Quick subdomain fix

policy/policy-data.go

@@ -117,7 +117,7 @@ func (padb *PolicyAuthorityDatabaseImpl) CheckRules(host string, requireWhitelis
 	for _, r := range rules {
 		switch r.Type {
 		case blacklisted:
-			if strings.HasPrefix(host, r.Host) {
+			if strings.HasPrefix(host, r.Host+".") || host == r.Host {
 				bRules = append(bRules, r.Host)
 			}
 		case whitelisted:

policy/policy-data_test.go

@@ -56,4 +56,9 @@ func TestGet(t *testing.T) {
 	test.AssertNotError(t, err, "Hostname should be whitelisted")
 	err = p.CheckRules("a.a.com", true)
 	test.AssertError(t, err, "Hostname isn't explicitly whitelisted")
+
+	err = p.CheckRules("ab.com", false)
+	test.AssertNotError(t, err, "Hostname should not be blacklisted")
+	err = p.CheckRules(".b.com", false)
+	test.AssertError(t, err, "Hostname should be blacklisted")
 }