Class: PromptSanitizer::Engines::SecretsEngine

Inherits:
Object
  • Object
show all
Defined in:
lib/prompt_sanitizer/engines/secrets_engine.rb

Overview

Secrets Engine — Layer 1 of prompt-sanitizer (secrets branch).

Detects credentials, API keys, tokens, and connection strings that should never reach an LLM. Runs alongside the RegexEngine on every sanitize() call.

Defined Under Namespace

Classes: Pattern

Constant Summary collapse

PATTERNS = 
[
  # ── JWT (header.payload.signature) ────────────────────────────────────
  Pattern.new(
    entity_type: EntityType::JWT,
    regex:       /eyJ[a-zA-Z0-9_\-]{10,}\.eyJ[a-zA-Z0-9_\-]{10,}\.[a-zA-Z0-9_\-]{10,}/,
    confidence:  0.99,
    label:       "JWT"
  ),

  # ── Bearer token ──────────────────────────────────────────────────────
  Pattern.new(
    entity_type: EntityType::BEARER_TOKEN,
    regex:       /(?:Authorization\s*:\s*)?Bearer\s+([a-zA-Z0-9_\-\.]{20,})/i,
    confidence:  0.92,
    label:       "Bearer token"
  ),

  # ── AWS Access Key ID ──────────────────────────────────────────────────
  Pattern.new(
    entity_type: EntityType::AWS_ACCESS_KEY,
    regex:       /(?<![A-Z0-9])(?:A3T[A-Z0-9]|AKIA|AGPA|AIDA|AROA|AIPA|ANPA|ANVA|ASIA)[A-Z0-9]{16}(?![A-Z0-9])/,
    confidence:  0.99,
    label:       "AWS access key ID"
  ),

  # ── AWS Secret Access Key (context-anchored) ───────────────────────────
  Pattern.new(
    entity_type: EntityType::AWS_SECRET_KEY,
    regex:       /(?:aws_secret(?:_access)?_key|secret_access_key)\s*[=:"'\s]\s*([a-zA-Z0-9+\/]{40})/i,
    confidence:  0.97,
    label:       "AWS secret access key"
  ),

  # ── OpenAI API key ─────────────────────────────────────────────────────
  Pattern.new(
    entity_type: EntityType::API_KEY,
    regex:       /sk-(?:proj-|org-)?[a-zA-Z0-9_\-T]{20,}/,
    confidence:  0.97,
    label:       "OpenAI API key"
  ),

  # ── Anthropic API key ──────────────────────────────────────────────────
  Pattern.new(
    entity_type: EntityType::API_KEY,
    regex:       /sk-ant-(?:api\d{2}-)?[a-zA-Z0-9_\-]{20,}/,
    confidence:  0.99,
    label:       "Anthropic API key"
  ),

  # ── GitHub Personal Access Token (classic) ─────────────────────────────
  Pattern.new(
    entity_type: EntityType::API_KEY,
    regex:       /ghp_[a-zA-Z0-9]{36}/,
    confidence:  0.99,
    label:       "GitHub PAT (classic)"
  ),

  # ── GitHub Fine-grained PAT ────────────────────────────────────────────
  Pattern.new(
    entity_type: EntityType::API_KEY,
    regex:       /github_pat_[a-zA-Z0-9_]{82}/,
    confidence:  0.99,
    label:       "GitHub fine-grained PAT"
  ),

  # ── GitHub OAuth / server-to-server / refresh ──────────────────────────
  Pattern.new(
    entity_type: EntityType::API_KEY,
    regex:       /(?:gho|ghs|ghr)_[a-zA-Z0-9]{36}/,
    confidence:  0.99,
    label:       "GitHub OAuth/server token"
  ),

  # ── Slack tokens ───────────────────────────────────────────────────────
  Pattern.new(
    entity_type: EntityType::API_KEY,
    regex:       /xox[baprs]-(?:[0-9a-zA-Z]{4,}-)+[0-9a-zA-Z]{4,}/,
    confidence:  0.98,
    label:       "Slack token"
  ),

  # ── Stripe secret / publishable key ───────────────────────────────────
  Pattern.new(
    entity_type: EntityType::API_KEY,
    regex:       /(?:sk|pk)_(?:live|test)_[a-zA-Z0-9]{24,}/,
    confidence:  0.99,
    label:       "Stripe API key"
  ),

  # ── Twilio Account SID ─────────────────────────────────────────────────
  Pattern.new(
    entity_type: EntityType::API_KEY,
    regex:       /AC[a-f0-9]{32}/,
    confidence:  0.90,
    label:       "Twilio Account SID"
  ),

  # ── Twilio Auth Token ──────────────────────────────────────────────────
  Pattern.new(
    entity_type: EntityType::API_KEY,
    regex:       /(?:auth_token|TWILIO_AUTH_TOKEN)\s*[=:"'\s]\s*([a-f0-9]{32})/i,
    confidence:  0.97,
    label:       "Twilio Auth Token"
  ),

  # ── Google API key ─────────────────────────────────────────────────────
  Pattern.new(
    entity_type: EntityType::API_KEY,
    regex:       /AIza[0-9A-Za-z_\-]{35}/,
    confidence:  0.99,
    label:       "Google API key"
  ),

  # ── SendGrid API key ───────────────────────────────────────────────────
  Pattern.new(
    entity_type: EntityType::API_KEY,
    regex:       /SG\.[a-zA-Z0-9_\-]{22}\.[a-zA-Z0-9_\-]{43}/,
    confidence:  0.99,
    label:       "SendGrid API key"
  ),

  # ── Mailchimp API key ──────────────────────────────────────────────────
  Pattern.new(
    entity_type: EntityType::API_KEY,
    regex:       /[a-f0-9]{32}-us\d{1,2}/,
    confidence:  0.90,
    label:       "Mailchimp API key"
  ),

  # ── HuggingFace token ──────────────────────────────────────────────────
  Pattern.new(
    entity_type: EntityType::API_KEY,
    regex:       /hf_[a-zA-Z0-9]{34,}/,
    confidence:  0.99,
    label:       "HuggingFace token"
  ),

  # ── PEM private key header ─────────────────────────────────────────────
  Pattern.new(
    entity_type: EntityType::PRIVATE_KEY,
    regex:       /-----BEGIN (?:RSA |EC |DSA |OPENSSH |ENCRYPTED |PGP )?PRIVATE KEY-----/,
    confidence:  0.99,
    label:       "PEM private key"
  ),

  # ── Database connection strings ────────────────────────────────────────
  Pattern.new(
    entity_type: EntityType::DB_CONNECTION,
    regex:       /(?:postgres(?:ql)?|mysql|mariadb|mongodb(?:\+srv)?|rediss?|mssql|sqlserver|oracle|clickhouse|cassandra|couchdb|neo4j):\/\/[^\s'"`<>\n]{8,}/i,
    confidence:  0.97,
    label:       "Database connection string"
  ),

  # ── Generic secret assignment (SECRET_KEY=..., api_key: '...') ─────────
  Pattern.new(
    entity_type: EntityType::API_KEY,
    regex:       /(?:secret[_\-]?key|api[_\-]?key|access[_\-]?token|auth[_\-]?token|private[_\-]?key|client[_\-]?secret)\s*[=:"'\s]+\s*([a-zA-Z0-9_\-\.+\/]{16,})/i,
    confidence:  0.80,
    label:       "Generic secret assignment"
  ),
].freeze

Instance Method Summary collapse

Constructor Details

#initialize ⇒ SecretsEngine

── Instance ─────────────────────────────────────────────────────────────



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# File 'lib/prompt_sanitizer/engines/secrets_engine.rb', line 176

def initialize
  @patterns = PATTERNS.dup
end

Instance Method Details

#add_pattern(entity_type, regex, label: "custom secret", confidence: 0.85) ⇒ Object

Register a custom secret pattern at runtime.



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# File 'lib/prompt_sanitizer/engines/secrets_engine.rb', line 181

def add_pattern(entity_type, regex, label: "custom secret", confidence: 0.85)
  @patterns << Pattern.new(
    entity_type: entity_type,
    regex:       regex,
    confidence:  confidence,
    label:       label
  )
end

#detect(text) ⇒ Object

Scan text for secrets and return an Array of DetectedEntity. When the pattern has a capturing group, the captured value and its offsets are used; otherwise the full match is used.



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# File 'lib/prompt_sanitizer/engines/secrets_engine.rb', line 193

def detect(text)
  safe_text = text.encode("UTF-8", invalid: :replace, undef: :replace, replace: "")
  entities  = []

  @patterns.each do |pat|
    safe_text.scan(pat.regex) do
      m = Regexp.last_match

      # Use capture group 1 when present (strips surrounding context)
      if m.captures.any?
        value     = m[1]
        start_pos = m.begin(1)
        end_pos   = m.end(1)
      else
        value     = m[0]
        start_pos = m.begin(0)
        end_pos   = m.end(0)
      end

      next if value.nil? || value.empty?

      entities << DetectedEntity.new(
        entity_type: pat.entity_type,
        original:    value,
        replacement: nil,
        start_pos:   start_pos,
        end_pos:     end_pos,
        confidence:  pat.confidence,
        layer:       :secrets
      )
    end
  end

  entities
end