dom/quota/DecryptingInputStream.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   5  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_dom_quota_DecryptingInputStream_h
   8 #define mozilla_dom_quota_DecryptingInputStream_h
   9
  10 // Local includes
  11 #include "EncryptedBlock.h"
  12
  13 // Global includes
  14 #include <cstddef>
  15 #include <cstdint>
  16 #include "ErrorList.h"
  17 #include "mozilla/InitializedOnce.h"
  18 #include "mozilla/Maybe.h"
  19 #include "mozilla/NotNull.h"
  20 #include "mozilla/ipc/InputStreamParams.h"
  21 #include "nsCOMPtr.h"
  22 #include "nsICloneableInputStream.h"
  23 #include "nsIIPCSerializableInputStream.h"
  24 #include "nsIInputStream.h"
  25 #include "nsISeekableStream.h"
  26 #include "nsISupports.h"
  27 #include "nsITellableStream.h"
  28 #include "nsTArray.h"
  29 #include "nscore.h"
  30
  31 template <class T>
  32 class nsCOMPtr;
  33
  34 namespace mozilla::dom::quota {
  35
  36 class DecryptingInputStreamBase : public nsIInputStream,
  37                                   public nsISeekableStream,
  38                                   public nsICloneableInputStream,
  39                                   public nsIIPCSerializableInputStream {
  40  public:
  41   NS_DECL_THREADSAFE_ISUPPORTS
  42
  43   NS_IMETHOD Read(char* aBuf, uint32_t aCount, uint32_t* _retval) final;
  44   NS_IMETHOD IsNonBlocking(bool* _retval) final;
  45
  46   NS_IMETHOD SetEOF() final;
  47
  48   using nsICloneableInputStream::GetCloneable;
  49   NS_IMETHOD GetCloneable(bool* aCloneable) final;
  50
  51   void SerializedComplexity(uint32_t aMaxSize, uint32_t* aSizeUsed,
  52                             uint32_t* aPipes,
  53                             uint32_t* aTransferables) override;
  54
  55  protected:
  56   DecryptingInputStreamBase(MovingNotNull<nsCOMPtr<nsIInputStream>> aBaseStream,
  57                             size_t aBlockSize);
  58
  59   // For deserialization only.
  60   DecryptingInputStreamBase() = default;
  61
  62   virtual ~DecryptingInputStreamBase() = default;
  63
  64   void Init(MovingNotNull<nsCOMPtr<nsIInputStream>> aBaseStream,
  65             size_t aBlockSize);
  66
  67   // Convenience routine to determine how many bytes of plain data
  68   // we currently have in our plain buffer.
  69   size_t PlainLength() const;
  70
  71   size_t EncryptedBufferLength() const;
  72
  73   LazyInitializedOnceEarlyDestructible<const NotNull<nsCOMPtr<nsIInputStream>>>
  74       mBaseStream;
  75   LazyInitializedOnce<const NotNull<nsISeekableStream*>> mBaseSeekableStream;
  76   LazyInitializedOnce<const NotNull<nsICloneableInputStream*>>
  77       mBaseCloneableInputStream;
  78   LazyInitializedOnce<const NotNull<nsIIPCSerializableInputStream*>>
  79       mBaseIPCSerializableInputStream;
  80
  81   // Number of bytes of plain data in mPlainBuffer.
  82   size_t mPlainBytes = 0;
  83
  84   // Next byte of mPlainBuffer to return in ReadSegments().
  85   size_t mNextByte = 0;
  86
  87   LazyInitializedOnceNotNull<const size_t> mBlockSize;
  88 };
  89
  90 // Wraps another nsIInputStream which contains data written using
  91 // EncryptingOutputStream with a compatible CipherStategy and key. See the
  92 // remarks on EncryptingOutputStream.
  93 template <typename CipherStrategy>
  94 class DecryptingInputStream final : public DecryptingInputStreamBase {
  95  public:
  96   // Construct a new blocking stream to decrypt the given base stream.  The
  97   // base stream must also be blocking.  The base stream does not have to be
  98   // buffered.
  99   DecryptingInputStream(MovingNotNull<nsCOMPtr<nsIInputStream>> aBaseStream,
 100                         size_t aBlockSize,
 101                         typename CipherStrategy::KeyType aKey);
 102
 103   // For deserialization only.
 104   explicit DecryptingInputStream();
 105
 106   nsresult BaseStreamStatus();
 107
 108   NS_IMETHOD Close() override;
 109   NS_IMETHOD Available(uint64_t* _retval) override;
 110   NS_IMETHOD StreamStatus() override;
 111   NS_IMETHOD ReadSegments(nsWriteSegmentFun aWriter, void* aClosure,
 112                           uint32_t aCount, uint32_t* _retval) override;
 113
 114   NS_DECL_NSITELLABLESTREAM
 115
 116   NS_IMETHOD Seek(int32_t aWhence, int64_t aOffset) override;
 117
 118   NS_IMETHOD Clone(nsIInputStream** _retval) override;
 119
 120   void Serialize(mozilla::ipc::InputStreamParams& aParams, uint32_t aMaxSize,
 121                  uint32_t* aSizeUsed) override;
 122
 123   bool Deserialize(const mozilla::ipc::InputStreamParams& aParams) override;
 124
 125  private:
 126   ~DecryptingInputStream();
 127
 128   // Parse the next chunk of data.  This populates mPlainBuffer (until the
 129   // stream position is at EOF).
 130   nsresult ParseNextChunk(bool aCheckAvailableBytes, uint32_t* aBytesReadOut);
 131
 132   // Convenience routine to Read() from the base stream until we get
 133   // the given number of bytes or reach EOF.
 134   //
 135   // aBuf                   - The buffer to write the bytes into.
 136   // aCount                 - Max number of bytes to read. If the stream closes
 137   //                          fewer bytes my be read.
 138   // aMinValidCount         - A minimum expected number of bytes.  If we find
 139   //                          fewer than this many bytes, then return
 140   //                          NS_ERROR_CORRUPTED_CONTENT.  If nothing was read
 141   //                          due due to EOF (aBytesReadOut == 0), then NS_OK is
 142   //                          returned.
 143   // aCheckAvailableBytes   - boolean flag controlling whether ReadAll should
 144   //                          check available bytes before calling underlying
 145   //                          Read method.
 146   // aBytesReadOut          - An out parameter indicating how many bytes were
 147   //                          read.
 148   nsresult ReadAll(char* aBuf, uint32_t aCount, uint32_t aMinValidCount,
 149                    bool aCheckAvailableBytes, uint32_t* aBytesReadOut);
 150
 151   bool EnsureBuffers();
 152
 153   // This method may change the current position in the stream.
 154   nsresult EnsureDecryptedStreamSize();
 155
 156   CipherStrategy mCipherStrategy;
 157   LazyInitializedOnce<const typename CipherStrategy::KeyType> mKey;
 158
 159   // Buffer to hold encrypted data.  Must copy here since we need a
 160   // flat buffer to run the decryption process on.
 161   using EncryptedBlockType = EncryptedBlock<CipherStrategy::BlockPrefixLength,
 162                                             CipherStrategy::BasicBlockSize>;
 163   Maybe<EncryptedBlockType> mEncryptedBlock;
 164
 165   // Buffer storing the resulting plain data.
 166   nsTArray<uint8_t> mPlainBuffer;
 167
 168   LazyInitializedOnce<const int64_t> mDecryptedStreamSize;
 169 };
 170
 171 }  // namespace mozilla::dom::quota
 172
 173 #endif