revoke_crt.py: Update _b64 function.

- Convert `b` to `bytes` if it is a `str`.
- Convert the base64 encoded `bytes` to `str` before using `replace`
  for stripping `=`.

1 files changed, 4 insertions, 1 deletions

diff --git a/revoke_crt.py b/revoke_crt.py
index e976cb2..22d2660 100644
--- a/revoke_crt.py
+++ b/revoke_crt.py
@@ -19,7 +19,10 @@ def revoke_crt(pubkey, crt):
 
     def _b64(b):
         "Shortcut function to go from bytes to jwt base64 string"
-        return base64.urlsafe_b64encode(b).replace("=", "")
+        if type(b) is str:
+            b = b.encode()
+
+        return base64.urlsafe_b64encode(b).decode().replace("=", "")
 
     def _a64(a):
         "Shortcut function to go from jwt base64 string to bytes"