1 files changed, 49 insertions, 0 deletions
diff --git a/python/itsdangerous/encoding.py b/python/itsdangerous/encoding.py
new file mode 100644
index 0000000..1e28969
--- /dev/null
+++ b/python/itsdangerous/encoding.py
@@ -0,0 +1,49 @@
+import base64
+import string
+import struct
+
+from ._compat import text_type
+from .exc import BadData
+
+
+def want_bytes(s, encoding="utf-8", errors="strict"):
+    if isinstance(s, text_type):
+        s = s.encode(encoding, errors)
+    return s
+
+
+def base64_encode(string):
+    """Base64 encode a string of bytes or text. The resulting bytes are
+    safe to use in URLs.
+    """
+    string = want_bytes(string)
+    return base64.urlsafe_b64encode(string).rstrip(b"=")
+
+
+def base64_decode(string):
+    """Base64 decode a URL-safe string of bytes or text. The result is
+    bytes.
+    """
+    string = want_bytes(string, encoding="ascii", errors="ignore")
+    string += b"=" * (-len(string) % 4)
+
+    try:
+        return base64.urlsafe_b64decode(string)
+    except (TypeError, ValueError):
+        raise BadData("Invalid base64-encoded data")
+
+
+# The alphabet used by base64.urlsafe_*
+_base64_alphabet = (string.ascii_letters + string.digits + "-_=").encode("ascii")
+
+_int64_struct = struct.Struct(">Q")
+_int_to_bytes = _int64_struct.pack
+_bytes_to_int = _int64_struct.unpack
+
+
+def int_to_bytes(num):
+    return _int_to_bytes(num).lstrip(b"\x00")
+
+
+def bytes_to_int(bytestr):
+    return _bytes_to_int(bytestr.rjust(8, b"\x00"))[0]