This is the command ykchalresp that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator
PROGRAM:
NAME
ykchalresp - Perform challenge-response operation with YubiKey
SYNOPSIS
ykchalresp [-1 | -2] [-H] [-Y] [-N] [-x] [-v] [-6] [-8] [-t] [-V] [-h]
DESCRIPTION
Send a challenge to a YubiKey, and read the response. The YubiKey can be configured with
two different C/R modes -- the standard one is a 160 bits HMAC-SHA1, and the other is a
YubiKey OTP mimicing mode, meaning two subsequent calls with the same challenge will
result in different responses.
OPTIONS
-1 send the challenge to slot 1. This is the default.
-2 send the challenge to slot 2.
-H send a 64 byte HMAC challenge. This is the default.
-Y send a 6 byte Yubico OTP challenge.
-N non-blocking mode -- abort if the YubiKey is configured to require a key press
before sending the response.
-x challenge is hex encoded.
-v enable verbose mode.
-6 output the response in OATH format, 6 digits.
-8 output the response in OATH format, 8 digits.
-t use current time as challenge instead of reading challenge from command line (as in
default TOTP mode, seconds since 1970-01-01 00:00:00 / 30 encoded as an 8 byte
challenge).
-V print tool version and exit.
EXAMPLE
The YubiKey challenge-response operation can be demonstrated using the NIST PUB 198 A.2
test vector.
First, program a YubiKey with the test vector :
$ ykpersonalize -2 -ochal-resp -ochal-hmac -ohmac-lt64 -a 303132333435363738393a3b3c3d3e3f40414243
...
Commit? (y/n) [n]: y
$
Now, send the NIST test challenge to the YubiKey and verify the result matches the
expected :
$ ykchalresp -2 'Sample #2'
0922d3405faa3d194f82a45830737d5cc6c75d24
$
Use ykchalresp online using onworks.net services