TOTP OpenLDAP support
----------------------

slapd-totp.c provides support for RFC 6238 TOTP Time-based One
Time Passwords in OpenLDAP using SHA-1, SHA-256, and SHA-512.
For instance, one could have the LDAP attribute:

userPassword: {TOTP1}GEZDGNBVGY3TQOJQGEZDGNBVGY3TQOJQ

which encodes the key '12345678901234567890'.

It can also encode credentials consisting of a TOTP and a static
password.  The format for this is:

userPassword: {TOTP1ANDPW}GEZDGNBVGY3TQOJQGEZDGNBVGY3TQOJQ|<some_other_passwd>

where <some_other_passwd> can be any scheme currently understood
by OpenLDAP.  For example, using '{SHA}5en6G6MezRroT3XKqkdPOmY/BfQ='
would encode the above TOTP with a static password of 'secret'.  To
authenticate using this scheme, enter the static password immediately
followed by the TOTP, for example 'secret123456'.


Building
--------

1) Customize the LDAP_SRC variable in Makefile to point to the OpenLDAP
source root.

2) Run 'make' to produce slapd-totp.so

3) Copy slapd-totp.so somewhere permanent.

4) Edit your slapd.conf (eg. /etc/ldap/slapd.conf), and add:

moduleload ...path/to/slapd-totp.so

5) This module replaces the function of the slapo-lastbind overlay. You
cannot use that overlay on the same database as this one.

6) Restart slapd.


Configuring
-----------

The {TOTP1}, {TOTP256}, {TOTP512}, {TOTP1ANDPW}, {TOTP256ANDPW},
and {TOTP512ANDPW} password schemes should now be recognised.

You can also tell OpenLDAP to use one of these new schemes when processing LDAP
Password Modify Extended Operations, thanks to the password-hash option in
slapd.conf. For example:

password-hash	{TOTP1}

TOTP password schemes will only work on databases that have a rootdn and the
totp overlay configured:

database mdb
rootdn "..."
...

overlay totp



Testing
-------

The TOTP1 algorithm is compatible with Google Authenticator.

---

This work is part of OpenLDAP Software <http://www.openldap.org/>.

Copyright 2015-2021 The OpenLDAP Foundation.
Portions Copyright 2015 by Howard Chu, Symas Corp.
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted only as authorized by the OpenLDAP
Public License.

A copy of this license is available in the file LICENSE in the
top-level directory of the distribution or, alternatively, at
<http://www.OpenLDAP.org/license.html>.

