Changes for page KerberosAndLDAP

Summary

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

Details

Page properties

Content

...	...	@@ -22,10 +22,10 @@
22	22
23	23	===== Load ##kerberos LDAP## schema: =====
24	24
25		-Now you need to load the kerberos schema into the LDAP server on the Synology.
	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	26
27	27	(% style="color:#400" %)
28		-##{{{$ 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}}}##
	28	+##{{{$ zcat /usr/share/doc/krb5-kdc-ldap/kerberos.openldap.ldif.gz | ldapadd -H ldaps://nas.example.com/ -D cn=config -W}}}##
29	29	##{{{Enter LDAP Password:}}}##
30	30	##{{{adding new entry "cn=kerberos,cn=schema,cn=config"}}}##
31	31	##{{{$}}}##
...	...	@@ -33,10 +33,10 @@
33	33
34	34	===== Create Index on krbPrincipalName: =====
35	35
36		-Having an index on the ##krbPrincipalName## improves performance and also suppresses some log messages if ##slapd## is configured to log more than default for the database(s) where you intend to store Kerberos data. As this is OpenLDAP on the Synology, it does not use ##mdb## format, it uses ##bdb##. If you install ##slapd## on Debian, it uses ##mdb## format. It is different database format, but the principle is the same.
	36	+Having an index on the ##krbPrincipalName## improves performance and also suppresses some log messages if ##slapd## is configured to log more than default for the database(s) where you intend to store Kerberos data. As this is OpenLDAP on the Synology, it does not use ##mdb## format, it uses ##bdb##. If you install ##slapd## on Debian, it uses ##mdb## format. It is different database format, but the principle is the same. Again, as you are modifying config, the DN is ##cn=config##. Interestingly, it is still the main password you set for the Synology LDAP server.
37	37
38	38	(% style="color:#400" %)
39		-##{{{$ ldapmodify -H ldap://nas.example.com/ -D uid=root,cn=users,dc=example,dc=com -W <<EOF}}}##
	39	+##{{{$ ldapmodify -H ldaps://nas.example.com/ -D cn=config -W <<EOF}}}##
40	40	##{{{dn: olcDatabase={1}bdb,cn=config}}}##
41	41	##{{{add: olcDbIndex}}}##
42	42	##{{{olcDbIndex: krbPrincipalName eq,pres,sub}}}##
...	...	@@ -48,7 +48,7 @@
48	48
49	49	===== Create principals kadmin and kdc: =====
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##.
	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}##.
52	52
53	53	(% style="color:#400" %)
54	54	##{{{$ ldapadd -H ldap://nas.example.com/ -D uid=root,cn=users,dc=example,dc=com -W <<EOF}}}##
...	...	@@ -56,47 +56,43 @@
56	56	##{{{objectClass: organizationalUnit}}}##
57	57	##{{{objectClass: top}}}##
58	58	##{{{ou: kerberos}}}##
59		-## ##
60		-##{{{dn: uid=kdc,ou=kerberos,dc=example,dc=com}}}##
61		-##{{{uid: kdc}}}##
62		-##{{{objectClass: account}}}##
63		-##{{{objectClass: simpleSecurityObject}}}##
64		-##{{{userPassword: {CRYPT}x}}}##
	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>}}}##
65	65	##{{{description: Kerberos KDC Account}}}##
66		-## ##
67		-##{{{dn: uid=kadmin,ou=kerberos,dc=example,dc=com}}}##
68		-##{{{uid: kadmin}}}##
69		-##{{{objectClass: account}}}##
70		-##{{{objectClass: simpleSecurityObject}}}##
71		-##{{{userPassword: {CRYPT}x}}}##
72		-##{{{description: Kerberos Admin Server Account}}}##
73		-##{{{EOF}}}##
74		-##{{{Enter LDAP Password:}}}##
75		-## ##
76		-##{{{adding new entry "ou=kerberos,dc=example,dc=com"}}}##
77		-## ##
78		-##{{{adding new entry "uid=kdc,ou=kerberos,dc=example,dc=com"}}}##
79		-## ##
80		-##{{{adding new entry "uid=kadmin,ou=kerberos,dc=example,dc=com"}}}##
81	81
82		-
83		-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:
84		-
85	85	(% style="color:#400" %)
86		-##{{{dn: cn=kadmin,ou=kerberos,ou=Services,dc=example,dc=com}}}##
87		-##{{{sn: kadmin}}}##
	74	+##{{{dn: cn=kadmin,ou=kerberos,dc=example,dc=com}}}##
88	88	##{{{cn: kadmin}}}##
	76	+##{{{sn: kadmin}}}##
89	89	##{{{objectClass: person}}}##
90	90	##{{{objectClass: pwdPolicy}}}##
91	91	##{{{pwdAttribute: userPassword}}}##
92	92	##{{{pwdMinLength: 8}}}##
93	93	##{{{pwdCheckQuality: 2}}}##
94		-##{{{pwdPolicySubentry: cn=kadmin,ou=kerberos,ou=Services,dc=example,dc=com}}}##
95		-##{{{userPassword: {SSHA}<hashed password>}}}##
96		-##{{{description: Kerberos Admin Server Account}}}##
	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:}}}##
97	97
98		-and that seems to have worked out fine as my KDC is fully functioning.
	88	+(% style="color:#400" %)
	89	+##{{{adding new entry "ou=kerberos,dc=example,dc=com"}}}##
99	99
100		-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.
	91	+(% style="color:#400" %)
	92	+##{{{adding new entry "cn=kdc,ou=kerberos,dc=example,dc=com"}}}##
101	101
102		-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.
	94	+(% style="color:#400" %)
	95	+##{{{adding new entry "cn=kadmin,ou=kerberos,dc=example,dc=com"}}}##
	96	+
	97	+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.
	98	+