Walter Takashi Nakamura

21 papers C 1Journal 8Unranked 12
YearRankTypeTitle / Venue / Authors
2026 J jnl
J. Syst. Softw.
João Vitor Souza Rocha, Igor Scaliante Wiese, Ivanilton Polato, Marco Aurélio Graciotto Silva, Reginaldo Ré, Igor Steinmacher, Walter Takashi Nakamura
2025 J jnl
J. Interact. Syst.
Walter Takashi Nakamura, Edson César Cunha de Oliveira, Elaine Harada Teixeira de Oliveira, Tayana Conte
2025 conf
SBQS
Luis F. G. Campos, Leonardo C. Marques, Walter Takashi Nakamura
2025 J jnl
CoRR
Luis F. G. Campos, Leonardo C. Marques, Walter Takashi Nakamura
2024 conf
SBSI
Lucas Vieira de Carvalho, Pedro Henrique Dias Valle, Bhruno Roan Leifheit, Luis Jorge Enrique Rivero Cabrejos, Walter Takashi Nakamura, Guilherme Corredato Guerino, Renato De Souza Garcia, Williamson Silva
2023 J jnl
Int. J. Hum. Comput. Interact.
Walter Takashi Nakamura, Leonardo C. Marques, David F. Redmiles, Elaine Harada T. de Oliveira, Tayana Conte
2023 conf
IHC
Walter Takashi Nakamura, Edson César Cunha de Oliveira, Elaine Harada T. de Oliveira, Tayana Conte
2022 conf
ICEIS (2)
Eduardo A. Jesus, Guilherme Corredato Guerino, Pedro Henrique Dias Valle, Walter Takashi Nakamura, Ana Carolina Oran, Renato Balancieri, Thiago Adriano Coleti, Marcelo Morandini, Bruna Ferreira, Williamson Silva
2022 conf
SBQS
Sérgio Ricardo De Oliveira Cavalcante, Bruno Gadelha, Edson Oliveira, Igor Steinmacher, Walter Takashi Nakamura, Tayana Conte
2022 conf
ICEIS (2)
Marcus Barbosa, Walter Takashi Nakamura, Pedro Henrique Dias Valle, Guilherme Corredato Guerino, Alice Fonseca Finger, Gabriel Machado Lunardi, Williamson Silva
2022 J jnl
J. Syst. Softw.
Walter Takashi Nakamura, Edson César Cunha de Oliveira, Elaine Harada Teixeira de Oliveira, David F. Redmiles, Tayana Conte
2021 J jnl
Sensors
Walter Takashi Nakamura, Iftekhar Ahmed, David F. Redmiles, Edson Oliveira, David Fernandes, Elaine Harada Teixeira de Oliveira, Tayana Conte
2021 conf
SBQS
Walter Takashi Nakamura, José Cezar de Souza Filho, Lígia Márcia Teixeira, Afonso Silva, Rógenis Pereira da Silva, Bruno Gadelha, Tayana Conte
2021 conf
ICEIS (2)
José Cezar de Souza Filho, Walter Takashi Nakamura, Lígia Márcia Teixeira, Rógenis Pereira da Silva, Bruno F. Gadelha, Tayana Uchôa Conte
2021 J jnl
Sensors
Leonardo C. Marques, Patrícia Gomes Fernandes Matsubara, Walter Takashi Nakamura, Bruna Moraes Ferreira, Igor Scaliante Wiese, Bruno F. Gadelha, Luciana Martinez Zaina, David F. Redmiles, Tayana Uchôa Conte
2020 conf
ICEIS (2)
Walter Takashi Nakamura, Leonardo C. Marques, Bruna Ferreira, Simone D. J. Barbosa, Tayana Conte
2019 J jnl
Revista Brasileira de Informática na Educ.
Walter Takashi Nakamura, Leonardo Carneiro Marques, Luis Rivero, Elaine H. T. Oliveira, Tayana Conte
2019 conf
CHI Extended Abstracts
Walter Takashi Nakamura, Elaine Harada T. de Oliveira, Tayana Conte
2019 conf
SBES
Leonardo C. Marques, Patrícia Matsubara, Walter Takashi Nakamura, Igor Wiese, Luciana A. M. Zaina, Tayana Conte
2018 C conf
SEKE
Leonardo C. Marques, Walter Takashi Nakamura, Natasha M. Costa Valentim, Luis Rivero, Tayana Conte
2017 conf
ICEIS (3)
Walter Takashi Nakamura, Elaine Harada Teixeira de Oliveira, Tayana Conte
tests/unit/test_decompile_utils.py
← Index tests/unit/test_decompile_utils.py python
"""Unit tests for decompiler utility modules:
- bninja/utils/hashes.py
- bninja/utils/json_encoder.py
- bninja/analysis/low_level_normalization.py
"""
import hashlib
import json
import pytest


# ============================================================================
# 1a. hashes.py
# ============================================================================

from redb.extractors.decompiler.bninja.utils.hashes import (
    calculate_md5,
    calculate_sha256,
    calculate_tlsh,
)


class TestCalculateMD5:
    def test_calculate_md5_known_value(self):
        expected = hashlib.md5(b"test").hexdigest()
        assert calculate_md5("test") == expected

    def test_calculate_md5_empty(self):
        expected = hashlib.md5(b"").hexdigest()
        assert calculate_md5("") == expected


class TestCalculateSHA256:
    def test_calculate_sha256_known_value(self):
        expected = hashlib.sha256(b"hello world").hexdigest()
        assert calculate_sha256("hello world") == expected

    def test_calculate_sha256_empty_string(self):
        result = calculate_sha256("")
        assert len(result) == 64
        assert all(c in "0123456789abcdef" for c in result)


class TestCalculateTLSH:
    def test_calculate_tlsh_long_data(self):
        # TLSH requires >= 50 bytes
        data = "A" * 100
        result = calculate_tlsh(data)
        assert result is not None
        assert isinstance(result, str)

    def test_calculate_tlsh_short_data(self):
        data = "A" * 10
        result = calculate_tlsh(data)
        assert result is None

    def test_calculate_tlsh_deterministic(self):
        data = "x" * 200
        assert calculate_tlsh(data) == calculate_tlsh(data)



# ============================================================================
# 1b. json_encoder.py
# ============================================================================

from redb.extractors.decompiler.bninja.utils.json_encoder import BinaryNinjaEncoder


class TestBinaryNinjaEncoder:
    def test_encode_value_confidence_object(self):
        obj = type("VC", (), {"value": 42, "confidence": 255})()
        result = json.dumps(obj, cls=BinaryNinjaEncoder)
        assert json.loads(result) == 42

    def test_encode_str_fallback(self):
        obj = type("Obj", (), {"__str__": lambda self: "custom_repr"})()
        result = json.dumps(obj, cls=BinaryNinjaEncoder)
        assert json.loads(result) == "custom_repr"

    def test_encode_normal_types(self):
        data = {"a": 1, "b": [2, 3], "c": "hello"}
        result = json.dumps(data, cls=BinaryNinjaEncoder)
        assert json.loads(result) == data

    def test_encode_set_via_str(self):
        # Python sets have __str__, so BinaryNinjaEncoder converts them
        # to their string repr instead of raising TypeError.
        result = json.dumps(set([1, 2, 3]), cls=BinaryNinjaEncoder)
        parsed = json.loads(result)
        assert isinstance(parsed, str)
        assert "1" in parsed


# ============================================================================
# 1c. low_level_normalization.py
# ============================================================================

from redb.extractors.decompiler.bninja.analysis.low_level_normalization import (
    LowLevelNormalization,
)


class MockIL:
    """Mock IL node for normalization tests."""
    def __init__(self, operation, operands=None):
        self.operation = operation
        self.operands = operands or []


class TestLowLevelNormalization:
    def setup_method(self):
        self.normalizer = LowLevelNormalization()

    def test_normalize_single_instruction(self):
        node = MockIL(operation=5)
        result = self.normalizer.normalize_instruction_all_levels(node)
        assert result == [5]

    def test_normalize_nested_operands(self):
        child1 = MockIL(operation=10)
        child2 = MockIL(operation=20)
        root = MockIL(operation=1, operands=[child1, child2])
        result = self.normalizer.normalize_instruction_all_levels(root)
        assert result == [1, 10, 20]

    def test_normalize_empty_operands(self):
        node = MockIL(operation=42, operands=[])
        result = self.normalizer.normalize_instruction_all_levels(node)
        assert result == [42]

    def test_normalize_list_operands(self):
        # Simulates phi-node style list operands
        inner = MockIL(operation=99)
        node = MockIL(operation=7, operands=[[inner]])
        result = self.normalizer.normalize_instruction_all_levels(node)
        assert result == [7, 99]

    def test_normalize_none_input(self):
        result = self.normalizer.normalize_instruction_all_levels(None)
        assert result == []