philiprehberger-mask

Data masking library — auto-detect and redact PII (emails, credit cards, SSNs, tokens) in strings and nested structures.

Requirements

Ruby >= 3.1

Installation

Add to your Gemfile:

gem "philiprehberger-mask"

Then run:

bundle install

Or install directly:

gem install philiprehberger-mask

Usage

require "philiprehberger/mask"

Philiprehberger::Mask.scrub("Contact us at user@example.com")
# => "Contact us at u***@e******.com"

Hash Scrubbing

Philiprehberger::Mask.scrub_hash({
  name: "Alice",
  email: "alice@example.com",
  password: "secret123",
  nested: { ssn: "123-45-6789" }
})
# => { name: "Alice", email: "a***@e******.com", password: "[FILTERED]", nested: { ssn: "***-**-6789" } }

Custom Patterns

Philiprehberger::Mask.configure do |c|
  c.add_pattern(:order_id, /ORD-\d{10}/, replacement: "ORD-XXXXXXXXXX")
end

Built-in Detectors

Detector	Pattern	Masking
Email	`user@example.com`	`u*@e****.com`
Credit Card	`4111-1111-1111-1111`	`**--**-1111`
SSN	`123-45-6789`	`*--6789`
Phone	`555-123-4567`	`*-*-4567`
IP Address	`192.168.1.1`	`*...*`
JWT	`eyJ...`	`[REDACTED_JWT]`

API

Method	Description
`Mask.scrub(string)`	Detect and redact PII in a string
`Mask.scrub_hash(hash, keys: nil)`	Deep-walk and redact hash values
`Mask.configure { \|c\| ... }`	Register custom patterns
`Mask.reset_configuration!`	Reset to default patterns

Development

bundle install
bundle exec rspec      # Run tests
bundle exec rubocop    # Check code style

License

MIT