• Sly
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  • Registered: 2009-06-27
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Topic: RFID based Wake On Lan

Here's the a project I'm thinking of at the moment. Basically it's a small idea for saving power. Alot of us nerds out here leave our computers on, probably just for the sake of boot up times right?

My idea is to use a cheap reader like the Touchatag and either something like the marvell power plug computers or just a router with a usb port. Then when someone enters the house they can just put their tag on the reader and it will instantly send the wake up on lan command to the right computer.

How much power it would actually save, I'm not honestly sure. I already have the parts (Touchatag reader + ASUS Wl500g running DD-WRT) so it's just a case of software.

From what I can tell all I need to do is:

- Compile LibNFC for ARM
- Create a Daemon to do the job

So, what do people think? genius or dumbest idea ever?

  • rconty
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Re: RFID based Wake On Lan

Hi Sly,

Sly wrote:

From what I can tell all I need to do is:

- Compile LibNFC for ARM
- Create a Daemon to do the job

Using libnfc with Touchatag depends on libpcsclite and ccid. So, you will need to compile them too.

But want some good news ?
SVN "portability" branch run actually fine under ARM and MIPS and it should be included in OpenWrt on libnfc next release with dependencies.

For "clean" daemon, I suggest to try to use PAM (Pluggable authentication module) which will allow to use another authentication method in future, like biometric reader, without code modification.

Conclusion, if you want to start coding now, let me know : i'll share my actual pieces of code : OpenWrt's Makefiles, and a "start" of PAM authentication module which already works and able to login in linux sessions BUT based on UID so NOT secure at all !

http://www.libnfc.org/community/topic/4 … e-classic/

Romuald Conty
  • Sly
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Re: RFID based Wake On Lan

rconty wrote:

Hi Sly,

But want some good news ?
SVN "portability" branch run actually fine under ARM and MIPS and it should be included in OpenWrt on libnfc next release with dependencies.

For "clean" daemon, I suggest to try to use PAM (Pluggable authentication module) which will allow to use another authentication method in future, like biometric reader, without code modification.

Conclusion, if you want to start coding now, let me know : i'll share my actual pieces of code : OpenWrt's Makefiles, and a "start" of PAM authentication module which already works and able to login in linux sessions BUT based on UID so NOT secure at all !

http://www.libnfc.org/community/topic/4 … e-classic/

Well, I don't see why I'd need to work with PAM as effectively all that's needed is a lookup table in the daemon that matches the UID of the Tag to the correct MAC address of the computer, it doesn't need to be all that secure unless my idea is furthered to included automatic logins, which would be good but it's nessecary for a starting concept.

Thank you for the good news though! It could still be a good while before I get round to working on it but at least now I think it's pretty possible to work on.

  • rconty
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Re: RFID based Wake On Lan

Hi Sly,

Sly wrote:

Well, I don't see why I'd need to work with PAM

As I said it will allow you to change authentication method and doesn't depends directly on libnfc, etc.

Sly wrote:

as effectively all that's needed is a lookup table in the daemon that matches the UID of the Tag to the correct MAC address of the computer

Humm, I see but it could be more flexible if you are able to run executables or scripts depending on user which logon using a tag.

Romuald Conty
  • rconty
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Re: RFID based Wake On Lan

rconty wrote:
Sly wrote:

Well, I don't see why I'd need to work with PAM

As I said it will allow you to change authentication method and doesn't depends directly on libnfc, etc.

Due to lack of event handling, I have to change my mind about PAM: even it offer flexibility for authentication method, it's not usable to handle events like "user try to authenticate" (in our case: "tag inserted") and somethings like that.

That's a problem for many developers, even on desktop: fingerprint readers, smartcard readers or nfc readers doesn't allow to autologin (without login enter and validation) using PAM via current GDM/KDM.

rconty wrote:

Humm, I see but it could be more flexible if you are able to run executables or scripts depending on user which logon using a tag.

If you are interesting in, I am currently writing an nfc events handler which allow me to launch applications on tag inserted and tag removed.

Romuald Conty
  • Registered: 2010-04-06
  • Posts: 1

Re: RFID based Wake On Lan

Hi!
I've just start searching info for my project and I've finished here wink
I've also programmed a PAM module that allows the user to be authenticated based on a DESFIRE UID.

The problem is the same as yours: PAM is not even oriented, so even if a default user is indicated in, for example, KDM, there is still need to press the "enter" key to start authentication. I hope I'm being able to describe the situation in a clear way.

Any idea to achieve a mechanism to allow automatic login with no keyboard? Perhaps PAM-script?

Thanks a lot!

  • rconty
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Re: RFID based Wake On Lan

kazola wrote:

I've also programmed a PAM module that allows the user to be authenticated based on a DESFIRE UID.

Does it use libnfc ? Is code free ?

kazola wrote:

The problem is the same as yours: PAM is not even oriented, so even if a default user is indicated in, for example, KDM, there is still need to press the "enter" key to start authentication. I hope I'm being able to describe the situation in a clear way.

Any idea to achieve a mechanism to allow automatic login with no keyboard? Perhaps PAM-script?

Fingerprint users have the same problem more than 5 years,
https://bugs.kde.org/show_bug.cgi?id=116682
https://bugs.kde.org/show_bug.cgi?id=105631

There are some improvements around fingerprint like KDM plugin : http://websvn.kde.org/trunk/playground/ … ngerprint/

Romuald Conty