Additional OAuth2 providers (#1010)

* add google+

* sort signin oauth2 providers based on the name so order is always the same

* update auth tip for google+

* add gitlab provider

* add bitbucket provider (and some go fmt)

* add twitter provider

* add facebook provider

* add dropbox provider

* add openid connect provider incl. new format of tips section in "Add New Source"

* lower the amount of disk storage for each session to prevent issues while building cross platform (and disk overflow)

* imports according to goimport and code style

* make it possible to set custom urls to gitlab and github provider (only these could have a different host)

* split up oauth2 into multiple files

* small typo in comment

* fix indention

* fix indentation

* fix new line before external import

* fix layout of signin part

* update "broken" dependency

1 files changed, 30 insertions, 7 deletions

diff --git a/routers/admin/auths.go b/routers/admin/auths.go
index 345494b4f6..eb7c7e8e93 100644
--- a/routers/admin/auths.go
+++ b/routers/admin/auths.go
@@ -7,16 +7,17 @@ package admin
 import (
 	"fmt"
 
-	"github.com/Unknwon/com"
-	"github.com/go-xorm/core"
-
 	"code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/modules/auth"
 	"code.gitea.io/gitea/modules/auth/ldap"
+	"code.gitea.io/gitea/modules/auth/oauth2"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/context"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
+
+	"github.com/Unknwon/com"
+	"github.com/go-xorm/core"
 )
 
 const (
@@ -77,6 +78,7 @@ func NewAuthSource(ctx *context.Context) {
 	ctx.Data["SecurityProtocols"] = securityProtocols
 	ctx.Data["SMTPAuths"] = models.SMTPAuths
 	ctx.Data["OAuth2Providers"] = models.OAuth2Providers
+	ctx.Data["OAuth2DefaultCustomURLMappings"] = models.OAuth2DefaultCustomURLMappings
 
 	// only the first as default
 	for key := range models.OAuth2Providers {
@@ -123,10 +125,23 @@ func parseSMTPConfig(form auth.AuthenticationForm) *models.SMTPConfig {
 }
 
 func parseOAuth2Config(form auth.AuthenticationForm) *models.OAuth2Config {
+	var customURLMapping *oauth2.CustomURLMapping
+	if form.Oauth2UseCustomURL {
+		customURLMapping = &oauth2.CustomURLMapping{
+			TokenURL:   form.Oauth2TokenURL,
+			AuthURL:    form.Oauth2AuthURL,
+			ProfileURL: form.Oauth2ProfileURL,
+			EmailURL:   form.Oauth2EmailURL,
+		}
+	} else {
+		customURLMapping = nil
+	}
 	return &models.OAuth2Config{
-		Provider:     form.Oauth2Provider,
-		ClientID:     form.Oauth2Key,
-		ClientSecret: form.Oauth2Secret,
+		Provider:                      form.Oauth2Provider,
+		ClientID:                      form.Oauth2Key,
+		ClientSecret:                  form.Oauth2Secret,
+		OpenIDConnectAutoDiscoveryURL: form.OpenIDConnectAutoDiscoveryURL,
+		CustomURLMapping:              customURLMapping,
 	}
 }
 
@@ -142,6 +157,7 @@ func NewAuthSourcePost(ctx *context.Context, form auth.AuthenticationForm) {
 	ctx.Data["SecurityProtocols"] = securityProtocols
 	ctx.Data["SMTPAuths"] = models.SMTPAuths
 	ctx.Data["OAuth2Providers"] = models.OAuth2Providers
+	ctx.Data["OAuth2DefaultCustomURLMappings"] = models.OAuth2DefaultCustomURLMappings
 
 	hasTLS := false
 	var config core.Conversion
@@ -199,6 +215,7 @@ func EditAuthSource(ctx *context.Context) {
 	ctx.Data["SecurityProtocols"] = securityProtocols
 	ctx.Data["SMTPAuths"] = models.SMTPAuths
 	ctx.Data["OAuth2Providers"] = models.OAuth2Providers
+	ctx.Data["OAuth2DefaultCustomURLMappings"] = models.OAuth2DefaultCustomURLMappings
 
 	source, err := models.GetLoginSourceByID(ctx.ParamsInt64(":authid"))
 	if err != nil {
@@ -222,6 +239,7 @@ func EditAuthSourcePost(ctx *context.Context, form auth.AuthenticationForm) {
 
 	ctx.Data["SMTPAuths"] = models.SMTPAuths
 	ctx.Data["OAuth2Providers"] = models.OAuth2Providers
+	ctx.Data["OAuth2DefaultCustomURLMappings"] = models.OAuth2DefaultCustomURLMappings
 
 	source, err := models.GetLoginSourceByID(ctx.ParamsInt64(":authid"))
 	if err != nil {
@@ -257,7 +275,12 @@ func EditAuthSourcePost(ctx *context.Context, form auth.AuthenticationForm) {
 	source.IsActived = form.IsActive
 	source.Cfg = config
 	if err := models.UpdateSource(source); err != nil {
-		ctx.Handle(500, "UpdateSource", err)
+		if models.IsErrOpenIDConnectInitialize(err) {
+			ctx.Flash.Error(err.Error(), true)
+			ctx.HTML(200, tplAuthEdit)
+		} else {
+			ctx.Handle(500, "UpdateSource", err)
+		}
 		return
 	}
 	log.Trace("Authentication changed by admin(%s): %d", ctx.User.Name, source.ID)