Provided by: dacs_1.4.40-2_amd64 bug


       dacs_passwd - manage private DACS passwords


       dacs_passwd [dacsoptions[1]]


       This program is part of the DACS suite.

       The dacs_passwd web service is used to manage usernames and passwords recognized by
       local_passwd_authenticate[2], a DACS authentication module. This utility serves a similar
       purpose for local_passwd_authenticate that Apache's htpasswd(1)[3] command does for its
       mod_authn_file[4] and mod_authn_dbm[5] modules. These accounts and passwords are used only
       by local_passwd_authenticate and are completely separate from any other accounts and

           Much of the functionality of this program is also available as a DACS utility,
           dacspasswd(1)[6], which operates on the same password files. Because dacs_admin(8)[7]
           provides the same functionality and more, dacs_passwd may be removed in a future

           This web service enforces several requirements over and above those specified by its
           access control rule. The USERNAME argument must be syntactically valid and lowercase.
           The user must already be authenticated. To change his password, a (non-admin) user
           must enter his current password.

           The default DACS ACL restricts use of this web service to a DACS administrator and to
           users who are setting the password for their own DACS account at the receiving
           jurisdiction. Administrators should ensure that the ACL for dacs_passwd is correct for
           their environment.


   Web Service Arguments
       In addition to the standard CGI arguments[8], dacs_passwd understands the following CGI

           The following operations are supported:

           ·   ADD

               Like SET but add or replace an entry for USERNAME.

           ·   DELETE

               Delete the account for USERNAME.

           ·   DISABLE

               Disable the account for USERNAME.

           ·   ENABLE

               Enable the account for USERNAME.

           ·   LIST

               List USERNAME, if it exists, otherwise all usernames. A disabled account is
               indicated by a '*' (which is not a valid character in a username).

           ·   SET

               Sets or resets a DACS password for USERNAME to NEW_PASSWORD. The
               CONFIRM_NEW_PASSWORD argument must also be given and be identical to NEW_PASSWORD.
               Unless the operation is performed by a DACS administrator (i.e., an
               ADMIN_IDENTITY[9]) or disabled by the PASSWORD_OPS_NEED_PASSWORD[10] directive,
               the current password for USERNAME must be given as PASSWORD.

                   For users other than a DACS administrator, a password must meet certain
                   requirements on its length and the character set from which it is comprised.
                   Note that these requirements are only significant at the time a password is
                   set or changed; existing passwords are unaffected by changes to the
                   configuration directives. Please refer to the PASSWORD_CONSTRAINTS[11]

                   Users should be made aware of security issues related to passwords, including
                   better techniques for selecting passwords and keeping them private.

                   How to choose better passwords
                   Most users can benefit from adopting a method for password selection similar
                   to the one described in this proposal[12]. It suggests that users construct
                   site-specific passwords from three separate components:

                    1. PIN-1, a short, random string that is common to all of the user's
                       passwords, kept secret, and unlikely to be in any dictionary;

                    2. SITE, a string that is derived from a site's name (or domain name) using
                       some simple and easy-to-remember procedure (e.g., using an obvious
                       abbreviation or prefix, or the first four letters or consonents, perhaps
                       mixing upper and lower case); and

                    3. PIN-2, a short, site-specific random string that is different for each of
                       the user's passwords, and not likely to be in any dictionary.

                   PIN-1 is memorized by the user. The other two components may be written down
                   but must be kept in a relatively secure location (such as in the user's wallet
                   or in a locked desk drawer).

                   The user forms passwords by combining these three components in any order that
                   is easy to remember, like:

                       SITE PIN-2 PIN-1

                   Following that ordering, for the site, a user might select the
                   password "exampleRB8s#i8", where "example" (component 2, SITE) is derived from
                   the site's domain name, "RB8s" is a random string used with this password only
                   (component 3, PIN-2), and "#i8" is the user's secret PIN (component 1, PIN-1).
                   Because it is probably difficult to remember, the user might create a note
                   with " RB8s" written on it but not PIN-1.

                   For, the same user might select the password "httpd33ABB#i8".

                   For the site, the user might select the password "dacsceIM#i8".

                   Note that because the characters comprising PIN-1 must be acceptable in all
                   sites' passwords, and some sites accept a rather limited character set for
                   their passwords, it may be necessary to restrict PIN-1 to the alphanumeric
                   alphabet. The other two components can be chosen from whatever password
                   characters are permitted by the particular site. As some sites unfortunately
                   allow only relatively short passwords, it is preferable to shorten SITE rather
                   than either of the other two components.

                   Provided the basic rules are followed, a user can strengthen the method by
                   making minor changes. As a simple example, one or more separating characters,
                   also from a restricted character set, might be added before and after the
                   middle component:

                       SITE Z PIN-2 Z PIN-1

                   In this example, a 'Z' is used as a separating character.

                   Since most people are not very good at it, the random strings should be chosen
                   using a good-quality random generator, such as the random()[13] function:

                       % dacsexpr -e "random(string, 4, 'a-zA-Z0-9,./;@#')"

                   Or, on FreeBSD or macOS:

                       % jot -r -c 20 33 126 | rs -g 0 4

                   In addition to being difficult to guess because of their random components and
                   reasonably large character set, these passwords are different for each site;
                   should one password be compromised, the others are not immediately available
                   to an attacker. Similarly, the written strings cannot be immediately exploited
                   if they are stolen or copied. The strength of the method can be increased by
                   making either or both PIN components longer, chosen from a larger space of
                   characters, or by inserting one or more characters between components.
                   Software is available to help evaluate password strength (e.g., How Big is
                   Your Haystack?[14]), but avoid giving out the actual password you intend to

           Either PASSWD (the default) or SIMPLE, case insensitively, to select between the item
           types passwds and simple, respectively. The requested item type must be configured
           (see dacs.conf(5)[15]).

           The DACS username of interest.

           By default, output is emitted in HTML. Several varieties of XML output can be
           selected, however, using the FORMAT argument (please refer to dacs(1)[16] and


       The program exits 0 if everything was fine, 1 if an error occurred.


       dacspasswd(1)[6], dacs_admin(8)[7], dacs.conf(5)[18]


       Distributed Systems Software ([19])


       Copyright © 2003-2017 Distributed Systems Software. See the LICENSE[20] file that
       accompanies the distribution for licensing information.


        1. dacsoptions

        2. local_passwd_authenticate

        3. htpasswd(1)

        4. mod_authn_file

        5. mod_authn_dbm

        6. dacspasswd(1)

        7. dacs_admin(8)

        8. standard CGI arguments




       12. this proposal

       13. random()

       14. How Big is Your Haystack?

       15. dacs.conf(5)

       16. dacs(1)

       17. dacs_passwd.dtd

       18. dacs.conf(5)


       20. LICENSE