diff --git a/app/models/screened_email.rb b/app/models/screened_email.rb
index f10c80a8b..a7bb72f3e 100644
--- a/app/models/screened_email.rb
+++ b/app/models/screened_email.rb
@@ -17,11 +17,43 @@ class ScreenedEmail < ActiveRecord::Base
end
def self.should_block?(email)
- screened_email = ScreenedEmail.find_by(email: email)
+ screened_emails = ScreenedEmail.order(created_at: :desc).limit(100)
+
+ distances = {}
+ screened_emails.each { |se| distances[se.email] = levenshtein(se.email, email) }
+
+ max_distance = SiteSetting.levenshtein_distance_spammer_emails
+ screened_email = screened_emails.select { |se| distances[se.email] <= max_distance }
+ .sort { |se| distances[se.email] }
+ .first
+
screened_email.record_match! if screened_email
+
screened_email && screened_email.action_type == actions[:block]
end
+ def self.levenshtein(first, second)
+ matrix = [(0..first.length).to_a]
+ (1..second.length).each do |j|
+ matrix << [j] + [0] * (first.length)
+ end
+
+ (1..second.length).each do |i|
+ (1..first.length).each do |j|
+ if first[j-1] == second[i-1]
+ matrix[i][j] = matrix[i-1][j-1]
+ else
+ matrix[i][j] = [
+ matrix[i-1][j],
+ matrix[i][j-1],
+ matrix[i-1][j-1],
+ ].min + 1
+ end
+ end
+ end
+ return matrix.last.last
+ end
+
end
# == Schema Information
diff --git a/config/locales/server.en.yml b/config/locales/server.en.yml
index 55ec23ac3..ab1220244 100644
--- a/config/locales/server.en.yml
+++ b/config/locales/server.en.yml
@@ -890,6 +890,8 @@ en:
white_listed_spam_host_domains: "A pipe-delimited list of domains excluded from spam host testing, new users will be able to create an unrestricted count of posts with links to this domain"
staff_like_weight: "Extra weighting factor given to likes when performed by staff."
+ levenshtein_distance_spammer_emails: "Number of characters different from a known spammer email."
+
reply_by_email_enabled: "Enable replying to topics via email"
reply_by_email_address: "Template for reply by email incoming email address, for example: %{reply_key}@reply.example.com or replies+%{reply_key}@example.com"
diff --git a/config/site_settings.yml b/config/site_settings.yml
index a7a17f987..ca749c54c 100644
--- a/config/site_settings.yml
+++ b/config/site_settings.yml
@@ -527,6 +527,7 @@ spam:
white_listed_spam_host_domains:
default: ''
type: list
+ levenshtein_distance_spammer_emails: 2
rate_limits:
unique_posts_mins:
diff --git a/spec/models/screened_email_spec.rb b/spec/models/screened_email_spec.rb
index 3e242034b..e607a7a0c 100644
--- a/spec/models/screened_email_spec.rb
+++ b/spec/models/screened_email_spec.rb
@@ -3,33 +3,34 @@ require 'spec_helper'
describe ScreenedEmail do
let(:email) { 'block@spamfromhome.org' }
+ let(:similar_email) { 'bl0ck@spamfromhome.org' }
describe "new record" do
it "sets a default action_type" do
- described_class.create(email: email).action_type.should == described_class.actions[:block]
+ ScreenedEmail.create(email: email).action_type.should == ScreenedEmail.actions[:block]
end
it "last_match_at is null" do
# If we manually load the table with some emails, we can see whether those emails
# have ever been blocked by looking at last_match_at.
- described_class.create(email: email).last_match_at.should be_nil
+ ScreenedEmail.create(email: email).last_match_at.should be_nil
end
end
describe '#block' do
context 'email is not being blocked' do
it 'creates a new record with default action of :block' do
- record = described_class.block(email)
+ record = ScreenedEmail.block(email)
record.should_not be_new_record
record.email.should == email
- record.action_type.should == described_class.actions[:block]
+ record.action_type.should == ScreenedEmail.actions[:block]
end
it 'lets action_type be overriden' do
- record = described_class.block(email, action_type: described_class.actions[:do_nothing])
+ record = ScreenedEmail.block(email, action_type: ScreenedEmail.actions[:do_nothing])
record.should_not be_new_record
record.email.should == email
- record.action_type.should == described_class.actions[:do_nothing]
+ record.action_type.should == ScreenedEmail.actions[:do_nothing]
end
end
@@ -37,22 +38,34 @@ describe ScreenedEmail do
let!(:existing) { Fabricate(:screened_email, email: email) }
it "doesn't create a new record" do
- expect { described_class.block(email) }.to_not change { described_class.count }
+ expect { ScreenedEmail.block(email) }.to_not change { ScreenedEmail.count }
end
it "returns the existing record" do
- described_class.block(email).should == existing
+ ScreenedEmail.block(email).should == existing
end
end
end
describe '#should_block?' do
- subject { described_class.should_block?(email) }
+ subject { ScreenedEmail.should_block?(email) }
it "returns false if a record with the email doesn't exist" do
subject.should be_false
end
+ it "returns true when there is a record with the email" do
+ ScreenedEmail.should_block?(email).should be_false
+ ScreenedEmail.create(email: email).save
+ ScreenedEmail.should_block?(email).should be_true
+ end
+
+ it "returns true when there is a record with a similar email" do
+ ScreenedEmail.should_block?(email).should be_false
+ ScreenedEmail.create(email: similar_email).save
+ ScreenedEmail.should_block?(email).should be_true
+ end
+
shared_examples "when a ScreenedEmail record matches" do
it "updates statistics" do
Timecop.freeze(Time.zone.now) do
@@ -63,13 +76,13 @@ describe ScreenedEmail do
end
context "action_type is :block" do
- let!(:screened_email) { Fabricate(:screened_email, email: email, action_type: described_class.actions[:block]) }
+ let!(:screened_email) { Fabricate(:screened_email, email: email, action_type: ScreenedEmail.actions[:block]) }
it { should be_true }
include_examples "when a ScreenedEmail record matches"
end
context "action_type is :do_nothing" do
- let!(:screened_email) { Fabricate(:screened_email, email: email, action_type: described_class.actions[:do_nothing]) }
+ let!(:screened_email) { Fabricate(:screened_email, email: email, action_type: ScreenedEmail.actions[:do_nothing]) }
it { should be_false }
include_examples "when a ScreenedEmail record matches"
end