Distinguish between user and owner passwords.

core/fpdfapi/fpdf_parser/cpdf_security_handler.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 "core/fpdfapi/fpdf_parser/cpdf_security_handler.h"
 
 #include <time.h>
 
@@ skipping 49 matching lines @@
     for (int i = 0; i < 50; i++) {
       CRYPT_MD5Generate(digest, copy_len, digest);
     }
   }
   FXSYS_memset(key, 0, keylen);
   FXSYS_memcpy(key, digest, copy_len);
 }
 
 }  // namespace
 
-CPDF_SecurityHandler::CPDF_SecurityHandler() {
-  m_Version = 0;
-  m_Revision = 0;
-  m_pParser = NULL;
-  m_pEncryptDict = NULL;
-  m_Permissions = 0;
-  m_Cipher = FXCIPHER_NONE;
-  m_KeyLen = 0;
-}
+CPDF_SecurityHandler::CPDF_SecurityHandler()
+    : m_Version(0),
+      m_Revision(0),
+      m_pParser(nullptr),
+      m_pEncryptDict(nullptr),
+      m_Permissions(0),
+      m_Cipher(FXCIPHER_NONE),
+      m_KeyLen(0),
+      m_bOwnerUnlocked(false) {}
 
 CPDF_SecurityHandler::~CPDF_SecurityHandler() {}
 
 CPDF_CryptoHandler* CPDF_SecurityHandler::CreateCryptoHandler() {
   return new CPDF_CryptoHandler;
 }
 
 FX_BOOL CPDF_SecurityHandler::OnInit(CPDF_Parser* pParser,
                                      CPDF_Dictionary* pEncryptDict) {
   m_pParser = pParser;
   if (!LoadDict(pEncryptDict)) {
     return FALSE;
   }
   if (m_Cipher == FXCIPHER_NONE) {
     return TRUE;
   }
   return CheckSecurity(m_KeyLen);
 }
+
 FX_BOOL CPDF_SecurityHandler::CheckSecurity(int32_t key_len) {
   CFX_ByteString password = m_pParser->GetPassword();
-  if (CheckPassword(password.raw_str(), password.GetLength(), TRUE,
+  if (!password.IsEmpty() &&
+      CheckPassword(password.raw_str(), password.GetLength(), TRUE,

[Tom Sepez, 2016/05/23 16:30:26]

Nit: candiadate for taking a const CFX_ByteStringC& rather than discreet ptr/len
pairs.

[Lei Zhang, 2016/05/23 18:41:24]

Yep. I will take care of this in a follow up CL.

                     m_EncryptKey, key_len)) {
-    if (password.IsEmpty()) {
-      if (!CheckPassword(password.raw_str(), password.GetLength(), FALSE,
-                         m_EncryptKey, key_len)) {
-        return FALSE;
-      }
-    }
+    m_bOwnerUnlocked = true;
     return TRUE;
   }
   return CheckPassword(password.raw_str(), password.GetLength(), FALSE,
                        m_EncryptKey, key_len);
 }
+
 uint32_t CPDF_SecurityHandler::GetPermissions() {
-  return m_Permissions;
+  return m_bOwnerUnlocked ? 0xFFFFFFFF : m_Permissions;
 }
 
 static FX_BOOL LoadCryptInfo(CPDF_Dictionary* pEncryptDict,
                              const CFX_ByteString& name,
                              int& cipher,
                              int& keylen) {
   int Version = pEncryptDict->GetIntegerBy("V");
   cipher = FXCIPHER_RC4;
   keylen = 0;
   if (Version >= 4) {
@@ skipping 572 matching lines @@
   buf[11] = 'b';
   uint8_t* aes = FX_Alloc(uint8_t, 2048);
   CRYPT_AESSetKey(aes, 16, key, 32, TRUE);
   uint8_t iv[16], buf1[16];
   FXSYS_memset(iv, 0, 16);
   CRYPT_AESSetIV(aes, iv);
   CRYPT_AESEncrypt(aes, buf1, buf, 16);
   FX_Free(aes);
   pEncryptDict->SetAtString("Perms", CFX_ByteString(buf1, 16));
 }