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 {
  39     union {
  40         uint32_t w[16]; /* input buffer */
  41         uint8_t b[64];
  42     } u;
  43     uint64_t size; /* count of hashed bytes. */
  44     unsigned H[22]; /* 5 state variables, 16 tmp values, 1 extra */
  45     bool mDone;
  46
  47   public:
  48     MFBT_API SHA1Sum();
  49
  50     static const size_t HashSize = 20;
  51     typedef uint8_t Hash[HashSize];
  52
  53     /* Add len bytes of dataIn to the data sequence being hashed. */
  54     MFBT_API void update(const void* dataIn, uint32_t len);
  55
  56     /* Compute the final hash of all data into hashOut. */
  57     MFBT_API void finish(SHA1Sum::Hash& hashOut);
  58 };
  59
  60 } /* namespace mozilla */
  61
  62 #endif /* mozilla_SHA1_h */