---
# CodeQL Custom Model - SSRF Protection Sanitizers
# This file declares functions that sanitize user-controlled input for SSRF protection.
#
# Architecture: 4-Layer Defense-in-Depth
# Layer 1: Format Validation (utils.ValidateURL)
# Layer 2: Security Validation (security.ValidateExternalURL) - DNS resolution + IP blocking
# Layer 3: Connection-Time Validation (ssrfSafeDialer) - Re-resolve DNS, re-validate IPs
# Layer 4: Request Execution (TestURLConnectivity) - HEAD request, 5s timeout, max 2 redirects
#
# Blocked IP Ranges (13+ CIDR blocks):
# - RFC 1918: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16
# - Loopback: 127.0.0.0/8, ::1/128
# - Link-Local: 169.254.0.0/16 (AWS/GCP/Azure metadata), fe80::/10
# - Reserved: 0.0.0.0/8, 240.0.0.0/4, 255.255.255.255/32
# - IPv6 Unique Local: fc00::/7
#
# Reference: /docs/plans/current_spec.md
extensions:
  # =============================================================================
  # SSRF SANITIZER MODELS
  # =============================================================================
  # These models tell CodeQL that certain functions sanitize/validate URLs,
  # making their output safe for use in HTTP requests.
  #
  # IMPORTANT: For SSRF protection, we use 'sinkModel' with 'request-forgery'
  # to mark inputs as sanitized sinks, AND 'neutralModel' to prevent taint
  # propagation through validation functions.
  # =============================================================================

  # Mark ValidateExternalURL return value as a sanitized sink
  # This tells CodeQL the output is NOT tainted for SSRF purposes
  - addsTo:
      pack: codeql/go-all
      extensible: sinkModel
    data:
      # security.ValidateExternalURL validates and sanitizes URLs by:
      # 1. Validating URL format and scheme
      # 2. Performing DNS resolution with timeout
      # 3. Blocking private/reserved IP ranges (13+ CIDR blocks)
      # 4. Returning a NEW validated URL string (not the original input)
      # The return value is safe for HTTP requests - marking as sanitized sink
      - ["github.com/Wikid82/charon/backend/internal/security", "ValidateExternalURL", "Argument[0]", "request-forgery", "manual"]

  # Mark validation functions as neutral (don't propagate taint through them)
  - addsTo:
      pack: codeql/go-all
      extensible: neutralModel
    data:
      # network.IsPrivateIP is a validation function (neutral - doesn't propagate taint)
      - ["github.com/Wikid82/charon/backend/internal/network", "IsPrivateIP", "manual"]
      # TestURLConnectivity validates URLs internally via security.ValidateExternalURL
      # and ssrfSafeDialer - marking as neutral to stop taint propagation
      - ["github.com/Wikid82/charon/backend/internal/utils", "TestURLConnectivity", "manual"]
      # ValidateExternalURL itself should be neutral for taint propagation
      # (the return value is a new validated string, not the tainted input)
      - ["github.com/Wikid82/charon/backend/internal/security", "ValidateExternalURL", "manual"]

  # Mark log sanitization functions as sanitizers for log injection (CWE-117)
  # These functions remove newlines and control characters from user input before logging
  - addsTo:
      pack: codeql/go-all
      extensible: summaryModel
    data:
      # util.SanitizeForLog sanitizes strings by:
      # 1. Replacing \r\n and \n with spaces
      # 2. Removing all control characters [\x00-\x1F\x7F]
      # Input: Argument[0] (unsanitized string)
      # Output: ReturnValue[0] (sanitized string - safe for logging)
      - ["github.com/Wikid82/charon/backend/internal/util", "SanitizeForLog", "Argument[0]", "ReturnValue[0]", "taint", "manual"]
      # handlers.sanitizeForLog is a local sanitizer with same behavior
      - ["github.com/Wikid82/charon/backend/internal/api/handlers", "sanitizeForLog", "Argument[0]", "ReturnValue[0]", "taint", "manual"]
