Logging in AWS Network Firewall with server-side encryption and customer-provided keys

If your logging destination uses server-side encryption with keys that are stored in AWS Key Management Service (SSE-KMS) and you use a customer managed key (KMS key), you must give Network Firewall permission to use your KMS key. To do this, you add a key policy to the KMS key for your chosen destination to permit Network Firewall logging to write your log files to the destination.

Policy for an Amazon S3 bucket

Add the following key policy to your KMS key to allow Network Firewall to log to your Amazon S3 bucket.

{
    "Sid": "Allow Network Firewall to use the key",
    "Effect": "Allow",
    "Principal": {
        "Service": [
            "delivery.logs.amazonaws.com"
        ]
    },
    "Action": "kms:GenerateDataKey*",
    "Resource": "*"
}

Note

Network Firewall supports encryption with Amazon S3 buckets for key type Amazon S3 key (SSE-S3) and for AWS Key Management Service (SSE-KMS) AWS KMS keys. Network Firewall doesn't support encryption for AWS Key Management Service keys that are managed by AWS.

Policy for a CloudWatch Logs log group

For a CloudWatch Logs log group, the service principal requires access to the logs for the Region. This is the same as for all encrypted CloudWatch Logs log streams. For more information about log data encryption in CloudWatch Logs, see Encrypt Log Data in CloudWatch Logs Using AWS KMS.

Add the following key policy to your KMS key to allow Network Firewall to log to your CloudWatch Logs log group.

{
    "Effect": "Allow",
    "Principal": {
        "Service": "logs.{region}.amazonaws.com"
    },
    "Action": [
        "kms:Encrypt*",
        "kms:Decrypt*",
        "kms:ReEncrypt*",
        "kms:GenerateDataKey*",
        "kms:Describe*"
    ],
    "Resource": "*"
}

Policy for a Firehose delivery stream

For Firehose delivery streams, you allow the service principal to generate keys so that it can put the logging records.

Add the following key policy to your KMS key to allow Network Firewall to log to your Firehose delivery stream.

{
    "Sid": "Allow Network Firewall logs to use the key",
    "Effect": "Allow",
    "Principal": {
        "Service": [
            "delivery.logs.amazonaws.com"
        ]
    },
    "Action": "kms:GenerateDataKey*",
    "Resource": "*"
}