1 // Copyright 2016 PDFium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
6 
7 #ifndef CORE_FPDFAPI_PARSER_CPDF_CRYPTO_HANDLER_H_
8 #define CORE_FPDFAPI_PARSER_CPDF_CRYPTO_HANDLER_H_
9 
10 #include <memory>
11 
12 #include "core/fdrm/fx_crypt.h"
13 #include "core/fxcrt/cfx_binarybuf.h"
14 #include "core/fxcrt/fx_memory_wrappers.h"
15 #include "core/fxcrt/fx_string.h"
16 #include "core/fxcrt/fx_system.h"
17 #include "third_party/base/span.h"
18 
19 class CPDF_Dictionary;
20 class CPDF_Object;
21 class CPDF_SecurityHandler;
22 
23 class CPDF_CryptoHandler {
24  public:
25   CPDF_CryptoHandler(int cipher, const uint8_t* key, size_t keylen);
26   ~CPDF_CryptoHandler();
27 
28   static bool IsSignatureDictionary(const CPDF_Dictionary* dictionary);
29 
30   bool DecryptObjectTree(RetainPtr<CPDF_Object> object);
31   size_t EncryptGetSize(pdfium::span<const uint8_t> source) const;
32   bool EncryptContent(uint32_t objnum,
33                       uint32_t gennum,
34                       pdfium::span<const uint8_t> source,
35                       uint8_t* dest_buf,
36                       uint32_t& dest_size);
37 
38   bool IsCipherAES() const;
39 
40  private:
41   uint32_t DecryptGetSize(uint32_t src_size);
42   void* DecryptStart(uint32_t objnum, uint32_t gennum);
43   ByteString Decrypt(uint32_t objnum, uint32_t gennum, const ByteString& str);
44   bool DecryptStream(void* context,
45                      pdfium::span<const uint8_t> source,
46                      CFX_BinaryBuf& dest_buf);
47   bool DecryptFinish(void* context, CFX_BinaryBuf& dest_buf);
48 
49   void PopulateKey(uint32_t objnum, uint32_t gennum, uint8_t* key);
50   void CryptBlock(bool bEncrypt,
51                   uint32_t objnum,
52                   uint32_t gennum,
53                   pdfium::span<const uint8_t> source,
54                   uint8_t* dest_buf,
55                   uint32_t& dest_size);
56   void* CryptStart(uint32_t objnum, uint32_t gennum, bool bEncrypt);
57   bool CryptStream(void* context,
58                    pdfium::span<const uint8_t> source,
59                    CFX_BinaryBuf& dest_buf,
60                    bool bEncrypt);
61   bool CryptFinish(void* context, CFX_BinaryBuf& dest_buf, bool bEncrypt);
62 
63   const size_t m_KeyLen;
64   const int m_Cipher;
65   std::unique_ptr<CRYPT_aes_context, FxFreeDeleter> m_pAESContext;
66   uint8_t m_EncryptKey[32];
67 };
68 
69 #endif  // CORE_FPDFAPI_PARSER_CPDF_CRYPTO_HANDLER_H_
70