Security/Safe Browsing
Note: The Safe Browsing feature in Firefox has been renamed to Phishing Protection, but it's still known as Safe Browsing internally.
Download Protection and Tracking protection have their own separate pages.
History
Google Safe Browsing was an anti-phishing extension released by Google on labs.google.com in December 2005. Google has released this extension to the Mozilla Foundation under MPL 1.1/GPL 2.0/LGPL 2.1 in order that it might be used as part of Firefox if desired. We've landed this change on the trunk as a global extension as of 7 March 2006. You can read the discussion that lead up to to its integration in https://bugzilla.mozilla.org/show_bug.cgi?id=329292
Google is migrating Safe Browsing to v4 protocol since 2015 and we are now working on integrating to our code base with a incremental approach. That is, we will be landing v4 patches progressively and leave v2 up and running until v4 is extensively tested. In other words, v2 and v4 will co-exist for a while to make sure Safe Browsing feature not broken. See https://wiki.mozilla.org/Security/Safe_Browsing/V4_Implementation to know the plans and milestones for v4 implementation.
Prefs
- browser.safebrowsing.blockedURIs.enabled: enable the plugin stability blocking (no override or UI)
- browser.safebrowsing.debug: show debugging info from the JavaScript list update code on the command line
- browser.safebrowsing.id: what SAFEBROWSING_ID in gethashURL and updateURL maps to
- browser.safebrowsing.malware.enabled: enable malware protection (includes unwanted as well)
- browser.safebrowsing.provider.google.gethashURL: server endpoint for completions of malware and phishing lists
- browser.safebrowsing.provider.google.lists: list of tables coming from the Google Safe Browsing service
- browser.safebrowsing.provider.google.reportURL: probably unused
- browser.safebrowsing.provider.google.updateURL: server endpoint for malware and phishing list updates
- browser.safebrowsing.provider.google.lastupdatetime: timestamp (in ms) of when the last list update happened.
- browser.safebrowsing.provider.google.nextupdatetime: timestamp (in ms) of when the list should next be downloaded.
- browser.safebrowsing.reportMalwareMistakeURL: destination for the "This isn't an attack site" button (after ignoring the interstitial warning)
- browser.safebrowsing.reportPhishMistakeURL: destination for the "This isn't a web forgery" button (after ignoring the interstitial warning)
- browser.safebrowsing.reportPhishURL: destination for the "Help | Report Web Forgery" menu item
- urlclassifier.blockedTable: list of tables to use for the plugin stability blocking
- urlclassifier.disallow_completions: list of tables for which we never call gethash
- urlclassifier.gethashnoise: the number of fake entries to add to any gethash calls
- urlclassifier.gethash.timeout_ms: the timeout after which gethash requests should be aborted
- urlclassifier.malwareTable: list of tables to use when looking for malware (they need to be named *-malware-* or *-unwanted-*)
- urlclassifier.max-complete-age
- urlclassifier.phishTable: list of tables to use when looking for phishing (they need to be named *-phish-*)
Firefox 49 and earlier:
- browser.safebrowsing.enabled: enable phishing protection
Firefox 50 and later:
- browser.safebrowsing.phishing.enabled: enable phishing protection
Documentation
- Safe Browsing Protocol v2.2 and v4
- Design Documentation
- Server Spec
- Client Spec
- SUMO
- Overview of how Safe Browsing works in Firefox
Engineering
Product/Component: Toolkit/Safe Browsing
- Tracking bug
- The Firefox implementation is split into a few parts:
- browser/components/safebrowsing/ (front-end tests)
- netwerk/base/nsChannelClassifier
- toolkit/components/url-classifier/ (includes the list manager)
- Local store is in:
- ~/.cache/mozilla/firefox/XXXX/safebrowsing/ on Linux
- ~/Library/Caches/Firefox/Profiles/XXXX/safebrowsing/ on Mac
- C:\Users\XXXX\AppData\Local\mozilla\firefox\profiles\XXXX\safebrowsing\ on Windows
- itisatrap.org test pages
- Telemetry dashboard
Code walkthrough
Both nsBaseChannel::Open() and nsBaseChannel::AsyncOpen() ask for the channel to be "classified" by nsChannelClassifier. There is also a local-only classification that is requested by tracking protection.
The classifier determines the type of URL that it is and then returns the appropriate NS_ERROR code. That causes the channel to be cancelled with that error code.
When the classification state of the page changes, the appropriate UI is shown.
QA
- Test pages
- Malware, phishing, unwanted software and forbidden hard-coded test URLs
- Phishtank (real phishing sites)
- Google test pages (we don't implement: Clank Warnings, Client-side phishing detection, Bad IP Warnings)
- Meta QA bug
- Info on why certain URLs are blocked
- Script to dump the contents of the local store
- UI tests (Marionette)
- Mozmill test for initial list download (needs to be ported to Marionette)
To turn on debugging output, export the following environment variable:
MOZ_LOG="UrlClassifierDbService:5,nsChannelClassifier:5,UrlClassifierProtocolParser:5,UrlClassifierStreamUpdater:5,UrlClassifierPrefixSet:5"
and also see the browser.safebrowsing.debug pref to see debugging output from the JS pieces of Safe Browsing.
Telemetry
- Performance
- URLCLASSIFIER_CL_CHECK_TIME: how long a Safe Browsing lookup took
- URLCLASSIFIER_CL_UPDATE_TIME: how long table updates takes
- URLCLASSIFIER_LOOKUP_TIME: time spent in the dbservice while doing a lookup
- URLCLASSIFIER_PS_CONSTRUCT_TIME: time spent constructing a PrefixSet
- URLCLASSIFIER_PS_FALLOCATE_TIME: time spent allocating a PrefixSet
- URLCLASSIFIER_PS_FILELOAD_TIME: time spent loading PrefixSet from disk
- Server-related
- URLCLASSIFIER_COMPLETE_TIMEOUT: whether or not a client timed out while contacting the gethash server
- URLCLASSIFIER_COMPLETE_REMOTE_STATUS: HTTP status code returned by the gethash server
- URLCLASSIFIER_UPDATE_REMOTE_STATUS: HTTP status code returned by the update server
- Database size
- URLCLASSIFIER_LC_COMPLETIONS: number of entries in the completion cache
- URLCLASSIFIER_LC_PREFIXES: number of entries in the prefix cache
Links
- Google reporting forms:
- Malware
- Phishing -- Firefox-specific
- Phishing error (false positive) -- Firefox-specific