dom/security/SRICheck.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
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_dom_SRICheck_h
   8 #define mozilla_dom_SRICheck_h
   9
  10 #include "nsTString.h"
  11 #include "nsStringFwd.h"
  12 #include "nsCOMPtr.h"
  13 #include "nsICryptoHash.h"
  14
  15 class nsIChannel;
  16 class nsIConsoleReportCollector;
  17
  18 namespace mozilla::dom {
  19
  20 class SRIMetadata;
  21
  22 class SRICheck final {
  23  public:
  24   /**
  25    * Parse the multiple hashes specified in the integrity attribute and
  26    * return the strongest supported hash.
  27    */
  28   static nsresult IntegrityMetadata(const nsAString& aMetadataList,
  29                                     const nsACString& aSourceFileURI,
  30                                     nsIConsoleReportCollector* aReporter,
  31                                     SRIMetadata* outMetadata);
  32 };
  33
  34 // The SRICheckDataVerifier can be used in 2 different mode:
  35 //
  36 // 1. The streaming mode involves reading bytes from an input, and to use
  37 //    the |Update| function to stream new bytes, and to use the |Verify|
  38 //    function to check the hash of the content with the hash provided by
  39 //    the metadata.
  40 //
  41 //    Optionally, one can serialize the verified hash with |ExportDataSummary|,
  42 //    in a buffer in order to rely on the second mode the next time.
  43 //
  44 // 2. The pre-computed mode, involves reading a hash with |ImportDataSummary|,
  45 //    which got exported by the SRICheckDataVerifier and potentially cached, and
  46 //    then use the |Verify| function to check against the hash provided by the
  47 //    metadata.
  48 class SRICheckDataVerifier final {
  49  public:
  50   SRICheckDataVerifier(const SRIMetadata& aMetadata,
  51                        const nsACString& aSourceFileURI,
  52                        nsIConsoleReportCollector* aReporter);
  53
  54   // Append the following bytes to the content used to compute the hash. Once
  55   // all bytes are streamed, use the Verify function to check the integrity.
  56   nsresult Update(uint32_t aStringLen, const uint8_t* aString);
  57
  58   // Verify that the computed hash corresponds to the metadata.
  59   nsresult Verify(const SRIMetadata& aMetadata, nsIChannel* aChannel,
  60                   const nsACString& aSourceFileURI,
  61                   nsIConsoleReportCollector* aReporter);
  62
  63   bool IsComplete() const { return mComplete; }
  64
  65   // Report the length of the computed hash and its type, such that we can
  66   // reserve the space for encoding it in a vector.
  67   uint32_t DataSummaryLength();
  68   static uint32_t EmptyDataSummaryLength();
  69
  70   // Write the computed hash and its type in a pre-allocated buffer.
  71   nsresult ExportDataSummary(uint32_t aDataLen, uint8_t* aData);
  72   static nsresult ExportEmptyDataSummary(uint32_t aDataLen, uint8_t* aData);
  73
  74   // Report the length of the computed hash and its type, such that we can
  75   // skip these data while reading a buffer.
  76   static nsresult DataSummaryLength(uint32_t aDataLen, const uint8_t* aData,
  77                                     uint32_t* length);
  78
  79   // Extract the computed hash and its type, such that we can |Verify| if it
  80   // matches the metadata. The buffer should be at least the same size or
  81   // larger than the value returned by |DataSummaryLength|.
  82   nsresult ImportDataSummary(uint32_t aDataLen, const uint8_t* aData);
  83
  84  private:
  85   nsCOMPtr<nsICryptoHash> mCryptoHash;
  86   nsAutoCString mComputedHash;
  87   size_t mBytesHashed;
  88   uint32_t mHashLength;
  89   int8_t mHashType;
  90   bool mInvalidMetadata;
  91   bool mComplete;
  92
  93   nsresult EnsureCryptoHash();
  94   nsresult Finish();
  95   nsresult VerifyHash(const SRIMetadata& aMetadata, uint32_t aHashIndex,
  96                       const nsACString& aSourceFileURI,
  97                       nsIConsoleReportCollector* aReporter);
  98 };
  99
 100 }  // namespace mozilla::dom
 101
 102 #endif  // mozilla_dom_SRICheck_h