diff --git a/koji/util.py b/koji/util.py
index f0d9cc3f..4b2a3a7f 100644
--- a/koji/util.py
+++ b/koji/util.py
@@ -20,6 +20,7 @@
 
 from __future__ import absolute_import
 from __future__ import division
+import base64
 import calendar
 import datetime
 import hashlib
@@ -142,6 +143,42 @@ def printList(l):
         return ret
 
 
+def base64encode(s, as_bytes=False):
+    """Helper function to encode string or bytes as base64
+
+    This function returns a string unless as_bytes is True
+    """
+    if six.PY2:
+        return base64.b64encode(s)
+
+    if isinstance(s, str):
+        s = s.encode('utf8')
+    data = base64.b64encode(s)
+    if as_bytes:
+        return data
+    else:
+        # ascii is always good enough for base64 encoded data
+        return data.decode('ascii')
+
+
+# We don't need a decode wrapper, but we define this for naming consistency
+base64decode = base64.b64decode
+
+
+def decode_bytes(data, fallback='iso8859-15'):
+    """Decode a bytes-like object that is expected to be a valid string
+
+    First utf8 is tried, then the fallback (defaults to iso8859-15).
+    The fallback behavior can be disabled by setting the option to None.
+    """
+    try:
+        return data.decode('utf8')
+    except UnicodeDecodeError:
+        if fallback:
+            return data.decode(fallback)
+        raise
+
+
 def multi_fnmatch(s, patterns):
     """Returns true if s matches any pattern in the list
 
diff --git a/tests/test_lib/test_base64.py b/tests/test_lib/test_base64.py
new file mode 100644
index 00000000..8c8c42ee
--- /dev/null
+++ b/tests/test_lib/test_base64.py
@@ -0,0 +1,28 @@
+# coding=utf-8
+from __future__ import absolute_import
+import mock
+import six
+try:
+    import unittest2 as unittest
+except ImportError:
+    import unittest
+
+from koji.util import base64encode, base64decode
+
+
+class Base64EncodeTestCase(unittest.TestCase):
+
+    DATA = [
+            # list of pairs [string, encoded_string]
+            [b'Hello World', 'SGVsbG8gV29ybGQ='],
+            [b'BZh91AY&SY\x14\x99\\\xcf\x05y\r\x7f\xff\xff',
+                'QlpoOTFBWSZTWRSZXM8FeQ1///8=']
+            ]
+
+    def test_base64encode(self):
+        for s, expected in self.DATA:
+            result = base64encode(s)
+            self.assertEqual(result, expected)
+            if six.PY3:
+                result = base64encode(s, as_bytes=True)
+                self.assertEqual(result, expected.encode('ascii'))