destiny-2-Sunrise/Sunrise/src/middleware/crypto/sha256.h

#pragma once

#include <array>
#include <cstddef>
#include <span>

namespace sunrise::middleware::crypto::sha256 {

/** SHA-256 produces 32 bytes. */
inline constexpr std::size_t kDigestSize = 32;

/** One finished SHA-256 digest. */
using Digest = std::array<std::byte, kDigestSize>;

/**
 * Hashes one buffer.
 * @param input Bytes to hash.
 * @param output Receives the digest only on success.
 * @return True when Windows completed the hash.
 */
[[nodiscard]] bool hash(std::span<const std::byte> input, Digest& output) noexcept;

/**
 * Hashes two buffers as one concatenated message.
 * The SRP scrambling parameter is defined over a concatenation, so it needs no scratch copy.
 * @param first Leading bytes.
 * @param second Trailing bytes.
 * @param output Receives the digest only on success.
 * @return True when Windows completed the hash.
 */
[[nodiscard]] bool hash_pair(std::span<const std::byte> first,
                             std::span<const std::byte> second,
                             Digest& output) noexcept;

} // namespace sunrise::middleware::crypto::sha256