feat: add DID-based authentication middleware

pkg/common/didauth/producer/context.go

@@ -0,0 +1,20 @@
+package producer
+
+import (
+	"github.com/labstack/echo/v4"
+	"github.com/onsonr/sonr/crypto/ucan"
+	"github.com/onsonr/sonr/crypto/ucan/store"
+	"github.com/onsonr/sonr/pkg/common/ipfs"
+)
+
+type ProducerContext struct {
+	echo.Context
+	// TokenParser is the attentuations assigned to the producer service
+	TokenParser *ucan.TokenParser
+
+	// TokenStore is the token store used to store and retrieve tokens
+	TokenStore store.IPFSTokenStore
+
+	// IPFSClient is the IPFS client used to resolve the UCAN
+	IPFSClient ipfs.Client
+}

pkg/common/didauth/producer/middleware.go

@@ -0,0 +1,38 @@
+package producer
+
+import (
+	"github.com/onsonr/sonr/crypto/mpc"
+	"github.com/onsonr/sonr/crypto/ucan"
+	"github.com/onsonr/sonr/crypto/ucan/store"
+	"github.com/onsonr/sonr/pkg/common/ipfs"
+
+	"github.com/labstack/echo/v4"
+)
+
+// Middleware returns middleware to spawn controllers and validate UCAN tokens
+func Middleware(ipfs ipfs.Client, perms ucan.Permissions) echo.MiddlewareFunc {
+	// Setup token store and parser
+	store := store.NewIPFSTokenStore(ipfs)
+	parser := ucan.NewTokenParser(perms.GetConstructor(), store, store)
+
+	// Return middleware
+	return func(next echo.HandlerFunc) echo.HandlerFunc {
+		return func(c echo.Context) error {
+			ctx := ProducerContext{
+				Context:     c,
+				IPFSClient:  ipfs,
+				TokenParser: parser,
+				TokenStore:  store,
+			}
+			return next(ctx)
+		}
+	}
+}
+
+func NewKeyset(c echo.Context) (mpc.Keyset, error) {
+	ks, err := mpc.NewKeyset()
+	if err != nil {
+		return nil, err
+	}
+	return ks, nil
+}