Fix various bits of error-handling in NSSDecryptor.

chrome/utility/importer/nss_decryptor.cc

 // Copyright (c) 2012 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/utility/importer/nss_decryptor.h"
 
 #include <string>
 #include <vector>
 
 #include "base/base64.h"
@@ skipping 48 matching lines @@
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */
 
 base::string16 NSSDecryptor::Decrypt(const std::string& crypt) const {
   // Do nothing if NSS is not loaded.
   if (!is_nss_initialized_)
     return base::string16();
 
+  if (crypt.empty())
+    return base::string16();
+
   // The old style password is encoded in base64. They are identified
   // by a leading '~'. Otherwise, we should decrypt the text.
   std::string plain;
   if (crypt[0] != '~') {
     std::string decoded_data;
-    base::Base64Decode(crypt, &decoded_data);
+    if (!base::Base64Decode(crypt, &decoded_data))
+      return base::string16();
     PK11SlotInfo* slot = GetKeySlotForDB();
     SECStatus result = PK11_Authenticate(slot, PR_TRUE, NULL);
     if (result != SECSuccess) {
       FreeSlot(slot);
       return base::string16();
     }
 
     SECItem request;
     request.data = reinterpret_cast<unsigned char*>(
         const_cast<char*>(decoded_data.data()));
     request.len = static_cast<unsigned int>(decoded_data.size());
     SECItem reply;
     reply.data = NULL;
     reply.len = 0;
 #if defined(USE_NSS)
     result = PK11SDR_DecryptWithSlot(slot, &request, &reply, NULL);
 #else
     result = PK11SDR_Decrypt(&request, &reply, NULL);
 #endif  // defined(USE_NSS)
     if (result == SECSuccess)
       plain.assign(reinterpret_cast<char*>(reply.data), reply.len);
 
     SECITEM_FreeItem(&reply, PR_FALSE);
     FreeSlot(slot);
   } else {
     // Deletes the leading '~' before decoding.
-    base::Base64Decode(crypt.substr(1), &plain);
+    if (!base::Base64Decode(crypt.substr(1), &plain))
+      return base::string16();
   }
 
   return base::UTF8ToUTF16(plain);
 }
 
 // There are three versions of password files. They store saved user
 // names and passwords.
 // References:
 // http://kb.mozillazine.org/Signons.txt
 // http://kb.mozillazine.org/Signons2.txt
@@ skipping 183 matching lines @@
     // The user name, password and action.
     form.username_element = s2.ColumnString16(3);
     form.username_value = Decrypt(s2.ColumnString(5));
     form.password_element = s2.ColumnString16(4);
     form.password_value = Decrypt(s2.ColumnString(6));
     form.action = GURL(s2.ColumnString(2)).ReplaceComponents(rep);
     forms->push_back(form);
   }
   return true;
 }