Added ability to get authorization code

cmd/config.go

@@ -1,6 +1,75 @@
 package cmd
 
-import "github.com/spf13/cobra"
+import (
+	"davidallendj/oidc-auth/internal/util"
+	"log"
+	"os"
+	"path/filepath"
+
+	"github.com/spf13/cobra"
+	yaml "gopkg.in/yaml.v2"
+)
+
+type Config struct {
+	Host         string   `yaml:"host"`
+	Port         int      `yaml:"port"`
+	RedirectUri  []string `yaml:"redirect-uri"`
+	State        string   `yaml:"state"`
+	ResponseType string   `yaml:"response-type"`
+	Scope        []string `yaml:"scope"`
+	ClientId     string   `yaml:"client.id"`
+	ClientSecret string   `yaml:"client.secret"`
+	OIDCHost     string   `yaml:"oidc.host"`
+	OIDCPort     int      `yaml:"oidc.port"`
+}
+
+func NewConfig() Config {
+	return Config{
+		Host:         "127.0.0.1",
+		Port:         3333,
+		RedirectUri:  []string{""},
+		State:        util.RandomString(20),
+		ResponseType: "code",
+		Scope:        []string{"openid", "profile", "email"},
+		ClientId:     "",
+		ClientSecret: "",
+		OIDCHost:     "127.0.0.1",
+		OIDCPort:     80,
+	}
+}
+
+func LoadConfig(path string) Config {
+	var c Config = NewConfig()
+	file, err := os.ReadFile(path)
+	if err != nil {
+		log.Printf("failed to read config file: %v\n", err)
+		return c
+	}
+	err = yaml.Unmarshal(file, &c)
+	if err != nil {
+		log.Fatalf("failed to unmarshal config: %v\n", err)
+		return c
+	}
+	return c
+}
+
+func SaveDefaultConfig(path string) {
+	path = filepath.Clean(path)
+	if path == "" || path == "." {
+		path = "config.yaml"
+	}
+	var c = NewConfig()
+	data, err := yaml.Marshal(c)
+	if err != nil {
+		log.Printf("failed to marshal config: %v\n", err)
+		return
+	}
+	err = os.WriteFile(path, data, os.ModePerm)
+	if err != nil {
+		log.Printf("failed to write default config file: %v\n", err)
+		return
+	}
+}
 
 var configCmd = &cobra.Command{
 	Use:   "config",
@@ -8,7 +77,7 @@ var configCmd = &cobra.Command{
 	Run: func(cmd *cobra.Command, args []string) {
 		// create a new config at all args (paths)
 		for _, path := range args {
-			_ = path
+			SaveDefaultConfig(path)
 		}
 	},
 }

cmd/login.go

@@ -1,7 +1,6 @@
 package cmd
 
 import (
-	"davidallendj/oidc-auth/internal/oauth"
 	"davidallendj/oidc-auth/internal/oidc"
 	"davidallendj/oidc-auth/internal/server"
 	"davidallendj/oidc-auth/internal/util"
@@ -13,36 +12,33 @@ import (
 	"github.com/spf13/cobra"
 )
 
-var (
-	host         string
-	port         int
-	redirectUri  = []string{""}
-	state        = ""
-	responseType = "code"
-	scope        = []string{"email", "profile", "openid"}
-	client       oauth.Client
-)
-
 var loginCmd = &cobra.Command{
 	Use:   "login",
 	Short: "Start the login flow",
 	Run: func(cmd *cobra.Command, args []string) {
+		if configPath != "" {
+			config = LoadConfig(configPath)
+		} else {
+			config = NewConfig()
+		}
 		oidcProvider := oidc.NewOIDCProvider()
+		oidcProvider.Host = config.OIDCHost
+		oidcProvider.Port = config.OIDCPort
 		var authorizationUrl = util.BuildAuthorizationUrl(
 			oidcProvider.GetAuthorizeUrl(),
-			client.Id,
-			redirectUri,
-			util.RandomString(20),
-			responseType,
-			[]string{"email", "profile", "openid"},
+			config.ClientId,
+			config.RedirectUri,
+			config.State,
+			config.ResponseType,
+			config.Scope,
 		)
 
 		// print the authorization URL for the user to log in
 		fmt.Printf("Login with identity provider: %s\n", authorizationUrl)
 
-		// start a HTTP server to listen for callback responses
+		// authorize oauth client and listen for callback from provider
 		fmt.Printf("Waiting for response from OIDC provider...\n")
-		err := server.Start(host, port)
+		code, err := server.WaitForAuthorizationCode(config.Host, config.Port)
 		if errors.Is(err, http.ErrServerClosed) {
 			fmt.Printf("server closed\n")
 		} else if err != nil {
@@ -50,7 +46,8 @@ var loginCmd = &cobra.Command{
 			os.Exit(1)
 		}
 
-		// extract code from response and exchange for bearer token
+		// use code from response and exchange for bearer token
+		server.FetchToken(code, oidcProvider.GetTokenUrl(), config.ClientId, config.ClientSecret, config.State, config.RedirectUri)
 
 		// extract ID token and save user info
 
@@ -61,12 +58,12 @@ var loginCmd = &cobra.Command{
 }
 
 func init() {
-	loginCmd.Flags().StringVar(&client.Id, "client.id", "", "set the client ID")
-	loginCmd.Flags().StringSliceVar(&redirectUri, "redirect-uri", []string{""}, "set the redirect URI")
-	loginCmd.Flags().StringVar(&responseType, "response-type", "code", "set the response-type")
-	loginCmd.Flags().StringSliceVar(&scope, "scope", []string{"openid", "email"}, "set the scopes")
-	loginCmd.Flags().StringVar(&state, "state", util.RandomString(20), "set the state")
-	loginCmd.Flags().StringVar(&host, "host", "127.0.0.1", "set the listening host")
-	loginCmd.Flags().IntVar(&port, "port", 3333, "set the listening port")
+	loginCmd.Flags().StringVar(&config.ClientId, "client.id", config.ClientId, "set the client ID")
+	loginCmd.Flags().StringSliceVar(&config.RedirectUri, "redirect-uri", config.RedirectUri, "set the redirect URI")
+	loginCmd.Flags().StringVar(&config.ResponseType, "response-type", config.ResponseType, "set the response-type")
+	loginCmd.Flags().StringSliceVar(&config.Scope, "scope", config.Scope, "set the scopes")
+	loginCmd.Flags().StringVar(&config.State, "state", config.State, "set the state")
+	loginCmd.Flags().StringVar(&config.Host, "host", config.Host, "set the listening host")
+	loginCmd.Flags().IntVar(&config.Port, "port", config.Port, "set the listening port")
 	rootCmd.AddCommand(loginCmd)
 }

cmd/root.go

@@ -7,7 +7,10 @@ import (
 	"github.com/spf13/cobra"
 )
 
-var configPath = ""
+var (
+	configPath = ""
+	config     Config
+)
 var rootCmd = &cobra.Command{
 	Use:   "oidc",
 	Short: "An experimental OIDC helper tool for handling logins",
@@ -18,11 +21,11 @@ var rootCmd = &cobra.Command{
 
 func Execute() {
 	if err := rootCmd.Execute(); err != nil {
-		fmt.Fprintf(os.Stderr, "Whoops. There was an error while executing your CLI '%s'", err)
+		fmt.Fprintf(os.Stderr, "failed to start CLI: %s", err)
 		os.Exit(1)
 	}
 }
 
 func init() {
-	rootCmd.Flags().StringVar(&configPath, "config", "", "set the config path")
+	rootCmd.PersistentFlags().StringVar(&configPath, "config", "", "set the config path")
 }

go.mod

@@ -2,7 +2,10 @@ module davidallendj/oidc-auth
 
 go 1.22.0
 
-require github.com/spf13/cobra v1.8.0
+require (
+	github.com/spf13/cobra v1.8.0
+	gopkg.in/yaml.v2 v2.4.0
+)
 
 require (
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect

go.sum

@@ -6,5 +6,8 @@ github.com/spf13/cobra v1.8.0 h1:7aJaZx1B85qltLMc546zn58BxxfZdR/W22ej9CFoEf0=
 github.com/spf13/cobra v1.8.0/go.mod h1:WXLWApfZ71AjXPya3WOlMsY9yMs7YeiHhFVlvLyhcho=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
+gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

internal/oidc/oidc.go

@@ -1,7 +1,10 @@
 package oidc
 
+import "fmt"
+
 type OpenIDConnectProvider struct {
 	Host              string
+	Port              int
 	AuthorizeEndpoint string
 	TokenEndpoint     string
 	ConfigEndpoint    string
@@ -9,17 +12,24 @@ type OpenIDConnectProvider struct {
 
 func NewOIDCProvider() *OpenIDConnectProvider {
 	return &OpenIDConnectProvider{
-		Host:              "https://gitlab.newmexicoconsortium.org",
+		Host:              "127.0.0.1",
+		Port:              80,
 		AuthorizeEndpoint: "/oauth/authorize",
 		TokenEndpoint:     "/oauth/token",
 	}
 }
 
 func (oidc *OpenIDConnectProvider) GetAuthorizeUrl() string {
+	if oidc.Port != 80 {
+		return fmt.Sprintf("%s:%d", oidc.Host, oidc.Port) + oidc.AuthorizeEndpoint
+	}
 	return oidc.Host + oidc.AuthorizeEndpoint
 }
 
 func (oidc *OpenIDConnectProvider) GetTokenUrl() string {
+	if oidc.Port != 80 {
+		return fmt.Sprintf("%s:%d", oidc.Host, oidc.Port) + oidc.TokenEndpoint
+	}
 	return oidc.Host + oidc.TokenEndpoint
 }
 

internal/server/server.go

@@ -1,16 +1,48 @@
 package server
 
 import (
+	"davidallendj/oidc-auth/internal/util"
 	"fmt"
 	"net/http"
+	"net/url"
+	"os"
+	"strings"
 )
 
-func Start(host string, port int) error {
-	http.HandleFunc("/oauth/callback", getAuthorizationCode)
-	err := http.ListenAndServe(host+":"+fmt.Sprintf("%d", port), nil)
-	return err
+func WaitForAuthorizationCode(host string, port int) (string, error) {
+	var code string
+	s := &http.Server{
+		Addr: fmt.Sprintf("%s:%d", host, port),
+	}
+	http.HandleFunc("/oauth/callback", func(w http.ResponseWriter, r *http.Request) {
+		// get the code from the OIDC provider
+		if r != nil {
+			code = r.URL.Query().Get("code")
+			fmt.Printf("Authorization Code: %v\n", code)
+		}
+		s.Close()
+
+	})
+	return code, s.ListenAndServe()
 }
 
-func getAuthorizationCode(w http.ResponseWriter, r *http.Request) {
-	fmt.Printf("response from OIDC provider: %v\n", r)
+func FetchToken(code string, remoteUrl string, clientId string, clientSecret string, state string, redirectUri []string) (string, error) {
+	var token string
+	data := url.Values{
+		"grant_type":    {"authorization_code"},
+		"code":          {code},
+		"client_id":     {clientId},
+		"client_secret": {clientSecret},
+		"state":         {state},
+		"redirect_uri":  {util.EncodeURL(strings.Join(redirectUri, ","))},
+	}
+	res, err := http.PostForm(remoteUrl, data)
+	if err != nil {
+		fmt.Printf("failed to get token: %s\n", err)
+		os.Exit(1)
+	}
+
+	fmt.Printf("request URL: %s\n", remoteUrl)
+	fmt.Printf("token response: %v\n", res)
+	return token, nil
 }

internal/util/util.go

@@ -1,18 +1,19 @@
 package util
 
 import (
+	"encoding/base64"
 	"math/rand"
+	"net/url"
 	"strings"
 )
 
-const letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
-const (
-	letterIdxBits = 6                    // 6 bits to represent a letter index
-	letterIdxMask = 1<<letterIdxBits - 1 // All 1-bits, as many as letterIdxBits
-	letterIdxMax  = 63 / letterIdxBits   // # of letter indices fitting in 63 bits
-)
-
 func RandomString(n int) string {
+	const letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+	const (
+		letterIdxBits = 6                    // 6 bits to represent a letter index
+		letterIdxMask = 1<<letterIdxBits - 1 // All 1-bits, as many as letterIdxBits
+		letterIdxMax  = 63 / letterIdxBits   // # of letter indices fitting in 63 bits
+	)
 	b := make([]byte, n)
 	// A rand.Int63() generates 63 random bits, enough for letterIdxMax letters!
 	for i, cache, remain := n-1, rand.Int63(), letterIdxMax; i >= 0; {
@@ -31,9 +32,17 @@ func RandomString(n int) string {
 }
 
 func BuildAuthorizationUrl(authEndpoint string, clientId string, redirectUri []string, state string, responseType string, scope []string) string {
-	return authEndpoint + "?" + "cilent_id=" + clientId +
-		"&redirect_url=" + strings.Join(redirectUri, ",") +
+	return authEndpoint + "?" + "client_id=" + clientId +
+		"&redirect_uri=" + EncodeURL(strings.Join(redirectUri, ",")) +
 		"&response_type=" + responseType +
 		"&state=" + state +
 		"&scope=" + strings.Join(scope, "+")
 }
+
+func EncodeURL(s string) string {
+	return url.QueryEscape(s)
+}
+
+func EncodeBase64(s string) string {
+	return base64.StdEncoding.EncodeToString([]byte(s))
+}