Enabling and disabling CloudTrail log file encryption with the AWS CLI

This topic describes how to enable and disable SSE-KMS log file encryption for CloudTrail by using the AWS CLI. For background information, see Encrypting CloudTrail log files with AWS KMS keys (SSE-KMS).

Enabling CloudTrail log file encryption by using the AWS CLI

• Enable log file encryption for a trail

• Enable log file encryption for an event data store

Enable log file encryption for a trail

1. Create a key with the AWS CLI. The key that you create must be in the same Region as the S3 bucket that receives your CloudTrail log files. For this step, you use the AWS KMS create-key command.

2. Get the existing key policy so that you can modify it for use with CloudTrail. You can retrieve the key policy with the AWS KMS get-key-policy command.

3. Add required sections to the key policy so that CloudTrail can encrypt and users can decrypt your log files. Be sure that all users who read the log files are granted decrypt permissions. Do not change existing sections of the policy. For information about the policy sections to include, see Configure AWS KMS key policies for CloudTrail.

4. Attach the modified JSON policy file to the key by using the AWS KMS put-key-policy command.

5. Run the CloudTrail create-trail or update-trail command with the --kms-key-id parameter. This command enables log encryption.

   aws cloudtrail update-trail --name Default --kms-key-id alias/MyKmsKey

   The --kms-key-id parameter specifies the key whose policy you modified for CloudTrail. It can be any one of the following formats:

   • Alias Name. Example: alias/MyAliasName

   • Alias ARN. Example: arn:aws:kms:us-east-2:123456789012:alias/MyAliasName

   • Key ARN. Example: arn:aws:kms:us-east-2:123456789012:key/12345678-1234-1234-1234-123456789012

   • Globally unique key ID. Example: 12345678-1234-1234-1234-123456789012

   The following is an example response:

   {
       "IncludeGlobalServiceEvents": true, 
       "Name": "Default", 
       "TrailARN": "arn:aws:cloudtrail:us-east-2:123456789012:trail/Default", 
       "LogFileValidationEnabled": false,
       "KmsKeyId": "arn:aws:kms:us-east-2:123456789012:key/12345678-1234-1234-1234-123456789012", 
       "S3BucketName": "my-bucket-name"
   }

   The presence of the KmsKeyId element indicates that log file encryption has been enabled. The encrypted log files should appear in your bucket in about 5 minutes.

Enable log file encryption for an event data store

1. Create a key with the AWS CLI. The key that you create must be in the same Region as the event data store. For this step, run the AWS KMS create-key command.

2. Get the existing key policy to edit for use with CloudTrail. You can get the key policy by running the AWS KMS get-key-policy command.

3. Add required sections to the key policy so that CloudTrail can encrypt and users can decrypt your log files. Be sure that all users who read the log files are granted decrypt permissions. Do not change existing sections of the policy. For information about the policy sections to include, see Configure AWS KMS key policies for CloudTrail.

4. Attach the edited JSON policy file to the key by running the AWS KMS put-key-policy command.

5. Run the CloudTrail create-event-data-store or update-event-data-store command, and add the --kms-key-id parameter. This command enables log encryption.

   aws cloudtrail update-event-data-store --name my-event-data-store --kms-key-id alias/MyKmsKey

   The --kms-key-id parameter specifies the key whose policy you modified for CloudTrail. It can be any one of the following four formats:

   • Alias Name. Example: alias/MyAliasName

   • Alias ARN. Example: arn:aws:kms:us-east-2:123456789012:alias/MyAliasName

   • Key ARN. Example: arn:aws:kms:us-east-1:123456789012:key/12345678-1234-1234-1234-123456789012

   • Globally unique key ID. Example: 12345678-1234-1234-1234-123456789012

   The following is an example response:

   {
       "Name": "my-event-data-store",
       "ARN": "arn:aws:cloudtrail:us-east-1:12345678910:eventdatastore/EXAMPLEf852-4e8f-8bd1-bcf6cEXAMPLE",
       "RetentionPeriod": "90",
       "KmsKeyId": "arn:aws:kms:us-east-1:123456789012:key/12345678-1234-1234-1234-123456789012"
       "MultiRegionEnabled": false,
       "OrganizationEnabled": false,
       "TerminationProtectionEnabled": true,
       "AdvancedEventSelectors": [{
           "Name": "Select all external events",
           "FieldSelectors": [{
               "Field": "eventCategory",
               "Equals": [
                   "ActivityAuditLog"
               ]
           }]
       }]
   }

   The presence of the KmsKeyId element indicates that log file encryption has been enabled. The encrypted log files should appear in your event data store in about 5 minutes.

Disabling CloudTrail log file encryption by using the AWS CLI

To stop encrypting logs on a trail, run update-trail and pass an empty string to the kms-key-id parameter:

aws cloudtrail update-trail --name my-test-trail --kms-key-id ""

The following is an example response:

{
    "IncludeGlobalServiceEvents": true, 
    "Name": "Default", 
    "TrailARN": "arn:aws:cloudtrail:us-east-2:123456789012:trail/Default", 
    "LogFileValidationEnabled": false, 
    "S3BucketName": "my-bucket-name"
}

The absence of the KmsKeyId value indicates that log file encryption is no longer enabled.

Important

You cannot stop log file encryption on an event data store.