Revert of Move remote_db_manager into the safe_browsing_db component.

chrome/browser/safe_browsing/safe_browsing_api_handler_util.cc

Index: chrome/browser/safe_browsing/safe_browsing_api_handler_util.cc
diff --git a/chrome/browser/safe_browsing/safe_browsing_api_handler_util.cc b/chrome/browser/safe_browsing/safe_browsing_api_handler_util.cc
new file mode 100644
index 0000000000000000000000000000000000000000..897ad4079be90a83be1f1818220afd87eabcad7e
--- /dev/null
+++ b/chrome/browser/safe_browsing/safe_browsing_api_handler_util.cc
@@ -0,0 +1,167 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/safe_browsing/safe_browsing_api_handler_util.h"
+
+#include <stddef.h>
+
+#include <string>
+
+#include "base/json/json_reader.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/metrics/histogram_macros.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/values.h"
+#include "chrome/browser/safe_browsing/metadata.pb.h"
+#include "chrome/browser/safe_browsing/safe_browsing_util.h"
+
+
+namespace safe_browsing {
+namespace {
+
+// JSON metatdata keys. These are are fixed in the Java-side API.
+const char kJsonKeyMatches[] = "matches";
+const char kJsonKeyThreatType[] = "threat_type";
+
+// Do not reorder or delete.  Make sure changes are reflected in
+// SB2RemoteCallThreatSubType.
+enum UmaThreatSubType {
+  UMA_THREAT_SUB_TYPE_NOT_SET = 0,
+  UMA_THREAT_SUB_TYPE_LANDING = 1,
+  UMA_THREAT_SUB_TYPE_DISTRIBUTION = 2,
+  UMA_THREAT_SUB_TYPE_UNKNOWN = 3,
+  UMA_THREAT_SUB_TYPE_MAX_VALUE
+};
+
+void ReportUmaThreatSubType(SBThreatType threat_type,
+                            UmaThreatSubType sub_type) {
+  if (threat_type == SB_THREAT_TYPE_URL_MALWARE) {
+    UMA_HISTOGRAM_ENUMERATION(
+        "SB2.RemoteCall.ThreatSubType.PotentiallyHarmfulApp", sub_type,
+        UMA_THREAT_SUB_TYPE_MAX_VALUE);
+  } else {
+    UMA_HISTOGRAM_ENUMERATION(
+        "SB2.RemoteCall.ThreatSubType.SocialEngineering", sub_type,
+        UMA_THREAT_SUB_TYPE_MAX_VALUE);
+  }
+}
+
+// Parse the extra key/value pair(s) added by Safe Browsing backend.  To make
+// it binary compatible with the Pver3 metadata that UIManager expects to
+// deserialize, we convert it to a MalwarePatternType.
+//
+// TODO(nparker):  When chrome desktop is converted to use Pver4, convert this
+// to the new proto instead.
+const std::string ParseExtraMetadataToPB(const base::DictionaryValue* match,
+                                         SBThreatType threat_type) {
+  std::string pattern_key;
+  if (threat_type == SB_THREAT_TYPE_URL_MALWARE) {
+    pattern_key = "pha_pattern_type";
+  } else {
+    DCHECK(threat_type == SB_THREAT_TYPE_URL_PHISHING);
+    pattern_key = "se_pattern_type";
+  }
+
+  std::string pattern_type;
+  if (!match->GetString(pattern_key, &pattern_type)) {
+    ReportUmaThreatSubType(threat_type, UMA_THREAT_SUB_TYPE_NOT_SET);
+    return std::string();
+  }
+
+  MalwarePatternType pb;
+  if (pattern_type == "LANDING") {
+    pb.set_pattern_type(MalwarePatternType::LANDING);
+    ReportUmaThreatSubType(threat_type, UMA_THREAT_SUB_TYPE_LANDING);
+  } else if (pattern_type == "DISTRIBUTION") {
+    pb.set_pattern_type(MalwarePatternType::DISTRIBUTION);
+    ReportUmaThreatSubType(threat_type, UMA_THREAT_SUB_TYPE_DISTRIBUTION);
+  } else {
+    ReportUmaThreatSubType(threat_type, UMA_THREAT_SUB_TYPE_UNKNOWN);
+    return std::string();
+  }
+
+  return pb.SerializeAsString();
+}
+
+int GetThreatSeverity(int java_threat_num) {
+  // Assign higher numbers to more severe threats.
+  switch (java_threat_num) {
+    case JAVA_THREAT_TYPE_POTENTIALLY_HARMFUL_APPLICATION:
+      return 2;
+    case JAVA_THREAT_TYPE_SOCIAL_ENGINEERING:
+      return 1;
+    default:
+      // Unknown threat type
+      return -1;
+  }
+}
+
+SBThreatType JavaToSBThreatType(int java_threat_num) {
+  switch (java_threat_num) {
+    case JAVA_THREAT_TYPE_POTENTIALLY_HARMFUL_APPLICATION:
+      return SB_THREAT_TYPE_URL_MALWARE;
+    case JAVA_THREAT_TYPE_SOCIAL_ENGINEERING:
+      return SB_THREAT_TYPE_URL_PHISHING;
+    default:
+      // Unknown threat type
+      return SB_THREAT_TYPE_SAFE;
+  }
+}
+
+}  // namespace
+
+
+// Valid examples:
+// {"matches":[{"threat_type":"5"}]}
+//   or
+// {"matches":[{"threat_type":"4"},
+//             {"threat_type":"5", "se_pattern_type":"LANDING"}]}
+UmaRemoteCallResult ParseJsonToThreatAndPB(const std::string& metadata_str,
+                                           SBThreatType* worst_threat,
+                                           std::string* metadata_pb_str) {
+  *worst_threat = SB_THREAT_TYPE_SAFE;  // Default to safe.
+  *metadata_pb_str = std::string();
+
+  if (metadata_str.empty())
+    return UMA_STATUS_JSON_EMPTY;
+
+  // Pick out the "matches" list.
+  scoped_ptr<base::Value> value = base::JSONReader::Read(metadata_str);
+  const base::ListValue* matches;
+  if (!value.get() || !value->IsType(base::Value::TYPE_DICTIONARY) ||
+      !(static_cast<base::DictionaryValue*>(value.get()))
+           ->GetList(kJsonKeyMatches, &matches)) {
+    return UMA_STATUS_JSON_FAILED_TO_PARSE;
+  }
+
+  // Go through each matched threat type and pick the most severe.
+  int worst_threat_num = -1;
+  const base::DictionaryValue* worst_match = nullptr;
+  for (size_t i = 0; i < matches->GetSize(); i++) {
+    // Get the threat number
+    const base::DictionaryValue* match;
+    std::string threat_num_str;
+    int java_threat_num = -1;
+    if (!matches->GetDictionary(i, &match) ||
+        !match->GetString(kJsonKeyThreatType, &threat_num_str) ||
+        !base::StringToInt(threat_num_str, &java_threat_num)) {
+      continue;  // Skip malformed list entries
+    }
+
+    if (GetThreatSeverity(java_threat_num) >
+        GetThreatSeverity(worst_threat_num)) {
+      worst_threat_num = java_threat_num;
+      worst_match = match;
+    }
+  }
+
+  *worst_threat = JavaToSBThreatType(worst_threat_num);
+  if (*worst_threat == SB_THREAT_TYPE_SAFE || !worst_match)
+    return UMA_STATUS_JSON_UNKNOWN_THREAT;
+  *metadata_pb_str = ParseExtraMetadataToPB(worst_match, *worst_threat);
+
+  return UMA_STATUS_UNSAFE;  // success
+}
+
+}  // namespace safe_browsing