nextcloud oauth (#10562)

Fix #7078

vendor/github.com/markbates/goth/providers/nextcloud/nextcloud.go

@@ -0,0 +1,208 @@
+// Package nextcloud implements the OAuth2 protocol for authenticating users through nextcloud.
+// This package can be used as a reference implementation of an OAuth2 provider for Goth.
+package nextcloud
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"io/ioutil"
+	"net/http"
+
+	"fmt"
+
+	"github.com/markbates/goth"
+	"golang.org/x/oauth2"
+)
+
+// These vars define the Authentication, Token, and Profile URLS for Nextcloud.
+// You have to set these values to something useful, because nextcloud is always
+// hosted somewhere.
+//
+var (
+	AuthURL    = "https://<own-server>/apps/oauth2/authorize"
+	TokenURL   = "https://<own-server>/apps/oauth2/api/v1/token"
+	ProfileURL = "https://<own-server>/ocs/v2.php/cloud/user?format=json"
+)
+
+// Provider is the implementation of `goth.Provider` for accessing Nextcloud.
+type Provider struct {
+	ClientKey    string
+	Secret       string
+	CallbackURL  string
+	HTTPClient   *http.Client
+	config       *oauth2.Config
+	providerName string
+	authURL      string
+	tokenURL     string
+	profileURL   string
+}
+
+// New is only here to fulfill the interface requirements and does not work properly without
+// setting your own Nextcloud connect parameters, more precisely AuthURL, TokenURL and ProfileURL.
+// Please use NewCustomisedDNS with the beginning of your URL or NewCustomiseURL.
+func New(clientKey, secret, callbackURL string, scopes ...string) *Provider {
+	return NewCustomisedURL(clientKey, secret, callbackURL, AuthURL, TokenURL, ProfileURL, scopes...)
+}
+
+// NewCustomisedURL create a working connection to your Nextcloud server given by the values
+// authURL, tokenURL and profileURL.
+// If you want to use a simpler method, please have a look at NewCustomisedDNS, which gets only
+// on parameter instead of three.
+func NewCustomisedURL(clientKey, secret, callbackURL, authURL, tokenURL, profileURL string, scopes ...string) *Provider {
+	p := &Provider{
+		ClientKey:    clientKey,
+		Secret:       secret,
+		CallbackURL:  callbackURL,
+		providerName: "nextcloud",
+		profileURL:   profileURL,
+	}
+	p.config = newConfig(p, authURL, tokenURL, scopes)
+	return p
+}
+
+// NewCustomisedDNS is the simplest method to create a provider based only on your key/secret
+// and the beginning of the URL to your server, e.g. https://my.server.name/
+func NewCustomisedDNS(clientKey, secret, callbackURL, nextcloudURL string, scopes ...string) *Provider {
+	return NewCustomisedURL(
+		clientKey,
+		secret,
+		callbackURL,
+		nextcloudURL+"/apps/oauth2/authorize",
+		nextcloudURL+"/apps/oauth2/api/v1/token",
+		nextcloudURL+"/ocs/v2.php/cloud/user?format=json",
+		scopes...,
+	)
+}
+
+// Name is the name used to retrieve this provider later.
+func (p *Provider) Name() string {
+	return p.providerName
+}
+
+// SetName is to update the name of the provider (needed in case of multiple providers of 1 type)
+func (p *Provider) SetName(name string) {
+	p.providerName = name
+}
+
+func (p *Provider) Client() *http.Client {
+	return goth.HTTPClientWithFallBack(p.HTTPClient)
+}
+
+// Debug is a no-op for the nextcloud package.
+func (p *Provider) Debug(debug bool) {}
+
+// BeginAuth asks Nextcloud for an authentication end-point.
+func (p *Provider) BeginAuth(state string) (goth.Session, error) {
+	return &Session{
+		AuthURL: p.config.AuthCodeURL(state),
+	}, nil
+}
+
+// FetchUser will go to Nextcloud and access basic information about the user.
+func (p *Provider) FetchUser(session goth.Session) (goth.User, error) {
+	sess := session.(*Session)
+	user := goth.User{
+		AccessToken:  sess.AccessToken,
+		Provider:     p.Name(),
+		RefreshToken: sess.RefreshToken,
+		ExpiresAt:    sess.ExpiresAt,
+	}
+
+	if user.AccessToken == "" {
+		// data is not yet retrieved since accessToken is still empty
+		return user, fmt.Errorf("%s cannot get user information without accessToken", p.providerName)
+	}
+
+	req, err := http.NewRequest("GET", p.profileURL, nil)
+	if err != nil {
+		return user, err
+	}
+	req.Header.Set("Authorization", "Bearer "+sess.AccessToken)
+	response, err := p.Client().Do(req)
+
+	if err != nil {
+		if response != nil {
+			response.Body.Close()
+		}
+		return user, err
+	}
+
+	defer response.Body.Close()
+
+	if response.StatusCode != http.StatusOK {
+		return user, fmt.Errorf("%s responded with a %d trying to fetch user information", p.providerName, response.StatusCode)
+	}
+
+	bits, err := ioutil.ReadAll(response.Body)
+	if err != nil {
+		return user, err
+	}
+
+	err = json.NewDecoder(bytes.NewReader(bits)).Decode(&user.RawData)
+	if err != nil {
+		return user, err
+	}
+
+	err = userFromReader(bytes.NewReader(bits), &user)
+
+	return user, err
+}
+
+func newConfig(provider *Provider, authURL, tokenURL string, scopes []string) *oauth2.Config {
+	c := &oauth2.Config{
+		ClientID:     provider.ClientKey,
+		ClientSecret: provider.Secret,
+		RedirectURL:  provider.CallbackURL,
+		Endpoint: oauth2.Endpoint{
+			AuthURL:  authURL,
+			TokenURL: tokenURL,
+		},
+		Scopes: []string{},
+	}
+
+	if len(scopes) > 0 {
+		for _, scope := range scopes {
+			c.Scopes = append(c.Scopes, scope)
+		}
+	}
+	return c
+}
+
+func userFromReader(r io.Reader, user *goth.User) error {
+	u := struct {
+		Ocs struct {
+			Data struct {
+				EMail       string `json:"email"`
+				DisplayName string `json:"display-name"`
+				ID          string `json:"id"`
+				Address     string `json:"address"`
+			}
+		} `json:"ocs"`
+	}{}
+	err := json.NewDecoder(r).Decode(&u)
+	if err != nil {
+		return err
+	}
+	user.Email = u.Ocs.Data.EMail
+	user.Name = u.Ocs.Data.DisplayName
+	user.UserID = u.Ocs.Data.ID
+	user.Location = u.Ocs.Data.Address
+	return nil
+}
+
+//RefreshTokenAvailable refresh token is provided by auth provider or not
+func (p *Provider) RefreshTokenAvailable() bool {
+	return true
+}
+
+//RefreshToken get new access token based on the refresh token
+func (p *Provider) RefreshToken(refreshToken string) (*oauth2.Token, error) {
+	token := &oauth2.Token{RefreshToken: refreshToken}
+	ts := p.config.TokenSource(goth.ContextForClient(p.Client()), token)
+	newToken, err := ts.Token()
+	if err != nil {
+		return nil, err
+	}
+	return newToken, err
+}