RFC 2649 (rfc2649) - Page 2 of 10
An LDAP Control and Schema for Holding Operation Signatures
Alternative Format: Original Text Document
RFC 2649 LDAP Control and Schema August 1999 1. Introduction In many environments clients require the ability to validiate the source and integrity of information provided by the directory. This document describes an LDAP message control which allows for the retrieval of digitally signed information. The perspective of this document is that the origin of the information that is stored in LDAP v3 accessible directories is the LDAP v3 client that creates the information. The source and integrity of the information is guaranteed by allowing for the digital signing of the operations that make changes to entries in the directory. The source and integrity of an individual LDAP connection can be guaranteed by making use of an underlying session layer that provides such services, such as TLS. Note that the integrity of an individual connection does not, in and of itself guarantee the integrity of the data that comes across the connection. This is due to the fact that the LDAP server is only capable of providing information that it has stored. In distributed and replicated environments, the fact that an entry has been successfully retrieved from a server may not be completely reassuring, if the entry in question was replicated from an untrusted domain. By making use of public key technology, and creating digitally signed transactions that are created by the LDAP v3 client as entries are created and modified, a complete journal of the history of the entry is available. Since each entry in the journal has been digitally signed with the private key of the creator, or modifier of the entry, the source and integrity of the directory entry can be validated by verifying the signature of each entry in the journal. Note that not all of the journal entries will have been signed by the same user. 1.1. Audit Trail Mechanism Signed directory operations is a straightforward application of S/MIME technology that also leverages the extensible framework that is provided by LDAP version 3. LDAP version 3 is defined in [4], and S/MIME is defined in [2]. The security used in S/MIME is based in the definitions in [1]. The basic idea is that the submitter of an LDAP operation that changes the directory information includes an LDAP version 3 control that includes either a signature of the operation, or a request that the LDAP server sign the operation on the behalf of the LDAP client. The result of the operation (in addition to the change of the directory information), is additional information that is attached to directory objects, that includes the audit trail of signed operations. The LDAP control is (OID = 1.2.840.113549.6.0.0): Greenblatt & Richard Experimental
