C2PA Python
Python bindings for the C2PA Content Authenticity Initiative (CAI) library
This library allows you to read and validate c2pa data in supported media files And to add signed manifests to supported media files.
Installation
pip install c2pa-python
Usage
Import
import c2pa-python as c2pa
Reading and Validating C2PA data in a file
Read any C2PA data from a given file
json_store = c2pa.verify_from_file_json("path/to/media_file.jpg", data_dir)
This will examine any supported media file for c2pa data and generate a JSON report of any data it finds. The report will include a validation_status field if any validation errors were found.
A media file may contain many manifests in a manifest store. The most recent manifest can be accessed by looking up the active_manifest field value in the manifests map.
If the optional data_dir is provided, any binary resources, such as thumbnails, icons and c2pa_data will be extracted into that directory. These files will be referenced by the identifier fields in the manifest store report.
Adding a Signed Manifest to a media file
The source is the media file which should receive new c2pa data. The destination will have a copy of the source with the data added. The manifest Json is a a JSON formatted string containing the data you want to add. (see: Generating SignerInfo for how to construct SignerInfo) The optional data_dir allows you to load resource files referenced from manifest_json identifiers. When building your manifest, any files referenced by identifier fields will be loaded relative to this path. This allows you to load thumbnails, icons and manifest data for ingredients
result = c2pa.add_manifest_to_file_json("path/to/source.jpg", "path/to/dest.jpg", manifest_json, sign_info, data_dir)
Generating SignerInfo
Set up the signer info from pem and key files.
certs = open("path/to/public_certs.pem","rb").read()
prv_key = open("path/to/private_key.pem","rb").read()
Then create a new SignerInfo instance using those keys. You must specify the signing algorithm used and may optionally add a time stamp authority URL.
sign_info = c2pa.SignerInfo(certs, priv_key, "es256", "http://timestamp.digicert.com")
Creating a Manifest Json Definition File
The manifest json string defines the c2pa to add to the file.
manifest_json = json.dumps({
"claim_generator": "python_test/0.1",
"assertions": [
{
"label": "c2pa.training-mining",
"data": {
"entries": {
"c2pa.ai_generative_training": { "use": "notAllowed" },
"c2pa.ai_inference": { "use": "notAllowed" },
"c2pa.ai_training": { "use": "notAllowed" },
"c2pa.data_mining": { "use": "notAllowed" }
}
}
}
]
})
Development
It is best to set up a virtual environment for development and testing https://virtualenv.pypa.io/en/latest/installation.html
We use maturin for packaging Rust in Python. It can can be installed with pip
pip install maturin
You will also need to install uniffi bindgen and pytest for testing
pip install uniffi_bindgen
pip install -U pytest
pip install <path to.whl> --force-reinstall
Testing
pytest
Supported file formats
| Extensions | MIME type |
|---|---|
avi |
video/msvideo, video/avi, application-msvideo |
avif |
image/avif |
c2pa |
application/x-c2pa-manifest-store |
dng |
image/x-adobe-dng |
heic |
image/heic |
heif |
image/heif |
jpg, jpeg |
image/jpeg |
m4a |
audio/mp4 |
mp4 |
video/mp4, application/mp4 |
mov |
video/quicktime |
png |
image/png |
svg |
image/svg+xml |
tif,tiff |
image/tiff |
wav |
audio/x-wav |
webp |
image/webp |
License
This package is distributed under the terms of both the MIT license and the Apache License (Version 2.0).
Note that some components and dependent crates are licensed under different terms; please check the license terms for each crate and component for details.
Contributions and feedback
We welcome contributions to this project. For information on contributing, providing feedback, and about ongoing work, see Contributing.
2 maintainers
Release files for c2pa-python 0.2.0
For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.
Source distribution (sdist)
| File | Size | Uploaded | |
|---|---|---|---|
| c2pa_python-0.2.0.tar.gz | 107.9 kB | Details |
Built distributions (wheels)
| File | Interpreter | ABI | Platform | Reset |
|---|---|---|---|---|
| c2pa_python-0.2.0-py3-none-manylinux_2_31_aarch64.whl | Python 3 | none | Linux glibc 2.31+ ARM64 | Details |
| c2pa_python-0.2.0-py3-none-macosx_11_0_arm64.whl | Python 3 | none | macOS 11.0+ ARM64 | Details |
Total release size: 8.7 MB
Release files / c2pa_python-0.2.0.tar.gz
| Download URL | c2pa_python-0.2.0.tar.gz |
|---|---|
| Size | 107.9 kB |
| Tags | Source |
|
SHA-256 checksum How to use checksums |
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| Download URL | c2pa_python-0.2.0-py3-none-manylinux_2_31_aarch64.whl |
|---|---|
| Size | 4.4 MB |
| Tags | Linux glibc 2.31+ ARM64 Python 3 |
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Release files / c2pa_python-0.2.0-py3-none-macosx_11_0_arm64.whl
| Download URL | c2pa_python-0.2.0-py3-none-macosx_11_0_arm64.whl |
|---|---|
| Size | 4.2 MB |
| Tags | Python 3 macOS 11.0+ ARM64 |
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SHA-256 checksum How to use checksums |
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