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tmathern merged 1 commit into from
Apr 24, 2026
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docs: Example for archive roundtrip #212

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169 changes: 169 additions & 0 deletions tests/builder.test.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,7 @@
#include <gtest/gtest.h>
#include <nlohmann/json.hpp>
#include <algorithm>
#include <fstream>
#include <functional>
#include <iostream>
#include <memory>
Expand Down Expand Up @@ -5858,3 +5859,171 @@ TEST_F(BuilderTest, CreateIntentViaContext)
}
ASSERT_TRUE(found_created) << "Expected c2pa.created action in active manifest";
}

TEST_F(BuilderTest, ArchiveIngredientRoundTripAndReuse)
{
auto context = c2pa::Context();
auto source_path = c2pa_test::get_fixture_path("A.jpg");

// Shared instance_id links the parentOf ingredient to a c2pa.opened action.
// Thos will make the archive valid
std::string instance_id = "xmp:iid:archive-roundtrip-0001";
json manifest_json = {
{"claim_generator_info", json::array({{{"name", "c2pa-test"}, {"version", "1.0"}}})},
{"assertions", json::array({
{
{"label", "c2pa.actions"},
{"data", {
{"actions", json::array({
{
{"action", "c2pa.opened"},
{"parameters", {
{"ingredientIds", json::array({instance_id})}
}}
}
})}
}}
}
})}
};

// 1. Builder1: add parentOf ingredient linked to c2pa.opened, no signing.
auto builder1 = c2pa::Builder(context, manifest_json.dump());
json ingredient = {
{"title", "A.jpg"},
{"relationship", "parentOf"},
{"instance_id", instance_id}
};
builder1.add_ingredient(ingredient.dump(), source_path);

// 2. Archive to .c2pa file.
auto archive_path = get_temp_path("roundtrip-ingredient.c2pa");
ASSERT_NO_THROW(builder1.to_archive(archive_path));
ASSERT_TRUE(fs::exists(archive_path));
ASSERT_GT(fs::file_size(archive_path), 0u);

// 3. Read archive back; manifest must parse and carry the ingredient.
std::ifstream archive_in(archive_path, std::ios::binary);
c2pa::Reader archive_reader(context, "application/c2pa", archive_in);
std::string archive_json;
ASSERT_NO_THROW(archive_json = archive_reader.json());

auto parsed = json::parse(archive_json);
ASSERT_TRUE(parsed.contains("active_manifest"));
std::string active = parsed["active_manifest"];
auto ingredients = parsed["manifests"][active]["ingredients"];
ASSERT_EQ(ingredients.size(), 1u);
EXPECT_EQ(ingredients[0]["title"], "A.jpg");
EXPECT_EQ(ingredients[0]["relationship"], "parentOf");

// 4. Builder2: fresh manifest (training.json) + add the archive as an ingredient.
auto builder2_manifest = c2pa_test::read_text_file(c2pa_test::get_fixture_path("training.json"));
auto builder2 = c2pa::Builder(context, builder2_manifest);
json ingredient_override = {
{"title", "A.jpg"},
{"relationship", "componentOf"}
};
ASSERT_NO_THROW(builder2.add_ingredient(ingredient_override.dump(), archive_path));

// 5. Sign builder2 and validate signed output.
auto signer = c2pa_test::create_test_signer();
auto output_path = get_temp_path("archive_reused_output.jpg");
std::vector<unsigned char> manifest_data;
ASSERT_NO_THROW(manifest_data = builder2.sign(source_path, output_path, signer));
ASSERT_FALSE(manifest_data.empty());

auto out_reader = c2pa::Reader(context, output_path);
std::string out_json;
ASSERT_NO_THROW(out_json = out_reader.json());
auto out_parsed = json::parse(out_json);
std::string out_active = out_parsed["active_manifest"];
auto out_ingredients = out_parsed["manifests"][out_active]["ingredients"];
ASSERT_EQ(out_ingredients.size(), 1u);
EXPECT_EQ(out_ingredients[0]["title"], "A.jpg");
EXPECT_EQ(out_ingredients[0]["relationship"], "componentOf");
}

TEST_F(BuilderTest, ArchiveIngredientWithProvenanceRoundTripAndReuse)
{
auto context = c2pa::Context();
auto source_path = c2pa_test::get_fixture_path("A.jpg");
auto ingredient_path = c2pa_test::get_fixture_path("C.jpg");

// Shared instance_id links the parentOf ingredient to a c2pa.opened action.
std::string instance_id = "xmp:iid:archive-roundtrip-provenance-0001";

json manifest_json = {
{"claim_generator_info", json::array({{{"name", "c2pa-test"}, {"version", "1.0"}}})},
{"assertions", json::array({
{
{"label", "c2pa.actions"},
{"data", {
{"actions", json::array({
{
{"action", "c2pa.opened"},
{"parameters", {
{"ingredientIds", json::array({instance_id})}
}}
}
})}
}}
}
})}
};

// 1. Builder1: add parentOf ingredient (C.jpg is C2PA-signed, has provenance).
auto builder1 = c2pa::Builder(context, manifest_json.dump());
json ingredient = {
{"title", "C.jpg"},
{"relationship", "parentOf"},
{"instance_id", instance_id}
};
builder1.add_ingredient(ingredient.dump(), ingredient_path);

// 2. Archive to .c2pa file.
auto archive_path = get_temp_path("roundtrip-provenance-ingredient.c2pa");
ASSERT_NO_THROW(builder1.to_archive(archive_path));
ASSERT_TRUE(fs::exists(archive_path));
ASSERT_GT(fs::file_size(archive_path), 0u);

// 3. Read archive back; manifest must parse and carry the ingredient.
std::ifstream archive_in(archive_path, std::ios::binary);
c2pa::Reader archive_reader(context, "application/c2pa", archive_in);
std::string archive_json;
ASSERT_NO_THROW(archive_json = archive_reader.json());
std::cout << archive_json << std::endl;

auto parsed = json::parse(archive_json);
ASSERT_TRUE(parsed.contains("active_manifest"));
std::string active = parsed["active_manifest"];
auto ingredients = parsed["manifests"][active]["ingredients"];
ASSERT_EQ(ingredients.size(), 1u);
EXPECT_EQ(ingredients[0]["title"], "C.jpg");
EXPECT_EQ(ingredients[0]["relationship"], "parentOf");

// 4. Builder2: fresh manifest + add the archive as an ingredient.
auto builder2_manifest = c2pa_test::read_text_file(c2pa_test::get_fixture_path("training.json"));
auto builder2 = c2pa::Builder(context, builder2_manifest);
json ingredient_override = {
{"title", "C.jpg"},
{"relationship", "componentOf"}
};
ASSERT_NO_THROW(builder2.add_ingredient(ingredient_override.dump(), archive_path));

// 5. Sign builder2 and validate signed output.
auto signer = c2pa_test::create_test_signer();
auto output_path = get_temp_path("archive_provenance_reused_output.jpg");
std::vector<unsigned char> manifest_data;
ASSERT_NO_THROW(manifest_data = builder2.sign(source_path, output_path, signer));
ASSERT_FALSE(manifest_data.empty());

auto out_reader = c2pa::Reader(context, output_path);
std::string out_json;
ASSERT_NO_THROW(out_json = out_reader.json());
auto out_parsed = json::parse(out_json);
std::string out_active = out_parsed["active_manifest"];
auto out_ingredients = out_parsed["manifests"][out_active]["ingredients"];
ASSERT_EQ(out_ingredients.size(), 1u);
EXPECT_EQ(out_ingredients[0]["title"], "C.jpg");
EXPECT_EQ(out_ingredients[0]["relationship"], "componentOf");
}
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