Merge pull request #1837 from MetaMask/i1833-levencheck

Levenshtein Checking Logic Added To Blacklist

4 files changed, 62 insertions, 8 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c5f727586..ab5d635d3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@
 
 - Fix bugs that could sometimes result in failed transactions after switching networks.
 - Include stack traces in txMeta's to better understand the life cycle of transactions
+- Enhance blacklister functionality to include levenshtein logic. (credit to @sogoiii and @409H for their help!)
 
 ## 3.9.1 2017-7-19
 
diff --git a/app/scripts/blacklister.js b/app/scripts/blacklister.js
index a45265a75..9337599cc 100644
--- a/app/scripts/blacklister.js
+++ b/app/scripts/blacklister.js
@@ -1,13 +1,41 @@
-const blacklistedDomains = require('etheraddresslookup/blacklists/domains.json')

+const levenshtein = require('fast-levenshtein')

+const blacklistedMetaMaskDomains = ['metamask.com']

+const blacklistedDomains = require('etheraddresslookup/blacklists/domains.json').concat(blacklistedMetaMaskDomains)

+const whitelistedMetaMaskDomains = ['metamask.io', 'www.metamask.io']

+const whitelistedDomains = require('etheraddresslookup/whitelists/domains.json').concat(whitelistedMetaMaskDomains)

+const LEVENSHTEIN_TOLERANCE = 4

+const LEVENSHTEIN_CHECKS = ['myetherwallet', 'myetheroll', 'ledgerwallet', 'metamask']

 

-function detectBlacklistedDomain() {

-  var strCurrentTab = window.location.hostname

-  if (blacklistedDomains && blacklistedDomains.includes(strCurrentTab)) {

-    window.location.href = 'https://metamask.io/phishing.html'

-  }

+

+// credit to @sogoiii and @409H for their help!

+// Return a boolean on whether or not a phish is detected.

+function isPhish(hostname) {

+  var strCurrentTab = hostname

+

+  // check if the domain is part of the whitelist.

+  if (whitelistedDomains && whitelistedDomains.includes(strCurrentTab)) { return false }

+

+  // check if the domain is part of the blacklist.

+  var isBlacklisted = blacklistedDomains && blacklistedDomains.includes(strCurrentTab)

+

+  // check for similar values.

+  var levenshteinMatched = false

+  var levenshteinForm = strCurrentTab.replace(/\./g, '')

+  LEVENSHTEIN_CHECKS.forEach((element) => {

+    if (levenshtein.get(element, levenshteinForm) < LEVENSHTEIN_TOLERANCE) {

+      levenshteinMatched = true

+    }

+  })

+

+  return isBlacklisted || levenshteinMatched

 }

 

-window.addEventListener('load', function() {

-  detectBlacklistedDomain()

+window.addEventListener('load', function () {

+  var hostnameToCheck = window.location.hostname

+  if (isPhish(hostnameToCheck)) {

+    // redirect to our phishing warning page.

+    window.location.href = 'https://metamask.io/phishing.html'

+  }

 })

 

+module.exports = isPhish

diff --git a/package.json b/package.json
index dcd25cda6..10afc8228 100644
--- a/package.json
+++ b/package.json
@@ -80,6 +80,7 @@
     "express": "^4.14.0",
     "extension-link-enabler": "^1.0.0",
     "extensionizer": "^1.0.0",
+    "fast-levenshtein": "^2.0.6",
     "gulp-eslint": "^2.0.0",
     "hat": "0.0.3",
     "idb-global": "^1.0.0",
diff --git a/test/unit/blacklister-test.js b/test/unit/blacklister-test.js
new file mode 100644
index 000000000..d9290795c
--- /dev/null
+++ b/test/unit/blacklister-test.js
@@ -0,0 +1,24 @@
+const assert = require('assert')
+const Blacklister = require('../../app/scripts/blacklister')
+
+
+describe('blacklister', function () {
+  describe('#isPhish', function () {
+    it('should not flag whitelisted values', function () {
+      var result = Blacklister('www.metamask.io')
+      assert(!result)
+    })
+    it('should flag explicit values', function () {
+      var result = Blacklister('metamask.com')
+      assert(result)
+    })
+    it('should flag levenshtein values', function () {
+      var result = Blacklister('metmask.io')
+      assert(result)
+    })
+    it('should not flag not-even-close values', function () {
+      var result = Blacklister('example.com')
+      assert(!result)
+    })
+  })
+})