formats/bmff/extractor_test.cc

// Copyright 2026 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

#include "formats/bmff/extractor.h"

#include <cstdint>
#include <limits>
#include <optional>
#include <string>
#include <vector>

#include "absl/log/check.h"
#include "absl/status/status.h"
#include "absl/status/status_matchers.h"
#include "absl/status/statusor.h"
#include "absl/strings/str_cat.h"
#include "absl/strings/string_view.h"
#include "constants/labels.h"
#include "formats/asset_box.h"
#include "formats/asset_byte_info.h"
#include "formats/bmff/test_utils.h"
#include "formats/byte_range.h"
#include "formats/extractor_result.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "riegeli/bytes/string_reader.h"
#include "testing/jumbf_utils.h"
#include "testing/test_string_utils.h"

namespace credentio {
namespace {

using ::absl_testing::StatusIs;
using ::credentio_testing::BigBox;
using ::credentio_testing::Box;
using ::credentio_testing::BoxFlags;
using ::credentio_testing::BoxVersion;
using ::credentio_testing::C2paBoxPayload;
using ::credentio_testing::ManifestBigBox;
using ::credentio_testing::ManifestBox;
using ::credentio_testing::Uint32Str;
using ::credentio_testing::Uint64Str;
using ::credentio_testing::UuidBoxPayload;
using ::testing::Eq;
using ::testing::HasSubstr;

constexpr int64_t kMaxChunkBytes = 10 * 1024 * 1024;  // 2 MiB

struct TestCase {
  std::string name;
  std::string contents;
  absl::StatusOr<ExtractorResult> result;
};

class ExtractorTest : public testing::TestWithParam<TestCase> {};

INSTANTIATE_TEST_SUITE_P(
    ExtractorTests, ExtractorTest,
    testing::ValuesIn({
        TestCase{
            .name = "EmptyContent",
            .contents = "",
            .result = absl::NotFoundError("No manifest store found"),
        },
        TestCase{
            .name = "C2paBox",
            .contents = absl::StrCat(Box("blah", "irrelevant content"),
                                     ManifestBox(/*merkle_offset=*/0, "foo")),
            .result = ExtractorResult{.manifest_store = "foo",
                                      .asset_byte_info =
                                          {.manifest_store_location =
                                               ByteRange{.offset = 26,
                                                         .length = 48}}},
        },
        TestCase{
            .name = "BigC2paBox",
            .contents = absl::StrCat(Box("blah", "irrelevant content"),
                                     ManifestBigBox(/*merkle_offset=*/0,
                                                    "foo")),
            .result = ExtractorResult{.manifest_store = "foo",
                                      .asset_byte_info =
                                          {.manifest_store_location =
                                               ByteRange{.offset = 26,
                                                         .length = 56}}},
        },
        TestCase{
            .name = "C2paBoxTooLarge",
            .contents = absl::StrCat(Box("blah", "irrelevant content"),
                                     ManifestBox(/*merkle_offset=*/0,
                                                 std::string(kMaxChunkBytes + 1,
                                                             'Z'))),
            .result = absl::NotFoundError("C2PA box is too large"),
        },
        TestCase{
            .name = "NoC2paBox",
            .contents = absl::StrCat(Box("blah", "irrelevant content"),
                                     Box("asdf", "more irrelevant content"),
                                     BigBox("zxcv", "whatever")),
            .result = absl::NotFoundError("No manifest store found"),
        },
        TestCase{
            .name = "C2paBoxAfterMoovIgnored",
            .contents = absl::StrCat(Box("blah", "irrelevant content"),
                                     Box("moov", "also irrelevant"),
                                     Box("uuid", absl::StrCat(kC2paBmffBoxUuid,
                                                              "foo"))),
            .result = absl::NotFoundError("No manifest store found"),
        },
        TestCase{
            .name = "C2paBoxAfterMdatIgnored",
            .contents = absl::StrCat(Box("blah", "irrelevant content"),
                                     Box("mdat", "also irrelevant"),
                                     Box("uuid", absl::StrCat(kC2paBmffBoxUuid,
                                                              "foo"))),
            .result = absl::NotFoundError("No manifest store found"),
        },
        TestCase{
            // Quoting
            // https://spec.c2pa.org/specifications/specifications/2.4/specs/C2PA_Specification.html#_embedded_2:
            // "If there are multiple C2PA Manifest Stores present in an asset,
            // they shall all be considered as invalid and the validation should
            // treat this as if no manifests were located."
            .name = "MultipleC2paBoxesIgnored",
            .contents = absl::StrCat(ManifestBox(/*merkle_offset=*/0, "foo"),
                                     ManifestBox(/*merkle_offset=*/0, "bar")),
            .result = absl::NotFoundError("Multiple manifest stores found"),
        },
        TestCase{
            .name = "NonC2paUuidBoxIgnored",
            .contents = absl::StrCat(Box("uuid",
                                         "abcdefghijklmnop not a C2PA box"),
                                     ManifestBox(/*merkle_offset=*/0, "foo")),
            .result =
                ExtractorResult{
                    .manifest_store = "foo",
                    .asset_byte_info = {.manifest_store_location =
                                            ByteRange{
                                                .offset = 39, .length = 48}}},
        },
        TestCase{
            .name = "TruncatedBoxHeader",
            .contents = "abcdefg",
            .result = absl::NotFoundError("No manifest store found"),
        },
        TestCase{
            .name = "TruncatedBoxPayload",
            .contents =
                []() {
                  std::string contents = Box("asdf", "payload");
                  contents.resize(contents.size() - 1);
                  return contents;
                }(),
            .result = absl::NotFoundError("truncated BMFF box"),
        },
        TestCase{
            .name = "TruncatedBoxPayloadHugeSize",
            .contents = absl::StrCat(
                Uint32Str(1), "asdf",
                Uint64Str(std::numeric_limits<int64_t>::max()), "payload"),
            .result = absl::NotFoundError("truncated BMFF box"),
        },
        TestCase{
            .name = "ShortUuidBox",
            .contents = Box("uuid", "foo"),
            .result = absl::NotFoundError("kUnexpectedEof"),
        },
        TestCase{
            .name = "InvalidBoxSize",
            .contents = absl::StrCat(Uint32Str(2), "asdf", "payload"),
            .result = absl::NotFoundError("kInvalidData"),
        },
        TestCase{
            .name = "InvalidBigBoxSize",
            .contents = absl::StrCat(Uint32Str(1), "asdf", Uint64Str(15),
                                     "payload"),
            .result = absl::NotFoundError("No manifest store found"),
        },
        TestCase{
            .name = "InvalidVersion",
            .contents = Box("uuid",
                            UuidBoxPayload(kC2paBmffBoxUuid, BoxVersion(1),
                                           BoxFlags(0), "")),
            .result = absl::NotFoundError("unsupported C2PA box version"),
        },
        TestCase{
            .name = "InvalidFlags",
            .contents = Box("uuid",
                            UuidBoxPayload(kC2paBmffBoxUuid, BoxVersion(0),
                                           BoxFlags(1), "")),
            .result = absl::NotFoundError("unsupported C2PA box flags"),
        },
        TestCase{
            .name = "NonManifestC2paBoxIgnored",
            .contents = absl::StrCat(
                Box("uuid", C2paBoxPayload("merkle", "ignored data")),
                ManifestBox(/*merkle_offset=*/0, "foo")),
            .result =
                ExtractorResult{
                    .manifest_store = "foo",
                    .asset_byte_info = {.manifest_store_location =
                                            ByteRange{
                                                .offset = 47, .length = 48}}},
        },
        TestCase{
            // Not enough bytes for the merkle offset.
            .name = "TruncatedManifestBox",
            .contents = Box("uuid", C2paBoxPayload("manifest", "asdfjkl")),
            .result = absl::NotFoundError("kUnexpectedEof"),
        },
    }),
    [](const testing::TestParamInfo<ExtractorTest::ParamType>& info) {
      return info.param.name;
    });

TEST_P(ExtractorTest, ExtractManifestStore) {
  riegeli::StringReader<> input(GetParam().contents);
  absl::StatusOr<std::string> result =
      BmffExtractor().ExtractManifestStore(input);

  absl::StatusOr<ExtractorResult> expected_result = GetParam().result;
  if (expected_result.ok()) {
    ABSL_ASSERT_OK(result);
    EXPECT_THAT(*result, Eq(expected_result->manifest_store));
  } else {
    EXPECT_THAT(result,
                StatusIs(expected_result.status().code(),
                         HasSubstr(expected_result.status().message())));
  }
}

TEST_P(ExtractorTest, ExtractWorksWhenPrefixPadded) {
  std::string contents = "padding" + GetParam().contents;
  riegeli::StringReader<> input(contents);

  ASSERT_TRUE(input.Seek(7));
  absl::StatusOr<std::string> result =
      BmffExtractor().ExtractManifestStore(input);

  absl::StatusOr<ExtractorResult> expected_result = GetParam().result;
  if (expected_result.ok()) {
    ABSL_ASSERT_OK(result);
    EXPECT_THAT(*result, Eq(expected_result->manifest_store));
  } else {
    EXPECT_THAT(result,
                StatusIs(expected_result.status().code(),
                         HasSubstr(expected_result.status().message())));
  }
}

TEST_P(ExtractorTest, ExtractManifestStoreLocation) {
  riegeli::StringReader<> input(GetParam().contents);
  absl::StatusOr<std::optional<ByteRange>> result =
      BmffExtractor().ExtractManifestStoreLocation(input,
                                                   /*options=*/{});

  absl::StatusOr<ExtractorResult> expected_result = GetParam().result;
  if (expected_result.ok()) {
    ABSL_ASSERT_OK(result);
    EXPECT_THAT(*result,
                Eq(expected_result->asset_byte_info.manifest_store_location));
  } else {
    EXPECT_THAT(result,
                StatusIs(expected_result.status().code(),
                         HasSubstr(expected_result.status().message())));
  }
}

TEST_P(ExtractorTest, ExtractBoxes) {
  riegeli::StringReader<> input(GetParam().contents);
  absl::StatusOr<std::vector<AssetBox>> result =
      BmffExtractor().ExtractBoxes(input,
                                   /*options=*/{});

  // BMFF does not have a concept of boxes, calling this method should always
  // fail.
  EXPECT_THAT(result, StatusIs(absl::StatusCode::kUnimplemented,
                               "BMFF does not have a concept of boxes"));
}

TEST(BmffExtractorTest, IsManifestStore) {
  EXPECT_TRUE(BmffExtractor().MightBeC2paManifestStore(
      CreateStartOfManifestStorePayload()));
}

}  // namespace
}  // namespace credentio