Changes for page KerberosAndLDAP

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1		-{{toc/}}
2		-
3	3	= Debian =
4	4
	3	+The guide I followed was [[https:~~/~~/wiki.debian.org/LDAP/OpenLDAPSetup#Kerberos>>https://wiki.debian.org/LDAP/OpenLDAPSetup#Kerberos]] which while it worked required some minor tweaks. I obtained edit privileges for the Debian Wiki and updated the guide with the fixes that I found. I however have a Synology NAS and that can run an LDAP Server. So this guide differs a little from the upstream Debian Guide.
5	5
6		-The guide I followed was https://wiki.debian.org/LDAP/OpenLDAPSetup#Kerberos[[https://wiki.debian.org/LDAP/OpenLDAPSetup#Kerberos]] which while it worked required some minor tweaks. I obtained edit privileges for the Debian Wiki and updated the guide with the fixes that I found. I however have a Synology NAS and that can run an LDAP Server. So this guide differs a little from the upstream Debian Guide.
7	7
8		-I will assume that you have installed the LDAP Server package on your NAS and gone through initial configuration steps, so it has a domain, there is a DN you can bind as and so forth. The Synology NAS can be leveraged for a multitude of things, and running DNS, DHCP, WebServices and Containers are but a few. I will also assume you have a Debian system (12.5 or later, though this guide should work with 11.x and likely 10.x as well) that will become your KDC and KAdmin server.
	6	+First, install the packages containing the LDAP-enabled Kerberos servers ([[krb5-kdc-ldap>>url:https://packages.debian.org/krb5-kdc-ldap]] and [[krb5-admin-server>>url:https://packages.debian.org/krb5-admin-server]]) and the [[schema2ldif>>url:https://packages.debian.org/schema2ldif]] tool:
9	9
10		-I also recommend that you create actual ~#~#.ldif~#~# files rather than use here-documents as used in this guide. It is far easier to make adjustments to things if you have a file to edit rather than having to type it all out again or paste it and then have to try and make edits to it without making mistakes. The guide is for illustration and expectation is that you do not follow it verbatim but adapt it to your needs.
	8	+##{{{$ sudo apt install krb5-kdc-ldap krb5-admin-server schema2ldif}}}##
11	11
12	12
13		-===== Install the packages containing the LDAP-enabled Kerberos servers ([[krb5-kdc-ldap>>url:https://packages.debian.org/krb5-kdc-ldap]] and [[krb5-admin-server>>url:https://packages.debian.org/krb5-admin-server]]) and the [[schema2ldif>>url:https://packages.debian.org/schema2ldif]] tool on your Debian host: =====
	11	+Then load the ##kerberos## schema:
14	14
15		-(% style="color:#400" %)
16		-##{{{$ sudo apt install krb5-kdc-ldap krb5-admin-server schema2ldif}}}##
	13	+##{{{$ zcat /usr/share/doc/krb5-kdc-ldap/kerberos.openldap.ldif.gz | ldapadd -H ldap:~/~/nas.fqdn/ -D uid=root,cn=users,dc=example,dc=com}}}##
17	17
	15	+##{{{Password:}}}##
18	18
19		-===== Load the ##kerberos## schema into the LDAP server on your Synology: =====
20		-
21		-(% style="color:#400" %)
22		-##{{{$ zcat /usr/share/doc/krb5-kdc-ldap/kerberos.openldap.ldif.gz | ldapadd -H ldap://nas.example.com/ -D uid=root,cn=users,dc=example,dc=com -W}}}##
23		-##{{{Enter LDAP Password:}}}##
24	24	##{{{adding new entry "cn=kerberos,cn=schema,cn=config"}}}##
	18	+
25	25	##{{{$}}}##
26	26
27	27
28		-===== Create Index on krbPrincipalName: =====
	22	+Having an index on the ##krbPrincipalName## improves performance and also suppresses some log messages if ##slapd## is configured to log more than default for the database(s) where you intend to store Kerberos data. As this is OpenLDAP on the Synology, it does not use mdb format, it uses bdb:
29	29
30		-Having an index on the ##krbPrincipalName## improves performance and also suppresses some log messages if ##slapd## is configured to log more than default for the database(s) where you intend to store Kerberos data. As this is OpenLDAP on the Synology, it does not use ~#~###mdb~#~### format, it uses ##~#~#bdb~#~###. If you install ~#~#slapd~#~# on Debian, it uses ~#~#mdb~#~# format.
	24	+##{{{$ sudo ldapmodify -H ldap://nas.fqhn <<EOF
	25	+dn: olcDatabase={1}bdb,cn=config
	26	+add: olcDbIndex
	27	+olcDbIndex: krbPrincipalName eq,pres,sub
	28	+EOF
	29	+Password:
31	31
32		-(% style="color:#400" %)
33		-##{{{$ ldapmodify -H ldap://nas.example.com/ -D uid=root,cn=users,dc=example,dc=com -W <<EOF}}}##
34		-##{{{dn: olcDatabase={1}bdb,cn=config}}}##
35		-##{{{add: olcDbIndex}}}##
36		-##{{{olcDbIndex: krbPrincipalName eq,pres,sub}}}##
37		-##{{{EOF}}}##
38		-##{{{Enter LDAP Password:}}}##
39		-##{{{modifying entry "olcDatabase={1}bdb,cn=config"}}}##
40		-##{{{$}}}##
	31	+modifying entry "olcDatabase={1}bdb,cn=config"
	32	+$
	33	+}}}##
41	41
42	42
43		-===== Create the two principals ~#~#kadmin~#~# and ~#~#kdc~#~#: =====
44	44
45		-Next, you need to create and configure two entries which will be used by the Kerberos servers to connect to OpenLDAP. As you will not run the Kerberos KDC and Admin Server on the same host as OpenLDAP, these steps are required. In order to keep things nicely separated, everything will be created under a separate ##organizationalUnit##.
	37	+Next, you need to create and configure two entries which will be used by the Kerberos servers to connect to OpenLDAP. If you are running Kerberos and OpenLDAP on the same system, these steps are optional, but recommended. In order to keep things nicely separated, everything will be created under a separate ##organizationalUnit##. Note that a simple bind (##-x -D##) is used instead of an ##EXTERNAL## bind since write access to the dc=example,dc=com DIT is necessary:
46	46
47		-(% style="color:#400" %)
48		-##{{{$ ldapadd -H ldap://nas.fqdn/ -D uid=root,cn=users,dc=example,dc=com -W <<EOF}}}##
49		-##{{{dn: ou=Services,dc=example,dc=com}}}##
50		-##{{{objectClass: organizationalUnit}}}##
51		-##{{{objectClass: top}}}##
52		-##{{{ou: Services}}}##
53		-## ##
54		-##{{{dn: ou=kerberos,ou=Services,dc=example,dc=com}}}##
55		-##{{{objectClass: organizationalUnit}}}##
56		-##{{{objectClass: top}}}##
57		-##{{{ou: kerberos}}}##
58		-## ##
59		-##{{{dn: uid=kdc,ou=kerberos,ou=Services,dc=example,dc=com}}}##
60		-##{{{uid: kdc}}}##
61		-##{{{objectClass: account}}}##
62		-##{{{objectClass: simpleSecurityObject}}}##
63		-##{{{userPassword: {CRYPT}x}}}##
64		-##{{{description: Kerberos KDC Account}}}##
65		-## ##
66		-##{{{dn: uid=kadmin,ou=kerberos,ou=Services,dc=example,dc=com}}}##
67		-##{{{uid: kadmin}}}##
68		-##{{{objectClass: account}}}##
69		-##{{{objectClass: simpleSecurityObject}}}##
70		-##{{{userPassword: {CRYPT}x}}}##
71		-##{{{description: Kerberos Admin Server Account}}}##
72		-##{{{EOF}}}##
73		-##{{{Enter LDAP Password:}}}##
74		-## ##
75		-##{{{adding new entry "ou=Services,dc=example,dc=com"}}}##
76		-## ##
77		-##{{{adding new entry "ou=kerberos,ou=Services,dc=example,dc=com"}}}##
78		-## ##
79		-##{{{adding new entry "uid=kdc,ou=kerberos,ou=Services,dc=example,dc=com"}}}##
80		-## ##
81		-##{{{adding new entry "uid=kadmin,ou=kerberos,ou=Services,dc=example,dc=com"}}}##
82	82
	40	+{{{# ldapadd -x -D cn=admin,dc=example,dc=com -W <<EOF
	41	+dn: ou=Services,dc=example,dc=com
	42	+objectClass: organizationalUnit
	43	+objectClass: top
	44	+ou: Services
83	83
84		-Now, it was at this point that I had a problem, because the LDAP server on the Synology did not like adding users with placeholder passwords, because Synology puts in place password policies. I ended up working around it using a different construct:
	46	+dn: ou=kerberos,ou=Services,dc=example,dc=com
	47	+objectClass: organizationalUnit
	48	+objectClass: top
	49	+ou: kerberos
85	85
86		-(% style="color:#400" %)
87		-##{{{dn: cn=kadmin,ou=kerberos,ou=Services,dc=example,dc=com}}}##
88		-##{{{sn: kadmin}}}##
89		-##{{{cn: kadmin}}}##
90		-##{{{objectClass: person}}}##
91		-##{{{objectClass: pwdPolicy}}}##
92		-##{{{pwdAttribute: userPassword}}}##
93		-##{{{pwdMinLength: 8}}}##
94		-##{{{pwdCheckQuality: 2}}}##
95		-##{{{pwdPolicySubentry: cn=kadmin,ou=kerberos,ou=Services,dc=example,dc=com}}}##
96		-##{{{userPassword: {SSHA}<hashed password>}}}##
97		-##{{{description: Kerberos Admin Server Account}}}##
	51	+dn: uid=kdc,ou=kerberos,ou=Services,dc=example,dc=com
	52	+uid: kdc
	53	+objectClass: account
	54	+objectClass: simpleSecurityObject
	55	+userPassword: {CRYPT}x
	56	+description: Kerberos KDC Account
98	98
99		-and that seems to have worked out fine as my KDC is fully functioning.
	58	+dn: uid=kadmin,ou=kerberos,ou=Services,dc=example,dc=com
	59	+uid: kadmin
	60	+objectClass: account
	61	+objectClass: simpleSecurityObject
	62	+userPassword: {CRYPT}x
	63	+description: Kerberos Admin Server Account
	64	+EOF
	65	+Enter LDAP Password: SECRET
100	100
101		-It required modifying the rest of the guide with the fact that it no longer was ##uid=kadmin## and ##uid=kdc##, but rather ##cn=kadmin## and ##cn=kdc##. The most important thing is that it works. As an aside, I am not sure it is required to have two nested Organisation Units, ##Services## and ##kerberos## - so I will likely re-deploy and get rid of the ##Services## Organisational Unit altogether. It shortens the DN's used for binds to LDAP and limits the risk for typos. I also find it highly unlikely that deploying this in a real organisation that there would be an existing Organisational Unit called '##kerberos##' while the risk for there being an existing department called '##Services##' is much more likely.
	67	+adding new entry "ou=Services,dc=example,dc=com"
102	102
103		-A note on the above workaround. In order to add a password policy on ##kadmin## and ##kdc## in LDAP, they have to have an attribute that is "physical". And when adding that object class the entries could no longer be a ##uid##. Hence the ##sn## and ##cn## parts. I spent a fair time looking things up as whenever I thought I made progress, something else turned out to be a blocker. When you create the ##{SSHA}## password hash, use ##slappasswd## from the ##slapd## package.
	69	+adding new entry "ou=kerberos,ou=Services,dc=example,dc=com"
	70	+
	71	+adding new entry "uid=kdc,ou=kerberos,ou=Services,dc=example,dc=com"
	72	+
	73	+adding new entry "uid=kadmin,ou=kerberos,ou=Services,dc=example,dc=com"}}}
	74	+
	75	+
	76	+