Sensitive Param Filter

sensitive-param-filter is a zero-dependency package designed to filter sensitive values from JavaScript objects. This package can be used to scrub logs, filer data before outputting to a UI, etc. The defaults provided with sensitive-param-filter should work well for most applications.

Installation

Install sensitive-param-filter to your project via either npm:

npm install @amaabca/sensitive-param-filter

or yarn:

yarn add @amaabca/sensitive-param-filter

Usage

const { SensitiveParamFilter } = require('@amaabca/sensitive-param-filter')
const paramFilter = new SensitiveParamFilter()
const rawObject = {
  Authorization: 'Bearer somedatatoken',
  body: {
    info: '{ "amount": 28.64, "credit_card": "4242424242424242", "cvv": "123" }'
  },
  method: 'POST',
  url: 'https://pay.example.com?user=bob.bobbington&password=asecurepassword1234'
}
const filteredObject = paramFilter.filter(rawObject)
// filteredObject = {
//   Authorization: 'FILTERED',
//   body: {
//     info: '{ "amount": 28.64, "credit_card": "FILTERED", "cvv": "FILTERED" }'
//   },
//   method: 'POST',
//   url: 'https://pay.example.com?user=bob.bobbington&password=FILTERED'
// }

Details

sensitive-param-filter examines keys to determine which values to filter. Key matching is done in a case-insensitive, partial-macthing manner (that is, if the param AUTH is provided, Authorization, AUTHENTICATION, etc. will be filtered).

Key Features

• Does not modify input objects
• Performs a deep copy of the input object (note that booleans, numbers, and strings - which are immutable - are technically copied by reference)
• Can be configued to filter out or leave "unexpected" objects (such as functions)
• Handles circular references
• Filters valid JSON strings
• Filters valid and malformed URL query params
• Filters Errors, Arrays, Maps, Sets, and simple objects

Options

const { SPFDefaultParams, SensitiveParamFilter } = require('@amaabca/sensitive-param-filter')
const filter = new SensitiveParamFilter({
  filterUnknown: false,
  params: SPFDefaultParams.concat(['data', 'email']),
  replacement: '***',
  whitelist: ['authentic', 'encryption_standard']
})

• filterUnknown: Indicates whether "unexpected" objects (such as functions) should be filtered or returned as-is. Defaults to true

• params: An array of string params to filter. These entries will be combined into a regex that is used by sensitive-param-filter. Setting this option overwrites the default array (SPFDefaultParams).

• replacement: The object to replace filtered values with. Defaults to 'FILTERED'.

• whitelist: An array of strings to exclude from filtering. For example, if pass_through is including in the whitelist, the key pass_through will not be filtered. Note that entries must match keys exactly to prevent filtering - that is, whitelisting secrets still causes secrets_store to be filtered.

Default Values

See defaults. Note that all of these values can be overridden via the options.

The default keys that are filtered are:

• auth
• bearer
• credit
• CVD
• CVV
• encrypt
• PAN
• pass
• secret
• token

License & Contributing

sensitive-param-filter uses the MIT license. See the license.

We welcome contributions. See contributing.