Parse the whitelist expressions from the phishing verdict response if

chrome/browser/safe_browsing/client_side_detection_service.cc

Index: chrome/browser/safe_browsing/client_side_detection_service.cc
diff --git a/chrome/browser/safe_browsing/client_side_detection_service.cc b/chrome/browser/safe_browsing/client_side_detection_service.cc
index 9e800ce141105b58414402910241fa90f49689b5..2ae761bfa98f87644adc2dea18340075cd0c1a93 100644
--- a/chrome/browser/safe_browsing/client_side_detection_service.cc
+++ b/chrome/browser/safe_browsing/client_side_detection_service.cc
@@ -413,7 +413,8 @@ void ClientSideDetectionService::HandlePhishingVerdict(
     // Cache response, possibly flushing an old one.
     cache_[info->phishing_url] =
         make_linked_ptr(new CacheState(response.phishy(), base::Time::Now()));
-    is_phishing = response.phishy();
+    is_phishing = (response.phishy() &&
+                   !IsFalsePositiveResponse(info->phishing_url, response));
   } else {
     DLOG(ERROR) << "Unable to get the server verdict for URL: "
                 << info->phishing_url << " status: " << status.status() << " "
@@ -607,4 +608,50 @@ bool ClientSideDetectionService::ModelHasValidHashIds(
   }
   return true;
 }
+
+// static
+bool ClientSideDetectionService::IsFalsePositiveResponse(
+    const GURL& url,
+    const ClientPhishingResponse& response) {
+  if (!response.phishy() || response.whitelist_expression_size() == 0) {
+    return false;
+  }
+  // This whitelist is special.  A particular URL gets whitelisted if it
+  // matches any of the expressions on the whitelist or if any of the whitelist
+  // entries matches the URL.
+
+  std::string host, path, query;
+  safe_browsing_util::CanonicalizeUrl(url, &host, &path, &query);
+  std::string canonical_url_as_pattern = host + path + query;
+
+  std::vector<std::string> url_patterns;
+  safe_browsing_util::GeneratePatternsToCheck(url, &url_patterns);
+
+  for (int i = 0; i < response.whitelist_expression_size(); ++i) {
+    GURL whitelisted_url(std::string("http://") +
+                         response.whitelist_expression(i));
+    if (!whitelisted_url.is_valid()) {
+      UMA_HISTOGRAM_COUNTS("SBClientPhishing.InvalidWhitelistExpression", 1);
+      continue;  // Skip invalid whitelist expressions.
+    }
+    // First, we check whether the canonical URL matches any of the whitelisted
+    // expressions.
+    for (size_t j = 0; j < url_patterns.size(); ++j) {
+      if (url_patterns[j] == response.whitelist_expression(i)) {
+        return true;
+      }
+    }
+    // Second, we consider the canonical URL as an expression and we check
+    // whether any of the whitelist entries matches that expression.
+    std::vector<std::string> whitelist_patterns;
+    safe_browsing_util::GeneratePatternsToCheck(whitelisted_url,
+                                                &whitelist_patterns);
+    for (size_t j = 0; j < whitelist_patterns.size(); ++j) {
+      if (whitelist_patterns[j] == canonical_url_as_pattern) {
+        return true;
+      }
+    }
+  }
+  return false;
+}
 }  // namespace safe_browsing