Revert of Simple: Move PVer4 related code from util.* to v4_protocol_manager_util.*

components/safe_browsing_db/util.cc

 // Copyright (c) 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 "components/safe_browsing_db/util.h"
 
 #include <stddef.h>
 
 #include "base/macros.h"
+#include "base/strings/string_util.h"
 #include "base/trace_event/trace_event.h"
-#include "components/safe_browsing_db/v4_protocol_manager_util.h"
 #include "crypto/sha2.h"
 #include "net/base/escape.h"
 #include "url/gurl.h"
+#include "url/url_util.h"
 
 namespace safe_browsing {
 
 // Utility functions -----------------------------------------------------------
 
 namespace {
 
 bool IsKnownList(const std::string& name) {
   for (size_t i = 0; i < arraysize(kAllLists); ++i) {
     if (!strcmp(kAllLists[i], name.c_str())) {
       return true;
     }
   }
   return false;
 }
 
+void GenerateHostVariantsToCheck(const std::string& host,
+                                 std::vector<std::string>* hosts) {
+  hosts->clear();
+
+  if (host.empty())
+    return;
+
+  // Per the Safe Browsing Protocol v2 spec, we try the host, and also up to 4
+  // hostnames formed by starting with the last 5 components and successively
+  // removing the leading component.  The last component isn't examined alone,
+  // since it's the TLD or a subcomponent thereof.
+  //
+  // Note that we don't need to be clever about stopping at the "real" eTLD --
+  // the data on the server side has been filtered to ensure it will not
+  // blacklist a whole TLD, and it's not significantly slower on our side to
+  // just check too much.
+  //
+  // Also note that because we have a simple blacklist, not some sort of complex
+  // whitelist-in-blacklist or vice versa, it doesn't matter what order we check
+  // these in.
+  const size_t kMaxHostsToCheck = 4;
+  bool skipped_last_component = false;
+  for (std::string::const_reverse_iterator i(host.rbegin());
+       i != host.rend() && hosts->size() < kMaxHostsToCheck; ++i) {
+    if (*i == '.') {
+      if (skipped_last_component)
+        hosts->push_back(std::string(i.base(), host.end()));
+      else
+        skipped_last_component = true;
+    }
+  }
+  hosts->push_back(host);
+}
+
+void GeneratePathVariantsToCheck(const std::string& path,
+                                 const std::string& query,
+                                 std::vector<std::string>* paths) {
+  paths->clear();
+
+  if (path.empty())
+    return;
+
+  // Per the Safe Browsing Protocol v2 spec, we try the exact path with/without
+  // the query parameters, and also up to 4 paths formed by starting at the root
+  // and adding more path components.
+  //
+  // As with the hosts above, it doesn't matter what order we check these in.
+  const size_t kMaxPathsToCheck = 4;
+  for (std::string::const_iterator i(path.begin());
+       i != path.end() && paths->size() < kMaxPathsToCheck; ++i) {
+    if (*i == '/')
+      paths->push_back(std::string(path.begin(), i + 1));
+  }
+
+  if (!paths->empty() && paths->back() != path)
+    paths->push_back(path);
+
+  if (!query.empty())
+    paths->push_back(path + "?" + query);
+}
+
 }  // namespace
 
 // ThreatMetadata ------------------------------------------------------------
 ThreatMetadata::ThreatMetadata()
     : threat_pattern_type(ThreatPatternType::NONE) {}
 
 ThreatMetadata::ThreatMetadata(const ThreatMetadata& other) = default;
 
 ThreatMetadata::~ThreatMetadata() {}
 
@@ skipping 106 matching lines @@
   SBFullHash hash_out;
   memcpy(hash_out.full_hash, hash_in.data(), crypto::kSHA256Length);
   return hash_out;
 }
 
 std::string SBFullHashToString(const SBFullHash& hash) {
   DCHECK_EQ(crypto::kSHA256Length, sizeof(hash.full_hash));
   return std::string(hash.full_hash, sizeof(hash.full_hash));
 }
 
+
+std::string Unescape(const std::string& url) {
+  std::string unescaped_str(url);
+  const int kMaxLoopIterations = 1024;
+  size_t old_size = 0;
+  int loop_var = 0;
+  do {
+    old_size = unescaped_str.size();
+    unescaped_str = net::UnescapeURLComponent(
+        unescaped_str,
+        net::UnescapeRule::SPOOFING_AND_CONTROL_CHARS |
+            net::UnescapeRule::SPACES | net::UnescapeRule::PATH_SEPARATORS |
+            net::UnescapeRule::URL_SPECIAL_CHARS_EXCEPT_PATH_SEPARATORS);
+  } while (old_size != unescaped_str.size() &&
+           ++loop_var <= kMaxLoopIterations);
+
+  return unescaped_str;
+}
+
+std::string Escape(const std::string& url) {
+  std::string escaped_str;
+  // The escaped string is larger so allocate double the length to reduce the
+  // chance of the string being grown.
+  escaped_str.reserve(url.length() * 2);
+  const char* kHexString = "0123456789ABCDEF";
+  for (size_t i = 0; i < url.length(); i++) {
+    unsigned char c = static_cast<unsigned char>(url[i]);
+    if (c <= ' ' || c > '~' || c == '#' || c == '%') {
+      escaped_str += '%';
+      escaped_str += kHexString[c >> 4];
+      escaped_str += kHexString[c & 0xf];
+    } else {
+      escaped_str += c;
+    }
+  }
+
+  return escaped_str;
+}
+
+std::string RemoveConsecutiveChars(base::StringPiece str, const char c) {
+  std::string output;
+  // Output is at most the length of the original string.
+  output.reserve(str.size());
+
+  size_t i = 0;
+  while (i < str.size()) {
+    output.append(1, str[i++]);
+    if (str[i - 1] == c) {
+      while (i < str.size() && str[i] == c) {
+        i++;
+      }
+    }
+  }
+
+  return output;
+}
+
+// Canonicalizes url as per Google Safe Browsing Specification.
+// See section 6.1 in
+// http://code.google.com/p/google-safe-browsing/wiki/Protocolv2Spec.
+void CanonicalizeUrl(const GURL& url,
+                     std::string* canonicalized_hostname,
+                     std::string* canonicalized_path,
+                     std::string* canonicalized_query) {
+  DCHECK(url.is_valid());
+
+  // We only canonicalize "normal" URLs.
+  if (!url.IsStandard())
+    return;
+
+  // Following canonicalization steps are excluded since url parsing takes care
+  // of those :-
+  // 1. Remove any tab (0x09), CR (0x0d), and LF (0x0a) chars from url.
+  //    (Exclude escaped version of these chars).
+  // 2. Normalize hostname to 4 dot-seperated decimal values.
+  // 3. Lowercase hostname.
+  // 4. Resolve path sequences "/../" and "/./".
+
+  // That leaves us with the following :-
+  // 1. Remove fragment in URL.
+  GURL url_without_fragment;
+  GURL::Replacements f_replacements;
+  f_replacements.ClearRef();
+  f_replacements.ClearUsername();
+  f_replacements.ClearPassword();
+  url_without_fragment = url.ReplaceComponents(f_replacements);
+
+  // 2. Do URL unescaping until no more hex encoded characters exist.
+  std::string url_unescaped_str(Unescape(url_without_fragment.spec()));
+  url::Parsed parsed;
+  url::ParseStandardURL(url_unescaped_str.data(), url_unescaped_str.length(),
+                        &parsed);
+
+  // 3. In hostname, remove all leading and trailing dots.
+  base::StringPiece host;
+  if (parsed.host.len > 0)
+    host.set(url_unescaped_str.data() + parsed.host.begin, parsed.host.len);
+
+  base::StringPiece host_without_end_dots =
+      base::TrimString(host, ".", base::TrimPositions::TRIM_ALL);
+
+  // 4. In hostname, replace consecutive dots with a single dot.
+  std::string host_without_consecutive_dots(RemoveConsecutiveChars(
+      host_without_end_dots, '.'));
+
+  // 5. In path, replace runs of consecutive slashes with a single slash.
+  base::StringPiece path;
+  if (parsed.path.len > 0)
+    path.set(url_unescaped_str.data() + parsed.path.begin, parsed.path.len);
+  std::string path_without_consecutive_slash(RemoveConsecutiveChars(path, '/'));
+
+  url::Replacements<char> hp_replacements;
+  hp_replacements.SetHost(
+      host_without_consecutive_dots.data(),
+      url::Component(0, host_without_consecutive_dots.length()));
+  hp_replacements.SetPath(
+      path_without_consecutive_slash.data(),
+      url::Component(0, path_without_consecutive_slash.length()));
+
+  std::string url_unescaped_with_can_hostpath;
+  url::StdStringCanonOutput output(&url_unescaped_with_can_hostpath);
+  url::Parsed temp_parsed;
+  url::ReplaceComponents(url_unescaped_str.data(),
+                         url_unescaped_str.length(),
+                         parsed,
+                         hp_replacements,
+                         NULL,
+                         &output,
+                         &temp_parsed);
+  output.Complete();
+
+  // 6. Step needed to revert escaping done in url::ReplaceComponents.
+  url_unescaped_with_can_hostpath = Unescape(url_unescaped_with_can_hostpath);
+
+  // 7. After performing all above steps, percent-escape all chars in url which
+  // are <= ASCII 32, >= 127, #, %. Escapes must be uppercase hex characters.
+  std::string escaped_canon_url_str(Escape(url_unescaped_with_can_hostpath));
+  url::Parsed final_parsed;
+  url::ParseStandardURL(escaped_canon_url_str.data(),
+                        escaped_canon_url_str.length(),
+                        &final_parsed);
+
+  if (canonicalized_hostname && final_parsed.host.len > 0) {
+    *canonicalized_hostname =
+        escaped_canon_url_str.substr(final_parsed.host.begin,
+                                     final_parsed.host.len);
+  }
+  if (canonicalized_path && final_parsed.path.len > 0) {
+    *canonicalized_path = escaped_canon_url_str.substr(final_parsed.path.begin,
+                                                       final_parsed.path.len);
+  }
+  if (canonicalized_query && final_parsed.query.len > 0) {
+    *canonicalized_query = escaped_canon_url_str.substr(
+        final_parsed.query.begin, final_parsed.query.len);
+  }
+}
+
 void UrlToFullHashes(const GURL& url,
                      bool include_whitelist_hashes,
                      std::vector<SBFullHash>* full_hashes) {
   // Include this function in traces because it's not cheap so it should be
   // called sparingly.
   TRACE_EVENT2("loader", "safe_browsing::UrlToFullHashes", "url", url.spec(),
                "include_whitelist_hashes", include_whitelist_hashes);
   std::string canon_host;
   std::string canon_path;
   std::string canon_query;
-  V4ProtocolManagerUtil::CanonicalizeUrl(url, &canon_host, &canon_path,
-                                         &canon_query);
+  CanonicalizeUrl(url, &canon_host, &canon_path, &canon_query);
 
   std::vector<std::string> hosts;
   if (url.HostIsIPAddress()) {
     hosts.push_back(url.host());
   } else {
-    V4ProtocolManagerUtil::GenerateHostVariantsToCheck(canon_host, &hosts);
+    GenerateHostVariantsToCheck(canon_host, &hosts);
   }
 
   std::vector<std::string> paths;
-  V4ProtocolManagerUtil::GeneratePathVariantsToCheck(canon_path, canon_query,
-                                                     &paths);
+  GeneratePathVariantsToCheck(canon_path, canon_query, &paths);
 
   for (const std::string& host : hosts) {
     for (const std::string& path : paths) {
       full_hashes->push_back(
           SBFullHashForString(host + path));
 
       // We may have /foo as path-prefix in the whitelist which should
       // also match with /foo/bar and /foo?bar.  Hence, for every path
       // that ends in '/' we also add the path without the slash.
       if (include_whitelist_hashes && path.size() > 1 && path.back() == '/') {
         full_hashes->push_back(SBFullHashForString(
             host + path.substr(0, path.size() - 1)));
       }
     }
   }
 }
 
+void GenerateHostsToCheck(const GURL& url, std::vector<std::string>* hosts) {
+  std::string canon_host;
+  CanonicalizeUrl(url, &canon_host, NULL, NULL);
+  GenerateHostVariantsToCheck(canon_host, hosts);
+}
+
+void GeneratePathsToCheck(const GURL& url, std::vector<std::string>* paths) {
+  std::string canon_path;
+  std::string canon_query;
+  CanonicalizeUrl(url, NULL, &canon_path, &canon_query);
+  GeneratePathVariantsToCheck(canon_path, canon_query, paths);
+}
+
+void GeneratePatternsToCheck(const GURL& url, std::vector<std::string>* urls) {
+  std::string canon_host;
+  std::string canon_path;
+  std::string canon_query;
+  CanonicalizeUrl(url, &canon_host, &canon_path, &canon_query);
+
+  std::vector<std::string> hosts, paths;
+  GenerateHostVariantsToCheck(canon_host, &hosts);
+  GeneratePathVariantsToCheck(canon_path, canon_query, &paths);
+  for (size_t h = 0; h < hosts.size(); ++h) {
+    for (size_t p = 0; p < paths.size(); ++p) {
+      urls->push_back(hosts[h] + paths[p]);
+    }
+  }
+}
+
 }  // namespace safe_browsing