Provided by:
oathtool_1.10.4-1_i386 
NAME
oathtool - OATH one-time password tool
SYNOPSIS
oathtool [OPTIONS]... [KEY [OTP]]...
DESCRIPTION
oathtool 1.10.4
Generate and validate OATH one-time passwords.
-h, --help
Print help and exit
-V, --version
Print version and exit
--hotp use event-based HOTP mode (default=on)
--totp use time-variant TOTP mode (default=off)
-c, --counter=COUNTER
HOTP counter value
-s, --time-step-size=DURATION TOTP time-step duration
(default=`30s')
-S, --start-time=TIME
when to start counting time steps for TOTP (default=`1970-01-01
00:00:00 UTC')
-N, --now=TIME
use this time as current time for TOTP (default=`now')
-d, --digits=DIGITS
number of digits in one-time password
-w, --window=WIDTH
window of counter values to test when validating OTPs
-v, --verbose
explain what is being done (default=off)
EXAMPLES
To generate the first event-based (HOTP) one-time password for an all-
zero key:
$ oathtool 00
328482
$
To generate the first 10 event-based one-time passwords using the same
secret key which is used in the examples of RFC 4226 use the -w
(--window) parameter:
$ oathtool -w 10 3132333435363738393031323334353637383930
755224
287082
359152
969429
338314
254676
287922
162583
399871
520489
403154
$
In the last output, the counter for the first OTP was 0, the second OTP
had a counter of 1, and so on.
To generate a particular OTP, use the -c (--counter) parameter to give
the exact position directly:
$ oathtool -c 5 3132333435363738393031323334353637383930
254676
$
To validate a HOTP one-time password supply the OTP last on the command
line:
$ oathtool -w 10 3132333435363738393031323334353637383930 969429
3
$
The output indicates the counter that was used. It works by starting
with counter 0 and increment until it founds a match (or not), within
the supplied window of 10 OTPs.
The tool supports time-variant one-time passwords, in so called TOTP
mode. Usage is similar, but --totp needs to be provided:
$ oathtool --totp 00
943388
$
Don't be alarmed if you do not get the same output, this is because the
output is time variant. To generate a TOTP for a particular fixed time
use the -N (--now) parameter:
$ oathtool --totp --now "2008-04-23 17:42:17 UTC" 00
974945
$
The format is a mostly free format human readable date string such as
"Sun, 29 Feb 2004 16:21:42 -0800" or "2004-02-29 16:21:42" or even
"next Thursday". It is the same used as the --date parameter of the
date(1) tool.
You may generate several TOTPs by specifying the --window parameter,
similar to how it works for HOTP. The OTPs generated here will be for
the initial time (normally current time) and then each following time
step (e.g., 30 second window).
$ oathtool --totp 00 -w5
815120
003818
814756
184042
582326
733842
$
You can validate a TOTP one-time password by supplying the secret and a
window parameter (number of time steps before or after current time):
$ oathtool --totp -w 5 00 `oathtool --totp 00`
0
$
Similar when generating TOTPs, you can use a -N (--now) parameter to
specify the time to use instead of the current time:
$ oathtool --totp --now="2005-03-18 01:58:29 UTC" -w 10000000
3132333435363738393031323334353637383930 89005924
4115227
$
The previous test uses values from the TOTP specification and will
stress test the tool because the expected window is around 4 million
time-steps.
There are two system parameters for TOTP: the time-step size and the
time start.
By default the time-step size is 30 seconds, which means you get a new
OTP every 30 seconds. You may modify this with the -s
(--time-step-size) parameter:
$ oathtool --totp --time-step-size=45s 00
109841
$
The values are valid ISO-8601 durations, see:
http://en.wikipedia.org/wiki/ISO_8601#Durations
The time start is normally 1970-01-01 00:00:00 UTC but you may change
it using the -S (--start-time):
$ oathtool --totp --start-time "1980-01-01 00:00:00 UTC" 00
273884
$
To get more information about what the tool is using use the -v
(--verbose) parameter. Finally, to generate the last TOTP (for SHA-1)
in the test vector table of draft-mraihi-totp-timebased-07 you can
invoke the tool like this:
$ oathtool --totp -v -N "2033-05-18 03:33:20 UTC" -d8
3132333435363738393031323334353637383930
Hex secret: 3132333435363738393031323334353637383930
Digits: 8
Window size: 0
Step size (seconds): 30
Start time: 1970-01-01 00:00:00 UTC (0)
Time now: 2033-05-18 03:33:20 UTC (2000000000)
Counter: 0x3F940AA (66666666)
69279037
$
AUTHOR
Written by Simon Josefsson.
REPORTING BUGS
Report bugs to: oath-toolkit-help@nongnu.org oathtool home page:
<http://www.nongnu.org/oath-toolkit/>
General help using GNU software: <http://www.gnu.org/gethelp/>
COPYRIGHT
Copyright © 2011 Simon Josefsson. License GPLv3+: GNU GPL version 3 or
later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.