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.
	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.
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:
	5	+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.
6	6
7		-{{{# apt install krb5-kdc-ldap krb5-admin-server schema2ldif}}}
8	8
9		-Then load the ##kerberos## schema:
	8	+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 on your Debian host:
10	10
	10	+(% style="color:red" %)
	11	+##{{{$ sudo apt install krb5-kdc-ldap krb5-admin-server schema2ldif}}}##
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	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:
	14	+Then load the ##kerberos## schema:
16	16
	16	+(% style="color:red" %)
	17	+##{{{$ 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 -W}}}##
	18	+##{{{Enter LDAP Password:}}}##
	19	+##{{{adding new entry "cn=kerberos,cn=schema,cn=config"}}}##
	20	+##{{{$}}}##
17	17
18		-{{{# ldapmodify -Q -Y EXTERNAL -H ldapi:/// <<EOF
19		-dn: olcDatabase={1}mdb,cn=config
20		-add: olcDbIndex
21		-olcDbIndex: krbPrincipalName eq,pres,sub
22		-EOF
23	23
24		-modifying entry "olcDatabase={1}mdb,cn=config"}}}
	23	+Having an index on the ##krbPrincipalName## improves performance and also suppresses some log messages if ##slapd## is configured to log more than default for the database(s) where you intend to store Kerberos data. As this is OpenLDAP on the Synology, it does not use ##mdb## format, it uses ##bdb##:
25	25
26		-Next, you need to create and configure two entries which will be used by the Kerberos servers to connect to OpenLDAP. If you are running Kerberos and OpenLDAP on the same system, these steps are optional, but recommended. In order to keep things nicely separated, everything will be created under a separate ##organizationalUnit##. Note that a simple bind (##-x -D##) is used instead of an ##EXTERNAL## bind since write access to the dc=example,dc=com DIT is necessary:
	25	+(% style="color:red" %)
	26	+##{{{$ ldapmodify -H ldap://nas.fqdn/ -D uid=root,cn=users,dc=example,dc=com -W <<EOF}}}##
	27	+##{{{dn: olcDatabase={1}bdb,cn=config}}}##
	28	+##{{{add: olcDbIndex}}}##
	29	+##{{{olcDbIndex: krbPrincipalName eq,pres,sub}}}##
	30	+##{{{EOF}}}##
	31	+##{{{Enter LDAP Password:}}}##
	32	+##{{{modifying entry "olcDatabase={1}bdb,cn=config"}}}##
	33	+##{{{$}}}##
27	27
28	28
29		-{{{# ldapadd -x -D cn=admin,dc=example,dc=com -W <<EOF
30		-dn: ou=Services,dc=example,dc=com
31		-objectClass: organizationalUnit
32		-objectClass: top
33		-ou: Services
	36	+Next, you need to create and configure two entries which will be used by the Kerberos servers to connect to OpenLDAP. As you will not run the Kerberos KDC and Admin Server on the same host as OpenLDAP, these steps are required. In order to keep things nicely separated, everything will be created under a separate ##organizationalUnit##.
34	34
35		-dn: ou=kerberos,ou=Services,dc=example,dc=com
36		-objectClass: organizationalUnit
37		-objectClass: top
38		-ou: kerberos
	38	+(% style="color:red" %)
	39	+##{{{$ ldapadd -H ldap://nas.fqdn/ -D uid=root,cn=users,dc=example,dc=com -W <<EOF}}}##
	40	+##{{{dn: ou=Services,dc=example,dc=com}}}##
	41	+##{{{objectClass: organizationalUnit}}}##
	42	+##{{{objectClass: top}}}##
	43	+##{{{ou: Services}}}##
	44	+## ##
	45	+##{{{dn: ou=kerberos,ou=Services,dc=example,dc=com}}}##
	46	+##{{{objectClass: organizationalUnit}}}##
	47	+##{{{objectClass: top}}}##
	48	+##{{{ou: kerberos}}}##
	49	+## ##
	50	+##{{{dn: uid=kdc,ou=kerberos,ou=Services,dc=example,dc=com}}}##
	51	+##{{{uid: kdc}}}##
	52	+##{{{objectClass: account}}}##
	53	+##{{{objectClass: simpleSecurityObject}}}##
	54	+##{{{userPassword: {CRYPT}x}}}##
	55	+##{{{description: Kerberos KDC Account}}}##
	56	+## ##
	57	+##{{{dn: uid=kadmin,ou=kerberos,ou=Services,dc=example,dc=com}}}##
	58	+##{{{uid: kadmin}}}##
	59	+##{{{objectClass: account}}}##
	60	+##{{{objectClass: simpleSecurityObject}}}##
	61	+##{{{userPassword: {CRYPT}x}}}##
	62	+##{{{description: Kerberos Admin Server Account}}}##
	63	+##{{{EOF}}}##
	64	+##{{{Enter LDAP Password:}}}##
	65	+## ##
	66	+##{{{adding new entry "ou=Services,dc=example,dc=com"}}}##
	67	+## ##
	68	+##{{{adding new entry "ou=kerberos,ou=Services,dc=example,dc=com"}}}##
	69	+## ##
	70	+##{{{adding new entry "uid=kdc,ou=kerberos,ou=Services,dc=example,dc=com"}}}##
	71	+## ##
	72	+##{{{adding new entry "uid=kadmin,ou=kerberos,ou=Services,dc=example,dc=com"}}}##
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
46	46
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
	75	+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:
55	55
56		-adding new entry "ou=Services,dc=example,dc=com"
	77	+(% style="color:red" %)
	78	+##{{{dn: cn=kadmin,ou=kerberos,ou=Services,dc=example,dc=com}}}##
	79	+##{{{sn: kadmin}}}##
	80	+##{{{cn: kadmin}}}##
	81	+##{{{objectClass: person}}}##
	82	+##{{{objectClass: pwdPolicy}}}##
	83	+##{{{pwdAttribute: userPassword}}}##
	84	+##{{{pwdMinLength: 8}}}##
	85	+##{{{pwdCheckQuality: 2}}}##
	86	+##{{{pwdPolicySubentry: cn=kadmin,ou=kerberos,ou=Services,dc=example,dc=com}}}##
	87	+##{{{userPassword: {SSHA}<hashed password>}}}##
	88	+##{{{description: Kerberos Admin Server Account}}}##
57	57
58		-adding new entry "ou=kerberos,ou=Services,dc=example,dc=com"
	90	+and that seems to have worked out fine as my KDC is fully functioning.
59	59
60		-adding new entry "uid=kdc,ou=kerberos,ou=Services,dc=example,dc=com"
	92	+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.
61	61
62		-adding new entry "uid=kadmin,ou=kerberos,ou=Services,dc=example,dc=com"}}}
63		-
64		-
65		-
	94	+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.