From 90207a39a44e9abd09257fca4dd5316d28abce2c Mon Sep 17 00:00:00 2001
From: Sean Whalen <whalenster@gmail.com>
Date: Thu, 18 Oct 2018 09:51:30 -0400
Subject: [PATCH] 4.3.5 - Fix base64 attachment decoding (#26)

---
 CHANGELOG.md              |  5 +++++
 parsedmarc/__version__.py |  2 +-
 parsedmarc/utils.py       | 20 +++++++++++++++++++-
 3 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9eb9ce4..14fb717 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+4.3.5
+-----
+
+- Fix base64 attachment decoding (#26)
+
 4.3.4
 -----
 
diff --git a/parsedmarc/__version__.py b/parsedmarc/__version__.py
index f401c5a..648f1fe 100644
--- a/parsedmarc/__version__.py
+++ b/parsedmarc/__version__.py
@@ -2,7 +2,7 @@
 
 import platform
 
-__version__ = "4.3.4"
+__version__ = "4.3.5"
 
 USER_AGENT = "Mozilla/5.0 ((0 {1})) parsedmarc/{2}".format(
             platform.system(),
diff --git a/parsedmarc/utils.py b/parsedmarc/utils.py
index 2221e57..6433594 100644
--- a/parsedmarc/utils.py
+++ b/parsedmarc/utils.py
@@ -34,6 +34,24 @@ class EmailParserError(RuntimeError):
     """Raised when an error parsing the email occurs"""
 
 
+def decode_base64(data):
+    """
+    Decodes a base64 string, with padding being optional
+
+    Args:
+        data: A base64 encoded string
+
+    Returns:
+        bytes: The decoded bytes
+
+    """
+    data = str(data)
+    missing_padding = len(data) % 4
+    if missing_padding != 0:
+        data += b'=' * (4 - missing_padding)
+    return base64.b64decode(data)
+
+
 def get_base_domain(domain):
     """
     Gets the base domain name for the given domain
@@ -458,7 +476,7 @@ def parse_email(data, strip_attachment_payloads=False):
                 payload = attachment["payload"]
                 if "content_transfer_encoding" in attachment:
                     if attachment["content_transfer_encoding"] == "base64":
-                        payload = base64.b64decode(payload)
+                        payload = decode_base64(payload)
                     else:
                         payload = str.encode(payload)
                 attachment["sha256"] = hashlib.sha256(payload).hexdigest()