openldap-technical February 2025

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28 participants
28 discussions

openldap TLSv1.0 is enabled
by Andre Rodier 16 May '25

16 May '25

Hello, I have configured OpenLDAP using SSL certificate, but I have a few issues. Here the TLS configuration, especially "olcTLSProtocolMin: 3.3" > # AUTO-GENERATED FILE - DO NOT EDIT!! Use ldapmodify. > # CRC32 c70363a6 > dn: cn=config > objectClass: olcGlobal > cn: config > olcArgsFile: /var/run/slapd/slapd.args > olcLogLevel: none > olcPidFile: /var/run/slapd/slapd.pid > olcToolThreads: 1 > structuralObjectClass: olcGlobal > entryUUID: 40ee991a-0efe-103d-855a-11ff3a5638b4 > creatorsName: cn=config > createTimestamp: 20221213065102Z > olcPasswordCryptSaltFormat: $6$%.16s > olcTLSCACertificateFile: /etc/ldap/certs/ldap.homebox.world.issuer.crt > olcTLSCertificateKeyFile: /etc/ldap/certs/ldap.homebox.world.key > olcTLSCertificateFile: /etc/ldap/certs/ldap.homebox.world.crt > olcTLSProtocolMin: 3.3 > entryCSN: 20221214054517.926245Z#000000#000#000000 > modifiersName: gidNumber=0+uidNumber=0,cn=peercred,cn=external,cn=auth > modifyTimestamp: 20221214054517Z But if I try sslscan: I see TLSv1.0, TLSv1.1 and TLSv1.2 enabled. Why ? > root@main:/etc/ldap/changes# sslscan ldap.homebox.world:636 > Version: 2.0.7 > OpenSSL 1.1.1n 15 Mar 2022 > > Connected to 2001:19f0:7402:86e:5400:4ff:fe38:b9b4 > > Testing SSL server ldap.homebox.world on port 636 using SNI name ldap.homebox.world > > SSL/TLS Protocols: > SSLv2 disabled > SSLv3 disabled > TLSv1.0 enabled > TLSv1.1 enabled > TLSv1.2 enabled > TLSv1.3 enabled > > TLS Fallback SCSV: > Server supports TLS Fallback SCSV > > TLS renegotiation: > Secure session renegotiation supported > > TLS Compression: > OpenSSL version does not support compression > Rebuild with zlib1g-dev package for zlib support > > Heartbleed: > TLSv1.3 not vulnerable to heartbleed > TLSv1.2 not vulnerable to heartbleed > TLSv1.1 not vulnerable to heartbleed > TLSv1.0 not vulnerable to heartbleed > > Supported Server Cipher(s): > Preferred TLSv1.3 128 bits TLS_AES_128_GCM_SHA256 Curve 25519 DHE 253 > Accepted TLSv1.3 256 bits TLS_AES_256_GCM_SHA384 Curve 25519 DHE 253 > Accepted TLSv1.3 256 bits TLS_CHACHA20_POLY1305_SHA256 Curve 25519 DHE 253 > Accepted TLSv1.3 128 bits TLS_AES_128_CCM_SHA256 Curve 25519 DHE 253 > Preferred TLSv1.2 256 bits ECDHE-RSA-AES256-GCM-SHA384 Curve 25519 DHE 253 > Accepted TLSv1.2 256 bits ECDHE-RSA-CHACHA20-POLY1305 Curve 25519 DHE 253 > Accepted TLSv1.2 128 bits ECDHE-RSA-AES128-GCM-SHA256 Curve 25519 DHE 253 > Accepted TLSv1.2 256 bits ECDHE-RSA-AES256-SHA Curve 25519 DHE 253 > Accepted TLSv1.2 128 bits ECDHE-RSA-AES128-SHA Curve 25519 DHE 253 > Accepted TLSv1.2 256 bits AES256-GCM-SHA384 > Accepted TLSv1.2 256 bits AES256-CCM > Accepted TLSv1.2 128 bits AES128-GCM-SHA256 > Accepted TLSv1.2 128 bits AES128-CCM > Accepted TLSv1.2 256 bits AES256-SHA > Accepted TLSv1.2 128 bits AES128-SHA > Preferred TLSv1.1 256 bits ECDHE-RSA-AES256-SHA Curve 25519 DHE 253 > Accepted TLSv1.1 128 bits ECDHE-RSA-AES128-SHA Curve 25519 DHE 253 > Accepted TLSv1.1 256 bits AES256-SHA > Accepted TLSv1.1 128 bits AES128-SHA > Preferred TLSv1.0 256 bits ECDHE-RSA-AES256-SHA Curve 25519 DHE 253 > Accepted TLSv1.0 128 bits ECDHE-RSA-AES128-SHA Curve 25519 DHE 253 > Accepted TLSv1.0 256 bits AES256-SHA > Accepted TLSv1.0 128 bits AES128-SHA > > Server Key Exchange Group(s): > TLSv1.3 128 bits secp256r1 (NIST P-256) > TLSv1.3 192 bits secp384r1 (NIST P-384) > TLSv1.3 260 bits secp521r1 (NIST P-521) > TLSv1.3 128 bits x25519 > TLSv1.3 224 bits x448 > TLSv1.3 112 bits ffdhe2048 > TLSv1.3 128 bits ffdhe3072 > TLSv1.3 150 bits ffdhe4096 > TLSv1.3 175 bits ffdhe6144 > TLSv1.3 192 bits ffdhe8192 > TLSv1.2 128 bits secp256r1 (NIST P-256) > TLSv1.2 192 bits secp384r1 (NIST P-384) > TLSv1.2 260 bits secp521r1 (NIST P-521) > TLSv1.2 128 bits x25519 > TLSv1.2 224 bits x448 > > SSL Certificate: > Signature Algorithm: sha256WithRSAEncryption > RSA Key Strength: 2048 > > Subject: ldap.homebox.world > Altnames: DNS:ldap.homebox.world > Issuer: (STAGING) Artificial Apricot R3 > > Not valid before: Dec 13 05:34:29 2022 GMT > Not valid after: Mar 13 05:34:28 2023 GMT Thanks for your insights. Andre

6 13

ldap proxy
by fred750164＠gmail.com 06 May '25

06 May '25

I want to set up an architecture that allows a client to query an LDAP backend via an LDAP proxy. I want the query from the client to be unsecured, but the proxied communication between the LDAP proxy and the LDAP backend to be secured through mutual TLS authentication via SASL EXTERNAL. What configurations need to be implemented on the LDAP proxy and the LDAP backend? I saw in the slapd-ldap(5) documentation that the idassert-bind parameter could be used on the LDAP proxy for the TLS connection via SASL EXTERNAL, and in the slapd.conf(5) documentation that the authz-regexp parameter could be used on the LDAP backend to allow querying with a DN extracted from the certificate on this LDAP backend. However, I am struggling to set it up. I use openldap 2.4. slapd.conf on proxy server: [...] Database ldap suffix dc=test,dc=com uri ldaps://mytest.com:636 idassert-bind mode=self bindmethod=sasl saslmech=EXTERNAL tls_cert=/etc/openldap/certs/server.crt tls_key=/etc/openldap/certs/server.key tls_cacert=/etc/ssl/certs/ca-bundle.crt tls_cacertdir=/etc/ssl/certs tls_crlcheck=none tls_reqcert=allow [...] slapd.conf on backend server: [...] # Modules moduleload back_mdb moduleload authz-regexp # TLS TLSCACertificateFile /opt/openldap/etc/openldap/certs/ca-certificates.crt TLSCertificateFile /opt/openldap/etc/openldap/certs/backend.crt TLSCertificateKeyFile /opt/openldap/etc/openldap/certs/backend.key TLSCipherSuite HIGH TLSVerifyClient demand sasl-Host mytest.com sasl-realm EXTERNAL authz-regexp ".*" "cn=user1,dc=test,dc=com" [...] proxy: ldapsearch -H ldaps://mytest.com -b "dc=appli,dc=test,dc=com" -Y EXTERNAL -ZZ ldap_start_tls: Can't contact LDAP server (-1) backend: 67895427.2b4074ce 0x7f7e6bffe6c0 TLS: can't accept: error:0A0000C7:SSL routines::peer did not return a certificate. Any help would be appreciated.

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Re: consumer replication net recovering
by Suresh Veliveli 12 Mar '25

12 Mar '25

This is another instance where replication stops. Dec 23 01:01:23 aaa-prod-aws-3 slapd[1182444]: syncrepl_entry: rid=143 LDAP_RES_SEARCH_ENTRY(LDAP_SYNC_MODIFY) csn=20241223060050.594465Z#000000#000#000000 tid 0x7f5aed0fb640 Dec 23 01:01:23 aaa-prod-aws-3 slapd[1182444]: syncrepl_entry: rid=143 be_search (0) Dec 23 01:01:23 aaa-prod-aws-3 slapd[1182444]: syncrepl_entry: rid=143 uid=xxxx,ou=People,dc=georgetown,dc=edu Dec 23 01:01:23 aaa-prod-aws-3 slapd[1182444]: syncrepl_entry: rid=143 be_modify uid=xxxxx,ou=People,dc=georgetown,dc=edu (0) Dec 23 01:01:23 aaa-prod-aws-3 slapd[1182444]: syncrepl_message_to_entry: rid=143 DN: uid=xxxxx,ou=People,dc=georgetown,dc=edu, UUID: db41232e-527d-103f-995c-4344349468b5 Dec 23 01:01:23 aaa-prod-aws-3 slapd[1182444]: syncrepl_entry: rid=143 LDAP_RES_SEARCH_ENTRY(LDAP_SYNC_MODIFY) csn=20241223060104.603554Z#000000#000#000000 tid 0x7f5aed0fb640 Dec 23 01:01:23 aaa-prod-aws-3 slapd[1182444]: syncrepl_entry: rid=143 be_search (0) Dec 23 01:01:23 aaa-prod-aws-3 slapd[1182444]: syncrepl_entry: rid=143 uid=yyyyy,ou=People,dc=georgetown,dc=edu Dec 23 01:01:23 aaa-prod-aws-3 slapd[1182444]: syncrepl_entry: rid=143 be_modify uid=yyyy,ou=People,dc=georgetown,dc=edu (0) No "syncrep_" messages were logged after the above. Regards, Suresh On Mon, Dec 23, 2024 at 2:42 PM Quanah Gibson-Mount <quanah(a)fast-mail.org> wrote: > > > --On Friday, December 20, 2024 5:46 PM -0500 Suresh Veliveli > <Suresh.Veliveli(a)georgetown.edu> wrote: > > > > > I do have these but no syncrepl_sync. > > > > > > Dec 12 08:59:30 aaa-prod-gcp-9 slapd[4165]: syncrepl_message_to_entry: > > rid=129 DN: uid=xxxx,ou=xxxx,dc=georgetown,dc=edu, UUID: > > 37387976-3ae0-103f-94fc-3b4be3361dc7 > > Dec 12 08:59:30 aaa-prod-gcp-9 slapd[4165]: syncrepl_entry: rid=129 > > LDAP_RES_SEARCH_ENTRY(LDAP_SYNC_MODIFY) > > csn=20241212135921.652395Z#000000#000#000000 tid 0x7f671b7fe640 > > Yes sorry, that was a typo on my end. > > "syncrepl_" sync messages. Specifically you want to see the ones that > have > "be_" in them, but not "be_search". I.e., be_add, be_modify, etc. They > show the result of the operation, something like: > > syncrepl_entry: rid=100 be_modify <DN> (<result code>) > > --Quanah > > -- Suresh Veliveli Sr. UNIX Systems Engineer Georgetown University University Information Services | Security Infrastructure and Policy-Identity and Collaboration 202-262-6676 (cell) | 202-687-3108 (work)

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manual page slapd-mdb.5 and "maxsize"
by Windl, Ulrich 03 Mar '25

03 Mar '25

Migrating to OpenLDAP 2.5 and MDB I hit the default 10MB limit (when trying to import a 6.8MB LDIF). Seeking how to extend the size online, I found: maxsize <bytes><https://manpages.debian.org/testing/slapd/slapd-mdb.5.en.html#maxsize> Specify the maximum size of the database in bytes. A memory map of this size is allocated at startup time and the database will not be allowed to grow beyond this size. The default is 10485760 bytes. This setting may be changed upward if the configured limit needs to be increased. However it's completely non-obvious that the name for cn=config is "olcDbMaxSize" (and not "olcMaxssize"). (The final MDB file size was about 23MB, including the indices) Kind regards, Ulrich Windl

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[authcid=<identity>] [authzid=<identity>]
by Stefan Kania 03 Mar '25

03 Mar '25

hi to all, I like to split the replication for cn=config and the object-db between to different kerberos-principals so I did the following (so far) 1. create to principals and a keytab for both of them. 2. configured k5start to get two different cchache files (one for each user) 3. Now I want to change my syncrepl from: --------------------------- dn: olcDatabase={0}config,cn=config changetype: modify replace: olcSyncRepl olcSyncRepl: rid=001 provider=ldaps://provider01.example.net bindmethod=sasl saslmech=gssapi searchbase="cn=config" type=refreshAndPersist retry="5 5 100 +" timeout=1 tls_reqcert=allow olcSyncRepl: rid=002 provider=ldaps://provider02.example.net bindmethod=sasl saslmech=gssapi searchbase="cn=config" type=refreshAndPersist retry="5 5 100 +" timeout=1 tls_reqcert=allow --------------------------- And ----------------------------- dn: olcDatabase={2}mdb,cn=config changetype: modify replace: olcSyncrepl olcSyncrepl: rid=101 provider=ldaps://provider01.example.net bindmethod=sasl saslmech=gssapi authzid=uid=krepl-main,cn=gssapi,cn=auth timeout=0 network-timeout=0 filter="(objectclass=*)" searchbase="dc=example,dc=net" scope=sub schemachecking=off type=refreshAndPersist retry="60 +" tls_reqcert=allow olcSyncrepl: rid=102 provider=ldaps://provider02.example.net bindmethod=sasl saslmech=gssapi authzid=uid=krepl-main,cn=gssapi,cn=auth timeout=0 network-timeout=0 filter="(objectclass=*)" searchbase="dc=example,dc=net" scope=sub schemachecking=off type=refreshAndPersist retry="60 +" keepalive=240:10:30 tls_reqcert=allow ----------------------------------- to use a different identity. I found the options [authcid=<identity>] [authzid=<identity>] But nothing how to configure these options. When I get the ticket for the user and do a ldapwhoami I'm getting dn:uid=krepl-config,cn=gssapi,cn=auth and dn:uid=krepl-main,cn=gssapi,cn=auth The DNs are: krbPrincipalName=krepl-krbPrincipalName=krepl-config(a)EXAMPLE.NET,cn=EXAMPLE.NET,cn=kerberos,dc=example,dc=net and krbPrincipalName=krepl-main(a)EXAMPLE.NET,cn=EXAMPLE.NET,cn=kerberos,dc=example,dc=net So which option du I have to take and what is the right value for the option? Stefan

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When init new consumers receiving: missing or invalid at 'pwdPolicySubentry'
by erikdewaard＠gmail.com 03 Mar '25

03 Mar '25

Hi, When bootstrapping consumers through replication (clean conf/data dir) receiving msgs about pwdPolicySubentry missing. Its not always the same: sometimes 4 msgs another time 60 etc. I have this on various consumers 2.5.17/2.6.7 I thought this could be related to some ordering, maybe the accounts were created before ppolicy cn=noexpirepasswordpolicy data was replicated? <167>2025-02-27T12:16:20.993758+01:00 consumer22 slapd[1098021]: slapd starting <167>2025-02-27T12:16:32.035015+01:00 consumer22 slapd[1098021]: ppolicy_get: policy subentry cn=noexpirepasswordpolicy,ou=policies,dc=company,dc=com missing or invalid at 'pwdPolicySubentry', no policy will be applied! <167>2025-02-27T12:16:35.580938+01:00 consumer22 slapd[1098021]: ppolicy_get: policy subentry cn=noexpirepasswordpolicy,ou=policies,dc=company,dc=com missing or invalid at 'pwdPolicySubentry', no policy will be applied! best regards

2 1

OpenLDAP Pass-through Authentication
by Dino Edwards 01 Mar '25

01 Mar '25

Hi, Trying to get pass-through authentication working however, I'm running to the following error in OpenLDAP: openldap | 679ceede.3aa31e0a 0x7f2ff617e6c0 conn=1004 op=1 SRCH attr=uid mail displayName openldap | 679ceede.3aa4b816 0x7f2ff617e6c0 conn=1004 op=1 SEARCH RESULT tag=101 err=0 qtime=0.000019 etime=0.000172 nentries=1 text= openldap | 679ceede.3aaafd88 0x7f2ff597d6c0 conn=1005 fd=14 ACCEPT from IP=172.16.32.1:47082 (IP=0.0.0.0:1389) openldap | 679ceede.3aab8f34 0x7f2ff597d6c0 conn=1005 op=0 BIND dn="cn=username(a)domain.tld,ou=users,dc=domain,dc=local <mailto:cn=username@domain.tld,ou=users,dc=domain,dc=local> " method=128 openldap | 679ceede.3aac9267 0x7f2ff597d6c0 SASL [conn=1005] Failure: cannot connect to saslauthd server: No such file or directory openldap | 679ceede.3aad25b9 0x7f2ff597d6c0 conn=1005 op=0 RESULT tag=97 err=49 qtime=0.000005 etime=0.000120 text= openldap | 679ceede.3ab0191f 0x7f2ff617e6c0 conn=1005 fd=14 closed (connection lost) openldap | 679ceede.3ab3d76a 0x7f2ff597d6c0 conn=1004 fd=13 closed (connection lost) I followed the admin docs at: https://www.openldap.org/doc/admin26/guide.html#Pass-Through%20authenticatio n Here's what I did: Created /usr/lib/sasl2/slapd.conf with the following content: mech_list: plain pwcheck_method: saslauthd saslauthd_path: /var/run/sasl2/mux Created /etc/saslauthd.conf with the following content: ldap_servers: ldap://192.168.xxx.xxx.xxx ldap_search_base: OU=Users,DC=domain,DC=tld ldap_filter: (uid=%u) ldap_bind_dn: CN=saslauthd,CN=Users,DC=domain,DC=tld ldap_password: somepassword Added a user that already exists in domain.tld in openldap with the following password: {SASL}username(a)domain.tld <mailto:%7bSASL%7dusername@domain.tld> I would appreciate some help on this. Thanks

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Transparent proxy to existing LDAP but with replacing specific attribute from another source
by Alexey D. Filimonov 28 Feb '25

28 Feb '25

Hi. A have Active Directory domain across 30+ domain controllers. In one single location, I have a server with corporate software that uses AD as normal ordinary LDAP with simple binds and it takes users. I want to add users their high quality photos, but I don't want them across all domain controllers in active directory. Can I build a proxy server with OpenLDAP that will proxy all requests to backend AD servers and return results, but for results it will replace one attribute, jpegPhoto, if it was requested, with some binary contents taken from elsewhere ?

2 1

olcDbMaxSize decrease possible?
by cyril＠stoll.info 27 Feb '25

27 Feb '25

Hi there For some reason I don't remember I set the olcDbMaxSize to 4 GB. Turns out that is way too large for our OpenLDAP servers. Both the admin guide and the slapd-mdb manpage state that "this setting may be changed upward". Unfortunately there is no mentioning of decreasing that size. On our servers the data.mdb and lock.mdb Files together are around 176 MB. I don't really expect a significant growth of our OpenLDAP Servers. So I guess that setting it to 1 GB or even just 500 MB would be more than enough for our needs in the coming years. So my question is, can I also decrease that size? Or should I just let it be at 4 GB even though we will never ever come close to that? Thanks a lot and best regards, Cyril

2 1

Querying a tree covered by multiple databases
by Norman Gray 27 Feb '25

27 Feb '25

Greetings. If I have a server which manages a tree split into two databases, one covering o=top, and one ou=sub,o=top, then a query against base o=top with subtree scope returns only objects within the first database, and not the second. Should I have expected that? (I didn't) [ This is a for-interest question. This isn't really a practical problem for me: I'm encountering it because I have a situation where I'm searching objects in ou=sub,o=top and in o=top, which would be on different servers in the real case, but which are in the same server as part of a test harness. Of course, I doubt it would be a good production design to have a tree split into multiple databases like this. ] That makes sense if the semantics of a search are that it searches a _database_, but it conflicts with the intuition that a search is of a _tree_, where I'd expect a search of o=top to implicitly include ou=sub,o=top as well. My problem is that I can't find where in the manual it tells me I should expect the former rather than the latter. What have I not read? Both ldapsearch(1) and ldap_search(3) discuss the scope in terms of sub_tree_, and don't mention databases (I wouldn't expect them to, since here a 'database' is an implementation detail of the LDAP server). Section 1.1 of TFM says 'A directory is a specialized database specifically designed for searching and browsing', but that's 'database' being used somewhat generically. Perhaps I should be looking at referrals? But the introduction of referrals in TFM suggest that these are a mechanism for referring clients to servers broadly 'elsewhere', and Sect. 5.3 documents olcReferral by saying that 'queries not local to one of the databases defined below will be referred to the LDAP server running on [another server]'. And queries to ou=sub,o=top _is_ 'local to one of the databases'. Best wishes, Norman -- Norman Gray : https://nxg.me.uk

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openldap-technical February 2025