Metadata-Version: 2.1
Name: cose
Version: 0.9.dev7
Summary: CBOR Object Signing and Encryption (COSE) implementation
Home-page: https://pycose.readthedocs.io/en/latest/
Author: Timothy Claeys
Author-email: timothy.claeys@gmail.com
License: BSD-3
Description: # pycose:snake:  --- CBOR Object Signing and Encryption
        [![Python package](https://github.com/TimothyClaeys/pycose/actions/workflows/python-package.yml/badge.svg)](https://github.com/TimothyClaeys/pycose/actions/workflows/python-package.yml)
        [![Documentation Status](https://readthedocs.org/projects/pycose/badge/?version=latest)](https://pycose.readthedocs.io/en/latest/?badge=latest)
        
        This project is a Python implementation of the IETF CBOR Encoded Message Syntax (COSE). COSE has reached RFC status and is now available at RFC 8152.
        
        
        ## Installation
        
        ```bash
        $ pip install cose
        ```
        
        :warning:**WARNING**:warning:: There is package on [PyPI](https://pypi.org/) called `pycose` which contains old code from this repository. Since I am not the maintainer I cannot update that package or remove it.
        
        ## What is COSE ?
        CBOR Encoded Message Syntax (COSE) is a data format for concise representation of small messages [RFC 8152](https://tools.ietf.org/html/rfc8152). COSE is optimized for low power devices. The messages can be encrypted, MAC'ed and signed. There are 6 different types of COSE messages:
        
        - **Encrypt0**: An encrypted COSE message with a single recipient. The payload and AAD are protected by a shared CEK (Content Encryption Keys)
        - **Encrypt**: An encrypted COSE message can have multiple recipients. For each recipient the CEK is encrypted with a KEK (Key Encryption Key) - using AES key wrap - and added to the message.
        - **MAC0**: An authenticated COSE message with one recipient.
        - **MAC**: An authenticated COSE message that can have multiple recipients. For each recipient, the authentication key is encrypted with a KEK and added to the message.
        - **Sign1**: A signed COSE message with a single signature.
        - **Sign**: A COSE message that has been signed by multiple entities (each signature is carried in a COSE signature structure, added to the message).
        
        A basic COSE message consists of 2 _information_ _buckets_ and the _payload_:
        
        - **Protected header**: This message field contains information that needs to be protected. This information is taken into account during the encryption, calculation of the MAC or the signature.
        - **Unprotected header**: The information contained in the unprotected header is not protected by the cryptographic algorithms.
        - **Payload**: Contains the payload of the message, protected (mac'ed, signed or encrypted) by the cryptographic algorithms.
        
        Additionally, based on the message type, other message fields can be added:
        
        - _MAC_ or _signature_ (for **MAC0** or **Sign1** messages)
        - _COSE recipients_ or _COSE signatures_ (for **MAC**, **Encrypt**, and **Sign** messages)
        
        ## Examples
        
        ### Encoding
        
        ```python
        from binascii import unhexlify
        from cose.messages import Enc0Message
        from cose.keys import SymmetricKey
        
        # Create a COSE Encrypt0 Message
        msg = Enc0Message(
            phdr={'ALG': 'A128GCM', 'IV': unhexlify(b'01010101010101010101010101010101')},
            uhdr={'KID': b'meriadoc.brandybuck@buckland.example'},
            payload='a secret message'.encode('utf-8')
        )
        
        # Create a COSE Symmetric Key
        cose_key = SymmetricKey(key=unhexlify(b'000102030405060708090a0b0c0d0e0f'))
        msg.key = cose_key
        
        # Performs encryption and CBOR serialization
        msg.encode()
        b'\xd0\x83U\xa2\x01\x01\x05P\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\xa1\x04X$meriadoc.brandybuck@buckland.exampleX \xc4\xaf\x85\xacJQ4\x93\x19\x93\xec\n\x18c\xa6\xe8\xc6n\xf4\xc9\xac\x161^\xe6\xfe\xcd\x9b.\x1cy\xa1'
        ```
        
        ### Decoding
        ```python
        from binascii import unhexlify
        from cose.messages import CoseMessage
        from cose.keys import SymmetricKey
        
        # message bytes (CBOR encoded)
        msg =  b'\xd0\x83U\xa2\x01\x01\x05P\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\xa1\x04X$meriadoc.brandybuck@buckland.exampleX \xc4\xaf\x85\xacJQ4\x93\x19\x93\xec\n\x18c\xa6\xe8\xc6n\xf4\xc9\xac\x161^\xe6\xfe\xcd\x9b.\x1cy\xa1'
        
        cose_msg = CoseMessage.decode(msg)
        
        # Create a COSE Symmetric Key
        cose_key = SymmetricKey(key=unhexlify(b'000102030405060708090a0b0c0d0e0f'))
        cose_msg.key = cose_key
        
        cose_msg.decrypt()
        b'a secret message'
        ```
        
        ### More examples
        More examples can be found [here](https://pycose.readthedocs.io/en/latest/examples.html)
        
        ## Testing
        
        To run the test suite you need `pytest`:
        ```shell
        $ pip install pytest
        ```
        Move to the root of the repository and type:
        
        ```shell
        $ pytest
        ```
        
        ## Cryptography
        
        The project depends on [pyca/cryptography](https://github.com/pyca/cryptography) for all cryptographic operations, except the deterministic ECDSA algorithm. For deterministic ECDSA `cose` uses [python-ecdsa](https://github.com/warner/python-ecdsa). 
        
        ## Documentation
        
        More documentation on COSE and the `cose` API can be found at: https://pycose.readthedocs.io
        
        
Keywords: COSE,Internet of Things,CBOR,object security,EDHOC,OSCORE,cryptography
Platform: platform-independent
Classifier: Development Status :: 3 - Alpha
Classifier: Intended Audience :: Developers
Classifier: Topic :: Internet
Classifier: Topic :: Communications
Classifier: Topic :: Software Development
Classifier: Topic :: System :: Networking
Classifier: License :: OSI Approved :: BSD License
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.6
Classifier: Programming Language :: Python :: 3.7
Classifier: Programming Language :: Python :: 3.8
Requires-Python: >=3.6
Description-Content-Type: text/markdown
