Function FUZZ_TARGET

src/test/fuzz/crypto_diff_fuzz_chacha20.cpp:268–329

}

FUZZ_TARGET(crypto_diff_fuzz_chacha20)
{
    FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};

    ChaCha20 chacha20;
    ECRYPT_ctx ctx;
    // D. J. Bernstein doesn't initialise ctx to 0 while Bitcoin Core initialises chacha20 to 0 in the constructor
    for (int i = 0; i < 16; i++) {
        ctx.input[i] = 0;
    }

    if (fuzzed_data_provider.ConsumeBool()) {
        const std::vector<unsigned char> key = ConsumeFixedLengthByteVector(fuzzed_data_provider, fuzzed_data_provider.ConsumeIntegralInRange<size_t>(16, 32));
        chacha20 = ChaCha20{key.data(), key.size()};
        ECRYPT_keysetup(&ctx, key.data(), key.size() * 8, 0);
        // ECRYPT_keysetup() doesn't set the counter and nonce to 0 while SetKey() does
        uint8_t iv[8] = {0, 0, 0, 0, 0, 0, 0, 0};
        ECRYPT_ivsetup(&ctx, iv);
    }

    LIMITED_WHILE (fuzzed_data_provider.ConsumeBool(), 3000) {
        CallOneOf(
            fuzzed_data_provider,
            [&] {
                const std::vector<unsigned char> key = ConsumeFixedLengthByteVector(fuzzed_data_provider, fuzzed_data_provider.ConsumeIntegralInRange<size_t>(16, 32));
                chacha20.SetKey(key.data(), key.size());
                ECRYPT_keysetup(&ctx, key.data(), key.size() * 8, 0);
                // ECRYPT_keysetup() doesn't set the counter and nonce to 0 while SetKey() does
                uint8_t iv[8] = {0, 0, 0, 0, 0, 0, 0, 0};
                ECRYPT_ivsetup(&ctx, iv);
            },
            [&] {
                uint64_t iv = fuzzed_data_provider.ConsumeIntegral<uint64_t>();
                chacha20.SetIV(iv);
                ctx.input[14] = iv;
                ctx.input[15] = iv >> 32;
            },
            [&] {
                uint64_t counter = fuzzed_data_provider.ConsumeIntegral<uint64_t>();
                chacha20.Seek(counter);
                ctx.input[12] = counter;
                ctx.input[13] = counter >> 32;
            },
            [&] {
                uint32_t integralInRange = fuzzed_data_provider.ConsumeIntegralInRange<size_t>(0, 4096);
                std::vector<uint8_t> output(integralInRange);
                chacha20.Keystream(output.data(), output.size());
                std::vector<uint8_t> djb_output(integralInRange);
                ECRYPT_keystream_bytes(&ctx, djb_output.data(), djb_output.size());
                assert(output == djb_output);
            },
            [&] {
                uint32_t integralInRange = fuzzed_data_provider.ConsumeIntegralInRange<size_t>(0, 4096);
                std::vector<uint8_t> output(integralInRange);
                const std::vector<uint8_t> input = ConsumeFixedLengthByteVector(fuzzed_data_provider, output.size());
                chacha20.Crypt(input.data(), output.data(), input.size());
                std::vector<uint8_t> djb_output(integralInRange);
                ECRYPT_encrypt_bytes(&ctx, input.data(), djb_output.data(), input.size());