InformationCloudTrail log file validation creates a digitally signed digest file containing a hash of each log that CloudTrail writes to S3. These digest files can be used to determine whether a log file was changed, deleted, or unchanged after CloudTrail delivered the log. It is recommended that file validation be enabled on all CloudTrails.
Enabling log file validation will provide additional integrity checking of CloudTrail logs.
SolutionPerform the following to enable log file validation on a given trail:
Sign in to the AWS Management Console and open the IAM console at https://console.aws.amazon.com/cloudtrail
Click on Trails on the left navigation pane
Click on target trail
Within the S3 section click on the edit icon (pencil)
Click on the Yes radio button in section Enable log file validation
From Command Line:
aws cloudtrail update-trail --name <trail_name> --enable-log-file-validation
Note that periodic validation of logs using these digests can be performed by running the following command:
aws cloudtrail validate-logs --trail-arn <trail_arn> --start-time <start_time> --end-time <end_time>