mfbt/SHA1.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 /* Simple class for computing SHA1. */
   8
   9 #ifndef mozilla_SHA1_h
  10 #define mozilla_SHA1_h
  11
  12 #include "mozilla/Types.h"
  13
  14 #include <stddef.h>
  15 #include <stdint.h>
  16
  17 namespace mozilla {
  18
  19 /**
  20  * This class computes the SHA1 hash of a byte sequence, or of the concatenation
  21  * of multiple sequences.  For example, computing the SHA1 of two sequences of
  22  * bytes could be done as follows:
  23  *
  24  *   void SHA1(const uint8_t* buf1, uint32_t size1,
  25  *             const uint8_t* buf2, uint32_t size2,
  26  *             SHA1Sum::Hash& hash)
  27  *   {
  28  *     SHA1Sum s;
  29  *     s.update(buf1, size1);
  30  *     s.update(buf2, size2);
  31  *     s.finish(hash);
  32  *   }
  33  *
  34  * The finish method may only be called once and cannot be followed by calls
  35  * to update.
  36  */
  37 class SHA1Sum {
  38   union {
  39     uint32_t mW[16]; /* input buffer */
  40     uint8_t mB[64];
  41   } mU;
  42   uint64_t mSize;  /* count of hashed bytes. */
  43   unsigned mH[22]; /* 5 state variables, 16 tmp values, 1 extra */
  44   bool mDone;
  45
  46  public:
  47   MFBT_API SHA1Sum();
  48
  49   static const size_t kHashSize = 20;
  50   typedef uint8_t Hash[kHashSize];
  51
  52   /* Add len bytes of dataIn to the data sequence being hashed. */
  53   MFBT_API void update(const void* aData, uint32_t aLength);
  54
  55   /* Compute the final hash of all data into hashOut. */
  56   MFBT_API void finish(SHA1Sum::Hash& aHashOut);
  57 };
  58
  59 } /* namespace mozilla */
  60
  61 #endif /* mozilla_SHA1_h */