Chapter 9. Encrypting the replication changelog

Encrypt the replication changelog to increase the security of your instance, in case that an attacker gains access to the file system of your server.

Changelog encryption uses the server’s TLS encryption key and the same PIN to unlock the key. You must either enter the PIN manually upon server startup or use a PIN file.

Directory Server uses randomly generated symmetric cipher keys to encrypt and decrypt the changelog. The server uses a separate key for each configured cipher. These keys are wrapped using the public key from the server’s TLS certificate, and the resulting wrapped key is stored within the server’s configuration files. The effective strength of the attribute encryption is the same as the strength of the server’s TLS key used for wrapping. Without access to the server’s private key and the PIN, it is not possible to recover the symmetric keys from the wrapped copies.

9.1. Encrypting the changelog using the command line

To increase the security in a replication topology, encrypt the changelog on suppliers and hubs. This procedure describes how to enable changelog encryption for the dc=example,dc=com suffix.

Prerequisites

  • The server has TLS encryption enabled.
  • The host is a supplier or hub in a replication topology.

Procedure

  1. Export the changelog, for example, to the /tmp/changelog.ldif file: 

    # dsconf -D "cn=Directory Manager" ldap://server.example.com replication export-changelog to-ldif -o /tmp/changelog.ldif -r "dc=example,dc=com"

  2. Enable change log encryption for the dc=example,dc=com suffix: 

    # dsconf -D "cn=Directory Manager" ldap://server.example.com replication --suffix "dc=example,dc=com" --encrypt

  3. Import the changelog from the /tmp/changelog.ldif file: 

    # dsconf -D "cn=Directory Manager" ldap://server.example.com replication import-changelog from-ldif -r "dc=example,dc=com" /tmp/changelog.ldif

  4. Restart the instance: 

    # dsctl instance_name restart

Verification

  1. Make a change in the LDAP directory, such as updating an entry.

  2. Stop the instance: 

    # dsctl instance_name stop

  3. List the suffixes and their corresponding databases: 

    # dsconf -D "cn=Directory Manager" ldap://server.example.com backend suffix list
dc=example,dc=com (userroot)

    Note the name of the database for which you enabled changelog encryption.

  4. Enter the following command to display parts of the changelog: 

    # dbscan -f /var/lib/dirsrv/slapd-instance_name/db/userroot/replication_changelog.db | tail -50

    If the changelog is encrypted, you see only encrypted data.

  5. Start the instance. 

    # dsctl instance_name start

Additional resources