Changes for page KerberosAndLDAP

Summary

• Page properties (1 modified, 0 added, 0 removed)

Details

Page properties

Content

...	...	@@ -1,132 +3,72 @@
1		-{{toc/}}
2		-
3	3	= Debian =
4	4
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.
	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.
6	6
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	+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:
8	8
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.
10		-
11		-**The guide is for illustration. Expectation is that you do not follow it verbatim but adapt it to your needs.**
12		-
13		-
14		-===== Install packages: =====
15		-
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.
18		-
19		-(% style="color:#400" %)
20	20	##{{{$ sudo apt install krb5-kdc-ldap krb5-admin-server schema2ldif}}}##
21	21
22	22
23		-===== Load ##kerberos LDAP## schema: =====
	10	+Then load the ##kerberos## schema:
24	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.
	12	+##{{{$ 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 Password: adding new entry "cn=kerberos,cn=schema,cn=config" $}}}##
26	26
27		-(% style="color:#400" %)
28		-##{{{$ 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:}}}##
30		-##{{{adding new entry "cn=kerberos,cn=schema,cn=config"}}}##
31		-##{{{$}}}##
32	32
33	33
34		-===== Create Index on krbPrincipalName: =====
	16	+And add an index on the ##krbPrincipalName## (improves performance and also suppresses some log messages if ##slapd## is configured to log more than default) for the database(s) where you intend to store Kerberos data:
35	35
36		-Having an index on the ##krbPrincipalName## improves performance and also suppresses some log messages if ##slapd## is configured to log more than default for the database(s) where you intend to store Kerberos data. As this is OpenLDAP on the Synology, it does not use ##mdb## format, it uses ##bdb##. If you install ##slapd## on Debian, it uses ##mdb## format. It is different database format, but the principle is the same. Again, as you are modifying config, the DN is ##cn=config##. Interestingly, it is still the main password you set for the Synology LDAP server.
	18	+{{{# ldapmodify -H ldap:~/~/nas.fqhn <<EOF
37	37
38		-(% style="color:#400" %)
39		-##{{{$ 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"}}}##
46		-##{{{$}}}##
	20	+dn: olcDatabase={1}bdb,cn=config
47	47
	22	+add: olcDbIndex
48	48
49		-===== Create principals kadmin and kdc: =====
	24	+olcDbIndex: krbPrincipalName eq,pres,sub
50	50
51		-Next, you create and configure two entries which will be used by the Kerberos servers to connect to OpenLDAP. As you will not run the Kerberos KDC and Admin Server on the same host as OpenLDAP, these steps are required. In order to keep things nicely separated, everything will be created under a separate ##organizationalUnit##. I diverge from the official Debian guide here as I do not agree with the DN they use. I also had to make changes to the DNs of ##kdc## and ##kadmin## due to ##pwdPolicy## applied by Synology to their LDAP server. The official guide will have you use placeholder passwords and that does not work with the Synology LDAP server. You need to generate them upfront with ##slappasswd -h {SSHA}##.
	26	+EOF
52	52
53		-(% style="color:#400" %)
54		-##{{{$ 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}}}##
	28	+modifying entry "olcDatabase={1}bdb,cn=config"
59	59
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}}}##
	30	+}}}
72	72
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	87
88		-(% style="color:#400" %)
89		-##{{{adding new entry "ou=kerberos,dc=example,dc=com"}}}##
	33	+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:
90	90
91		-(% style="color:#400" %)
92		-##{{{adding new entry "cn=kdc,ou=kerberos,dc=example,dc=com"}}}##
93	93
94		-(% style="color:#400" %)
95		-##{{{adding new entry "cn=kadmin,ou=kerberos,dc=example,dc=com"}}}##
	36	+{{{# ldapadd -x -D cn=admin,dc=example,dc=com -W <<EOF
	37	+dn: ou=Services,dc=example,dc=com
	38	+objectClass: organizationalUnit
	39	+objectClass: top
	40	+ou: Services
96	96
	42	+dn: ou=kerberos,ou=Services,dc=example,dc=com
	43	+objectClass: organizationalUnit
	44	+objectClass: top
	45	+ou: kerberos
97	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.
	47	+dn: uid=kdc,ou=kerberos,ou=Services,dc=example,dc=com
	48	+uid: kdc
	49	+objectClass: account
	50	+objectClass: simpleSecurityObject
	51	+userPassword: {CRYPT}x
	52	+description: Kerberos KDC Account
99	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		-
	54	+dn: uid=kadmin,ou=kerberos,ou=Services,dc=example,dc=com
	55	+uid: kadmin
	56	+objectClass: account
	57	+objectClass: simpleSecurityObject
	58	+userPassword: {CRYPT}x
	59	+description: Kerberos Admin Server Account
122	122	EOF
	61	+Enter LDAP Password: SECRET
123	123
124		-Enter LDAP Password:
125		-modifying entry "olcDatabase={1}bdb,cn=config"
	63	+adding new entry "ou=Services,dc=example,dc=com"
126	126
127		-$
	65	+adding new entry "ou=kerberos,ou=Services,dc=example,dc=com"
128	128
	67	+adding new entry "uid=kdc,ou=kerberos,ou=Services,dc=example,dc=com"
129	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.
	69	+adding new entry "uid=kadmin,ou=kerberos,ou=Services,dc=example,dc=com"}}}
131	131
	71	+
132	132