show an example of gin middleware for authorization and authentication

README.md

@@ -74,6 +74,10 @@ Note that at this time, we do not currently support rotating the master key.
 - If does not exist...it uses a default config defined in the code inline
 3. Finally, it loads the config/.env file and adds the env variables defined in this file to the final SSIServiceConfig
 
+### Authentication and Authorization
+
+The ssi server uses the Gin framework from Golang, which allows various kinds of middleware. Look in `pkg/middleware/Authentication.go` and `pkg/middleware/Authorization.go` for details on how you can wire up authentication and authorization for your use case.
+
 ## Pre-built images to use
 
 There are pre-build images built by github actions on each merge to the main branch, which you can access here:

pkg/server/middleware/Authentication.go

@@ -0,0 +1,41 @@
+package middleware
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+)
+
+/*
+To use this middleware, you need to add it to your gin router in server.go:
+
+// setUpEngine creates the gin engine and sets up the middleware based on config
+func setUpEngine(cfg config.ServerConfig, shutdown chan os.Signal) *gin.Engine {
+	gin.ForceConsoleColor()
+	middlewares := gin.HandlersChain{
+		gin.Recovery(),
+		gin.Logger(),
+		middleware.Errors(shutdown),
+		middleware.AuthMiddleware(),
+		middleware.AuthorizationMiddleware(),
+	}
+
+
+*/
+
+func AuthMiddleware() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		token := c.GetHeader("Authorization")
+		// This is a dummy check here. You should do your actual JWT token verification.
+		if token == "IF YOU SET IT TO THIS VALUE IT WILL FAIL" {
+			c.JSON(http.StatusUnauthorized, gin.H{"error": "Authorization is required"})
+			c.Abort()
+			return
+		}
+		// Assuming that the token is valid and we got the user info from the JWT token.
+		// You should replace it with actual user info.
+		user := "user"
+		c.Set("user", user)
+		c.Next()
+	}
+}

pkg/server/middleware/Authorization.go

@@ -0,0 +1,45 @@
+package middleware
+
+import (
+	"github.com/gin-gonic/gin"
+)
+
+/*
+To use this middleware, you need to add it to your gin router in server.go:
+
+// setUpEngine creates the gin engine and sets up the middleware based on config
+func setUpEngine(cfg config.ServerConfig, shutdown chan os.Signal) *gin.Engine {
+	gin.ForceConsoleColor()
+	middlewares := gin.HandlersChain{
+		gin.Recovery(),
+		gin.Logger(),
+		middleware.Errors(shutdown),
+		middleware.AuthMiddleware(),
+	}
+
+*/
+
+func AuthorizationMiddleware() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		userRole := "userRole" // Retrieve user role from the JWT or context
+		path := c.FullPath()
+
+		switch {
+
+		case userRole == "admin":
+			// Admin has access to every endpoint
+			c.Next()
+
+		case userRole == "user" && path != "/admin-endpoint":
+			// Users do not have access to the admin endpoint
+			c.Next()
+
+		default:
+			// Normally you would return a 403 here, but for the sake of the example we will just call next
+			// c.JSON(http.StatusForbidden, gin.H{"error": "Forbidden"})
+			// c.Abort()
+			// return
+			c.Next()
+		}
+	}
+}