add user database code

roc_fnb/util/base64.py

@@ -0,0 +1,30 @@
+from base64 import b64encode
+from binascii import a2b_base64
+import binascii
+
+
+def base64_decode(string: str|bytes) -> bytes:
+    """
+    Python's base64.b64_decode requires padding to be correct. This does not.
+
+    What silly bullshit.
+    """
+    encoded: bytes = string.encode() if isinstance(string, str) else string
+    # padc = 4 - len(encoded) % 4
+    # if padc == 4:
+    #     padc = 0
+    # fixed = encoded + b'=' * padc
+    fixed = encoded + b'===='
+    try:
+        return a2b_base64(fixed, strict_mode=False)
+    except binascii.Error as e:
+        print(f'{string=!r}\n{len(string)=!r}\n{padc=!r}\n{fixed=!r}\n{len(fixed)=!r}')
+        raise e
+
+def base64_encode(data: bytes) -> str:
+    """
+    Return a base64 encoded string with no padding
+
+    Python's b64encode returns bytes. Why?
+    """
+    return b64encode(data).decode('utf-8').rstrip('=')

roc_fnb/util/test_base64.py

@@ -0,0 +1,11 @@
+from random import randbytes
+
+from roc_fnb.util.base64 import *
+
+
+def test_encode_and_decode():
+    for size in range(20-40):
+        data = randbytes(32)
+        string = base64_encode(data)
+        decoded = base64_decode(string)
+        assert data == decoded