of my free time for more than a month now. I'm in my last stretch, but I have to do some weird things. Maybe I'm just trying to squeeze more out of the key than most would. For example, when I'm in my laptop and I ssh to my desktop and use sudo, I want it to use the key connected to the laptop to authenticate me. At the same time, if I walk over to the desktop and use sudo, I want it to seek the key in the desktop. Same if I use gpg or anything else that wants to use the key. As part of this, to make use of the key as transparent to me as possible, I'm finding myself making a compiled executable to override gpg and gpgconf to unshare the mount namespace and bind mount a socket specified by environment variable over the default gpg-agent socket, because there seems to be no easier way to override the gpg-agent socket path via environment variable. gnupg seems to have no such environment variable, and while other utilities query the socket path via gpgconf, gpg itself seems to just know what it is... You know what... I'm starting to realize that's not going to work... Programs that query gpgconf would connect to the wrong agent. I gotta figure out how gpg knows the gpg-agent socket path... Since it doesn't call gpgconf, I wonder if it shares an .o file with it...

xienze 8y ago
>For example, when I'm in my laptop and I ssh to my desktop and use sudo, I want it to use the key connected to the laptop to authenticate me. At the same time, if I walk over to the desktop and use sudo, I want it to seek the key in the desktop. Same if I use gpg or anything else that wants to use the key. This can easily be done, I do it all the time. You have to set up both YKs to have the same PGP keys and then use gpg as your SSH agent.
- jolmg 8y ago
  That would be enough, if I would compromise to forego use of sudo and relogin with ssh as root. I really would preper to keep the ability to only sudo the parts of composed commands that need it in my non-root shell session, though, which is why I'm still looking into this. This effort will also allow me to use gpg and the programs that depend on it like my password manager, pass, to use the correct agent.

tomatocracy 8y ago

The feature the 4 has which the Neo doesn't which matters most to me is 'touch to confirm key operation' when used via USB. I'm quite surprised how little this seems to be known - a hardware key which will sign anything a potential piece of malware or malicious actor asks for without question (assuming said malware is able to steal the PIN or get access to the appropriate agent socket which is not too much of a stretch) is a lesser improvement over pure software keys (sure, you can get the same effect by plugging and unplugging but thats a pain). On the other hand, NFC is pretty much essential to me for use on an android phone. If this has both then I will look carefully at upgrading.

lvh 8y ago
Wait, seriously? Not even the OpenPGP applet/with ykman configuration? In what modes does it do that? That’s send-it-back bad.
- tomatocracy 8y ago
  Certainly for the OpenPGP applet, require touch to sign/auth/enc was introduced with the Yubikey 4. For U2F touch is always required and you do get an option on the NEO to require touch for Yubico challenge/response. Not sure about the PIV or TOTP applets.
  - lvh 8y ago
    Dang, TIL; I could've sworn I've made that work on a NEO. PIV mode presumably also has forced touch/reauth for signing?
patcheudor 8y ago
This makes sense for enterprise uses where an organization wants to keep private key material off a server, but don't want to spend the money for a enterprise security key manager.
- tomatocracy 8y ago
  Yes - I'm not saying it shouldn't be possible to configure it that way but it is not great that (at least for OpenPGP) there's no way to set it to require physical interaction to gain access to key functions on the NEO.

piotrkubisa 8y ago

> I think the YK5's biggest problem is that the YK Neo and 4, which have been out for years, were already so good. I'd say YK5 is in "mature"/"stability" product cycle, what means it is good time to buy it whether you haven't yet purchased any MFA key.