From 87e03631f591cd13fbf0585dafca23c0d87e7687 Mon Sep 17 00:00:00 2001
From: Doug Coleman <doug.coleman@gmail.com>
Date: Fri, 9 Apr 2021 09:23:28 -0500
Subject: [PATCH] base64: Add a version of url-base64 that trims trailing ===
 for jwt.

See https://tools.ietf.org/html/rfc7519
and
https://stackoverflow.com/questions/49082844/how-could-firebase-send-a-jwt-token-which-payload-contains-an-underscore-charact
---
 basis/base64/base64-tests.factor | 6 ++++++
 basis/base64/base64.factor       | 3 +++
 2 files changed, 9 insertions(+)

diff --git a/basis/base64/base64-tests.factor b/basis/base64/base64-tests.factor
index 8821f9654c..3593fe2c7d 100644
--- a/basis/base64/base64-tests.factor
+++ b/basis/base64/base64-tests.factor
@@ -47,3 +47,9 @@ kernel sequences splitting strings tools.test ;
 
 { "01a-b_cd" } [ "\xd3V\xbeo\xf7\x1d" >urlsafe-base64 "" like ] unit-test
 { "\xd3V\xbeo\xf7\x1d" } [ "01a-b_cd" urlsafe-base64> "" like ] unit-test
+
+{ "eyJhIjoiYmNkIn0" }
+[ "{\"a\":\"bcd\"}" >urlsafe-base64-jwt >string ] unit-test
+
+{ "{\"a\":\"bcd\"}" }
+[ "{\"a\":\"bcd\"}" >urlsafe-base64-jwt urlsafe-base64> >string ] unit-test
\ No newline at end of file
diff --git a/basis/base64/base64.factor b/basis/base64/base64.factor
index e9b9b62d13..a85768aafe 100644
--- a/basis/base64/base64.factor
+++ b/basis/base64/base64.factor
@@ -146,6 +146,9 @@ PRIVATE>
         { CHAR: / CHAR: _ }
     } substitute ;
 
+: >urlsafe-base64-jwt ( seq -- base64 )
+    >urlsafe-base64 [ CHAR: = = ] trim-tail ;
+
 : urlsafe-base64> ( base64 -- seq )
     H{
         { CHAR: - CHAR: + }
-- 
2.34.1