S3 - Encryption

Enable Bucket Encryption

The following policy will enable bucket encryption on all s3 buckets.

policies:
  - name: s3-set-bucket-encryption
    resource: s3
    actions:
      - type: set-bucket-encryption
        crypto: AES256
        enabled: True

Remediate Existing

Will scan all keys in the bucket for unencrypted keys and by default remediate them such that they are encrypted.

policies:
  - name: s3-key-encryption
    resource: s3
    actions:
      - type: encrypt-keys
        crypto: aws:kms

Options

  • crypto for determining the crypto mechanism, this can either be aws:kms or AES256 (default)
  • key-id for specifiying the customer KMS key to use for the SSE, if the crypto value passed is aws:kms the AWS default KMS key will be used instead.
  • report-only generate reports of unencrypted keys in a bucket, but do not remediate them.

Remediate Incoming

Note: the set-bucket-encryption action is a much more effective way of enabling encryption on a bucket.

Will scan all newly created objects and remediate them such that they are encrypted.

policies:
  - name: s3-attach-encryption
    resource: s3
    actions:
      - type: attach-encrypt
        role: arn:aws:iam::123456789012:role/my-role
        topic: arn:aws:sns::123456789012:my-topic

Options

  • role for the role the encrypting Lambda should run as (not necessary if you provide --assume-role on the command line).
  • topic for the SNS topic to subscribe the Lambda to. If you set topic to default then we will reuse any existing SNS topic that specifies s3:ObjectCreated:*, or set one up if needed. If topic is missing, then we’ll attach via a bucket notification.

Bucket Policy

Note: the set-bucket-encryption action is a much more effective way of enabling encryption on a bucket.

Adds an encryption required bucket policy and merges with extant policy statements. Note filters should be used to avoid hitting any buckets that are being written to by AWS services, as these do not write encrypted and will be blocked by this policy.

policies:
  - name: s3-encryption-policy
    resource: s3
    actions:
     - encryption-policy