# PyVckit
PyVckit is a library for:
- sign verifiable credentials
- verify verifiable credentials
- generate verifiable presentations
- verify verifiable submissions

This library is strongly inspired by [SpruceId didkit](https://github.com/spruceid/didkit) and aims to maintain compatibility with it.

For now the supported cryptography is only EdDSA with a signature Ed25519Signature2018.

# Install
For now the installation is from the repository:
```sh
    python -m venv env
    source env/bin/activate
    git clone https://gitea.pangea.org/ereuse/pyvckit.git
    cd pyvckit
    pip install -r requirements.txt
    pip install -e .
```

# Cli
The mode of use under the command line would be the following:

## generate a key pair:
```sh
    python did.py -n keys > keypair.json
```

## generate a did identifier:

### did key
```sh
  python did.py -n did -k keypair.json
```

### did web
```sh
  python did.py -n did -k keypair.json -u https://localhost/user1/dids/
```

## generate an example signed credential:
An example of a credential is generated, which is the one that appears in the credential_tmpl template in the file [templates.py](templates.py)
```sh
    python sign_vc.py -k keypair.json > credential_signed.json
```

## verify a signed credential:
```sh
    python verify_vc.py credential_signed.json
```

## generate a verifiable presentation:
```sh
    python sign_vp.py -k keypair.json -c credential_signed.json > presentation_signed.json
```

## verify a verifiable presentation:
```sh
    python verify_vp.py presentation_signed.json
```

# Use as a library
In the tests you can find examples of use. Now I will explain the usual cases

## generate a key pair:
```python
    from pyvckit.did import generate_keys
    key = generate_keys()
```

## generate a did identifier:

### did key
```python
    from pyvckit.did import generate_keys, generate_did
    key = generate_keys()
    did = generate_did(key)
```

### did web
```python
    from pyvckit.did import generate_keys, generate_did
    key = generate_keys()
    url = "https://localhost/user1/dids/"
    did = generate_did(key, url)
```

## generate a signed credential:
Assuming **credential** is a valid credential.
**credential** is a string variable
```python
    from pyvckit.did import generate_keys, generate_did, get_signing_key
    from pyvckit.sign_vc import sign

    key = generate_keys()
    did = generate_did(key)
    signing_key = get_signing_key(key)
    vc = sign(credential, signing_key, did)
```

## verify a signed credential:
Assuming **vc** is a properly signed verifiable credential
```python
    import json
    from pyvckit.verify import verify_vc

    verified = verify_vc(json.dumps(vc))
```

## generate a verifiable presentation:
```python
    from pyvckit.did import generate_keys, generate_did, get_signing_key
    from pyvckit.sign_vp import sign_vp

    holder_key = generate_keys()
    holder_did = generate_did(holder_key)
    holder_signing_key = get_signing_key(holder_key)
    vp = sign_vp(holder_signing_key, holder_did, vc_string)
```

## verify a verifiable presentation:
```python
    from pyvckit.verify_vp import verify_vp
    verified = verify_vp(json.dumps(vp))
```

## creation of did document:
This command will create a json document and a url path where to place this document. The did must be a web did.
This document is an example and in production it must be adapted to contain the revoked verifiable credentials.
```python
    from pyvckit.did import generate_keys, generate_did, gen_did_document

    key = generate_keys()
    url = "https://localhost/did-registry"
    did = generate_did(key, url)
    definitive_url, document = gen_did_document(did, key)
```