vcl/inc/pdf/IPDFEncryptor.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  */
   9
  10 #pragma once
  11
  12 #include <rtl/ustring.hxx>
  13 #include <vector>
  14
  15 namespace vcl
  16 {
  17 struct PDFEncryptionProperties;
  18 }
  19
  20 namespace com::sun::star::beans
  21 {
  22 class XMaterialHolder;
  23 }
  24 namespace com::sun::star::uno
  25 {
  26 template <typename> class Reference;
  27 }
  28
  29 namespace vcl::pdf
  30 {
  31 /** Interface for encrypting the PDF content
  32  *
  33  * This interface makes it possible to have multiple versions and
  34  * revisions of PDF encryption, but all using the same interface,
  35  * so the implementation details are hidden from the outside. This
  36  * also makes it easier to add new implementations in the future as
  37  * we only need to write a new implementation of this interface.
  38  */
  39 class IPDFEncryptor
  40 {
  41 private:
  42     /* set to true if the following stream must be encrypted, used inside writeBuffer() */
  43     bool m_bEncryptThisStream = false;
  44
  45 public:
  46     virtual ~IPDFEncryptor() {}
  47
  48     /** PDF encryption version */
  49     virtual sal_Int32 getVersion() = 0;
  50     /** PDF encryption revision */
  51     virtual sal_Int32 getRevision() = 0;
  52
  53     /** the numerical value of the access permissions, according to PDF spec, must be signed */
  54     virtual sal_Int32 getAccessPermissions() = 0;
  55     virtual bool isMetadataEncrypted() = 0;
  56
  57     /** Encrypted access permission
  58      *
  59      * Depending on the encryption revision this may not be available. In that
  60      * case we can expect empty content.
  61      */
  62     virtual std::vector<sal_uInt8> getEncryptedAccessPermissions(std::vector<sal_uInt8>& /*rKey*/)
  63     {
  64         return std::vector<sal_uInt8>();
  65     }
  66
  67     /** Length of the key in bits (i.e. 256 = 256bits) */
  68     virtual sal_Int32 getKeyLength() = 0;
  69
  70     /** Prepares the encryption when the password is entered */
  71     virtual bool prepareEncryption(
  72         const css::uno::Reference<css::beans::XMaterialHolder>& xEncryptionMaterialHolder,
  73         PDFEncryptionProperties& rProperties)
  74         = 0;
  75
  76     /** Set up the keys and does a sanity check */
  77     virtual void setupKeysAndCheck(PDFEncryptionProperties& rProperties) = 0;
  78
  79     /** Setup before we start encrypting - remembers the key */
  80     virtual void setupEncryption(std::vector<sal_uInt8>& rEncryptionKey, sal_Int32 nObject) = 0;
  81
  82     /** Calculate the size of the output (by default the same as input) */
  83     virtual sal_uInt64 calculateSizeIncludingHeader(sal_uInt64 nSize) { return nSize; }
  84
  85     /** Encrypts the input and stores into the output */
  86     virtual void encrypt(const void* pInput, sal_uInt64 nInputSize, std::vector<sal_uInt8>& rOutput,
  87                          sal_uInt64 nOutputSize)
  88         = 0;
  89
  90     void enableStreamEncryption() { m_bEncryptThisStream = true; }
  91     void disableStreamEncryption() { m_bEncryptThisStream = false; }
  92     bool isStreamEncryptionEnabled() { return m_bEncryptThisStream; }
  93 };
  94 }
  95
  96 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */