stoken(1)stoken(1)NAMEstoken - software token for cryptographic authentication
SYNOPSISstoken [tokencode] [--stdin] [--force] [opts]
stoken import {--file=file|--token=token_string} [--force] [opts]
stoken setpin [opts]
stoken setpass [opts]
stoken show [--seed] [opts]
stoken export [{--blocks|--iphone|--android|--v3|--sdtid}] [opts]
stoken issue [--template=file]
stoken help
stoken version
DESCRIPTIONstoken is a software token compatible with RSA SecurID 128-bit (AES)
tokens. The command-line interface provides facilities for importing
new tokens, displaying the current tokencode, encrypting the seed with
a user-specified password, storing the user's PIN alongside the token,
and viewing or exporting the token data.
BASIC USAGE
Use stoken import to decode a token string and write it into
~/.stokenrc. This may prompt for a device ID and/or password,
depending on what options your administrator used to create the token.
The token string can be provided on the command line, or read from a
text file.
stoken will autodetect the following types of token strings:
286510182209303756117707012447003320623006...
29658-21098-45467-64675-65731-01441-11337...
Pure numeric (81-digit) "ctf" (compressed token format) strings,
with or without dashes. These may have been furnished as-is, or
they could have been derived from an sdtid file by the RSA
TokenConverter program.
com.rsa.securid.iphone://ctf?ctfData=229639330774927764401...
iPhone-compatible token strings.
http://127.0.0.1/securid/ctf?ctfData=250494932146245277466...
http://127.0.0.1/securid/ctf?ctfData=AwAAfBc3QSopPxxjLGnxf...
Android-compatible token strings.
<?xml version=...
RSA sdtid-formatted XML files. These should be imported from a
file: stoken import --file=FILE.SDTID.
Tokens supplied as QR codes can be converted back to standard URIs by
running zbarimg(1) on the image file.
The device ID, if used, can be viewed in the "about" menu for the RSA
soft token app on the phone. Numeric ctf strings and smartphone tokens
bound to a device ID contain a seed that is encrypted using the device
ID, so the ID must be furnished before stoken can successfully import
the token. sdtid files can be imported without knowledge of the device
ID, as long as the password (if any) is known.
By default, stoken import will refuse to overwrite an existing token in
~/.stokenrc. The --force switch overrides this check.
stoken import will normally prompt for a new password, which is used to
encrypt the seed before storing it in ~/.stokenrc. This can be
bypassed by entering an empty password, or specifying --new-password=''
on the command line. It is recommended to choose a longer, hard-to-
guess passphrase for this purpose.
After a token has been imported, running stoken with no arguments will
prompt for any required password or PIN, then display the current
tokencode.
Tokencodes are computed from the raw (decrypted) seed data, the current
time of day, and the PIN. If the same seed is installed on multiple
devices, they should all produce identical tokencodes. If they do not,
double-check the timezone setting and consider using NTP to synchronize
the system time to a known good source.
stoken setpin can be used to save the PIN in ~/.stokenrc. Not all
tokens will require a PIN; this can be configured by the SecurID
administrator when generating new tokens. Setting an empty PIN will
remove the PIN from ~/.stokenrc so that the user will be prompted every
time it is required. See the SECURITY CONSIDERATIONS section below for
additional details.
stoken setpass encrypts the seed and PIN (if present) in ~/.stokenrc
with a user-selectable password or passphrase. If an empty password is
entered, the password will be removed. See the SECURITY CONSIDERATIONS
section below for additional details.
VIEWING TOKENSstoken show displays information about the current token, typically
read from ~/.stokenrc. The --seed option displays the encrypted and
decrypted seed bytes (which should be treated as sensitive data, as
they can be used to derive tokencodes).
stoken export translates the current token into a format suitable for
importation to another device. It can be used in conjunction with
qrencode(1) to send a token to a smartphone:
qrencode -l H `stoken export --random --android` -o - | display -
stoken issue generates a new software token in XML sdtid format. A
template file, itself in sdtid format, may be provided to override some
or all of the human-readable fields. This would permit appropriate
serial numbers, expiration dates, usernames, etc. to be specified. If
Secret, Seed, or MAC fields are present in the template file, they will
be ignored.
GLOBAL OPTIONS
--rcfile=file
Use an alternate .stokenrc configuration file. This is
typically used to support multiple tokens on the same user's
UNIX account. Note that the .stokenrc file stores additional
data (such as the PIN), so it cannot be parsed as a "raw" token
string by stoken--file.
--password=password, -p password
Use a password supplied from the command line, instead of
prompting the user. See notes in SECURITY CONSIDERATIONS below.
--pin=pin, -n pin
Use a PIN supplied from the command line, instead of prompting
the user. See notes in SECURITY CONSIDERATIONS below. If you
save your PIN in ~/.stokenrc, note that --pin=0000 is often
required when activating a new soft token for the first time.
OTHER OPTIONS
--new-password=password
Supply the encryption password from the command line for
operations that write out a token string or .stokenrc file:
import, export, setpass, and issue. See notes in SECURITY
CONSIDERATIONS below.
--keep-password
If the token in the .stokenrc file is protected with a password,
retain the same password when exporting the token. By default,
the export operation will not encrypt the token with a password;
note that it may not be possible to enter all possible passwords
on devices with limited text input capabilities (such as feature
phones).
--new-pin=pin
Supply a new PIN from the command line for the setpin operation.
See notes in SECURITY CONSIDERATIONS below.
--new-devid=devid
Used with the export or issue command to encrypt the new token
with a specific device ID. This is only used for testing
purposes.
--blocks, --iphone, --android, --v3
Used with the export command to select the output format. See
examples in BASIC USAGE. By default, the export command will
print an unformatted 81-digit string to standard output.
--sdtid, --xml
These options are synonyms. Both export a token to standard
output in RSA's sdtid XML format.
--template=file
Used with the export or issue commands to override fields in the
XML output. The template file should look like any standard
sdtid file, but all fields are optional and will default to
reasonably sane values if omitted. This can be used to force
the output XML to use a specific serial number, user name,
expiration date, etc. Correct MAC checksums will be
(re)computed on the provided values. See the examples directory
in the source distribution for more information.
--use-time={unix_time|+offset|-offset}
Instead of generating a tokencode based on the current time of
day, force a specific time, or adjust the current time based on
a positive or negative offset (specified in seconds). This is
only used for testing purposes.
--stdin, -s
When generating a tokencode that requires either a password or
PIN, read the password or PIN as single line from standard
input. This is intended to allow external programs to call
stoken to generate single-use passwords without user
intervention; see NON-INTERACTIVE USE below.
--force, -f
Override token expiration date checks (for tokencode) or token
overwrite checks (for import).
--batch, -b
Abort with an error exit code if any user input is required.
Intended for automated operation and testing.
--file=file
Read a ctf string, an Android/iPhone URI, or an XML sdtid token
from file instead of the .stokenrc configuration. Most stoken
commands accept this flag, but it is expected that the typical
user will save his token in ~/.stokenrc instead of supplying it
by hand on every invocation. Typically --file and --token are
only used for the import command.
--token=token_string
Use a token from the command line instead of the .stokenrc file.
See above notes on --file.
--random
Generate a random token on the fly. Used for testing or
demonstrations only. These tokens should not be used for real
authentication.
--help, -h
Display basic usage information.
--version, -v
Display version information.
SECURITY CONSIDERATIONS
Software tokens, unlike hardware tokens, are relatively easy to
replicate. Systems that store soft token seeds should be carefully
guarded to prevent unauthorized disclosure. The use of whole-disk
encryption, such as TrueCrypt, is strongly recommended for laptops and
other portable devices that are easily lost or stolen.
stoken permits users to store their PIN in ~/.stokenrc to allow for
automated (scriptable) generation of tokencodes, but the risks of this
approach should be carefully weighed against the benefits.
Using the setpass command to encrypt the seed and PIN in ~/.stokenrc
provides some degree of protection against unauthorized access, but
does not necessarily cover all possible attack vectors. A host that is
already compromised (e.g. running a keylogger) will not provide
adequate protection for any seed(s) stored on it.
stoken encryption passwords may be up to 40 characters long. A longer
passphrase constructed from several random words can provide more
protection from brute-force attacks than a shorter password.
Entering a password or PIN on the command line is generally unsafe on
multiuser systems, as other users may be able to view the command line
arguments in ps or similar utilities. The command line could also be
cached in shell history files.
stoken attempts to lock pages to prevent swapping out to disk, but does
not scrub secrets from process memory.
NON-INTERACTIVE USE
Other applications, such as VPN clients, may want to invoke stoken non-
interactively to generate single-use passwords. Three usage modes are
supported, depending on the level of security (and/or convenience) that
is required:
No password or PIN
The user configures stoken to print a tokencode immediately upon
invocation, with no prompts, by using setpin to store the PIN in
~/.stokenrc and using setpass to set an empty password. The other
application can then invoke stoken--batch and read the tokencode
through a pipe from standard output.
This provides no security for the seed, but may be useful in
applications where (re-)authentication is frequent or unattended
operation is required.
Save the PIN and set a password
The user configures stoken to encrypt the ~/.stokenrc secrets with a
password using setpass, then saves the PIN with setpin. The PIN and
the seed will both be encrypted with the password. The other
application will request the password from the user, then call stoken--stdin, write the password to stoken's standard input through a pipe,
and read back a tokencode from stoken's standard output.
No password; prompt for the PIN
Similar to above, but set an empty password using setpass, do not save
the PIN in ~/.stokenrc, and pass the PIN to stoken--stdin via standard
input.
BUGS/TODO
sdtid support is still new and may choke on unexpected input. As a
short-term workaround you can try commenting out the sanity checks in
sdtid_decrypt() to see if the problem goes away.
Features under development include: 30-second tokens, v3 ctf strings,
hardware token seeds (and the stoken split command needed to work with
them), and support for non-Linux hosts.
Patches are always welcome.
SEE ALSOstoken-gui(1).
FILES
~/.stokenrc
Default configuration file.
AUTHOR
Kevin Cernekee <cernekee@gmail.com>
2012-09-09 stoken(1)
