mfbt/SHA1.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 /* Simple class for computing SHA1. */
   7
   8 #ifndef mozilla_SHA1_h_
   9 #define mozilla_SHA1_h_
  10
  11 #include "mozilla/StandardInteger.h"
  12 #include "mozilla/Types.h"
  13
  14 #include <stddef.h>
  15
  16 namespace mozilla {
  17
  18 /**
  19  * This class computes the SHA1 hash of a byte sequence, or of the concatenation
  20  * of multiple sequences.  For example, computing the SHA1 of two sequences of
  21  * bytes could be done as follows:
  22  *
  23  *   void SHA1(const uint8_t* buf1, uint32_t size1,
  24  *             const uint8_t* buf2, uint32_t size2,
  25  *             SHA1Sum::Hash& hash)
  26  *   {
  27  *     SHA1Sum s;
  28  *     s.update(buf1, size1);
  29  *     s.update(buf2, size2);
  30  *     s.finish(hash);
  31  *   }
  32  *
  33  * The finish method may only be called once and cannot be followed by calls
  34  * to update.
  35  */
  36 class SHA1Sum
  37 {
  38     union {
  39         uint32_t w[16]; /* input buffer */
  40         uint8_t b[64];
  41     } u;
  42     uint64_t size; /* count of hashed bytes. */
  43     unsigned H[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 HashSize = 20;
  50     typedef uint8_t Hash[HashSize];
  51
  52     /* Add len bytes of dataIn to the data sequence being hashed. */
  53     MFBT_API void update(const void* dataIn, uint32_t len);
  54
  55     /* Compute the final hash of all data into hashOut. */
  56     MFBT_API void finish(SHA1Sum::Hash& hashOut);
  57 };
  58
  59 } /* namespace mozilla */
  60
  61 #endif /* mozilla_SHA1_h_ */