Sync: Do not generate non-UTF8 names for delete directives.

BUG=371184

Review URL: https://codereview.chromium.org/273283002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@270035 0039d316-1c4b-4281-b951-d872f2087c98

base/rand_util.h

@@ -39,10 +39,11 @@ BASE_EXPORT double BitsToOpenEndedUnitInterval(uint64 bits);
 // See crypto/ for cryptographically secure random number generation APIs.
 BASE_EXPORT void RandBytes(void* output, size_t output_length);
 
-// Fills a string of length |length| with with random data and returns it.
+// Fills a string of length |length| with random data and returns it.
 // |length| should be nonzero.
 //
 // Note that this is a variation of |RandBytes| with a different return type.
+// The returned string is likely not ASCII/UTF-8. Use with care.
 //
 // WARNING:
 // Do not use for security-sensitive purposes.

chrome/browser/history/delete_directive_handler.cc

@@ -18,6 +18,15 @@
 
 namespace {
 
+std::string RandASCIIString(size_t length) {
+  std::string result;
+  const int kMin = static_cast<int>(' ');
+  const int kMax = static_cast<int>('~');
+  for (size_t i = 0; i < length; ++i)
+    result.push_back(static_cast<char>(base::RandInt(kMin, kMax)));
+  return result;
+}
+
 std::string DeleteDirectiveToString(
     const sync_pb::HistoryDeleteDirectiveSpecifics& delete_directive) {
   scoped_ptr<base::DictionaryValue> value(
@@ -354,7 +363,7 @@ syncer::SyncError DeleteDirectiveHandler::ProcessLocalDeleteDirective(
 
   // Generate a random sync tag since history delete directives don't
   // have a 'built-in' ID.  8 bytes should suffice.
-  std::string sync_tag = base::RandBytesAsString(8);
+  std::string sync_tag = RandASCIIString(8);
   sync_pb::EntitySpecifics entity_specifics;
   entity_specifics.mutable_history_delete_directive()->CopyFrom(
       delete_directive);

sync/internal_api/write_node.cc

@@ -57,6 +57,7 @@ void WriteNode::SetTitle(const std::string& title) {
   if (type != BOOKMARKS && needs_encryption) {
     new_legal_title = kEncryptedString;
   } else {
+    DCHECK(base::IsStringUTF8(title));
     SyncAPINameToServerName(title, &new_legal_title);
     base::TruncateUTF8ToByteSize(new_legal_title, 255, &new_legal_title);
   }