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C2PA iOS

[!WARNING] This library is currently in alpha and the API will likely change. Do not use for anything other than early testing.

Tests

This project provides iOS bindings to the C2PA (Content Authenticity Initiative) libraries. It wraps the C2PA Rust implementation (c2pa-rs) using its C API bindings.

Overview​

C2PA iOS offers:

  • iOS/macOS support via Swift Package/XCFramework
  • Native Swift APIs for reading, verifying, and signing content with C2PA manifests
  • Stream-based APIs for flexible data handling
  • Builder APIs for creating custom manifests
  • Comprehensive test suite with example application
  • Hardware-backed signing with Secure Enclave (iOS devices)

Repository Structure​

c2pa-ios/
├── Library/              # Swift Package containing the C2PA library
│   ├── Sources/         # Library source code
│   │   └── C2PA/       # Main library implementation
│   ├── Frameworks/     # Pre-built XCFramework
│   │   └── C2PAC.xcframework/
│   └── Tests/          # Unit tests
│       └── C2PATests/  # Test implementations
├── TestApp/            # iOS app for running tests with UI
├── ExampleApp/         # Sample iOS app for implementation reference
├── TestShared/         # Shared test utilities and fixtures
├── SigningServer/      # Local test server for signing operations
├── C2PA.xcworkspace/   # Xcode workspace tying everything together
└── Makefile           # Build automation (wraps xcodebuild/swift commands)

Requirements​

iOS​

  • iOS 15.0+ / macOS 11.0+
  • Xcode 13.0+
  • Swift 5.9+

Development​

  • Xcode Command Line Tools
  • Make

Quick Start​

Building the Library​

# Build the complete library with XCFramework
make library

# Build iOS framework (release configuration)
make ios-framework

# Run all tests
make test

# Run library tests only
make test-library

# Generate test coverage
make coverage

Running Applications​

# Run the test app in iOS Simulator
make run-test-app

# Run the example app in iOS Simulator
make run-example-app

# Build entire workspace
make workspace-build

Working with the Signing Server​

# Start the local signing server
make signing-server-start

# Check server status
make signing-server-status

# Stop the server
make signing-server-stop

# Run tests with signing server
make tests-with-server

Installation​

Swift Package Manager​

You can add C2PA iOS as a Swift Package Manager dependency:

dependencies: [
    .package(url: "https://github.com/contentauth/c2pa-ios.git", from: "0.0.1")
]

In your target, add the dependency:

targets: [
    .target(
        name: "YourTarget",
        dependencies: [.product(name: "C2PA", package: "c2pa-ios")]
    )
]

Local Development​

For local development without using a released version:

  1. Clone the repository
  2. Open C2PA.xcworkspace in Xcode
  3. Build using the workspace schemes or use the Makefile commands

Usage​

Basic File Operations​

import C2PA

// Read C2PA data from a file
do {
    let manifestJSON = try C2PA.readFile(at: imageURL)
    print("C2PA manifest: \(manifestJSON)")
} catch {
    print("Error reading C2PA data: \(error)")
}

// Sign a file with C2PA data
let signerInfo = SignerInfo(
    algorithm: .es256,
    certificatePEM: certificatePEM,
    privateKeyPEM: privateKeyPEM,
    tsaURL: nil
)

let manifestJSON = """
{
    "claim_generator": "MyApp/1.0",
    "title": "Signed Image",
    "format": "image/jpeg"
}
"""

try C2PA.signFile(
    source: inputURL,
    destination: outputURL,
    manifestJSON: manifestJSON,
    signerInfo: signerInfo
)

Stream-Based APIs​

// Create stream from data
let imageData = try Data(contentsOf: imageURL)
let stream = try Stream(data: imageData)

// Read with Reader API
let reader = try Reader(format: "image/jpeg", stream: stream)
let manifestJSON = try reader.json()

// Sign with Builder API
let builder = try Builder(manifestJSON: manifestJSON)
let signer = try Signer(info: signerInfo)

let sourceStream = try Stream(data: imageData)
let destStream = try Stream(fileURL: outputURL)

let manifestData = try builder.sign(
    format: "image/jpeg",
    source: sourceStream,
    destination: destStream,
    signer: signer
)

Building from Source​

  1. Clone this repository:

    git clone https://github.com/contentauth/c2pa-ios.git
    cd c2pa-ios

  2. Build the iOS framework:

    # Build library framework
    make library

    # Or build entire workspace
    make workspace-build

  3. Run tests:

    # Run all tests
    make test

    # Run with coverage
    make coverage

Makefile Targets​

The project includes a comprehensive Makefile with various targets:

  • library - Build the C2PA library framework
  • ios-framework - Build iOS framework (release configuration)
  • test - Run all tests (alias for test-library)
  • test-library - Run library unit tests only
  • tests - Run all tests including UI tests
  • coverage - Generate test coverage report
  • workspace-build - Build entire workspace
  • run-test-app - Run test app in simulator
  • run-example-app - Run example app in simulator
  • signing-server-start - Start signing server
  • signing-server-stop - Stop signing server
  • signing-server-status - Check server status
  • tests-with-server - Run tests with signing server
  • clean - Clean build artifacts
  • lint - Run SwiftLint on the codebase
  • help - Show all available targets

Test App​

The app includes comprehensive tests covering all major C2PA operations. Run the app and tap "Run All Tests" to see the library in action.

  • C2PA Library Version - Display current library version
  • Error Handling - Proper error handling for invalid files
  • Reading C2PA Data - Extract manifest data from signed images
  • Stream APIs - Demonstrate flexible stream-based operations
  • Builder APIs - Sign images with custom manifest data
  • No-Embed Manifests - Create cloud/sidecar manifests
  • Resource Management - Add and extract resources (thumbnails, etc.)
  • Ingredient Support - Handle ingredient relationships
  • Archive Operations - Work with C2PA archives
  • Custom Signers - Implement callback-based signing
  • Hardware Signing - Use Secure Enclave for signing (iOS devices)

Test Signing Server​

For testing certificate enrollment and C2PA signing, a Swift-based signing server is included:

# Start the test server
make signing-server-start

The server runs on http://localhost:8080 and provides:

  • Certificate Authority: Signs Certificate Signing Requests (CSRs) for testing
  • C2PA Signing: Server-side C2PA manifest signing
  • Bearer Token Authentication: For development/testing only

Key Endpoints​

  • GET /health - Health check
  • POST /api/v1/certificates/sign - Sign a CSR
  • POST /api/v1/c2pa/sign - Sign image with C2PA manifest

⚠️ Testing Only: This server is intended for development and testing only. For production use, implement proper authentication and security measures.

License​

This project is licensed under the Apache License, Version 2.0 and MIT - see the LICENSE-APACHE and LICENSE-MIT files for details.