rules:
- id: aws-elasticsearch-nodetonode-encryption-not-enabled
  patterns:
  - pattern-either:
    - pattern: |
        resource "aws_elasticsearch_domain" $ANYTHING {
          ...
          node_to_node_encryption {
            ...
            enabled = false
            ...
          }
          ...
        }
    - pattern: |
        resource "aws_elasticsearch_domain" $ANYTHING {
          ...
          cluster_config {
            ...
            instance_count = $COUNT
            ...
          }
        }
  - pattern-not-inside: |
      resource "aws_elasticsearch_domain" $ANYTHING {
        ...
        cluster_config {
          ...
          instance_count = $COUNT
          ...
        }
        node_to_node_encryption {
          ...
          enabled = true
          ...
        }
      }
  - metavariable-comparison:
      metavariable: $COUNT
      comparison: $COUNT > 1
  message: >-
    Ensure all Elasticsearch has node-to-node encryption enabled.	
  metadata:
    category: security
    technology:
    - terraform
    - aws
    owasp:
    - A03:2017 - Sensitive Data Exposure
    - A02:2021 - Cryptographic Failures
    cwe:
    - 'CWE-326: Inadequate Encryption Strength'
    references:
    - https://owasp.org/Top10/A02_2021-Cryptographic_Failures
    subcategory:
    - vuln
    likelihood: LOW
    impact: MEDIUM
    confidence: MEDIUM
  languages: [hcl]
  severity: WARNING