Add key-related APIs in the security-proxy-auth service to enable support for external JWT verification

[lindseysimple]

🚀 Feature Request

Relevant Package [REQUIRED]

This feature request is for EdgeX services use the AuthenticationHandlerFunc middleware provided by go-mod-bootstrap module.

Description [REQUIRED]

Relates to edgexfoundry/go-mod-bootstrap#810.

Currently the /auth API invokes the SecretStoreAuthenticationHandlerFunc middleware from go-mod-bootstrap under the hook which only supports the JWT verification from the secret provider (OpenBAO) while using the API gateway.

edgex-go/internal/security/proxyauth/init.go

Lines 54 to 60 in 0ef5369

	authenticationHook := handlers.SecretStoreAuthenticationHandlerFunc(secretProvider, lc)
	// Common
	_ = controller.NewCommonController(dic, b.router, b.serviceName, edgex.Version)
	// Run authentication hook for a nil route
	b.router.GET("/auth", emptyHandler, authenticationHook)

The need arises to authenticate users using JWTs issued by an external JWT provider when accessing EdgeX services via the API gateway.

Describe the solution you'd like

Add the POST key and GET verification key APIs in security-proxy-auth service to support the verification of JWT issued from external JWT provider.

• The POST key API is used for users to upload the public key for verifying the JWT issued by the external issuers.
• The GET verification key API is utilized by the AuthenticationHandlerFunc in the go-mod-bootstrap module to verify JWTs issued by external issuers for each EdgeX service that integrates with the go-mod-bootstrap module.