Vade is a framework for working with VCs and DIDs from different providers and on different platforms in a constant manner.
Even if the actual implementation and logic behind them may change, Vade offers a consistent interface to work with them.
It has been developed with wasm support in mind to allow it not only to run on servers but also on different clients
with limited resources like IoT devices.
The name "Vade" is an acronym for "VC and DID engine" and focuses on working with VCs and DIDs. It has been designed with the idea of offering a consistent interface to work with while supporting to move the actual work into plugins.
This library is currently under development. Behavior, as well as provided exports, may change over time.
Documentation about Vades functions and their meaning can be found here.
Vade is relying on plugins to run interact provider specific logic. The current set of Plugins can be seen below:
| Method | Info |
|---|---|
| did:evan |  |
| did:example | vade-example-plugin |
| (universal resolver method list) | in development |
More coming soon. To write your own plugins, have a look at writing own plugins.
| Method | Info |
|---|---|
| did:evan | |
More coming soon. To write your own plugins, have a look at writing own plugins.
use vade::Vade;
use some_crate:ExamplePlugin;
use vade::VadePlugin;
struct ExamplePlugin { }
impl ExamplePlugin { pub fn new() -> Self { ExamplePlugin {} } }
impl VadePlugin for ExamplePlugin {}
async fn example_vade_usage() {
let ep: ExamplePlugin = ExamplePlugin::new();
let mut vade = Vade::new();
vade.register_plugin(Box::from(ep));
match vade.did_create("did:example", "", "").await {
Ok(results) => {
let result = results[0].as_ref().unwrap().to_string();
println!("created did: {}", result);
},
Err(e) => panic!(format!("could not create did; {}", e)),
};
}As you can see, an instance of ExamplePlugin is created and handed over to a Vade instance with register_plugin. To be a valid argument for this, ExamplePlugin needs to implement VadePlugin.
Vade delegates the call all functions with the same name as the functions of VadePlugin to all registered plugins, so the result of such calls is a Vec of optional String values (Vec<Option<String>>).
Calls of plugin related functions follow the rule set described here:
- a
Vadeinstance delegates all calls of plugin related functions to all registered plugins - those
VadePlugininstances then may or may not process the request - requests may be ignored due to not being implemented or due to ignoring them due to plugin internal logic (e.g. if a did method is not supported by the plugin, requests for this method are usually ignored)
- ignored plugin requests do not end up in the result
Vec, so aVademay have registered multiple plugins, but if only on plugin caters to a certain did method, calls related to this method will only yield a single result
The current set of features can be grouped into 3 clusters:
- management functions
- DID interaction
- zero knowledge proof VC interaction
Registers a new plugin. See VadePlugin for details about how they work.
Creates a new DID. May also persist a DID document for it, depending on plugin implementation.
Fetch data about a DID. This usually returns a DID document.
Updates data related to a DID. May also persist a DID document for it, depending on plugin implementation.
vc_zkp_create_credential_schema
Creates a new zero-knowledge proof credential schema. The schema specifies properties a credential includes, both optional and mandatory.
vc_zkp_create_credential_definition
Creates a new zero-knowledge proof credential definition. A credential definition holds cryptographic key material and is needed by an issuer to issue a credential, thus needs to be created before issuance. A credential definition is always bound to one credential schema.
vc_zkp_create_credential_proposal
Creates a new zero-knowledge proof credential proposal. This message is the first in the credential issuance flow.
vc_zkp_create_credential_offer
Creates a new zero-knowledge proof credential offer. This message is the response to a credential proposal.
Requests a credential. This message is the response to a credential offering.
vc_zkp_create_revocation_registry_definition
Creates a new revocation registry definition. The definition consists of a public and a private part. The public part holds the cryptographic material needed to create non-revocation proofs. The private part needs to reside with the registry owner and is used to revoke credentials.
vc_zkp_update_revocation_registry
Updates a revocation registry for a zero-knowledge proof. This step is necessary after revocation one or more credentials.
Issues a new credential. This requires an issued schema, credential definition, an active revocation registry and a credential request message.
Revokes a credential. After revocation the published revocation registry needs to be updated with information returned by this function.
Requests a zero-knowledge proof for one or more credentials issued under one or more specific schemas.
Presents a proof for a zero-knowledge proof credential. A proof presentation is the response to a proof request.
Verifies a one or multiple proofs sent in a proof presentation.
Calls a custom function. Plugins may subscribe to such custom calls, that are not part of the default set of Vades default feature set, which allows to add custom plugin logic while using `Vade. Examples for this may be connection handling and key generation.
Except for the management functions all functions will be delegated to plugins. Plugins handling follows the following rules:
- a
Vadeinstance delegates all calls of plugin related functions to all registered plugins - those
VadePlugininstances then may or may not process the request - requests may be ignored due to not being implemented or due to ignoring them due to plugin internal logic (e.g. if a did method is not supported by the plugin, requests for this method are usually ignored)
- ignored plugin requests do not end up in the result
Vec, so aVademay have registered multiple plugins, but if only on plugin caters to a certain did method, calls related to this method will only yield a single result
Writing own plugin is rather simple, an example and details how to write them can be found in the VadePlugin documentation.
Vade supports Wasm! ^^
For an example how to use Vade in Wasm and a how to guide, have a look at our vade-wasm-example project.