Changes for page KerberosAndLDAP

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1	1	= Debian =
2	2
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	+The guide I followed was 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 from the upstream Debian Guide.
4	4
	7	+Assumption is 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. It is also assumed 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.
5	5
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	+Recommendation is 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.
7	7
8		-##{{{$ sudo apt install krb5-kdc-ldap krb5-admin-server schema2ldif}}}##
	11	+**The guide is for illustration. Expectation is that you do not follow it verbatim but adapt it to your needs.**
9	9
10	10
11		-Then load the ##kerberos## schema:
	14	+===== Install packages: =====
12	12
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}}}##
	16	+(% class="wikigeneratedid" %)
	17	+The packages you need are [[krb5-kdc-ldap>>url:https://packages.debian.org/krb5-kdc-ldap]], [[krb5-admin-server>>url:https://packages.debian.org/krb5-admin-server]] for the actual KDC and [[schema2ldif>>url:https://packages.debian.org/schema2ldif]]  plus [[slapd>>https://packages.debian.org/search?keywords=slapd]] for adding the schema and ##slappasswd##. They are to be installed on your designated Debian host.
14	14
15		-##{{{Password:}}}##
	19	+(% style="color:#400" %)
	20	+##{{{$ sudo apt install krb5-kdc-ldap krb5-admin-server schema2ldif}}}##
16	16
	22	+
	23	+===== Load ##kerberos LDAP## schema: =====
	24	+
	25	+Now you need to load the kerberos schema into the LDAP server on the Synology. And here you need to use the ##cn=config## DN.
	26	+
	27	+(% style="color:#400" %)
	28	+##{{{$ zcat /usr/share/doc/krb5-kdc-ldap/kerberos.openldap.ldif.gz | ldapadd -H ldaps://nas.example.com/ -D cn=config -W}}}##
	29	+##{{{Enter LDAP Password:}}}##
17	17	##{{{adding new entry "cn=kerberos,cn=schema,cn=config"}}}##
	31	+##{{{$}}}##
18	18
	33	+
	34	+===== Create Index on krbPrincipalName: =====
	35	+
	36	+Having an index on the ##krbPrincipalName## improves performance and also suppresses some log messages if ##slapd## is configured to log more than default for the database(s) where you intend to store Kerberos data. As this is OpenLDAP on the Synology, it does not use ##mdb## format, it uses ##bdb##. If you install ##slapd## on Debian, it uses ##mdb## format. It is different database format, but the principle is the same. Again, as you are modifying config, the DN is ##cn=config##. Interestingly, it is still the main password you set for the Synology LDAP server.
	37	+
	38	+(% style="color:#400" %)
	39	+##{{{$ ldapmodify -H ldaps://nas.example.com/ -D cn=config -W <<EOF}}}##
	40	+##{{{dn: olcDatabase={1}bdb,cn=config}}}##
	41	+##{{{add: olcDbIndex}}}##
	42	+##{{{olcDbIndex: krbPrincipalName eq,pres,sub}}}##
	43	+##{{{EOF}}}##
	44	+##{{{Enter LDAP Password:}}}##
	45	+##{{{modifying entry "olcDatabase={1}bdb,cn=config"}}}##
19	19	##{{{$}}}##
20	20
21	21
22		-Having an index on the ##krbPrincipalName## improves performance and also suppresses some log messages if ##slapd## is configured to log more than default for the database(s) where you intend to store Kerberos data. As this is OpenLDAP on the Synology, it does not use mdb format, it uses bdb:
	49	+===== Create principals kadmin and kdc: =====
23	23
24		-##{{{$ 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:
	51	+Next, you 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##. I diverge from the official Debian guide here as I do not agree with the DN they use. I also had to make changes to the DNs of ##kdc## and ##kadmin## due to ##pwdPolicy## applied by Synology to their LDAP server. The official guide will have you use placeholder passwords and that does not work with the Synology LDAP server. You need to generate them upfront with ##slappasswd -h {SSHA}##.
30	30
31		-modifying entry "olcDatabase={1}bdb,cn=config"
32		-$
33		-}}}##
	53	+(% style="color:#400" %)
	54	+##{{{$ ldapadd -H ldap://nas.example.com/ -D uid=root,cn=users,dc=example,dc=com -W <<EOF}}}##
	55	+##{{{dn: ou=kerberos,dc=example,dc=com}}}##
	56	+##{{{objectClass: organizationalUnit}}}##
	57	+##{{{objectClass: top}}}##
	58	+##{{{ou: kerberos}}}##
34	34
	60	+(% style="color:#400" %)
	61	+##{{{dn: cn=kdc,ou=kerberos,dc=example,dc=com}}}##
	62	+##{{{cn: kdc}}}##
	63	+##{{{sn: kdc}}}##
	64	+##{{{objectClass: person}}}##
	65	+##{{{objectClass: pwdPolicy}}}##
	66	+##{{{pwdAttribute: userPassword}}}##
	67	+##{{{pwdMinLength: 8}}}##
	68	+##{{{pwdCheckQuality: 2}}}##
	69	+##{{{pwdPolicySubentry: cn=kdc,ou=kerberos,dc=example,dc=com}}}##
	70	+##{{{userPassword: {SSHA}<password-hash>}}}##
	71	+##{{{description: Kerberos KDC Account}}}##
35	35
	73	+(% style="color:#400" %)
	74	+##{{{dn: cn=kadmin,ou=kerberos,dc=example,dc=com}}}##
	75	+##{{{cn: kadmin}}}##
	76	+##{{{sn: kadmin}}}##
	77	+##{{{objectClass: person}}}##
	78	+##{{{objectClass: pwdPolicy}}}##
	79	+##{{{pwdAttribute: userPassword}}}##
	80	+##{{{pwdMinLength: 8}}}##
	81	+##{{{pwdCheckQuality: 2}}}##
	82	+##{{{pwdPolicySubentry: cn=kadmin,ou=kerberos,dc=example,dc=com}}}##
	83	+##{{{userPassword: {SSHA}<password-hash>}}}##
	84	+##{{{description: Kerberos KDC Account}}}##
	85	+##{{{EOF}}}##
	86	+##{{{Enter LDAP Password:}}}##
36	36
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:
	88	+(% style="color:#400" %)
	89	+##{{{adding new entry "ou=kerberos,dc=example,dc=com"}}}##
38	38
	91	+(% style="color:#400" %)
	92	+##{{{adding new entry "cn=kdc,ou=kerberos,dc=example,dc=com"}}}##
39	39
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
	94	+(% style="color:#400" %)
	95	+##{{{adding new entry "cn=kadmin,ou=kerberos,dc=example,dc=com"}}}##
45	45
46		-dn: ou=kerberos,ou=Services,dc=example,dc=com
47		-objectClass: organizationalUnit
48		-objectClass: top
49		-ou: kerberos
50	50
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	+Synology LDAP server did not like adding users with placeholder passwords, because Synology puts in place password policies. Hence changing this to a ##cn## instead of a ##uid##. It seems to have worked out fine as my KDC is fully functioning.
57	57
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
66	66
67		-adding new entry "ou=Services,dc=example,dc=com"
	101	+===== Grant kdc and kadmin permissions: =====
68	68
69		-adding new entry "ou=kerberos,ou=Services,dc=example,dc=com"
	103	+This switches back to the ##cn=config## DN as you are changing the permissions.
70	70
71		-adding new entry "uid=kdc,ou=kerberos,ou=Services,dc=example,dc=com"
	105	+$ ldapmodify -H ldaps:~/~/ds723.trudheim.com -W -D cn=config <<EOF
72	72
73		-adding new entry "uid=kadmin,ou=kerberos,ou=Services,dc=example,dc=com"}}}
	107	+dn: olcDatabase={1}bdb,cn=config
	108	+add: olcAccess
	109	+olcAccess: {0}to attrs=krbPrincipalKey
	110	+ by anonymous auth
	111	+ by dn.exact="cn=kdc,ou=kerberos,dc=trudheim,dc=com" write
	112	+ by dn.exact="cn=kadmin,ou=kerberos,dc=trudheim,dc=com" write
	113	+ by self write
	114	+ by * none
	115	+-
	116	+add: olcAccess
	117	+olcAccess: {1}to dn.subtree="cn=krbContainer,ou=kerberos,dc=example,dc=com"
	118	+ by dn.exact="cn=kdc,ou=kerberos,dc=trudheim,dc=com" write
	119	+ by dn.exact="cn=kadmin,ou=kerberos,dc=trudheim,dc=com" write
	120	+ by * none
74	74
	122	+EOF
75	75
	124	+Enter LDAP Password:
	125	+modifying entry "olcDatabase={1}bdb,cn=config"
	126	+
	127	+$
	128	+
	129	+
	130	+Note that we now reference our kdc and kadmin accounts and we grant them permission to the krbContainer which will house all our kerberos principals. Give both of them write access, because we do want to have the ability to track last login and lock accounts if there are login failures. We like security.
	131	+
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