LDAP APIs

1. LDAP APIs CNS 4650 Fall 2004 Rev. 2

2. LDAP C APIs • OpenLDAP • Mozilla/Netscape • Novell LDAP SDK • Microsoft ADSI

3. LDAP C APIs • Most of the LDAP C SDKs are similar • Based of the LDAP RFC • Usually slight difference between each

4. PERL LDAP API • Original PERL LDAP API was PerLDAP • Net::LDAP preferred API • Net::LDAP does not require a C compiler to install

5. Other APIs • PHP • Python • Java (JLDAP @ http://www.openldap.org)

6. Basic LDAP Search Steps • Create connection • Bind (if needed) • Perform search • Display results • Close connection

7. Create Connection C API PERL API #include <ldap.h> LDAP *ld //LDAP Handle ld = ldap_init(”ldap.somewhere.com”, 389); use Net::LDAP; my $conn = new Net::LDAP("tux.sinemas.net"); ld - LDAP Handle ldap_init() - allocate LDAP handle ldap_open() is also available. But, eventually it will be dropped. ldap_init() is preferred because a LDAP handle is allocated but no connection occurs. conn - LDAP Handle Net::LDAP() - allocate LDAP handle

8. Bind (if necessary) C API PERL API ... rc = ldap_simple_bind_s(ld, MY_DN, MY_PWD); ... ... $conn->bind(dn=>MY_DN,password=>MY_PWD) ... rc - integer return value ldap_simple_bind_s() - simple bind ld - LDAP Handle MY_DN: dn of user to authenticate MY_PWD: password of user There are other ldap_bind_* functions for SASL, Kerberos IV, etc. conn - LDAP Handle conn->bind() - simple bind

9. Perform Search C API PERL API ... rc = ldap_search(ld, base, scope, filter, attrs, attrsonly); ... ... $mesg = $conn->search(base=>base,scope=>scope, filter=>filter, attrs=>attrs); ... rc - integer return value ldap_search() - search ld - LDAP Handle base: where to search from (ou=dev) scope: LDAP_SCOPE_ONELEVEL or LDAP_SCOPE_SUB filter: What to look for attrs: what I want returned attrsonly: 0 or 1 return attribute name and values mesg - Search return value conn->search() - search base: where to search from (ou=dev) scope: sub or onelevel filter: What to look for attrs: what I want returned

10. Search Filters • Filter is encased in ( ) • Wildcard - * • Boolean • & - AND • | - OR • ! - NOT • Examples • (cn=Dan Sinema) • (&(cn=Dan Sinema)(objectclass=user)) • (cn=Dan *)

11. Perform Search C API PERL API ... rc = ldap_search(ld, base, scope, filter, attrs, attrsonly); ... ... $mesg = $conn->search(base=>base,scope=>scope, filter=>filter, attrs=>attrs); ... rc - integer return value ldap_search() - search ld - LDAP Handle base: where to search from (ou=dev) scope: LDAP_SCOPE_ONELEVEL or LDAP_SCOPE_SUB filter: What to look for attrs: what I want returned attrsonly: 0 or 1 return attribute name and values mesg - Search return value conn->search() - search base: where to search from (ou=dev) scope: sub or onelevel filter: What to look for attrs: what I want returned

12. Display Results C API LDAPMessage *result, e; char* attribute; BerElement *ber; char** vals; ... e = ldap_first_entry(ld, result ) ... attribute = ldap_first_attribute(ld, e, ber ) ... vals = ldap_get_values(ld, e, attribute) result, e: LDAPMessage structure attribute: char string ber - BER structure (LDAP returns data BER encoded) vals: array of strings ldap_first_entry(): Get first returned entry, use ldap_next_entry() after ldap_first_attribute(): Get the first attribute of the entry ldap_get_values(): Get the attribute values

13. Display Results PERL API ... $ldif = new Net::LDAP::LDIF("-","w"); for ($i = 0; $i < $mesg->count; $i++) { my $entry = $mesg->entry($i); $ldif->write_entry($entry); } $ldif->done; ... ldif - allows printing of entries in LDIF format mesg - LDAP Handle entry - Entry contained in the LDAP Handle ldif->write_entry() - write in an LDIF format

14. Close Connections C API PERL API ... rc = ldap_unbind(ld); ... ... $conn->unbind; ... rc - integer return value ldap_unbind() - destroy LDAP handle ld - LDAP Handle conn - LDAP Handle conn->unbind() - destroy LDAP Handle

15. Resources • http://www.openldap.org - Manual Pages (C Language) • http://www.manning.com/donley - Source Code (PERL)