From 7562d887e159f404c8d752271310f4432f246656 Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
Date: Wed, 12 May 2021 15:04:51 +0100
Subject: Change the format of access tokens away from macaroons (#5588)

---
 synapse/util/stringutils.py | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

(limited to 'synapse/util/stringutils.py')

diff --git a/synapse/util/stringutils.py b/synapse/util/stringutils.py
index cd82777f80..4f25cd1d26 100644
--- a/synapse/util/stringutils.py
+++ b/synapse/util/stringutils.py
@@ -220,3 +220,23 @@ def strtobool(val: str) -> bool:
         return False
     else:
         raise ValueError("invalid truth value %r" % (val,))
+
+
+_BASE62 = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
+
+
+def base62_encode(num: int, minwidth: int = 1) -> str:
+    """Encode a number using base62
+
+    Args:
+        num: number to be encoded
+        minwidth: width to pad to, if the number is small
+    """
+    res = ""
+    while num:
+        num, rem = divmod(num, 62)
+        res = _BASE62[rem] + res
+
+    # pad to minimum width
+    pad = "0" * (minwidth - len(res))
+    return pad + res
-- 
cgit 1.5.1