rules:
- id: weak-hashes-sha1
  message: >-
    Should not use SHA1 to generate hashes. There is a proven SHA1 hash collision
    by Google, which could lead to vulnerabilities.
    Use SHA256, SHA3 or other hashing functions instead.
  metadata:
    cwe:
    - 'CWE-328: Use of Weak Hash'
    references:
    - https://security.googleblog.com/2017/02/announcing-first-sha1-collision.html
    - https://shattered.io/
    category: security
    technology:
    - ruby
    owasp:
    - A03:2017 - Sensitive Data Exposure
    - A02:2021 - Cryptographic Failures
    - A04:2025 - Cryptographic Failures
    subcategory:
    - vuln
    likelihood: LOW
    impact: MEDIUM
    confidence: MEDIUM
  languages:
  - ruby
  severity: WARNING
  pattern-either:
  - pattern: Digest::SHA1.$FUNC
  - pattern: OpenSSL::Digest::SHA1.$FUNC
  - pattern: OpenSSL::HMAC.$FUNC("sha1",...)