1YKCHALRESP(1)           YubiKey Personalization Tool M           YKCHALRESP(1)
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NAME

6       ykchalresp - Perform challenge-response operation with YubiKey
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SYNOPSIS

9       ykchalresp [-nkey] [-1 | -2] [-H | -Y] [-N] [-x] [-v] [-6 | -8] [-t]
10       [-iFILE] [-V] [-h]
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DESCRIPTION

13       Send a challenge to a YubiKey, and read the response. The YubiKey can
14       be configured with two different C/R modes — the standard one is a 160
15       bits HMAC-SHA1, and the other is a YubiKey OTP mimicking mode, meaning
16       two subsequent calls with the same challenge will result in different
17       responses.
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OPTIONS

20       -nkey
21           send the challenge to the nth key found.
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23       -1
24           send the challenge to slot 1. This is the default
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26       -2
27           send the challenge to slot 2.
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29       -H
30           send a 64 byte HMAC challenge. This is the default.
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32       -Y
33           send a 6 byte Yubico OTP challenge.
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35       -N
36           non-blocking mode — abort if the YubiKey is configured to require a
37           key press before sending the response.
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39       -x
40           challenge is hex encoded.
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42       -v
43           enable verbose mode.
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45       -6
46           output the response in OATH format, 6 digits.
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48       -8
49           output the response in OATH format, 8 digits.
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51       -t
52           use current time as challenge instead of reading challenge from
53           command line (as in default TOTP mode, seconds since 1970-01-01
54           00:00:00 / 30 encoded as an 8 byte challenge).
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56       -iFILE
57           take challenge from FILE instead of as an argument. If file is -
58           challenge is read from STDIN
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60       -V
61           print tool version and exit.
62

EXAMPLE

64       The YubiKey challenge-response operation can be demonstrated using the
65       NIST PUB 198 A.2 test vector.
66
67       First, program a YubiKey with the test vector :
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69           $ ykpersonalize -2 -ochal-resp -ochal-hmac -ohmac-lt64 -a303132333435363738393a3b3c3d3e3f40414243
70            ...
71           Commit? (y/n) [n]: y
72           $
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74       Now, send the NIST test challenge to the YubiKey and verify the result
75       matches the expected :
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77           $ ykchalresp -2 'Sample #2'
78           0922d3405faa3d194f82a45830737d5cc6c75d24
79           $
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BUGS

82       Report ykchalresp bugs in the issue tracker
83       https://github.com/Yubico/yubikey-personalization/issues
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SEE ALSO

86       The ykpersonalize home page
87       https://developers.yubico.com/yubikey-personalization/
88
89       YubiKeys can be obtained from Yubico http://www.yubico.com/
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93ykchalresp                      Version 1.19.1                   YKCHALRESP(1)
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