// Copyright (c) 2020 The Bitcoin Core developers

// Distributed under the MIT software license, see the accompanying

// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <crypto/poly1305.h>

#include <test/fuzz/FuzzedDataProvider.h>

#include <test/fuzz/fuzz.h>

#include <test/fuzz/util.h>

#include <cstdint>

#include <vector>

FUZZ_TARGET(crypto_poly1305)

{

    FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};

    const auto key = ConsumeFixedLengthByteVector<std::byte>(fuzzed_data_provider, Poly1305::KEYLEN);

    const auto in = ConsumeRandomLengthByteVector<std::byte>(fuzzed_data_provider);

    std::vector<std::byte> tag_out(Poly1305::TAGLEN);

    Poly1305{key}.Update(in).Finalize(tag_out);

}

FUZZ_TARGET(crypto_poly1305_split)

{

    FuzzedDataProvider provider{buffer.data(), buffer.size()};

    // Read key and instantiate two Poly1305 objects with it.

    auto key = provider.ConsumeBytes<std::byte>(Poly1305::KEYLEN);

    key.resize(Poly1305::KEYLEN);

    Poly1305 poly_full{key}, poly_split{key};

    // Vector that holds all bytes processed so far.

    std::vector<std::byte> total_input;

    // Process input in pieces.

    LIMITED_WHILE(provider.remaining_bytes(), 100) {

        auto in = ConsumeRandomLengthByteVector<std::byte>(provider);

        poly_split.Update(in);

        // Update total_input to match what was processed.

        total_input.insert(total_input.end(), in.begin(), in.end());

    }

    // Process entire input at once.

    poly_full.Update(total_input);

    // Verify both agree.

    std::array<std::byte, Poly1305::TAGLEN> tag_split, tag_full;

    poly_split.Finalize(tag_split);

    poly_full.Finalize(tag_full);

    assert(tag_full == tag_split);

}