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srptool(1) User Commands srptool(1)


srptool - GnuTLS SRP tool


srptool [ -flags] [ -flag [value]] [ --option-name[[=| ] value]]
All arguments must be options.


Simple program that emulates the programs in the Stanford SRP (Secure Remote Password) libraries using GnuTLS. It is intended for use in places where you don't expect SRP authentication to be the used for system users.
In brief, to use SRP you need to create two files. These are the password file that holds the users and the verifiers associated with them and the configuration file to hold the group parameters (called tpasswd.conf).


-d number, --debug=number
Enable debugging. This option takes an integer number as its argument. The value of number is constrained to being:
in the range  0 through 9999

Specifies the debug level.
-i number, --index=number
specify the index of the group parameters in tpasswd.conf to use. This option takes an integer number as its argument. The default number for this option is:
-u string, --username=string
specify a username.
-p string, --passwd=string
specify a password file.
-s number, --salt=number
specify salt size. This option takes an integer number as its argument.
just verify the password..
Verifies the password provided against the password file.
-v string, --passwd-conf=string
specify a password conf file..
Specify a filename or a PKCS #11 URL to read the CAs from.
Generate a password configuration file..
This generates a password configuration file (tpasswd.conf) containing the required for TLS parameters.
-h, --help
Display usage information and exit.
-!, --more-help
Pass the extended usage information through a pager.
-v [{v|c|n --version [{v|c|n}]}]
Output version of program and exit. The default mode is `v', a simple version. The `c' mode will print copyright information and `n' will print the full copyright notice.


To create tpasswd.conf which holds the g and n values for SRP protocol (generator and a large prime), run:

$ srptool --create-conf /etc/tpasswd.conf

This command will create /etc/tpasswd and will add user 'test' (you will also be prompted for a password). Verifiers are stored by default in the way libsrp expects.

$ srptool --passwd /etc/tpasswd --passwd-conf /etc/tpasswd.conf -u test

This command will check against a password. If the password matches the one in /etc/tpasswd you will get an ok.

$ srptool --passwd /etc/tpasswd --passwd-conf /etc/tpasswd.conf --verify -u test


One of the following exit values will be returned:
Successful program execution.
The operation failed or the command syntax was not valid.
libopts had an internal operational error. Please report it to Thank you.


gnutls-cli-debug (1), gnutls-serv (1), srptool (1), psktool (1), certtool (1)


Nikos Mavrogiannopoulos, Simon Josefsson and others; see /usr/share/doc/gnutls/AUTHORS for a complete list.


Copyright (C) 2000-2017 Free Software Foundation, and others all rights reserved. This program is released under the terms of the GNU General Public License, version 3 or later.


Please send bug reports to:


This manual page was AutoGen-erated from the srptool option definitions.
2018-10-06 3.5.8