fix(oauth2): enforce mandatory 2FA policy on OAuth2 authorize/grant endpoints (#38591)

Fixes #37407 

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

routers/web/auth/oauth2_provider.go

@@ -207,9 +207,24 @@ func IntrospectOAuth(ctx *context.Context) {
 	ctx.JSON(http.StatusOK, response)
 }
 
+func oauthDoerAuthorizePreCheck(ctx *context.Context, formState string) bool {
+	if ctx.DoerNeedTwoFactorAuth() {
+		handleAuthorizeError(ctx, AuthorizeError{
+			ErrorCode:        ErrorCodeAccessDenied,
+			ErrorDescription: "two-factor authentication is required",
+			State:            formState,
+		}, "")
+		return false
+	}
+	return true
+}
+
 // AuthorizeOAuth manages authorize requests
 func AuthorizeOAuth(ctx *context.Context) {
 	form := web.GetForm(ctx).(*forms.AuthorizationForm)
+	if !oauthDoerAuthorizePreCheck(ctx, form.State) {
+		return
+	}
 	errs := binding.Errors{}
 	errs = form.Validate(ctx.Req, errs)
 	if len(errs) > 0 {
@@ -385,6 +400,10 @@ func AuthorizeOAuth(ctx *context.Context) {
 // GrantApplicationOAuth manages the post request submitted when a user grants access to an application
 func GrantApplicationOAuth(ctx *context.Context) {
 	form := web.GetForm(ctx).(*forms.GrantApplicationForm)
+	if !oauthDoerAuthorizePreCheck(ctx, form.State) {
+		return
+	}
+
 	if ctx.Session.Get("client_id") != form.ClientID || ctx.Session.Get("state") != form.State ||
 		ctx.Session.Get("redirect_uri") != form.RedirectURI {
 		ctx.HTTPError(http.StatusBadRequest)