Okta Integration - Bring Okta OAuth as an available option (#128)

- Edited package.json for react bug
 	+ https://github.com/ReactTraining/react-router/issues/6630

README.md

@@ -15,7 +15,7 @@
 - Expirable Links
 - URL deletion
 - Multiple authorization strategies:
-    - Local authorization via OAuth 2.0 (Google, GitHub and Microsoft)
+    - Local authorization via OAuth 2.0 (Google, GitHub, Microsoft, and Okta)
     - Proxy authorization for running behind e.g. [Google IAP](https://cloud.google.com/iap/)
 - Easy [ShareX](https://github.com/ShareX/ShareX) integration
 - Dockerizable

config/example.yaml

@@ -1,5 +1,5 @@
 ListenAddr: ':8080' # Consists of 'IP:Port', e.g. ':8080' listens on any IP and on Port 8080
-BaseURL: 'http://localhost:3000' # Origin URL, required for the authentication via OAuth callback
+BaseURL: 'http://localhost:8080' # Origin URL, required for the authentication via OAuth callback
 DisplayURL: '' # (OPTIONAL) Display URL, how the apication will present itself in the UI - if not set, defaults to BaseURL
 Backend: boltdb # Can be 'boltdb' or 'redis'
 DataDir: ./data # Contains: the database and the private key
@@ -10,14 +10,18 @@ ShortedIDLength: 10 # Length of the random generated ID which is used for new sh
 AuthBackend: oauth # Can be 'oauth' or 'proxy'
 Google:  # only relevant when using the oauth authbackend
   ClientID: replace me
-  ClientSecret: replace me
+  ClientSecret: 'replace me'
 GitHub:  # only relevant when using the oauth authbackend
   ClientID: replace me
-  ClientSecret: replace me
+  ClientSecret: 'replace me'
   EndpointURL: # (OPTIONAL) URL for custom endpoint (currently only for github); e.g. 'https://github.mydomain.com'
 Microsoft:  # only relevant when using the oauth authbackend
   ClientID: replace me
   ClientSecret: 'replace me'
+Okta:  # only relevant when using the oauth authbackend
+  ClientID: replace me
+  ClientSecret: 'replace me'
+  EndpointURL: # (MANDATORY) Issuer URL from the OAuth API => Authorization Servers in Okta
 Proxy:  # only relevant when using the proxy authbackend
   RequireUserHeader: false # If true, will reject connections that do not have the UserHeader set
   UserHeader: "X-Goog-Authenticated-User-ID" # pull the unique user ID from this header

internal/handlers/auth.go

@@ -41,6 +41,11 @@ func (h *Handler) initOAuth() {
 		auth.WithAdapterWrapper(auth.NewMicrosoftAdapter(microsoft.ClientID, microsoft.ClientSecret), h.engine.Group("/api/v1/auth/microsoft"))
 		h.providers = append(h.providers, "microsoft")
 	}
+	okta := util.GetConfig().Okta
+	if okta.Enabled() {
+		auth.WithAdapterWrapper(auth.NewOktaAdapter(okta.ClientID, okta.ClientSecret, okta.EndpointURL), h.engine.Group("/api/v1/auth/okta"))
+		h.providers = append(h.providers, "okta")
+	}
 
 	h.engine.POST("/api/v1/auth/check", h.handleAuthCheck)
 }

internal/handlers/auth/okta.go

@@ -0,0 +1,84 @@
+package auth
+
+import (
+        "context"
+        "encoding/json"
+        "net/url"
+        "strings"
+
+        "github.com/mxschmitt/golang-url-shortener/internal/util"
+        "github.com/sirupsen/logrus"
+
+        "github.com/pkg/errors"
+        "golang.org/x/oauth2"
+)
+
+type oktaAdapter struct {
+        config *oauth2.Config
+}
+
+// NewOktaAdapter creates an oAuth adapter out of the credentials and the baseURL
+func NewOktaAdapter(clientID, clientSecret, endpointURL string) Adapter {
+
+        if endpointURL == "" {
+                logrus.Error("Configure Okta Endpoint")
+        }
+
+        return &oktaAdapter{&oauth2.Config{
+                ClientID:     clientID,
+                ClientSecret: clientSecret,
+                RedirectURL:  util.GetConfig().BaseURL + "/api/v1/auth/okta/callback",
+                Scopes: []string{
+                        "profile",
+                        "openid",
+                        "offline_access",
+                },
+                Endpoint: oauth2.Endpoint{
+                        AuthURL:  endpointURL + "/v1/authorize",
+                        TokenURL: endpointURL + "/v1/token",
+                },
+        }}
+}
+
+func (a *oktaAdapter) GetRedirectURL(state string) string {
+        return a.config.AuthCodeURL(state)
+}
+
+func (a *oktaAdapter) GetUserData(state, code string) (*user, error) {
+
+        logrus.Debugf("Getting User Data with state: %s, and code: %s", state, code)
+        oAuthToken, err := a.config.Exchange(context.Background(), code)
+        if err != nil {
+                return nil, errors.Wrap(err, "could not exchange code")
+        }
+        if util.GetConfig().Okta.EndpointURL == "" {
+                logrus.Error("Okta EndpointURL is Empty")
+        }
+        oktaUrl, err := url.Parse(util.GetConfig().Okta.EndpointURL)
+        if err != nil {
+                return nil, errors.Wrap(err, "could not parse Okta EndpointURL")
+        }
+        oktaBaseURL := strings.Replace(oktaUrl.String(), oktaUrl.RequestURI(), "", 1)
+        oAuthUserInfoReq, err := a.config.Client(context.Background(), oAuthToken).Get(oktaBaseURL + "/api/v1/users/me")
+        if err != nil {
+                return nil, errors.Wrap(err, "could not get user data")
+        }
+        defer oAuthUserInfoReq.Body.Close()
+        var oUser struct {
+                ID   int    `json:"sub"`
+                // Custom URL property for user Avatar can go here
+                Name string `json:"name"`
+        }
+        if err = json.NewDecoder(oAuthUserInfoReq.Body).Decode(&oUser); err != nil {
+                return nil, errors.Wrap(err, "decoding user info failed")
+        }
+        return &user{
+                ID:      string(oUser.ID),
+                Name:    oUser.Name,
+                Picture: util.GetConfig().BaseURL + "/images/okta_logo.png", // Default Okta Avatar
+        }, nil
+}
+
+func (a *oktaAdapter) GetOAuthProviderName() string {
+        return "okta"
+}

internal/util/config.go

@@ -28,6 +28,7 @@ type Configuration struct {
 	Google           oAuthConf     `yaml:"Google" env:"GOOGLE"`
 	GitHub           oAuthConf     `yaml:"GitHub" env:"GITHUB"`
 	Microsoft        oAuthConf     `yaml:"Microsoft" env:"MICROSOFT"`
+	Okta             oAuthConf     `yaml:"Okta" env:"OKTA"`
 	Proxy            proxyAuthConf `yaml:"Proxy" env:"PROXY"`
 	Redis            redisConf     `yaml:"Redis" env:"REDIS"`
 }
@@ -46,7 +47,7 @@ type redisConf struct {
 type oAuthConf struct {
 	ClientID     string `yaml:"ClientID" env:"CLIENT_ID"`
 	ClientSecret string `yaml:"ClientSecret" env:"CLIENT_SECRET"`
-	EndpointURL  string `yaml:"EndPointURL" env:"ENDPOINT_URL"` // optional for only GitHub
+	EndpointURL  string `yaml:"EndpointURL" env:"ENDPOINT_URL"` // Optional for GitHub, mandatory for Okta
 }
 
 type proxyAuthConf struct {
@@ -58,7 +59,7 @@ type proxyAuthConf struct {
 // Config contains the default values
 var Config = Configuration{
 	ListenAddr:       ":8080",
-	BaseURL:          "http://localhost:3000",
+	BaseURL:          "http://localhost:8080",
 	DisplayURL:       "",
 	DataDir:          "data",
 	Backend:          "boltdb",

web/package.json

@@ -35,6 +35,9 @@
     "test": "react-scripts test --env=jsdom",
     "eject": "react-scripts eject"
   },
+  "resolutions": {
+    "react-router": "4.3.1"
+  },  
   "browserslist": [
     ">0.2%",
     "not dead",

web/src/index.js

@@ -131,6 +131,12 @@ export default class BaseComponent extends Component {
                                 <Button style={{ backgroundColor: "#333", color: "white" }} onClick={this.onOAuthClick.bind(this, "github")}>
                                     <Icon name='github' /> Login with GitHub
                                 </Button>
+                            {info.providers.includes("okta") && <div className="ui divider"></div>}
+                            </div>}
+                            {info.providers.includes("okta") && <div>
+                                <Button style={{ color: "#007dc1" }} onClick={this.onOAuthClick.bind(this, "okta")}>
+                                    <Image src='/images/okta_logo.png' style={{ width: "16px", height: "16px", marginBottom: ".15em" }}  avatar /> Login with Okta
+                                </Button>
                             </div>}
                             {info.providers.includes("microsoft") && <div>
                                 <div className="ui divider"></div>