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

npm install sensitive-param-filter

import { SensitiveParamFilter } from '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'
// }

sensitive-param-filter examines keys to determine which values to filter. Partial matches and case-insensitive matches are filtered - if the key AUTH is provided, Authorization, AUTHENTICATION, etc. will be filtered.

• Does not modify input objects
• Performs a deep copy of the input object
• 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

import { SPFDefaultFilteredKeys, SensitiveParamFilter } from 'sensitive-param-filter'
const filter = new SensitiveParamFilter({
  filterUnknown: false,
  keysToFilter: SPFDefaultFilteredKeys.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

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

• 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.

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