rules:
- id: aws-cloudwatch-log-group-unencrypted
  patterns:
  - pattern: |
      resource "aws_cloudwatch_log_group" $ANYTHING {
        ...
      }
  - pattern-not-inside: |
      resource "aws_cloudwatch_log_group" $ANYTHING {
        ...
        kms_key_id = ...
        ...
      }
  message: >-
    By default, AWS CloudWatch Log Group is encrypted using AWS-managed keys.
    However, for added security, it's recommended to configure your own AWS KMS encryption key to protect your log group in CloudWatch.
    You can either create a new aws_kms_key resource or use the ARN of an existing key in your AWS account to do so.
  languages: [hcl]
  severity: WARNING
  metadata:
    owasp:
    - A02:2021 - Cryptographic Failures
    cwe:
    - 'CWE-732: Incorrect Permission Assignment for Critical Resource'
    technology:
    - aws
    - terraform
    category: security
    references:
    - https://cwe.mitre.org/data/definitions/732.html
    cwe2021-top25: true
    subcategory:
    - audit
    likelihood: LOW
    impact: LOW
    confidence: LOW