Class: CreditCardSanitizer

Inherits:
Object
  • Object
show all
Defined in:
lib/credit_card_sanitizer.rb

Defined Under Namespace

Classes: Candidate

Constant Summary collapse

CARD_COMPANIES =

github.com/Shopify/active_merchant/blob/master/lib/active_merchant/billing/credit_card_methods.rb#L5-L18

{
  'visa'               => /^4\d{12}(\d{3})?(\d{3})?$/,
  'master'             => /^(5[1-5]\d{4}|677189|222[1-9]\d{2}|22[3-9]\d{3}|2[3-6]\d{4}|27[01]\d{3}|2720\d{2})\d{10}$/,
  'discover'           => /^((6011|65\d{2}|64[4-9]\d)\d{12}|(62\d{14}))$/,
  'american_express'   => /^3[47]\d{13}$/,
  'diners_club'        => /^3(0[0-5]|[68]\d)\d{11}$/,
  'jcb'                => /^35(28|29|[3-8]\d)\d{12}$/,
  'switch'             => /^6759\d{12}(\d{2,3})?$/,
  'solo'               => /^6767\d{12}(\d{2,3})?$/,
  'dankort'            => /^5019\d{12}$/,
  'maestro'            => /^(5[06-8]|6\d)\d{10,17}$/,
  'forbrugsforeningen' => /^600722\d{10}$/,
  'laser'              => /^(6304|6706|6709|6771(?!89))\d{8}(\d{4}|\d{6,7})?$/
}.freeze
CARD_NUMBER_GROUPINGS = 
{
  'visa'               => [[4, 4, 4, 4]],
  'master'             => [[4, 4, 4, 4]],
  'discover'           => [[4, 4, 4, 4]],
  'american_express'   => [[4, 6, 5]],
  'diners_club'        => [[4, 6, 4]],
  'jcb'                => [[4, 4, 4, 4]],
  'switch'             => [[4, 4, 4, 4]],
  'solo'               => [[4, 4, 4, 4]],
  'dankort'            => [[4, 4, 4, 4]],
  'maestro'            => [[4], [5]],
  'forbrugsforeningen' => [[4, 4, 4, 4]],
  'laser'              => [[4, 4, 4, 4]]
}.freeze
ACCEPTED_PREFIX = 
/(?:cc|card|visa|amex)\z/i
ACCEPTED_POSTFIX = 
/\Aex/i
ALPHANUMERIC = 
/[[:alnum:]]/i
VALID_COMPANY_PREFIXES = 
Regexp.union(*CARD_COMPANIES.values)
EXPIRATION_DATE = 
/\s(?:0?[1-9]|1[0-2])(?:\/|-)(?:\d{4}|\d{2})(?:\D|$)/
LINE_NOISE_CHAR = 
/[^\w\n,()&.\/:;<>]/
LINE_NOISE = 
/#{LINE_NOISE_CHAR}{,5}/
NONEMPTY_LINE_NOISE = 
/#{LINE_NOISE_CHAR}{1,5}/
SCHEME_OR_PLUS = 
/((?:&#43;|\+)|(?:[a-zA-Z][\-+.a-zA-Z\d]{,9}):[^\s>]+)/
NUMBERS_WITH_LINE_NOISE = 
/#{SCHEME_OR_PLUS}?\d(?:#{LINE_NOISE}\d){10,30}/
DEFAULT_OPTIONS = 
{
  replacement_token: '▇',
  expose_first: 6,
  expose_last: 4,
  use_groupings: false,
  exclude_tracking_numbers: false,
  parse_flanking: false
}.freeze

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ CreditCardSanitizer

Create a new CreditCardSanitizer

Options

:replacement_character - the character that will replace digits for redaction. :expose_first - the number of leading digits that will not be redacted. :expose_last - the number of ending digits that will not be redacted. :use_groupings - require card number groupings to match to redact. :exclude_tracking_numbers - do not redact valid shipping company tracking numbers.



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# File 'lib/credit_card_sanitizer.rb', line 73

def initialize(options = {})
  @settings = DEFAULT_OPTIONS.merge(options)
end

Instance Attribute Details

#settings ⇒ Object (readonly)

Returns the value of attribute settings.



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# File 'lib/credit_card_sanitizer.rb', line 59

def settings
  @settings
end

Class Method Details

.parameter_filter(options = {}) ⇒ Object

A proc that can be used

text - the text containing potential credit card numbers

Examples

Rails.app.config.filter_parameters = [:password, CreditCardSanitizer.parameter_filter]

env = {
  "action_dispatch.request.parameters" => {"credit_card_number" => "4111 1111 1111 1111", "password" => "123"},
  "action_dispatch.parameter_filter" => Rails.app.config.filter_parameters
}

>> ActionDispatch::Request.new(env).filtered_parameters
=> {"credit_card_number" => "4111 11▇▇ ▇▇▇▇ 1111", "password" => "[FILTERED]"}

Returns a Proc that takes the key/value of the request parameter.



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# File 'lib/credit_card_sanitizer.rb', line 135

def self.parameter_filter(options = {})
  proc { |_, value| new(options).sanitize!(value) if value.is_a?(String) }
end

Instance Method Details

#sanitize!(text, options = {}) ⇒ Object

Finds credit card numbers and redacts digits from them

text - the text containing potential credit card numbers

Examples

# If the text contains a credit card number:
sanitize!("4111 1111 1111 1111")
#=> "4111 11▇▇ ▇▇▇▇ 1111"

# If the text does not contain a credit card number:
sanitize!("I want all your credit card numbers!")
#=> nil

Returns a String of the redacted text if a credit card number was detected. Returns nil if no credit card numbers were detected.



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# File 'lib/credit_card_sanitizer.rb', line 93

def sanitize!(text, options = {})
  options = @settings.merge(options)

  text.force_encoding(Encoding::UTF_8)
  text.scrub!('�')
  redacted = nil

  without_expiration(text) do
    text.gsub!(NUMBERS_WITH_LINE_NOISE) do |match|
      next match if $1

      candidate = Candidate.new(match, match.tr('^0-9', ''), $`, $')

      if valid_context?(candidate, options) && valid_numbers?(candidate, options)
        redacted = true
        redact_numbers(candidate, options)
      else
        match
      end
    end
  end

  redacted && text
end