| //====- SHA256.cpp - SHA256 implementation ---*- C++ -* ======// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| /* |
| * The SHA-256 Secure Hash Standard was published by NIST in 2002. |
| * |
| * http://csrc.nist.gov/publications/fips/fips180-2/fips180-2.pdf |
| * |
| * The implementation is based on nacl's sha256 implementation [0] and LLVM's |
| * pre-exsiting SHA1 code [1]. |
| * |
| * [0] https://hyperelliptic.org/nacl/nacl-20110221.tar.bz2 (public domain |
| * code) |
| * [1] llvm/lib/Support/SHA1.{h,cpp} |
| */ |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_SUPPORT_SHA256_H |
| #define LLVM_SUPPORT_SHA256_H |
| |
| #include <array> |
| #include <cstdint> |
| |
| namespace llvm { |
| |
| template <typename T> class ArrayRef; |
| class StringRef; |
| |
| class SHA256 { |
| public: |
| explicit SHA256() { init(); } |
| |
| /// Reinitialize the internal state |
| void init(); |
| |
| /// Digest more data. |
| void update(ArrayRef<uint8_t> Data); |
| |
| /// Digest more data. |
| void update(StringRef Str); |
| |
| /// Return a reference to the current raw 256-bits SHA256 for the digested |
| /// data since the last call to init(). This call will add data to the |
| /// internal state and as such is not suited for getting an intermediate |
| /// result (see result()). |
| StringRef final(); |
| |
| /// Return a reference to the current raw 256-bits SHA256 for the digested |
| /// data since the last call to init(). This is suitable for getting the |
| /// SHA256 at any time without invalidating the internal state so that more |
| /// calls can be made into update. |
| StringRef result(); |
| |
| /// Returns a raw 256-bit SHA256 hash for the given data. |
| static std::array<uint8_t, 32> hash(ArrayRef<uint8_t> Data); |
| |
| private: |
| /// Define some constants. |
| /// "static constexpr" would be cleaner but MSVC does not support it yet. |
| enum { BLOCK_LENGTH = 64 }; |
| enum { HASH_LENGTH = 32 }; |
| |
| // Internal State |
| struct { |
| union { |
| uint8_t C[BLOCK_LENGTH]; |
| uint32_t L[BLOCK_LENGTH / 4]; |
| } Buffer; |
| uint32_t State[HASH_LENGTH / 4]; |
| uint32_t ByteCount; |
| uint8_t BufferOffset; |
| } InternalState; |
| |
| // Internal copy of the hash, populated and accessed on calls to result() |
| uint32_t HashResult[HASH_LENGTH / 4]; |
| |
| // Helper |
| void writebyte(uint8_t data); |
| void hashBlock(); |
| void addUncounted(uint8_t data); |
| void pad(); |
| }; |
| |
| } // namespace llvm |
| |
| #endif // LLVM_SUPPORT_SHA256_H |