Amazon Linux 2023 must encrypt, via the OpenSSL TLS (ossl) driver, the transfer of audit records off-loaded onto a different system or media from the system being audited by rsyslog.

Information stored in one location is vulnerable to accidental or incidental deletion or alteration.

Off-loading is a common process in information systems with limited audit storage capacity.

Support for both internet and Unix domain sockets enables this utility to support both local and remote logging. Coupling this utility with "ossl" (a secure communications library implementing the SSL and TLS protocols) creates a method to securely encrypt and off-load auditing.

Verify Amazon Linux 2023 explicitly defines the OpenSSL TLS driver (ossl) for encrypted rsyslog offloading.

Search for an explicitly defined stream driver with the following command: $ sudo grep -rE 'StreamDriver\s*=\s*"ossl"|\$DefaultNetstreamDriver\s+ossl' /etc/rsyslog.conf /etc/rsyslog.d/ /etc/rsyslog.conf:$DefaultNetstreamDriver ossl

If the value of the "$DefaultNetstreamDriver" option is not set to "ossl" or the line is commented out, this is a finding.

Configure Amazon Linux 2023 to use the OpenSSL TLS driver (ossl) to encrypt offloaded audit records by setting the following options in "/etc/rsyslog.conf" or "/etc/rsyslog.d/[customfile].conf":

$DefaultNetstreamDriver ossl