feat: Add metadata support to custom detectors

[effortlessdevsec]

Feature Request: Add Metadata Support to Custom Detectors

Summary

Add support for a metadata field in custom detector configurations that automatically populates the ExtraData field in detector results. This would allow users to attach custom key-value metadata directly in the YAML configuration without requiring code changes.

Use Case

Currently, custom detectors can only set metadata programmatically in the code. Users should be able to define metadata directly in their custom detector YAML configuration files, which would then be automatically included in the ExtraData field of all results from that detector.

This would be useful for:

• Adding environment tags (e.g., environment: production)
• Adding team ownership information (e.g., team: security)
• Adding severity levels (e.g., severity: high)
• Adding rotation guides or documentation links
• Adding any custom contextual information that should be associated with detected secrets

Proposed Implementation

1. Proto Definition Update

Add a metadata field to the CustomRegex message in proto/custom_detectors.proto:

message CustomRegex {
  // ... existing fields ...
  map<string, string> metadata = 12;
}

2. Code Implementation

Update pkg/custom_detectors/custom_detectors.go to copy metadata from the detector configuration to ExtraData when creating results:

// In createResults function
if metadata := c.GetMetadata(); metadata != nil {
    for key, value := range metadata {
        result.ExtraData[key] = value
    }
}

Example Usage

YAML Configuration

detectors:
- name: my-api-key-detector
  keywords:
  - api
  - key
  regex:
    api_key: "your-regex-here"
  metadata:
    environment: "production"
    team: "security"
    severity: "high"
    rotation_guide: "https://example.com/rotate-api-keys"
    custom_field: "any value"

Result

All results from this detector would automatically include the metadata in ExtraData:

{
  "DetectorName": "my-api-key-detector",
  "ExtraData": {
    "name": "my-api-key-detector",
    "environment": "production",
    "team": "security",
    "severity": "high",
    "rotation_guide": "https://example.com/rotate-api-keys",
    "custom_field": "any value"
  }
}

[kashifkhan0771]

You need to run the command make protos after making changes in the .proto file.