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inte is offline inte
2014-05-13 , 19:47
Posts: 130 | Thanked: 77 times | Joined on Aug 2009
#1
Hi folks,

what do you people think about connecting a Smartcard-reader to the i2c interface? This would allow smartcard based authentification for e.g. gpg or ssh (and possibly to lock/unlock the whole device). The FSF fellowship smartcard is likely a good point to start and since most (if not all) necessary software is already available for linux/ARM it's rather the hardware implementation that need's to be done. There are several cheap and small serial card reader modules available and I presume it wouldn't be too much work to somehow attach a reader to the Jolla's i2c bus and stick a selfmade (3D-printed) TOH around it...
I'm not too much into hardware engineering (actually not at all), but I just wanted to bring this one in and I'm curious to hear your thoughts!

Thanks in advance,

Chris
Last edited by inte; 2014-05-13 at 19:55.
 

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inte is offline inte
2014-05-14 , 22:01
Posts: 130 | Thanked: 77 times | Joined on Aug 2009
#2
To be more precise:
Is it straight forward to connect this module (http://classic.parallax.com/product/32320) to the Jolla i2c bus to eventually use OpenPGP smartcards (http://en.m.wikipedia.org/wiki/OpenPGP_card)?

Thanks in advance,
Chris
Last edited by inte; 2014-05-14 at 22:07.
 
dirkvl is offline dirkvl
2014-05-15 , 06:19
Posts: 1,104 | Thanked: 5,652 times | Joined on Feb 2010 @ Holland
#3
Originally Posted by inte View Post
To be more precise:
Is it straight forward to connect this module (http://classic.parallax.com/product/32320) to the Jolla i2c bus to eventually use OpenPGP smartcards (http://en.m.wikipedia.org/wiki/OpenPGP_card)?

Thanks in advance,
Chris
cool idea

https://www.youtube.com/playlist?lis...C63828A483E756

that card reader does not uses i2c.
 
inte is offline inte
2014-05-15 , 07:16
Posts: 130 | Thanked: 77 times | Joined on Aug 2009
#4
Hi Dirk,

thanks for your hint!
It is probably easier to utilize something like http://www.hidglobal.com/products/em...s/omnikey/3111 then.
It's probably only necessary to level shift the Jollas output power to 5V (as in PS/2 specs) and to somehow connect the serial port to the i2c module.
The reader itself is known to work with linux...
thanks.
 
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kimmoli is offline kimmoli
2014-05-16 , 17:49
Posts: 562 | Thanked: 2,744 times | Joined on Dec 2013 @ Espoo, Finland
#5
you did ask ps2 connection to i2c in i2ctool thread, guessing it relates to this thread?

Originally Posted by inte View Post
I'm not (yet) in hardware development development but is it possible to somehow connect a serial device (ps/2 powered, 5v) to your interface?
This is >10years old, but http://www.nxp.com/documents/applica...te/AN10232.pdf

and http://www.nxp.com/documents/applica...te/AN10207.pdf

But i think "easiest" way is to use small microcontroller as I2C slave, and to interface to the PS/2 keyboard - it makes PS/2 data available to be read by phone - If want to experiment, use e.g. Arduino. Connect it to the phone with MyHalf

5V can be made with step-up converter.

All these parts are available from various sources (MyHalfs maybe not so many places)
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inte is offline inte
2014-05-17 , 07:23
Posts: 130 | Thanked: 77 times | Joined on Aug 2009
#6
As far as I understand, PS/2 is only needed for power and not for data. It would therefore only be necessary to somehow interface serial to i2c. I also came across this reader: http://www.horter.de/i2c/i2c-chipkar...pkarten_1.html which seems to be genuine i2c. No idea if it supports OpenPGP/Basiccards nor if it is supported by gnupg/ccid or pcscd, though.
I thought i2c is somehow a serial interface, maybe it is the best to start with a supported serial reader if connection to i2c is feasible.
 
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kimmoli is offline kimmoli
2014-05-17 , 10:44
Posts: 562 | Thanked: 2,744 times | Joined on Dec 2013 @ Espoo, Finland
#7
Originally Posted by inte View Post
As far as I understand, PS/2 is only needed for power and not for data. It would therefore only be necessary to somehow interface serial to i2c.
That omnikey 3111 does take power from PS2 connector , and for communications it uses RS-232 serial port.

Originally Posted by inte View Post
I also came across this reader: http://www.horter.de/i2c/i2c-chipkar...pkarten_1.html which seems to be genuine i2c. No idea if it supports OpenPGP/Basiccards nor if it is supported by gnupg/ccid or pcscd, though.
This is just a smart-card "connector" which supports only I2C based smart-cards (which can be quite directly connected to jolla, through a level converter possibly.) The smart-card is atually a EEPROM memory device.

Originally Posted by inte View Post
I thought i2c is somehow a serial interface, maybe it is the best to start with a supported serial reader if connection to i2c is feasible.
I2C is a serial interface, but it has nothing more to do with e.g. PC serial port or USB

To interface with all kind of smartcards, the omnikey 3111 seems plausible,but you would need something like http://talk.maemo.org/showthread.php?t=92382 and step-up DCDC converter to 5V power.

But to start with I2C smart-cards, you'll need to know supported voltage of the card, if it is 1.8V or 3.3V then you can connect it to phone with e.g. MyHalf circuitry.
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inte is offline inte
2014-05-17 , 16:24
Posts: 130 | Thanked: 77 times | Joined on Aug 2009
#8
Thanks for your detailed description.
I was just thinking that it might be feasible to build a i2c-iso7816 interface from the scratch, e.g. by utilizing a TDA8029 microprocessor as described here:
http://www.nxp.com/documents/applica...te/AN10207.pdf or http://www.bdtic.com/DownLoad/ST/AN2284.pdf

As far as I undestand the specifications (e.g. http://www.nxp.com/products/identifi...TDA8029HL.html) this could also work with 3,3V as supplied by jolla.

Interfacing from i2c to serial and then from serial to Iso7816 is maybe one step to much.
However, I have no clue how to obtain such a microprocessor, nor how to put the parts together nor how to write the code for both the microprocessor or the linux driver...
So, as long as no one else steps in and helps out with hard- and/or software design I guess it is the easiest (for me) to wait until you have your RS232-adaptor ready and I can play around with a serial reader and a 5V converter.
Thanks anyways!
 
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kimmoli is offline kimmoli
2014-05-18 , 06:35
Posts: 562 | Thanked: 2,744 times | Joined on Dec 2013 @ Espoo, Finland
#9
Originally Posted by inte View Post
However, I have no clue how to ...
My problem is that there is only roughly 8765 hours in a year.

I suggest to get yourself a Arduino or something and get started with things.
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inte is offline inte
2014-05-18 , 14:26
Posts: 130 | Thanked: 77 times | Joined on Aug 2009
#10
Originally Posted by kimmoli View Post
My problem is that there is only roughly 8765 hours in a year.

I suggest to get yourself a Arduino or something and get started with things.
Yes of course, I also have a real life and a real job
Just one more thing:
I found these card readers:
http://www.ineltek.com/ru/files/Insi...er_2012_03.pdf
Some of those come with Omnikey firmware which eradicates the linux-driver issue as Omnikey readers are supported by Linux pcscd already. Furthermore, all of them can run with 3,3 voltage as supplied by the Jolla.
The only thing that needs to be handled would be to somehow convert i2c to either UART or SPI, since none of the readers seems to support i2c out of the box. Is there any (straight forward) solution to connect a SPI device to an i2c bus? I would be willing to order those parts and play around with them if it sounds somewhat feasible.
 
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