1//==- SHA1.h - SHA1 implementation for LLVM                     --*- C++ -*-==//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8// This code is taken from public domain
9// (http://oauth.googlecode.com/svn/code/c/liboauth/src/sha1.c)
10// and modified by wrapping it in a C++ interface for LLVM,
11// and removing unnecessary code.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_SUPPORT_SHA1_H
16#define LLVM_SUPPORT_SHA1_H
17
18#include <array>
19#include <cstdint>
20
21namespace llvm {
22template <typename T> class ArrayRef;
23class StringRef;
24
25/// A class that wrap the SHA1 algorithm.
26class SHA1 {
27public:
28  SHA1() { init(); }
29
30  /// Reinitialize the internal state
31  void init();
32
33  /// Digest more data.
34  void update(ArrayRef<uint8_t> Data);
35
36  /// Digest more data.
37  void update(StringRef Str);
38
39  /// Return the current raw 160-bits SHA1 for the digested data
40  /// since the last call to init(). This call will add data to the internal
41  /// state and as such is not suited for getting an intermediate result
42  /// (see result()).
43  std::array<uint8_t, 20> final();
44
45  /// Return the current raw 160-bits SHA1 for the digested data
46  /// since the last call to init(). This is suitable for getting the SHA1 at
47  /// any time without invalidating the internal state so that more calls can be
48  /// made into update.
49  std::array<uint8_t, 20> result();
50
51  /// Returns a raw 160-bit SHA1 hash for the given data.
52  static std::array<uint8_t, 20> hash(ArrayRef<uint8_t> Data);
53
54private:
55  /// Define some constants.
56  /// "static constexpr" would be cleaner but MSVC does not support it yet.
57  enum { BLOCK_LENGTH = 64 };
58  enum { HASH_LENGTH = 20 };
59
60  // Internal State
61  struct {
62    union {
63      uint8_t C[BLOCK_LENGTH];
64      uint32_t L[BLOCK_LENGTH / 4];
65    } Buffer;
66    uint32_t State[HASH_LENGTH / 4];
67    uint32_t ByteCount;
68    uint8_t BufferOffset;
69  } InternalState;
70
71  // Helper
72  void writebyte(uint8_t data);
73  void hashBlock();
74  void addUncounted(uint8_t data);
75  void pad();
76
77  void final(std::array<uint32_t, HASH_LENGTH / 4> &HashResult);
78};
79
80} // end llvm namespace
81
82#endif
83