Argon2 OpenLDAP support
----------------------

pw-argon2.c provides support for ARGON2 hashed passwords in OpenLDAP. For
instance, one could have the LDAP attribute:

userPassword: {ARGON2}$argon2i$v=19$m=4096,t=3,p=1$c2FsdHNhbHQ$DKlexoEJUoZTmkAAC3SaMWk30El9/RvVhlqGo6afIng

or:

userPassword: {ARGON2}$argon2i$v=19$m=4096,t=3,p=1$c2FsdHNhbHRzYWx0$qOCkx9nMeFlaGOO4DUmPDgrlUbgMMuO9T1+vQCFuyzw

Both hash the password "secret", the first using the salt "saltsalt", the second using the salt "saltsaltsalt"

Building
--------

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

For initial testing you might also want to edit DEFS to define
SLAPD_ARGON2_DEBUG, which enables logging to stderr (don't leave this on
in production, as it prints passwords in cleartext).

2) Run 'make' to produce pw-argon2.so

3) Copy pw-argon2.so somewhere permanent.

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

moduleload ...path/to/pw-argon2.so

5) Restart slapd.


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

The {ARGON2} password scheme should now be recognised.

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

password-hash	{ARGON2}


Testing
-------

A quick way to test whether it's working is to customize the rootdn and
rootpw in slapd.conf, eg:

rootdn          "cn=admin,dc=example,dc=com"

# This hashes the string 'secret', with a random salt
rootpw          {ARGON2}$argon2i$v=19$m=4096,t=3,p=1$uJyf0UfB25SQTfX7oCyK2w$U45DJqEFwD0yFaLvTVyACHLvGMwzNGf19dvzPR8XvGc


Then to test, run something like:

ldapsearch -b "dc=example,dc=com" -D "cn=admin,dc=example,dc=com" -x -w secret


-- Test hashes:

Test hashes can be generated with argon2:
$ echo -n "secret" | argon2 "saltsalt" -e
$argon2i$v=19$m=4096,t=3,p=1$c2FsdHNhbHQ$DKlexoEJUoZTmkAAC3SaMWk30El9/RvVhlqGo6afIng

$ echo -n "secret" | argon2 "saltsaltsalt" -e
$argon2i$v=19$m=4096,t=3,p=1$c2FsdHNhbHRzYWx0$qOCkx9nMeFlaGOO4DUmPDgrlUbgMMuO9T1+vQCFuyzw

$ echo -n "secretsecret" | argon2 "saltsalt" -e
$argon2i$v=19$m=4096,t=3,p=1$c2FsdHNhbHQ$U0Pd/wEsssZ9bHezDA8oxHnWe01xftykEy+7ehM2vic

$ echo -n "secretsecret" | argon2 "saltsaltsalt" -e
$argon2i$v=19$m=4096,t=3,p=1$c2FsdHNhbHRzYWx0$fkvoOwKgVtlX9ZDqcHFyyArBvqnAM0Igca8SScB4Jsc



Alternatively we could modify an existing user's password with
ldappasswd, and then test binding as that user:

$ ldappasswd -D "cn=admin,dc=example,dc=com" -x -W -S uid=jturner,ou=People,dc=example,dc=com
New password: secret
Re-enter new password: secret
Enter LDAP Password: <cn=admin's password>

$ ldapsearch -b "dc=example,dc=com" -D "uid=jturner,ou=People,dc=example,dc=com" -x -w secret



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Copyright 2017-2021 The OpenLDAP Foundation.
All rights reserved.

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

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