Testing branches

utils/idhub_ssikit/README.md

@@ -0,0 +1,73 @@
+# Helper routines to manage DIDs/VC/VPs
+
+This module is a wrapper around the functions exported by SpruceID's `DIDKit` framework.
+
+## DID generation and storage
+
+For now DIDs are of the kind `did:key`, with planned support for `did:web` in the near future.
+
+Creation of a DID involves two steps:
+* Generate a unique DID controller key
+* Derive a `did:key` type from the key
+
+Both must be stored in the IdHub database and linked to a `User` for later retrieval.
+
+```python
+# Use case: generate and link a new DID for an existing user
+user = request.user # ...
+
+controller_key = idhub_ssikit.generate_did_controller_key()
+did_string = idhub_ssikit.keydid_from_controller_key(controller_key)
+
+
+did = idhub.models.DID(
+    did = did_string,
+    user = user
+)
+did_controller_key = idhub.models.DIDControllerKey(
+    key_material = controller_key,
+    owner_did = did 
+)
+
+did.save()
+did_controller_key.save()
+```
+
+## Verifiable Credential issuance
+
+Verifiable Credential templates are stored as Jinja2 (TBD) templates in `/schemas` folder. Please examine each template to see what data must be passed to it in order to render.
+
+The data passed to the template must at a minimum include:
+* issuer_did
+* subject_did
+* vc_id
+
+For example, in order to render `/schemas/member-credential.json`:
+
+```python
+from jinja2 import Environment, FileSystemLoader, select_autoescape
+import idhub_ssikit
+
+env = Environment(
+    loader=FileSystemLoader("vc_templates"),
+    autoescape=select_autoescape()
+)
+unsigned_vc_template = env.get_template("member-credential.json")
+
+issuer_user = request.user
+issuer_did = user.dids[0]  # TODO: Django ORM pseudocode
+issuer_did_controller_key = did.keys[0]  # TODO: Django ORM pseudocode
+
+data = {
+    "vc_id": "http://pangea.org/credentials/3731",
+    "issuer_did": issuer_did,
+    "subject_did": "did:web:[...]",
+    "issuance_date": "2020-08-19T21:41:50Z",
+    "subject_is_member_of": "Pangea"
+}
+signed_credential = idhub_ssikit.render_and_sign_credential(
+    unsigned_vc_template,
+    issuer_did_controller_key,
+    data
+)
+```