From 669364985e7b96f350dc489b3f30b513c7c0b569 Mon Sep 17 00:00:00 2001
From: Ben Toogood <bentoogood@gmail.com>
Date: Wed, 29 Apr 2020 09:21:17 +0100
Subject: [PATCH] JWT auth implementation

---
 auth/jwt/jwt.go   | 82 +++++++++++++++++++++++++++++++++++++++++++++++
 config/cmd/cmd.go |  2 ++
 2 files changed, 84 insertions(+)
 create mode 100644 auth/jwt/jwt.go

diff --git a/auth/jwt/jwt.go b/auth/jwt/jwt.go
new file mode 100644
index 00000000..9eb7b864
--- /dev/null
+++ b/auth/jwt/jwt.go
@@ -0,0 +1,82 @@
+package jwt
+
+import (
+	"errors"
+
+	"github.com/micro/go-micro/v2/auth"
+	"github.com/micro/go-micro/v2/auth/token"
+	jwtToken "github.com/micro/go-micro/v2/auth/token/jwt"
+)
+
+// NewAuth returns a new instance of the Auth service
+func NewAuth(opts ...auth.Option) auth.Auth {
+	j := new(jwt)
+	j.Init(opts...)
+	return j
+}
+
+// jwt is the service implementation of the Auth interface
+type jwt struct {
+	options auth.Options
+	jwt     token.Provider
+}
+
+func (j *jwt) String() string {
+	return "jwt"
+}
+
+func (j *jwt) Init(opts ...auth.Option) {
+	for _, o := range opts {
+		o(&j.options)
+	}
+
+	j.jwt = jwtToken.NewTokenProvider(
+		token.WithPrivateKey(j.options.PublicKey),
+		token.WithPublicKey(j.options.PublicKey),
+	)
+}
+
+func (j *jwt) Options() auth.Options {
+	return j.options
+}
+
+func (j *jwt) Generate(id string, opts ...auth.GenerateOption) (*auth.Account, error) {
+	return nil, errors.New("JWT does not support Generate, use the Token method")
+}
+
+func (j *jwt) Grant(role string, res *auth.Resource) error {
+	return errors.New("JWT does not support Grant")
+}
+
+func (j *jwt) Revoke(role string, res *auth.Resource) error {
+	return errors.New("JWT does not support Revoke")
+}
+
+func (j *jwt) Verify(acc *auth.Account, res *auth.Resource) error {
+	if acc == nil {
+		return auth.ErrForbidden
+	}
+	return nil
+}
+
+func (j *jwt) Inspect(token string) (*auth.Account, error) {
+	return j.jwt.Inspect(token)
+}
+
+func (j *jwt) Token(opts ...auth.TokenOption) (*auth.Token, error) {
+	options := auth.NewTokenOptions(opts...)
+	account := &auth.Account{
+		ID: options.ID,
+	}
+
+	tok, err := j.jwt.Generate(account, token.WithExpiry(options.Expiry))
+	if err != nil {
+		return nil, err
+	}
+
+	return &auth.Token{
+		Created:     tok.Created,
+		Expiry:      tok.Expiry,
+		AccessToken: tok.Token,
+	}, nil
+}
diff --git a/config/cmd/cmd.go b/config/cmd/cmd.go
index b5cd79f8..7cec8f99 100644
--- a/config/cmd/cmd.go
+++ b/config/cmd/cmd.go
@@ -70,6 +70,7 @@ import (
 	memTracer "github.com/micro/go-micro/v2/debug/trace/memory"
 
 	// auth
+	jwtAuth "github.com/micro/go-micro/v2/auth/jwt"
 	svcAuth "github.com/micro/go-micro/v2/auth/service"
 
 	// auth providers
@@ -369,6 +370,7 @@ var (
 
 	DefaultAuths = map[string]func(...auth.Option) auth.Auth{
 		"service": svcAuth.NewAuth,
+		"jwt":     jwtAuth.NewAuth,
 	}
 
 	DefaultAuthProviders = map[string]func(...provider.Option) provider.Provider{