The Data Masking plugin in TrustGate enables automatic redaction of sensitive information in incoming requests. This guide walks you through configuring a forwarding rule with data masking enabled to help protect fields such as passwords, API keys, and personal identifiers.

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Prerequisites

  • A TrustGate instance is running and accessible.
  • You have a valid Gateway and Service configured.
  • You have an API key with permission to create rules and plugins.

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Overview

The Data Masking plugin identifies sensitive data using either regex patterns or keyword matches, and replaces them with a configurable masking string. It supports:
  • Regex-based pattern matching
  • Fuzzy keyword detection
  • Case sensitivity configuration
  • Optional preservation of string length

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Use Case

You want to prevent downstream services from receiving user secrets such as:
  • API keys (e.g., secret_key)
  • Passwords in query parameters or body
  • Internal identifiers like INT-123456

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Step-by-Step: Add a Data Masking Rule

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1. Define the Rule Payload

Use the following JSON to create a forwarding rule with the data_masking plugin enabled: 
{
  "path": "/mask",
  "service_id": "{{service_id}}",
  "methods": ["POST"],
  "strip_path": true,
  "plugin_chain": [
    {
      "name": "data_masking",
      "enabled": true,
      "stage": "pre_request",
      "parallel": true,
      "priority": 1,
      "settings": {
        "similarity_threshold": 0.8,
        "apply_all": true,
        "rules": [
          {
            "pattern": "pattern_to_mask",
            "type": "keyword",
            "mask_with": "[MASKED_KEY]",
            "preserve_len": false,
            "fuzzy_match": true,
            "case_sensitive": false
          },
          {
            "pattern": "(?i)password=\\S+",
            "type": "regex",
            "mask_with": "[MASKED_PASSWORD]",
            "preserve_len": false
          },
          {
            "pattern": "INT-\\d{6}",
            "type": "regex",
            "mask_with": "[MASKED_ID]",
            "preserve_len": true
          }
        ]
      }
    }
  ],
  "active": true
}