Added option to use anonymity sets instead of cookies

Andrew committed May 02, 2018

commit 44f7956bad8662f1d28e3c97c7902d4201755548

Showing 6 changed files with 97 additions and 17 deletions

CHANGELOG.md +3 -2

@@	@@ -1,6 +1,7 @@
-	## 2.0.3 [unreleased]
+	## 2.1.0 [unreleased]

-	- Added IP masking
+	- Added option for IP masking
+	- Added option to use anonymity sets instead of cookies
	- Fixed `visitable` for Rails 4.2

	## 2.0.2

README.md +52 -0

@@	@@ -58,6 +58,37 @@ ahoy.track("My second event", {language: "JavaScript"});

	For Android, check out [Ahoy Android](https://github.com/instacart/ahoy-android). For other platforms, see the [API spec](#api-spec).

+	### GDPR Compliance [master]
+
+	Ahoy provides a number of options to help with [GDPR compliance](https://en.wikipedia.org/wiki/General_Data_Protection_Regulation).
+
+	Update `config/initializers/ahoy.rb` with:
+
+	```ruby
+	class Ahoy::Store < Ahoy::DatabaseStore
+	def authenticate(data)
+	# disables automatic linking of visits and users
+	end
+	end
+
+	Ahoy.mask_ips = true
+	Ahoy.cookies = false
+	```
+
+	This:
+
+	- Masks IP addresses
+	- Switches from cookies to anonymity sets
+	- Disables linking visits and users
+
+	If you use JavaScript tracking, also set:
+
+	```javascript
+	ahoy.configure({cookies: false});
+	```
+
+	Set [extended GDPR section](#gdpr-compliance-master-1) for more info.
+
	## How It Works

	### Visits
@@	@@ -314,6 +345,27 @@ Exceptions are rescued so analytics do not break your app. Ahoy uses [Safely](ht
	Safely.report_exception_method = ->(e) { Rollbar.error(e) }
	```

+	## GDPR Compliance [master]
+
+	### IP Masking
+
+	Ahoy can mask IPs with the same approach [Google Analytics uses for IP anonymization](https://support.google.com/analytics/answer/2763052). This means:
+
+	- For IPv4, the last octet is set to 0 (`8.8.4.4` becomes `8.8.4.0`)
+	- For IPv6, the last 80 bits are set to zeros (`2a03:2880:2110:df07:face:b00c::1` becomes `2a03:2880:2110::`)
+
+	```ruby
+	Ahoy.mask_ips = true
+	```
+
+	### Anonymity Sets & Cookies
+
+	Ahoy can switch from cookies to [anonymity sets](https://privacypatterns.org/patterns/Anonymity-set). Instead of cookies, visitors with the same IP mask and user agent are grouped together in an anonymity set.
+
+	```ruby
+	Ahoy.cookies = false
+	```
+
	## Development

	Ahoy is built with developers in mind. You can run the following code in your browser’s console.

ahoy.rb b/lib/ahoy.rb +3 -0

@@	@@ -24,6 +24,9 @@ module Ahoy
	mattr_accessor :visitor_duration
	self.visitor_duration = 2.years

+	mattr_accessor :cookies
+	self.cookies = true
+
	mattr_accessor :cookie_domain

	mattr_accessor :server_side_visits

ahoy/controller.rb b/lib/ahoy/controller.rb +7 -2

@@	@@ -21,8 +21,13 @@ module Ahoy
	end

	def set_ahoy_cookies
-	ahoy.set_visitor_cookie
-	ahoy.set_visit_cookie
+	if Ahoy.cookies
+	ahoy.set_visitor_cookie
+	ahoy.set_visit_cookie
+	else
+	# delete cookies if exist
+	ahoy.reset
+	end
	end

	def track_ahoy_visit

ahoy/tracker.rb b/lib/ahoy/tracker.rb +22 -5

@@	@@ -1,5 +1,9 @@
+	require "active_support/core_ext/digest/uuid"
+
	module Ahoy
	class Tracker
+	UUID_NAMESPACE = "a82ae811-5011-45ab-a728-569df7499c5f"
+
	attr_reader :request, :controller

	def initialize(**options)
@@	@@ -102,7 +106,7 @@ module Ahoy
	end

	def new_visit?
-	!existing_visit_token
+	Ahoy.cookies ? !existing_visit_token : visit.nil?
	end

	def new_visitor?
@@	@@ -156,7 +160,7 @@ module Ahoy
	end

	def missing_params?
-	if api? && Ahoy.protect_from_forgery
+	if Ahoy.cookies && api? && Ahoy.protect_from_forgery
	!(existing_visit_token && existing_visitor_token)
	else
	false
@@	@@ -164,6 +168,9 @@ module Ahoy
	end

	def set_cookie(name, value, duration = nil, use_domain = true)
+	# safety net
+	return unless Ahoy.cookies
+
	cookie = {
	value: value
	}
@@	@@ -174,7 +181,7 @@ module Ahoy
	end

	def delete_cookie(name)
-	request.cookie_jar.delete(name)
+	request.cookie_jar.delete(name) if request.cookie_jar[name]
	end

	def trusted_time(time = nil)
@@	@@ -200,6 +207,7 @@ module Ahoy
	def visit_token_helper
	@visit_token_helper \|\|= begin
	token = existing_visit_token
+	token \|\|= visit_hash unless Ahoy.cookies
	token \|\|= generate_id unless Ahoy.api_only
	token
	end
@@	@@ -208,6 +216,7 @@ module Ahoy
	def visitor_token_helper
	@visitor_token_helper \|\|= begin
	token = existing_visitor_token
+	token \|\|= visitor_hash unless Ahoy.cookies
	token \|\|= generate_id unless Ahoy.api_only
	token
	end
@@	@@ -216,7 +225,7 @@ module Ahoy
	def existing_visit_token
	@existing_visit_token \|\|= begin
	token = visit_header
-	token \|\|= visit_cookie unless api? && Ahoy.protect_from_forgery
+	token \|\|= visit_cookie if Ahoy.cookies && !(api? && Ahoy.protect_from_forgery)
	token \|\|= visit_param if api?
	token
	end
@@	@@ -225,12 +234,20 @@ module Ahoy
	def existing_visitor_token
	@existing_visitor_token \|\|= begin
	token = visitor_header
-	token \|\|= visitor_cookie unless api? && Ahoy.protect_from_forgery
+	token \|\|= visitor_cookie if Ahoy.cookies && !(api? && Ahoy.protect_from_forgery)
	token \|\|= visitor_param if api?
	token
	end
	end

+	def visit_hash
+	@visit_hash \|\|= Digest::UUID.uuid_v5(UUID_NAMESPACE, [Ahoy.mask_ip(request.remote_ip), request.user_agent].join("/"))
+	end
+
+	def visitor_hash
+	visit_hash
+	end
+
	def visit_cookie
	@visit_cookie \|\|= request && request.cookies["ahoy_visit"]
	end

vendor/assets/javascripts/ahoy.js +10 -8

@@	@@ -117,7 +117,8 @@
	platform: "Web",
	useBeacon: true,
	startOnReady: true,
-	trackVisits: true
+	trackVisits: true,
+	cookies: true
	};

	var ahoy = window.ahoy \|\| window.Ahoy \|\| {};
@@	@@ -228,7 +229,7 @@
	}

	function saveEventQueue() {
-	if (canStringify) {
+	if (config.cookies && canStringify) {
	setCookie("ahoy_events", JSON.stringify(eventQueue), 1);
	}
	}
@@	@@ -279,11 +280,12 @@

	function eventData(event) {
	var data = {
-	events: [event],
-	visit_token: event.visit_token,
-	visitor_token: event.visitor_token
+	events: [event]
	};
-	delete event.visit_token;
+	if (config.cookies) {
+	data.visit_token = event.visit_token;
+	data.visitor_token = event.visitor_token;
+	} delete event.visit_token;
	delete event.visitor_token;
	return data;
	}
@@	@@ -363,7 +365,7 @@
	visitorId = ahoy.getVisitorId();
	track = getCookie("ahoy_track");

-	if (config.trackVisits == false) {
+	if (config.cookies === false \|\| config.trackVisits === false) {
	log("Visit tracking disabled");
	setReady();
	} else if (visitId && visitorId && !track) {
@@	@@ -450,7 +452,7 @@
	};

	ready( function () {
-	if (!ahoy.getVisitId()) {
+	if (config.cookies && !ahoy.getVisitId()) {
	createVisit();
	}