We can find the classSchema available for each object class in active directory. As per the documentation of ApacheDS and OpenLDAP we could not find any class schema for finding Class identifiers, Possible attributes, Possible parents and Superclasses and auxiliary classes.
Do we have class schema available for OpenLDAP and ApacheDS? If no is there any way to find the system attributes for each object class for OpenLDAP and ApacheDS?
An ObjectClass is an LDAP Schema element AttributeType, these are defined in RFC 4512.
The complete set of object classes in an entry define the set of AttributeTypes that are required or allowed to be present. The STRUCTURAL class may also be used to link the entry with a NameForm, dITContentRules, and/or DITStructureRules.
Every LDAP Entry must have exactly one STRUCTURAL object class, and it may have zero or more AUXILIARY classes.
You can browse most of them (like the mentioned classSchema for AD) at ldapwiki.com
For most LDAP Server implementation the rootDSE has an attribute value for the defined in RFC 4512 section 4.4,
To discover the DN of the subschema (sub)entry holding the subschema controlling a particular entry, a client reads that entry's 'subschemaSubentry' operational attribute.
Typically this would be like subschemaSubentry: cn=schema. So a ldapsearch similar to:
ldapsearch -h yourLDAPDNS -b "cn=schema" -s base -D cn=admin,ou=...,dc=example,dc=com -w secretpassword "(objectclass=*)" > schema.ldif
Should put the schema definition into the schema.ldif file. Some ldapserver implementations use a slightly different format for the ldapsearch requiring the return attributes be specified:
ldapsearch -h yourLDAPDNS -b "cn=schema" -s base -D cn=admin,ou=...,dc=example,dc=com -w secretpassword "(objectclass=*)" attributeTypes objectClasses
