Changes for page KerberosAndLDAP
Last modified by Sirius Rayner-Karlsson on 2024/05/09 10:54
From version 17.1
edited by Sirius Rayner-Karlsson
on 2024/05/01 17:44
on 2024/05/01 17:44
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To version 10.1
edited by Sirius Rayner-Karlsson
on 2024/05/01 17:04
on 2024/05/01 17:04
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... ... @@ -2,84 +2,76 @@ 2 2 3 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 - 5 +{{{ 6 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: 7 7 8 -##{{{$ sudo apt install krb5-kdc-ldap krb5-admin-server schema2ldif}}}## 8 +##$ sudo apt install krb5-kdc-ldap krb5-admin-server schema2ldif## 9 +}}} 9 9 10 - 11 +{{{ 11 11 Then load the ##kerberos## schema: 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 -W}}}## 14 -##{{{Enter LDAP Password:}}}## 15 -##{{{adding new entry "cn=kerberos,cn=schema,cn=config"}}}## 16 -##{{{$}}}## 14 +##$ 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## 15 +##Password:## 17 17 17 +##adding new entry "cn=kerberos,cn=schema,cn=config"## 18 +}}} 18 18 19 -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##: 20 20 21 -##{{{$ ldapmodify -H ldap://nas.fqhn/ -D uid=root,cn=users,dc=example,dc=com -W <<EOF}}}## 22 -##{{{dn: olcDatabase={1}bdb,cn=config}}}## 23 -##{{{add: olcDbIndex}}}## 24 -##{{{olcDbIndex: krbPrincipalName eq,pres,sub}}}## 25 -##{{{EOF}}}## 26 -##{{{Enter LDAP Password:}}}## 27 -##{{{modifying entry "olcDatabase={1}bdb,cn=config"}}}## 28 -##{{{$}}}## 21 +And add an index on the ##krbPrincipalName## (improves performance and also suppresses some log messages if ##slapd## is configured to log more than default) for the database(s) where you intend to store Kerberos data: 29 29 23 +{{{# ldapmodify -H ldap:~/~/nas.fqhn <<EOF 30 30 31 - Next, you needto create andconfigure two entries which will be used by the Kerberos servers toconnect to OpenLDAP. As you will not run the Kerberos KDCand Admin Server onthe same hostasOpenLDAP, these steps are required. In order to keep things nicely separated, everything willbecreated under a separate ##organizationalUnit##.25 +dn: olcDatabase={1}bdb,cn=config 32 32 33 -##{{{$ ldapadd -H ldap://nas.fqhn/ -D uid=root,cn=users,dc=example,dc=com -W <<EOF}}}## 34 -##{{{dn: ou=Services,dc=example,dc=com}}}## 35 -##{{{objectClass: organizationalUnit}}}## 36 -##{{{objectClass: top}}}## 37 -##{{{ou: Services}}}## 38 -## ## 39 -##{{{dn: ou=kerberos,ou=Services,dc=example,dc=com}}}## 40 -##{{{objectClass: organizationalUnit}}}## 41 -##{{{objectClass: top}}}## 42 -##{{{ou: kerberos}}}## 43 -## ## 44 -##{{{dn: uid=kdc,ou=kerberos,ou=Services,dc=example,dc=com}}}## 45 -##{{{uid: kdc}}}## 46 -##{{{objectClass: account}}}## 47 -##{{{objectClass: simpleSecurityObject}}}## 48 -##{{{userPassword: {CRYPT}x}}}## 49 -##{{{description: Kerberos KDC Account}}}## 50 -## ## 51 -##{{{dn: uid=kadmin,ou=kerberos,ou=Services,dc=example,dc=com}}}## 52 -##{{{uid: kadmin}}}## 53 -##{{{objectClass: account}}}## 54 -##{{{objectClass: simpleSecurityObject}}}## 55 -##{{{userPassword: {CRYPT}x}}}## 56 -##{{{description: Kerberos Admin Server Account}}}## 57 -##{{{EOF}}}## 58 -##{{{Enter LDAP Password:}}}## 59 -## ## 60 -##{{{adding new entry "ou=Services,dc=example,dc=com"}}}## 61 -## ## 62 -##{{{adding new entry "ou=kerberos,ou=Services,dc=example,dc=com"}}}## 63 -## ## 64 -##{{{adding new entry "uid=kdc,ou=kerberos,ou=Services,dc=example,dc=com"}}}## 65 -## ## 66 -##{{{adding new entry "uid=kadmin,ou=kerberos,ou=Services,dc=example,dc=com"}}}## 27 +add: olcDbIndex 67 67 29 +olcDbIndex: krbPrincipalName eq,pres,sub 68 68 69 - 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. I ended up working around it using a different construct:31 +EOF 70 70 71 -##{{{dn: cn=kadmin,ou=kerberos,ou=Services,dc=example,dc=com}}}## 72 -##{{{sn: kadmin}}}## 73 -##{{{cn: kadmin}}}## 74 -##{{{objectClass: person}}}## 75 -##{{{objectClass: pwdPolicy}}}## 76 -##{{{pwdAttribute: userPassword}}}## 77 -##{{{pwdMinLength: 8}}}## 78 -##{{{pwdCheckQuality: 2}}}## 79 -##{{{pwdPolicySubentry: cn=kadmin,ou=kerberos,ou=Services,dc=example,dc=com}}}## 80 -##{{{userPassword: {SSHA}<hashed password>}}}## 81 -##{{{description: Kerberos Admin Server Account}}}## 33 +modifying entry "olcDatabase={1}bdb,cn=config" 82 82 83 - and that seems to have worked out fine as my KDC is fully functioning. 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.35 +}}} 84 84 37 + 38 +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: 39 + 40 + 41 +{{{# ldapadd -x -D cn=admin,dc=example,dc=com -W <<EOF 42 +dn: ou=Services,dc=example,dc=com 43 +objectClass: organizationalUnit 44 +objectClass: top 45 +ou: Services 46 + 47 +dn: ou=kerberos,ou=Services,dc=example,dc=com 48 +objectClass: organizationalUnit 49 +objectClass: top 50 +ou: kerberos 51 + 52 +dn: uid=kdc,ou=kerberos,ou=Services,dc=example,dc=com 53 +uid: kdc 54 +objectClass: account 55 +objectClass: simpleSecurityObject 56 +userPassword: {CRYPT}x 57 +description: Kerberos KDC Account 58 + 59 +dn: uid=kadmin,ou=kerberos,ou=Services,dc=example,dc=com 60 +uid: kadmin 61 +objectClass: account 62 +objectClass: simpleSecurityObject 63 +userPassword: {CRYPT}x 64 +description: Kerberos Admin Server Account 65 +EOF 66 +Enter LDAP Password: SECRET 67 + 68 +adding new entry "ou=Services,dc=example,dc=com" 69 + 70 +adding new entry "ou=kerberos,ou=Services,dc=example,dc=com" 71 + 72 +adding new entry "uid=kdc,ou=kerberos,ou=Services,dc=example,dc=com" 73 + 74 +adding new entry "uid=kadmin,ou=kerberos,ou=Services,dc=example,dc=com"}}} 75 + 76 + 85 85