From f1756c0c66ba835bcfcce6bec966f00b4011faf3 Mon Sep 17 00:00:00 2001
From: Enrico Marconi <enrico.marconi@hotmail.it>
Date: Thu, 25 Jul 2024 09:34:41 +0200
Subject: [PATCH] did:jwk resolution service

---
 bindings/grpc/proto/utils.proto     | 13 ++++++
 bindings/grpc/src/services/mod.rs   |  2 +-
 bindings/grpc/src/services/utils.rs | 66 ++++++++++++++++++++++++++++-
 3 files changed, 78 insertions(+), 3 deletions(-)

diff --git a/bindings/grpc/proto/utils.proto b/bindings/grpc/proto/utils.proto
index 87ea3f7054..2caa61244f 100644
--- a/bindings/grpc/proto/utils.proto
+++ b/bindings/grpc/proto/utils.proto
@@ -21,3 +21,16 @@ service Signing {
     rpc sign(DataSigningRequest) returns (DataSigningResponse);
 }
 
+message DidJwkResolutionRequest {
+    // did:jwk string
+    string did = 1;
+}
+
+message DidJwkResolutionResponse {
+    // JSON DID Document
+    string doc = 1;
+}
+
+service DidJwk {
+    rpc resolve(DidJwkResolutionRequest) returns (DidJwkResolutionResponse);
+}
\ No newline at end of file
diff --git a/bindings/grpc/src/services/mod.rs b/bindings/grpc/src/services/mod.rs
index 8c0a533499..8a4f197792 100644
--- a/bindings/grpc/src/services/mod.rs
+++ b/bindings/grpc/src/services/mod.rs
@@ -23,7 +23,7 @@ pub fn routes(client: &Client, stronghold: &StrongholdStorage) -> Routes {
   routes.add_service(domain_linkage::service(client));
   routes.add_service(document::service(client, stronghold));
   routes.add_service(status_list_2021::service());
-  routes.add_service(utils::service(stronghold));
+  utils::init_services(&mut routes, stronghold);
   routes.add_service(presentation::service(client));
 
   routes.routes()
diff --git a/bindings/grpc/src/services/utils.rs b/bindings/grpc/src/services/utils.rs
index 0e7d2fc570..a8214b332a 100644
--- a/bindings/grpc/src/services/utils.rs
+++ b/bindings/grpc/src/services/utils.rs
@@ -1,14 +1,26 @@
 // Copyright 2020-2024 IOTA Stiftung
 // SPDX-License-Identifier: Apache-2.0
 
+use _utils::did_jwk_server::DidJwk as DidJwkSvc;
+use _utils::did_jwk_server::DidJwkServer;
 use _utils::signing_server::Signing as SigningSvc;
 use _utils::signing_server::SigningServer;
 use _utils::DataSigningRequest;
 use _utils::DataSigningResponse;
+use _utils::DidJwkResolutionRequest;
+use _utils::DidJwkResolutionResponse;
+use anyhow::Context;
+use identity_iota::core::ToJson;
+use identity_iota::did::CoreDID;
+use identity_iota::document::DocumentBuilder;
 use identity_iota::storage::JwkStorage;
 use identity_iota::storage::KeyId;
 use identity_iota::storage::KeyStorageError;
+use identity_iota::verification::jwk::Jwk;
+use identity_iota::verification::jwu::decode_b64_json;
+use identity_iota::verification::VerificationMethod;
 use identity_stronghold::StrongholdStorage;
+use tonic::transport::server::RoutesBuilder;
 use tonic::Request;
 use tonic::Response;
 use tonic::Status;
@@ -62,6 +74,56 @@ impl SigningSvc for SigningService {
   }
 }
 
-pub fn service(stronghold: &StrongholdStorage) -> SigningServer<SigningService> {
-  SigningServer::new(SigningService::new(stronghold))
+pub fn init_services(routes: &mut RoutesBuilder, stronghold: &StrongholdStorage) {
+  routes.add_service(SigningServer::new(SigningService::new(stronghold)));
+  routes.add_service(DidJwkServer::new(DidJwkService {}));
+}
+
+#[derive(Debug)]
+pub struct DidJwkService {}
+
+#[tonic::async_trait]
+impl DidJwkSvc for DidJwkService {
+  #[tracing::instrument(
+    name = "utils/resolve_did_jwk",
+    skip_all,
+    fields(request = ?req.get_ref())
+    ret,
+    err,
+  )]
+  async fn resolve(&self, req: Request<DidJwkResolutionRequest>) -> Result<Response<DidJwkResolutionResponse>, Status> {
+    let DidJwkResolutionRequest { did } = req.into_inner();
+    let jwk = parse_did_jwk(&did).map_err(|e| Status::invalid_argument(e.to_string()))?;
+    let did = CoreDID::parse(did).expect("valid did:jwk");
+    let verification_method =
+      VerificationMethod::new_from_jwk(did.clone(), jwk, Some("0")).map_err(|e| Status::internal(e.to_string()))?;
+    let verification_method_id = verification_method.id().clone();
+    let doc = DocumentBuilder::default()
+      .id(did)
+      .verification_method(verification_method)
+      .assertion_method(verification_method_id.clone())
+      .authentication(verification_method_id.clone())
+      .capability_invocation(verification_method_id.clone())
+      .capability_delegation(verification_method_id.clone())
+      .key_agreement(verification_method_id)
+      .build()
+      .map_err(|e| Status::internal(e.to_string()))?;
+
+    Ok(Response::new(DidJwkResolutionResponse {
+      doc: doc.to_json().map_err(|e| Status::internal(e.to_string()))?,
+    }))
+  }
+}
+
+fn parse_did_jwk(did: &str) -> anyhow::Result<Jwk> {
+  let did_parts: [&str; 3] = did
+    .split(':')
+    .collect::<Vec<_>>()
+    .try_into()
+    .map_err(|_| anyhow::anyhow!("invalid did:jwk \"{did}\""))?;
+
+  match did_parts {
+    ["did", "jwk", data] => decode_b64_json(data).context("failed to deserialize JWK"),
+    _ => anyhow::bail!("invalid did:jwk string \"{did}\""),
+  }
 }