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NAMEstoken - software token for cryptographic authenticationSYNOPSISstoken [tokencode] [--stdin] [--force] [--next] [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 | --qr=file.png | --show-qr}] [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 USAGEUse 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:
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. 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
EXPORT OPTIONS
OTHER OPTIONS
SECURITY CONSIDERATIONSSoftware 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. Encoding QR tokens may expose the seed data through ps, and the --show-qr option writes temporary PNG files in /tmp. stoken attempts to lock pages to prevent swapping out to disk, but does not scrub secrets from process memory. NON-INTERACTIVE USEOther 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 PINThe 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 passwordThe 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 PINSimilar 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/TODOsdtid 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: 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
AUTHORKevin Cernekee <cernekee@gmail.com>
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