Proxmark3 community

iceman

Administrator

Registered: 2013-04-25

Posts: 9,538

Website

cryptlib inside the arm?

Been thinking if it is possible to have a cryptolib inside the arm instead of in the client?

Something like this?
https://www.das-labor.org/trac/browser/microcontroller-2/arm-crypto-lib?rev=4798&order=name

I have no clue about arm development and what the limits are,  but it feels like it would be faster in the arm and for standalone that might be an improvement of functionality.

charliex

Contributor

From: Los Angeles/Scotland

Registered: 2010-08-05

Posts: 70

Website

Re: cryptlib inside the arm?

crypto lib in the arm would be a few  orders of magnitude slower than even the slowest desktop pc.

iceman

Administrator

Registered: 2013-04-25

Posts: 9,538

Website

Re: cryptlib inside the arm?

Well, I didn't think of using the ARM for speedy decrypting routines but for standalone mode when snooping, replaying iclass, desfire...
It is true that the processor is slow.

charliex

Contributor

From: Los Angeles/Scotland

Registered: 2010-08-05

Posts: 70

Website

Re: cryptlib inside the arm?

yeah. you'd probably need the 512K version of the SAM7 though., i know my proxmark3 has it but most are 256K i believe.

iceman

Administrator

Registered: 2013-04-25

Posts: 9,538

Website

Re: cryptlib inside the arm?

no,problem, I've the 512 version.  Is't 512kb only flash rom?  and there is like 64kb flash ram?..  even less...

rule

Member

Registered: 2008-05-21

Posts: 417

Re: cryptlib inside the arm?

No need to upgrade, the AES implementation of the royalty free crypto library from Brian Gladman uses something like 12KB of flash and runs perfectly on the 256KB version of the proxmark

charliex

Contributor

From: Los Angeles/Scotland

Registered: 2010-08-05

Posts: 70

Website

Re: cryptlib inside the arm?

neat ,

yeah its the flash thats bigger, i figured since the pm3lcd went over, it was a lot tighter than it is. i'm using the 512B on all ours. they're both 64KB sram.

iceman

Administrator

Registered: 2013-04-25

Posts: 9,538

Website

Re: cryptlib inside the arm?

Sometimes, it is really frustrating to develop for the pm3... 
For example, I spent one day on trying to get a cryptolib inside the armsrc..  but I didn't realise that all the cryptolibs was for mingw32,.. and not for arm.. Headbanging the wall over and over again.
Now at least, there is des and aes inside the arm.. *yeah*

Desfire's capabilities of talking 3different ways (native, wrapped native, iso15..) is also hard to understand.. Which to use? depends on the desfire version..
Not having a blank desfire card also makes it hard to implement..

Changing the armsrc a bit,  flash the pm3,  try the changes,  repeat all over...   that takes the most time. At least I got the armsrc inside the VS2012 so I get some indications when the sourcecode has syntaxerrors improved the testing times...

pm3 --> hf 14a list
Recorded Activity

Start = Start of Start Bit, End = End of last modulation. Src = Source of Transfer
All times are in carrier periods (1/13.56Mhz)

     Start |       End | Src | Data
-----------|-----------|-----|--------
         0 |       992 | Rdr | 52
      2228 |      4596 | Tag | 44  03
      7040 |      9504 | Rdr | 93  20
     10676 |     16500 | Tag | 88  04  77  29  d2
     18688 |     29216 | Rdr | 93  70  88  04  77  29  d2  6c  76
     30388 |     33908 | Tag | 24  d8  36
     35200 |     37664 | Rdr | 95  20
     38836 |     44724 | Tag | 5a  86  34  80  68
     46848 |     57376 | Rdr | 95  70  5a  86  34  80  68  22  58
     58548 |     62132 | Tag | 20  fc  70
     63616 |     68384 | Rdr | e0  80  31  73
     69556 |     78836 | Tag | 06  75  77  81  02  80  02  f0
     81536 |     87392 | Rdr | 02  aa  00  23  42
    123316 |    146484 | Tag | 02  af  4b  69  91  03  cf  02  bf  e7  d8  aa  81  df  de  0c  0b  15  fa  4f
  11545344 |  11586976 | Rdr | 02  af  a6  13  e6  62  3b  62  7c  58  a2  55  51  28  58  e9  d6  36  d7  eb  e9  91  87  58  4d
 6e  1a  28  b0  86  a7  09  4b  06  b4  92

since the oyster is using AES, I needed to change from DES...
However,  I don't get a answer from my last call..

asper

Contributor

Registered: 2008-08-24

Posts: 1,409

Re: cryptlib inside the arm?

Try to increment the "waiting for tag answer" time; I had the same problem with epassports and increasing that delay makes the answer to appear (if I am correctthe default value is .