Enable SQLite's secure-delete at runtime so that

sql/connection.cc

 // Copyright (c) 2011 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 "sql/connection.h"
 
 #include <string.h>
 
 #include "base/file_path.h"
 #include "base/logging.h"
@@ skipping 358 matching lines @@
     if (!ExecuteWithTimeout(sql.c_str(), kBusyTimeout))
       NOTREACHED() << "Could not set page size: " << GetErrorMessage();
   }
 
   if (cache_size_ != 0) {
     const std::string sql = StringPrintf("PRAGMA cache_size=%d", cache_size_);
     if (!ExecuteWithTimeout(sql.c_str(), kBusyTimeout))
       NOTREACHED() << "Could not set cache size: " << GetErrorMessage();
   }
 
+  if (!ExecuteWithTimeout("PRAGMA secure_delete=ON", kBusyTimeout)) {
+    NOTREACHED() << "Could not enable secure_delete: " << GetErrorMessage();

[Scott Hess - ex-Googler, 2011/08/09 20:33:37]

NOTREACHED() means you'll never get to the Close() and false return.

Also, is it possible/likely that Chromium will be linked with versions of SQLite
which do not support this pragma?

[Paweł Hajdan Jr., 2011/08/09 23:05:00]

I used NOTREACHED() because code above uses it. However, NOTREACHED() will not
fire in Release mode, and in this case I believe it's really important to ensure
we succeed with running this pragma.
Possible, but not likely. If some distro breaks it it's their fault. And distros
do their testing too. It's only important to make it fail loudly, i.e. fail the
connection instead of just logging somewhere where possibly nobody is looking.

[Scott Hess - ex-Googler, 2011/08/09 23:13:44]

Doh!  You're right, for some reason I was thinking it did a CHECK() not a
DCHECK().
OK.  As long as the case was realized.

+    Close();
+    return false;
+  }
+
   return true;
 }
 
 void Connection::DoRollback() {
   Statement rollback(GetCachedStatement(SQL_FROM_HERE, "ROLLBACK"));
   if (rollback)
     rollback.Run();
 }
 
 void Connection::StatementRefCreated(StatementRef* ref) {
@@ skipping 22 matching lines @@
 
 int Connection::OnSqliteError(int err, sql::Statement *stmt) {
   if (error_delegate_.get())
     return error_delegate_->OnError(err, this, stmt);
   // The default handling is to assert on debug and to ignore on release.
   NOTREACHED() << GetErrorMessage();
   return err;
 }
 
 }  // namespace sql