[HN Gopher] Howdy - Windows Hello style facial authentication fo...
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Howdy - Windows Hello style facial authentication for Linux
Author : pabs3
Score : 112 points
Date : 2022-04-25 02:16 UTC (1 days ago)
(HTM) web link (github.com)
(TXT) w3m dump (github.com)
| dimensionc132 wrote:
| als0 wrote:
| Some cameras have depth sensors to defend against the printed
| photo attack. Are they easily useable by Howdy? FWIW, Windows
| Hello refuses to work without one of these sensors.
| lhl wrote:
| Sadly, looks like no:
| https://github.com/boltgolt/howdy/issues/521
|
| "Windows Hello uses the two IR emitters to generate a 3D image
| of your face, and is much more secure. To do this Hello lights
| up your face with the left emitter on even frames, and uses the
| right emitter on odd frames. This lights up your face in
| slightly different angles, which is not possible to be faked by
| simply printing a 2D photo.
|
| Unfortunately Howdy does not have control over these IR
| emitters and can't use this process"
| als0 wrote:
| > Unfortunately Howdy does not have control over these IR
| emitters
|
| Wasn't sure if "does not" means can't, so I did a search and
| discovered this interesting development:
| https://github.com/boltgolt/howdy/pull/611
| lhl wrote:
| Ah yeah, that's interesting. I was looking at the actual
| recognition code in howdy (basically leans on dlib's face
| detection), which doesn't seem to have any "3D" checker
| built in, but if it is just based on differential
| illumination, maybe it won't be so hard to simply make sure
| there are sufficient differences in the odd/even frames to
| distinguish a face as 3D.
|
| I suppose it could be weak to a "mask" attack, but you
| could add something like drishti to make sure you can real
| eyes in addition to a face.
|
| Note, even 3D sensors like Apple's FaceID can be broken
| with sufficient effort:
| https://www.wired.com/story/hackers-say-broke-face-id-
| securi...
|
| Multi-spectral processing might help in that case, but
| honestly, if this sort of attack is a real security threat,
| then you probably shouldn't be running biometric logins in
| the first place (and you should probably actually be using
| MFA).
| als0 wrote:
| Of course, this is all about authentication convenience
| and keeping the attacker bar high. The mask attack is a
| lot more expensive/difficult than printing out a photo
| (too easy).
| jszymborski wrote:
| > A note on security > This package is in no way as secure as a
| password and will never be. Although it's harder to fool than
| normal face recognition, a person who looks similar to you, or a
| well-printed photo of you could be enough to do it. Howdy is a
| more quick and convenient way of logging in, not a more secure
| one.
|
| Congrats to the author(s) for shipping a library, and having done
| so for some time now it seems (which is more than I've ever
| done).
|
| Can I ask if there's much of a point, though? Like why bother
| with the trouble of setting this up if I can just print a photo
| and have it unlock? At that point you're better off with a very
| weak and easy-to-remember password, no?
| bennyp101 wrote:
| Could be handy for having a computer the kids can use, just
| look at it and unlock it - dunno if that's easier than '123456'
| or no passwords, but I can see certain scenarios where a simple
| face match to unlock something would be cool
| JasonFruit wrote:
| The point is that some people want it despite its obvious
| flaws, and now they have it.
| bee_rider wrote:
| It claims to:
|
| > Use your built-in IR emitters and camera in combination with
| facial recognition to prove who you are.
|
| I wonder if the "could be enough to do it" is kind of
| pessimistic. That is, it is open source software -- you can
| install it on whatever computer you want, including one without
| an advanced IR camera. Or, the user could have some obscure IR
| camera, which might not be detected properly/might not have
| Linux drivers. It seems hard to make guarantees for arbitrary
| hardware.
| Boltgolt wrote:
| It's very pessimistic, no false positive reports over the
| last four years but i rather set expectations low.
| legalcorrection wrote:
| It's all about your threat model. The lock on your front door
| doesn't prevent someone with the right tools from getting in
| either, but it still provides meaningful security against large
| groups of potential attackers.
|
| FWIW, Windows Hello does try to defend against this attack by
| requiring special cameras that operate in the infrared band.
| mminer237 wrote:
| Howdy also says it will use infrared cameras if you have
| them.
| spicybright wrote:
| I wonder how it compares to windows Hello in terms of these
| attacks.
| Arainach wrote:
| Windows Hello requires specific hardware that, among other
| things, uses IR imaging to make it much more difficult to
| spoof.
| dspillett wrote:
| I'm still wary of biometrics for authentication no matter
| how difficult to spoof. They are also painful to revoke...
| lhl wrote:
| More difficult, but if you can capture an IR image of the
| user, it can be fed in directly if you have a device
| designed to spoof a USB webcam. A really interesting
| writeup from last year:
| https://www.cyberark.com/resources/threat-research-
| blog/bypa...
| charles_f wrote:
| Depends on the level of security you need. This would be enough
| for my personal laptop, where it's unlikely that I would be
| targeted by someone, even more so with the skills and time to
| go and bypass the protection, all that to access my hn account
| and the half dozen code bases I work on that are already open
| source. My password manager locks itself whenever I lock the
| computer, and my webmail has a 1h session. It is much more
| likely that it would be captured as part of a robbery, or
| stolen in a cafe, and be resold on craigslist, in which case
| this level of security is probably sufficient.
|
| My professional laptop _could_ be different if I was working on
| something of any importance. That is not the case, but there
| the risk reward is different, and I would probably keep it to
| password + sec key or something in these lines
| myself248 wrote:
| I wish I could restrict it to NOT working everywhere PAM
| works.
|
| For instance, only face-unlock my screen if it locked for
| inactivity, and less than 15 minutes ago. If I manually
| locked it, require password. If I've been gone too long,
| require password. For sudo and bootup, always require
| password.
|
| That would make the level of (in)security acceptable to me.
| In its present state, I don't think it's appropriate.
| lhl wrote:
| I was gonna say well, of course you should be able to
| configure it within PAM to only be used for certain
| authentication types, but it turns out one of the literally
| five pages in the wiki covers just that:
| https://github.com/boltgolt/howdy/wiki/Only-using-howdy-
| for-...
|
| And for anything PAM doesn't handle, since Howdy is just a
| Python lib/app, it's almost trivial to modify it to do
| anything else. You could just add your modifications into h
| ttps://github.com/boltgolt/howdy/blob/beta/howdy/src/compar
| ... (eg, make it autofail if a env/memory flag hasn't been
| set after first login, same with storing an inactivity
| flag, etc. Looks like the author is responsive taking pull
| requests, so you could even do it properly and get it
| upstreamed even: https://github.com/boltgolt/howdy/pulls?q=
| is%3Apr+is%3Aclose...
|
| As for appropriateness, it's fine if it's not your cup of
| tea, but with 3.6K stars and 220 forks, obviously it works
| great/is useful for a lot of people so I'm glad that the
| author released and maintains it, even if it's not for
| everyone.
| myself248 wrote:
| Whoah.
|
| Okay, thank you, I had not found that page in a brief
| glance. Which admittedly was probably not enough of a
| glance to give it a fair shot.
|
| That's pretty awesome, I will have to poke at it. I also
| have fingerprint login so I'm sure I can get up to some
| silly hijinks...
| mminer237 wrote:
| You can though:
| https://github.com/boltgolt/howdy/wiki/Only-using-howdy-
| for-...
| TYPE_FASTER wrote:
| At a first glance, it seems like a well done authentication
| system that handles video capture, integration with PAM, the
| workflow for managing faces/users, etc.
|
| As models evolve, they could be integrated without changing the
| other components.
|
| Also, I'd be curious to see how it compares to, say, Windows
| Hello. The nice thing about it being open source is you can
| change the confidence threshold for matching a face, and see
| the impact.
| ohthehugemanate wrote:
| AFAIK Windows hello uses an array of IR sensors to map the
| contours of your face, which is why "a well printed photo"
| doesn't fool it. this on the other hand, is based on face
| recognition and identification in the video feed from your
| webcam.
| Boltgolt wrote:
| It really does not, it's simply identifying you from a
| picture: https://docs.microsoft.com/en-us/windows-
| hardware/design/dev... Notice how Microsoft shows how Hello
| can't be fooled by phones or by a picture. Howdy uses the
| same IR camera of course and thus would also not be fooled
| by that picture. Some (industrial) printers DO print in the
| IR-spectrum and can fool both.
| gambiting wrote:
| >> Like why bother with the trouble of setting this up if I can
| just print a photo and have it unlock?
|
| The question is - who are you trying to protect against?
|
| Like, personally I'm worried about someone stealing my laptop.
| In that case, it's _extremely_ unlikely the thief would have a
| photo of me to use to unlock the laptop. Yes my wife or my
| friends would have access to pictures of me in high enough
| resolution to print and use to unlock it - but I 'm really not
| worried about them breaking in.
| spicybright wrote:
| I'm also willing to bet good money 99% of criminals don't
| care about the data and just want to flip it for cash.
|
| Unless you're being targeted by someone, of course. In that
| case you have way more problems to worry about than your
| laptop being unlocked...
| CJefferson wrote:
| I'm worried that "a well-printed photo of you" is enough to fool
| it.
|
| Both Windows Hello, and the Mac equivalent, can't be fooled by
| photos -- they require an IR camera, or camera which can measure
| depth.
|
| Claiming this is "Windows Hello style", if it can be fooled by a
| photo, is a bit misleading in my opinion.
| cpuguy83 wrote:
| I don't have a lot of faith in Windows Hello either.
|
| My 6 year old daughter was able to log into my admin account.
| They weren't even trying to do that, just opened the laptop and
| it's all like "Hello, Brian!" and logged into my account.
| Boltgolt wrote:
| Howdy is specifically made for IR cameras, normal cameras are
| not officially supported. Windows Hello works almost exactly
| the same way.
| yoavm wrote:
| I didn't try Howdy and so I'm not sure if and how it's
| enforced, but literally the second sentence in the README says
| it uses the IR camera too.
| nimbius wrote:
| friendly reminder: do not use facial authentication (or
| biometrics), ever.
|
| in a US court of law, things like blood and biometrics are NOT
| protected by the fifth amendment. law enforcement can (and have)
| compelled submission of fingerprints and faces to unlock devices.
| this includes immigration and customs officers demanding
| credentials from foreign nationals.
|
| complex passphrases however are protected under the fifth
| amendment, and are much more secure overall.
| samatman wrote:
| For Apple biometric ID this is purely theatre, because devices
| can be compelled rapidly to require passwords.
|
| If the cops concerns you, I recommend practicing the lock
| sequence, and if they don't, perhaps we're not citizens of the
| same country.
| [deleted]
| Boltgolt wrote:
| Hey main developer of Howdy here, bizarre to see this on HN :)
|
| To emphasize: Howdy is about convenience for people that are okay
| with a less secure installation. It can also be used as a second
| factor.
|
| 3.0.0 has been in the works for 2 years now and will introduce a
| GTK UI, native PAM module and many other changes. Let me know if
| you have any questions!
| spicybright wrote:
| I personally hate the idea of face ID, but this project is
| exactly the kind of stuff we need if we want (and forgive the
| meme,) the year of the linux laptop.
|
| - Implements a popular feature other OS's have
|
| - A cute knock off name, making it self-explanatory (this is
| actually fairly important for adoption!)
|
| - Integrates well with cli junky workflows
|
| > Using the central authentication system (PAM), this works
| everywhere you would otherwise need your password: Login, lock
| screen, sudo, su, etc.
|
| - A nearly perfect readme in the repo. 2 sentence summary of the
| project, concise instructions for building/installation, where
| the error log lives, etc. without being too long.
|
| There are a lot of repos I've seen with horrible readmes that
| don't even have a sentence of what the purpose of it is.
|
| Which is reasonable if the repo is just for development, but most
| of the time a link to the repo is the main download link/project
| landing page. The added friction leads to less adoption and usage
| of something otherwise useful.
|
| If you're making a project simmilair to this, I recommend taking
| notes :^)
| Spivak wrote:
| > I personally hate the idea of face ID
|
| I can kind of get why "Windows Hello" camera-based face id
| isn't exactly great but do you also think the same of Apple's
| "actually modeling your face" style? Because I was really
| apprehensive about it compared to a fingerprint reader but I've
| pretty much flipped 180.
| pabs3 wrote:
| There is no way to indicate login consent with biometric
| authentication; when you are asleep, your finger/face can be
| used without your consent. Really it should be called
| biometric identification, not authentication.
| scoopertrooper wrote:
| While biometrics are imperfect (because you can't change or
| even hide the key), it's not quite as bad as you make out.
|
| On iOS at least, it gains affirmative consent by you double
| clicking a button on the side. It also refuses to recognise
| your face if your eyes are closed.
| pabs3 wrote:
| The attacker could be pressing the button, or even
| opening your eyes for you :)
| nighthawk454 wrote:
| Wrenches are cheaper https://xkcd.com/538/
|
| It only works if you're close, alive, your eyes are both
| open, and looking right at it. I doubt that degree of
| specific physical attack is in most people's threat
| model. It's only backing a 4/6 digit pin for most people
| anyway. Realistically, it's not the weakest link.
| n8cpdx wrote:
| It's pretty strict and won't authenticate if I look too
| tired, so I think you'd have to be pretty careful about
| how you tape the unconscious victim's eyes (a conscious
| victim would just look away from the screen) to fool it.
|
| And if someone has full physical control over you such
| that they can open your eyes without consent, do you
| really care if they can unlock your phone? Your life is
| in their hands at that point anyway.
|
| You have to assume a persistent attacker with physical
| access will be able to crack the device regardless.
| pabs3 wrote:
| I'm thinking children or spouses, you may be able to
| trust them not to murder you in your sleep, but accessing
| your device while you sleep to be able to play some games
| or read your texts is something they would probably do.
| Closi wrote:
| > When you are asleep, your finger/face can be used without
| your consent.
|
| FaceID only works if your eyes are open for this reason.
| Boltgolt wrote:
| Howdy 3.0.0 will actually introduce a feature that allows
| login consent. Nod yes to authenticate, shake no to abort.
| https://github.com/boltgolt/howdy/wiki/Rubber-Stamp-
| Guide#av...
| pabs3 wrote:
| Having to blink a one-time code might be an interesting
| way to auth.
| cmroanirgo wrote:
| This sounds very promising. It'd be nice if audio
| verification was added and that the lip movement matches
| the audio. Maybe for v3.1?
| spicybright wrote:
| Mind sharing what made you flip?
|
| Apple's face modeling is miles better than a webcam for sure,
| and I'll admit I've never used a system like that before.
| nicce wrote:
| As long as you think face or fingerprint as an username and
| not as password, they are kinda fine. You should be able to
| change your password, so there are not good. They are also
| public information. For now, they work as they are still hard
| to fake, but that might change over time in the future.
| spicybright wrote:
| Yup, just gotta model your threats.
|
| I use finger print scanners at home because it's less
| keystrokes.
|
| But not on my phone. Both because my (trusted) friends
| sometimes need to borrow a phone, and also for the very
| rare chance police detain me and try to break into my phone
| without a warrant.
|
| Legally, you don't have to tell a cop your password, but
| they can physically force you to use your finger/face to
| unlock your phone.
| jeroenhd wrote:
| Windows Hello is more than just a webcam, the IR spectrum is
| a lot harder to fake (compared to, say, facial recognition in
| many Android phones). You'll need a picture taken with an IR
| camera, programmed into fake webcam hardware, to bypass it.
| Still far from perfect, but not as trivial to bypass as
| people seem to think.
|
| That said, the traditional fingerprint readers are more
| secure and just as easy to use. I don't understand why Apple
| shifted focus for mobile security onto facial recognition,
| especially with the development of under-screen fingerprint
| scanners in smartphones.
| whoopdedo wrote:
| Gloves?
| ChuckNorris89 wrote:
| Facemasks?
| spicybright wrote:
| I've never worn a glove that feels comfortable using a
| touchscreen in.
|
| Even medical latex-type gloves make keyboard typing near
| impossible for me (granted that might be because I'm
| right between sm and md size gloves so I have to wear
| slightly baggy mediums...)
| jodrellblank wrote:
| John Gruber / Daring Fireball has written several posts
| about FaceID, including:
|
| > "(Quoting Stratechery) TouchID made it far easier to have
| effective security for the vast majority of situations, and
| FaceID makes it invisible. [...] the first time I saw
| notifications be hidden and then revealed (as in the GIF
| above) through simply a glance produced the sort of
| surprise-and-delight that has traditionally characterized
| Apple's best products" -
| https://daringfireball.net/linked/2017/11/08/apple-at-its-
| be...
|
| > "(Quoting Tom's Guide) I've been using Face ID on the
| iPhone X for more than 24 hours, and I don't need a
| stopwatch to tell you that it unlocks my phone slower than
| when I was using Touch ID on my older iPhone 7 Plus". This
| is not a "workaround". This is how you're supposed to
| unlock iPhone X. Starting with a tap of the side button is
| not how you're supposed to do it -- you're creating a two-
| step process where you only need one. [...] The best way to
| use Face ID is to pretend it isn't even there, and just
| swipe up from the home indicator." -
| https://daringfireball.net/linked/2017/11/01/face-id-
| extra-s...
|
| > "(Quoting Michael Tsai) However, Face ID also has
| advantages. It works with gloves on, with wet fingers, and
| with dry/cracked skin. It's more convenient when the phone
| is in a dock or car mount where it would be hard to get my
| hand under it to put my thumb on the sensor." -
| https://daringfireball.net/linked/2019/03/01/tsai-iphone-
| se-...
| kompatible wrote:
| Face ID has been upgraded since 2019 and is now a lot
| faster than the initial iteration. Some people may argue
| Touch ID will always be faster, but I think actively
| looking at the phone is quicker than trying to put your
| finger in the right spot
| [deleted]
| jeroenhd wrote:
| I wear face masks more often than I wear gloves and I
| sure hope facial recognition doesn't just throw away half
| my face. Combine that with the fact that in certain Asian
| countries it was normal long before COVID to wear masks
| when you're not well and I'm not sure which one makes
| more business sense.
|
| With under-screen fingerprint scanners, or the power
| button fingerprint scanners on some phones, that "two
| step process" turns back into a single step. My unlock
| process is to put my finger on my screen (where the
| fingerprint scanner is) and pull it out of my pocket.
| It's honestly no different from the swipe up that you
| need to do on iOS. Because the scanner is on the front,
| it also works pretty flawlessly when it's attached to a
| mount of some sort.
|
| Wet hands are one place where improvements can be made,
| but modern fingeprint scanners are doing quite well in
| that space as well.
|
| I've used Google's facial recognition system for ages
| before I had a phone with a fingeprint scanner and it was
| always pretty snappy for me, but I didn't set it up with
| this phone and I haven't missed it so far.
| ravi-delia wrote:
| Mine actually works about half the time with a mask on.
| Seems weird, but I'm not complaining
| spicybright wrote:
| Most analyzing of face ID feature happened when it first
| came out before covid, so a lot of security claims are
| probably not fully accurate anymore (or at least are
| deserving of a re-evaluation)
|
| I have little basis for this assumption, but I imagine
| apple would compromise a bit of security to keep the
| feature people payed for working and just chop off half
| the face.
|
| Now what you really want to be doing is printing QR code
| masks to make up for the missing half of the face! /s
| kretaceous wrote:
| Absolutely. I don't use Howdy but I came here to say the same.
|
| I remember being impressed by the quality and honesty of the
| project and began my search for similar projects for
| fingerprint authentication.
|
| I sadly couldn't find anything that works. I use LM 20.3 on an
| ASUS Vivobook and apparently PAM doesn't support my in-built
| fingerprint scanner.
| guilhas wrote:
| Windows Hello can be used as a 2fa for some websites, without a
| fido2 USB, is there anything like this for Linux?
| yoavm wrote:
| https://github.com/danstiner/rust-u2f/ comes to mind
| tempfs wrote:
| Let's leave Microsoft's bad ideas on Windows mmmkay.
| nerdjon wrote:
| I will only use biometrics for authentication on a device that
| does 3 things:
|
| 1. if the device is turned off, I have to enter my
| passcode/password to enable biometrics authentication.
|
| 2. If after long enough of being on the biometrics are not used,
| it will require the passcode/password.
|
| 3. There is a quick shortcut to disable biometric authentication.
|
| To my knowledge iOS is the only one that does all 3. Mac does the
| first 2 for TouchID and annoyingly there is not a shortcut for
| the third available.
|
| Windows Hello seems like a half assed security measure since it
| is missing all 3. At quick glance this does the same.
| jeroenhd wrote:
| My Xiaomi does that too, although the quick shortcut is to just
| hold the power button down to force reboot it. I think it's
| just the PC space missing support for this.
|
| However, I think the emergency disable functionality in Windows
| Hello isn't really necessary. You can quickly disable
| biometrics on your phone from your pocket, but disabling it on
| a desktop or laptop is a lot harder to do inconspicuously.
|
| Because this is using PAM, you can configure it however you
| want. You can tell your system to allow user logins through
| biometrics but require a password for administrative tasks
| (doas/sudo) for example. You can also edit the source code and
| make it always fail if a certain file in a write-only directory
| is present and set up a keyboard shortcut that runs `touch
| /special/file/here`. You can even implement such a timer system
| by setting up a systemd timer that automatically creates such a
| file after a certain amount of time to make sure you need to
| reauthenticate.
|
| Setting up a reliable face recognition system that hooks into
| the right APIs is the hard part. That's what this project does.
| Customising it to serve your exact use case is relatively easy.
| NoGravitas wrote:
| Android does all three, though there's no way to configure the
| timeout for (2), and the timeout seems inappropriately long (72
| hours). At least, all these are the case on the Moto builds of
| Android 10. Could be different on other manufacturers.
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