Refactored and added client credentials flow

cmd/login.go

@@ -1,7 +1,7 @@
 package cmd
 
 import (
-	opaal "davidallendj/opaal/internal"
+	"davidallendj/opaal/internal/flows"
 	"fmt"
 	"os"
 
@@ -13,7 +13,7 @@ var loginCmd = &cobra.Command{
 	Short: "Start the login flow",
 	Run: func(cmd *cobra.Command, args []string) {
 		for {
-			err := opaal.Login(&config)
+			err := flows.Login(&config)
 			if err != nil {
 				fmt.Printf("%v\n", err)
 				os.Exit(1)
@@ -37,5 +37,6 @@ func init() {
 	loginCmd.Flags().BoolVar(&config.DecodeIdToken, "decode-id-token", config.DecodeIdToken, "decode and print ID token from identity provider")
 	loginCmd.Flags().BoolVar(&config.DecodeAccessToken, "decore-access-token", config.DecodeAccessToken, "decode and print access token from authorization server")
 	loginCmd.Flags().BoolVar(&config.RunOnce, "once", config.RunOnce, "set whether to run login once and exit")
+	loginCmd.Flags().StringVar(&config.GrantType, "grant-type", config.GrantType, "set the grant-type/authorization flow")
 	rootCmd.AddCommand(loginCmd)
 }

cmd/root.go

@@ -21,6 +21,18 @@ var rootCmd = &cobra.Command{
 	},
 }
 
+func Execute() {
+	if err := rootCmd.Execute(); err != nil {
+		fmt.Fprintf(os.Stderr, "failed to start CLI: %s", err)
+		os.Exit(1)
+	}
+}
+
+func init() {
+	cobra.OnInitialize(initConfig)
+	rootCmd.PersistentFlags().StringVar(&configPath, "config", "", "set the config path")
+}
+
 func initConfig() {
 	// load config if found or create a new one
 	if configPath != "" {
@@ -35,15 +47,3 @@ func initConfig() {
 		}
 	}
 }
-
-func Execute() {
-	if err := rootCmd.Execute(); err != nil {
-		fmt.Fprintf(os.Stderr, "failed to start CLI: %s", err)
-		os.Exit(1)
-	}
-}
-
-func init() {
-	cobra.OnInitialize(initConfig)
-	rootCmd.PersistentFlags().StringVar(&configPath, "config", "", "set the config path")
-}

config.yaml

@@ -16,6 +16,8 @@ urls:
   jwks_uri: http://git.towk.local:3000/login/oauth/keys
   login: http://127.0.0.1:4433/self-service/login/api
   login-flow-id: http://127.0.0.1:4433/self-service/login/flows?id={id}
+  register-client: http://127.0.0.1:4445/clients
+  authorize-client: http://127.0.0.1:4444/oauth2/authorize
 state: ""
 response-type: code
 decode-id-token: true

internal/client.go

@@ -129,12 +129,17 @@ func (client *Client) FetchCSRFToken(flowUrl string) error {
 func (client *Client) FetchTokenFromAuthenticationServer(code string, remoteUrl string, state string) ([]byte, error) {
 	data := url.Values{
 		"grant_type":    {"authorization_code"},
-		"code":          {code},
 		"client_id":     {client.Id},
 		"client_secret": {client.Secret},
-		"state":         {state},
 		"redirect_uri":  {strings.Join(client.RedirectUris, ",")},
 	}
+	// add optional params if valid
+	if code != "" {
+		data["code"] = []string{code}
+	}
+	if state != "" {
+		data["state"] = []string{state}
+	}
 	res, err := http.PostForm(remoteUrl, data)
 	if err != nil {
 		return nil, fmt.Errorf("failed to get ID token: %s", err)
@@ -151,9 +156,16 @@ func (client *Client) FetchTokenFromAuthorizationServer(remoteUrl string, jwt st
 	// hydra endpoint: /oauth/token
 	data := "grant_type=" + url.QueryEscape("urn:ietf:params:oauth:grant-type:jwt-bearer") +
 		"&client_id=" + client.Id +
-		"&client_secret=" + client.Secret +
-		"&scope=" + strings.Join(scope, "+") +
-		"&assertion=" + jwt
+		"&client_secret=" + client.Secret
+
+	// add optional params if valid
+	if jwt != "" {
+		data += "&assertion=" + jwt
+	}
+	if scope != nil || len(scope) > 0 {
+		data += "&scope=" + strings.Join(scope, "+")
+	}
+
 	fmt.Printf("encoded params: %v\n\n", data)
 	req, err := http.NewRequest("POST", remoteUrl, bytes.NewBuffer([]byte(data)))
 	req.Header.Add("Content-Type", "application/x-www-form-urlencoded")

internal/config.go

@@ -48,6 +48,11 @@ func NewConfig() Config {
 			AccessToken:     "",
 			TrustedIssuers:  "",
 			ServerConfig:    "",
+			JwksUri:         "",
+			Login:           "",
+			LoginFlowId:     "",
+			RegisterClient:  "",
+			AuthorizeClient: "",
 		},
 		OpenBrowser:       false,
 		DecodeIdToken:     false,

internal/flows/authorization_code.go

@@ -1,6 +1,7 @@
-package opaal
+package flows
 
 import (
+	opaal "davidallendj/opaal/internal"
 	"davidallendj/opaal/internal/oidc"
 	"encoding/json"
 	"errors"
@@ -12,15 +13,7 @@ import (
 	"github.com/davidallendj/go-utils/util"
 )
 
-func Login(config *Config) error {
-	if config == nil {
-		return fmt.Errorf("config is not valid")
-	}
-
-	// initialize client that will be used throughout login flow
-	server := NewServerWithConfig(config)
-	client := NewClientWithConfig(config)
-
+func AuthorizationCode(config *opaal.Config, server *opaal.Server, client *opaal.Client) error {
 	// initiate the login flow and get a flow ID and CSRF token
 	{
 		err := client.InitiateLoginFlow(config.ActionUrls.Login)
@@ -49,7 +42,7 @@ func Login(config *Config) error {
 	}
 
 	// check if all appropriate parameters are set in config
-	if !HasRequiredParams(config) {
+	if !opaal.HasRequiredParams(config) {
 		return fmt.Errorf("client ID must be set")
 	}
 

internal/flows/client_credentials.go

@@ -0,0 +1,29 @@
+package flows
+
+import (
+	opaal "davidallendj/opaal/internal"
+	"fmt"
+)
+
+func ClientCredentials(config *opaal.Config, server *opaal.Server, client *opaal.Client) error {
+	// register a new OAuth 2 client with authorization srever
+	_, err := client.RegisterOAuthClient(config.ActionUrls.RegisterClient, nil)
+	if err != nil {
+		return fmt.Errorf("failed to register OAuth client: %v", err)
+	}
+
+	// authorize the client
+	_, err = client.AuthorizeClient(config.ActionUrls.AuthorizeClient)
+	if err != nil {
+		return fmt.Errorf("failed to authorize client: %v", err)
+	}
+
+	// request a token from the authorization server
+	res, err := client.FetchTokenFromAuthorizationServer(config.ActionUrls.AccessToken, "", nil)
+	if err != nil {
+		return fmt.Errorf("failed to fetch token from authorization server: %v", err)
+	}
+
+	fmt.Printf("token: %v\n", string(res))
+	return nil
+}

internal/flows/login.go

@@ -0,0 +1,28 @@
+package flows
+
+import (
+	opaal "davidallendj/opaal/internal"
+	"fmt"
+)
+
+func Login(config *opaal.Config) error {
+	if config == nil {
+		return fmt.Errorf("config is not valid")
+	}
+
+	// initialize client that will be used throughout login flow
+	server := opaal.NewServerWithConfig(config)
+	client := opaal.NewClientWithConfig(config)
+
+	fmt.Printf("grant type: %v\n", config.GrantType)
+
+	if config.GrantType == "authorization_code" {
+		AuthorizationCode(config, server, client)
+	} else if config.GrantType == "client_credentials" {
+		ClientCredentials(config, server, client)
+	} else {
+		return fmt.Errorf("invalid grant type")
+	}
+
+	return nil
+}

internal/opaal.go

@@ -8,6 +8,8 @@ type ActionUrls struct {
 	JwksUri         string `yaml:"jwks_uri"`
 	Login           string `yaml:"login"`
 	LoginFlowId     string `yaml:"login-flow-id"`
+	RegisterClient  string `yaml:"register-client"`
+	AuthorizeClient string `yaml:"authorize-client"`
 }
 
 func HasRequiredParams(config *Config) bool {