rules:
- id: ruby-jwt-none-alg
  message: >-
    Detected use of the 'none' algorithm in a JWT token.
    The 'none' algorithm assumes the integrity of the token has already
    been verified. This would allow a malicious actor to forge a JWT token
    that will automatically be verified. Do not explicitly use the 'none'
    algorithm. Instead, use an algorithm such as 'HS256'.
  metadata:
    cwe: 'CWE-327: Use of a Broken or Risky Cryptographic Algorithm'
    owasp: 'A2: Broken Authentication'
    source-rule-url: https://r2c.dev/blog/2020/hardcoded-secrets-unverified-tokens-and-other-common-jwt-mistakes/
    category: security
    technology:
    - jwt
  languages: [ruby]
  severity: ERROR
  patterns:
  - pattern-inside: |
      require 'jwt'
      ...
  - pattern: |
      JWT.encode($PAYLOAD, $SECRET, 'none', ...)