Fix uninitialized okeybuf

core/src/fpdfapi/fpdf_parser/fpdf_parser_encrypt.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
  
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include <time.h>
 #include "../../../include/fpdfapi/fpdf_parser.h"
 #include "../../../include/fdrm/fx_crypt.h"
 const FX_BYTE defpasscode[32] = {
@@ skipping 442 matching lines @@
     FX_DWORD copy_len = key_len;
     if (copy_len > sizeof(digest)) {
         copy_len = sizeof(digest);
     }
     FXSYS_memcpy32(enckey, digest, copy_len);
     int okeylen = okey.GetLength();
     if (okeylen > 32) {
         okeylen = 32;
     }
     FX_BYTE okeybuf[64];
+    FXSYS_memset32(okeybuf, 0, sizeof(okeybuf));
     FXSYS_memcpy32(okeybuf, (FX_LPCSTR)okey, okeylen);
     if (m_Revision == 2) {
         CRYPT_ArcFourCryptBlock(okeybuf, okeylen, enckey, key_len);
     } else {
         for (int i = 19; i >= 0; i --) {
             FX_BYTE tempkey[32];
             for (int j = 0; j < m_KeyLen; j ++) {
                 tempkey[j] = enckey[j] ^ i;
             }
             CRYPT_ArcFourCryptBlock(okeybuf, okeylen, tempkey, key_len);
@@ skipping 475 matching lines @@
     m_pAESContext = NULL;
     m_Cipher = FXCIPHER_NONE;
     m_KeyLen = 0;
 }
 CPDF_StandardCryptoHandler::~CPDF_StandardCryptoHandler()
 {
     if (m_pAESContext) {
         FX_Free(m_pAESContext);
     }
 }