Changes for page KerberosAndLDAP

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1	1	= Debian =
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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
5		-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:
	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.
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7		-{{{# apt install krb5-kdc-ldap krb5-admin-server schema2ldif}}}
	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.
8	8
9		-Then load the ##kerberos## schema:
	11	+**The guide is for illustration. Expectation is that you do not follow it verbatim but adapt it to your needs.**
10	10
11	11
12		-{{{# zcat /usr/share/doc/krb5-kdc-ldap/kerberos.openldap.ldif.gz | ldapadd -Q -Y EXTERNAL -H ldapi:///
13		-adding new entry "cn=kerberos,cn=schema,cn=config"}}}
	14	+===== Install packages: =====
14	14
15		-And add 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:
	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.
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	19	+(% style="color:#400" %)
	20	+##{{{$ sudo apt install krb5-kdc-ldap krb5-admin-server schema2ldif}}}##
17	17
18		-{{{# ldapmodify -Q -Y EXTERNAL -H ldapi:/// <<EOF
19		-dn: olcDatabase={1}mdb,cn=config
20		-add: olcDbIndex
21		-olcDbIndex: krbPrincipalName eq,pres,sub
22		-EOF
23	23
24		-modifying entry "olcDatabase={1}mdb,cn=config"}}}
	23	+===== Load ##kerberos LDAP## schema: =====
25	25
26		-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:
	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.
27	27
	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:}}}##
	30	+##{{{adding new entry "cn=kerberos,cn=schema,cn=config"}}}##
	31	+##{{{$}}}##
28	28
29		-{{{# ldapadd -x -D cn=admin,dc=example,dc=com -W <<EOF
30		-dn: ou=Services,dc=example,dc=com
31		-objectClass: organizationalUnit
32		-objectClass: top
33		-ou: Services
34	34
35		-dn: ou=kerberos,ou=Services,dc=example,dc=com
36		-objectClass: organizationalUnit
37		-objectClass: top
38		-ou: kerberos
	34	+===== Create Index on krbPrincipalName: =====
39	39
40		-dn: uid=kdc,ou=kerberos,ou=Services,dc=example,dc=com
41		-uid: kdc
42		-objectClass: account
43		-objectClass: simpleSecurityObject
44		-userPassword: {CRYPT}x
45		-description: Kerberos KDC Account
	36	+Having an index on the ##krbPrincipalName## improves performance and also suppresses some log messages if ##slapd## is configured to log more than default for the database(s) where you intend to store Kerberos data. As this is OpenLDAP on the Synology, it does not use ##mdb## format, it uses ##bdb##. If you install ##slapd## on Debian, it uses ##mdb## format. It is different database format, but the principle is the same. Again, as you are modifying config, the DN is ##cn=config##. Interestingly, it is still the main password you set for the Synology LDAP server.
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47		-dn: uid=kadmin,ou=kerberos,ou=Services,dc=example,dc=com
48		-uid: kadmin
49		-objectClass: account
50		-objectClass: simpleSecurityObject
51		-userPassword: {CRYPT}x
52		-description: Kerberos Admin Server Account
53		-EOF
54		-Enter LDAP Password: SECRET
	38	+(% style="color:#400" %)
	39	+##{{{$ 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"}}}##
	46	+##{{{$}}}##
55	55
56		-adding new entry "ou=Services,dc=example,dc=com"
57	57
58		-adding new entry "ou=kerberos,ou=Services,dc=example,dc=com"
	49	+===== Create principals kadmin and kdc: =====
59	59
60		-adding new entry "uid=kdc,ou=kerberos,ou=Services,dc=example,dc=com"
	51	+Next, you create and configure two entries which will be used by the Kerberos servers to connect to OpenLDAP. As you will not run the Kerberos KDC and Admin Server on the same host as OpenLDAP, these steps are required. In order to keep things nicely separated, everything will be created under a separate ##organizationalUnit##. I diverge from the official Debian guide here as I do not agree with the DN they use. I also had to make changes to the DNs of ##kdc## and ##kadmin## due to ##pwdPolicy## applied by Synology to their LDAP server. The official guide will have you use placeholder passwords and that does not work with the Synology LDAP server. You need to generate them upfront with ##slappasswd -h {SSHA}##.
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62		-adding new entry "uid=kadmin,ou=kerberos,ou=Services,dc=example,dc=com"}}}
	53	+(% style="color:#400" %)
	54	+##{{{$ 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}}}##
63	63
	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}}}##
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	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:}}}##
	87	+
	88	+(% style="color:#400" %)
	89	+##{{{adding new entry "ou=kerberos,dc=example,dc=com"}}}##
	90	+
	91	+(% style="color:#400" %)
	92	+##{{{adding new entry "cn=kdc,ou=kerberos,dc=example,dc=com"}}}##
	93	+
	94	+(% style="color:#400" %)
	95	+##{{{adding new entry "cn=kadmin,ou=kerberos,dc=example,dc=com"}}}##
	96	+
	97	+
	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.
	99	+
	100	+
	101	+===== Grant kdc and kadmin permissions: =====
	102	+
	103	+This switches back to the ##cn=config## DN as you are changing the permissions.
	104	+
	105	+$ ldapmodify -H ldaps:~/~/ds723.trudheim.com -W -D cn=config <<EOF
	106	+
	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
	121	+
	122	+EOF
	123	+
	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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