From 542ef540939cbea0e58f4744a0216b68c9579ff6 Mon Sep 17 00:00:00 2001
From: Daniel Lamando <me@danopia.net>
Date: Thu, 8 Mar 2018 16:44:11 -0800
Subject: [PATCH] Strip JWT base64 padding before parsing. #560

---
 providers/google.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/providers/google.go b/providers/google.go
index 4bf108e..66406bd 100644
--- a/providers/google.go
+++ b/providers/google.go
@@ -67,7 +67,8 @@ func emailFromIdToken(idToken string) (string, error) {
 	// id_token is a base64 encode ID token payload
 	// https://developers.google.com/accounts/docs/OAuth2Login#obtainuserinfo
 	jwt := strings.Split(idToken, ".")
-	b, err := base64.RawURLEncoding.DecodeString(jwt[1])
+	jwtData := strings.TrimSuffix(jwt[1], "=")
+	b, err := base64.RawURLEncoding.DecodeString(jwtData)
 	if err != nil {
 		return "", err
 	}