Re: Different values for same challenge between yk std and y

2016-03-04T01:47:08+01:00

Can you make up some full parameters so you can share with us (i.e. let us see the secret key / challenge / response for a Standard and a YK4 - obviously not the one you're using)?

I just ran a couple tests and I don't see any differences. I tried with a YubiKey Standard, YubiKey 4, and YubiKey NEO:

(With Personalization Tool v 3.1.24 on Windows 10):
*Slot 2
*Require user input not selected
*Variable input
*Secret key - 6cc335d6b04852ea46178fda1d8849c65e166e68

Same credential programmed into slot 2 of all three YubiKeys. I then used ykchalresp in Command Prompt:

Code:

c:\ykpers-1.17.1-win64\bin>ykinfo -a
serial: 2245696
serial_hex: 224440
serial_modhex: ddfffc
version: 2.4.2
touch_level: 2307
programming_sequence: 3
slot1_status: 1
slot2_status: 1
vendor_id: 1050
product_id: 10

c:\ykpers-1.17.1-win64\bin>ykchalresp -2 0123456789012345678901234567890123456789012345678901234567891234
03ac3c14fb27e88a46268f3822bf226d89286016

c:\ykpers-1.17.1-win64\bin>ykinfo -a
serial: 4282000
serial_hex: 415690
serial_modhex: fbghkc
version: 3.4.7
touch_level: 10759
programming_sequence: 3
slot1_status: 1
slot2_status: 1
vendor_id: 1050
product_id: 116

c:\ykpers-1.17.1-win64\bin>ykchalresp -2 0123456789012345678901234567890123456789012345678901234567891234
03ac3c14fb27e88a46268f3822bf226d89286016

c:\ykpers-1.17.1-win64\bin>ykinfo -a
serial: 4227930
serial_hex: 40835a
serial_modhex: fcjegl
version: 4.2.7
touch_level: 519
programming_sequence: 3
slot1_status: 1
slot2_status: 1
vendor_id: 1050
product_id: 407

c:\ykpers-1.17.1-win64\bin>ykchalresp -2 0123456789012345678901234567890123456789012345678901234567891234
03ac3c14fb27e88a46268f3822bf226d89286016

Statistics: Posted by ChrisHalos — Fri Mar 04, 2016 1:47 am

Different values for same challenge between yk std and yk 4

2016-03-03T22:27:05+01:00

Hi,
We have been successfully using the yubikey standard for a while with the following configuration
Configuration Slot 2 configured for HMAC-SHA1 based Challenge-Response mode where we have configured multiple yubikeys with the same secret key in variable input mode. We use this in an application where it issues a specific challenge and validates the response.

Recently we bought the new yubikey 4 and programmed the yk4 with the same configuration as the std. However, we could not get the yk4 to work with our applications. Upon further testing using the "ykchalresp" program, i was able to verify that the yk4 is issuing a different response than the yk std for the exact same challenge and secret. I didn't see any information/documentation that indicated that the HMAC-SHA1 chal-resp behavior would have changed ?

Here are additional details
yk std firmware: 2.4.2
yk 4 firmware: 4.2.7
Personalization tool version: 3.1.24

Any idea why we are getting different results ?

Statistics: Posted by darshakthakore — Thu Mar 03, 2016 10:27 pm

Yubico Forum

Re: Different values for same challenge between yk std and y

Different values for same challenge between yk std and yk 4