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| Rev | Author | Line No. | Line |
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| 14 | pmbaty | 1 | //====- SHA256.cpp - SHA256 implementation ---*- C++ -* ======// |
| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | /* |
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| 9 | * The SHA-256 Secure Hash Standard was published by NIST in 2002. |
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| 10 | * |
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| 11 | * http://csrc.nist.gov/publications/fips/fips180-2/fips180-2.pdf |
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| 12 | * |
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| 13 | * The implementation is based on nacl's sha256 implementation [0] and LLVM's |
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| 14 | * pre-exsiting SHA1 code [1]. |
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| 15 | * |
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| 16 | * [0] https://hyperelliptic.org/nacl/nacl-20110221.tar.bz2 (public domain |
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| 17 | * code) |
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| 18 | * [1] llvm/lib/Support/SHA1.{h,cpp} |
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| 19 | */ |
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| 20 | //===----------------------------------------------------------------------===// |
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| 21 | |||
| 22 | #ifndef LLVM_SUPPORT_SHA256_H |
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| 23 | #define LLVM_SUPPORT_SHA256_H |
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| 24 | |||
| 25 | #include <array> |
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| 26 | #include <cstdint> |
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| 27 | |||
| 28 | namespace llvm { |
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| 29 | |||
| 30 | template <typename T> class ArrayRef; |
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| 31 | class StringRef; |
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| 32 | |||
| 33 | class SHA256 { |
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| 34 | public: |
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| 35 | explicit SHA256() { init(); } |
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| 36 | |||
| 37 | /// Reinitialize the internal state |
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| 38 | void init(); |
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| 39 | |||
| 40 | /// Digest more data. |
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| 41 | void update(ArrayRef<uint8_t> Data); |
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| 42 | |||
| 43 | /// Digest more data. |
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| 44 | void update(StringRef Str); |
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| 45 | |||
| 46 | /// Return the current raw 256-bits SHA256 for the digested |
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| 47 | /// data since the last call to init(). This call will add data to the |
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| 48 | /// internal state and as such is not suited for getting an intermediate |
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| 49 | /// result (see result()). |
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| 50 | std::array<uint8_t, 32> final(); |
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| 51 | |||
| 52 | /// Return the current raw 256-bits SHA256 for the digested |
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| 53 | /// data since the last call to init(). This is suitable for getting the |
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| 54 | /// SHA256 at any time without invalidating the internal state so that more |
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| 55 | /// calls can be made into update. |
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| 56 | std::array<uint8_t, 32> result(); |
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| 57 | |||
| 58 | /// Returns a raw 256-bit SHA256 hash for the given data. |
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| 59 | static std::array<uint8_t, 32> hash(ArrayRef<uint8_t> Data); |
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| 60 | |||
| 61 | private: |
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| 62 | /// Define some constants. |
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| 63 | /// "static constexpr" would be cleaner but MSVC does not support it yet. |
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| 64 | enum { BLOCK_LENGTH = 64 }; |
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| 65 | enum { HASH_LENGTH = 32 }; |
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| 66 | |||
| 67 | // Internal State |
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| 68 | struct { |
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| 69 | union { |
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| 70 | uint8_t C[BLOCK_LENGTH]; |
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| 71 | uint32_t L[BLOCK_LENGTH / 4]; |
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| 72 | } Buffer; |
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| 73 | uint32_t State[HASH_LENGTH / 4]; |
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| 74 | uint32_t ByteCount; |
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| 75 | uint8_t BufferOffset; |
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| 76 | } InternalState; |
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| 77 | |||
| 78 | // Helper |
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| 79 | void writebyte(uint8_t data); |
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| 80 | void hashBlock(); |
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| 81 | void addUncounted(uint8_t data); |
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| 82 | void pad(); |
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| 83 | |||
| 84 | void final(std::array<uint32_t, HASH_LENGTH / 4> &HashResult); |
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| 85 | }; |
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| 86 | |||
| 87 | } // namespace llvm |
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| 88 | |||
| 89 | #endif // LLVM_SUPPORT_SHA256_H |