v1.1.0 - Added validation and line formatting, fixed zero-length padding. Added tests.

.gitignore

@@ -2,3 +2,4 @@ __pycache__/
 dist/
 .*
 !.gitignore
+*.lock

README.md

@@ -6,7 +6,7 @@ Replaces the standard library's `base64.urlsafe_b64encode` and `base64.urlsafe_b
 
 ## Features
 
-- **URL safe**: Uses only characters that are safe for URLs and filenames
+- **Urlsafe**: Uses only characters that are safe for URLs and filenames
 - **No padding**: Removes trailing `=` characters for cleaner output
 - **String output**: Returns proper strings instead of bytes (unlike Python's standard library)
 - **Fast**: Based on Python stdlib, with constant-time padding restoration
@@ -35,6 +35,14 @@ data = base64url.dec(text)     # Recovers the bytes
 
 Base64 encode bytes to a URL-safe string without padding.
 
-### `dec(s: str) -> bytes`
+### `dec(s: str, *, validate=True) -> bytes`
 
-Decode URL-safe Base64 into bytes. Padding optional.
+Decode URL-safe Base64 into bytes. Padding optional. Set `validate=False` to silently ignore any unknown characters (Python base64 default behavior).
+
+### `enc_lines(data: bytes, length: int = 76) -> str`
+
+Encode with newlines inserted every `length` characters.
+
+### `dec_lines(s: str) -> bytes`
+
+Decode formatted input, ignoring all whitespace (but not other unknown characters).

base64url.py

@@ -1,18 +1,16 @@
-"""URL-safe Base64 encoding without padding.
-
-This format uses only characters that are safe for URLs, filenames etc.
-Refer to Python's urlsafe_b64encode and base64.urlsafe_b64decode for more details.
+"""Base64 encoding in urlsafe format without padding.
 
 Fixes Python base64 module's faults:
-- Padding "==" is optional and not produced by b64url.enc
-- Base64 type is str (stdlib is retarded and uses bytes)
-- Otherwise identical to urlsafe_b64encode/urlsafe_b64decode
+- Padding "==" is optional and not produced by base64url.enc
+- Base64 type is str (stdlib uses bytes)
+- Doesn't silently ignore invalid characters and produce garbage
 """
 
-from base64 import urlsafe_b64decode as _decode
+# We cannot use urlsafe_b64decode which misses the validation argument
+from base64 import b64decode as _decode
 from base64 import urlsafe_b64encode as _encode
 
-__all__ = ["enc", "dec"]
+__all__ = ["enc", "dec", "enc_lines", "dec_lines"]
 
 
 def enc(data: bytes) -> str:
@@ -20,7 +18,30 @@ def enc(data: bytes) -> str:
     return _encode(data).decode("ascii").rstrip("=")
 
 
-def dec(s: str) -> bytes:
-    """Decode URL-safe Base64 into bytes. Padding optional."""
+def dec(s: str, *, validate=True) -> bytes:
+    """Decode standard or urlsafe Base64, with or without padding.
+
+    Validation raises binascii.Error (ValueError) on invalid characters.
+    If False, any unrecognized characters are silently ignored.
+    """
     # Testing whether needs padding is slower, this is the fastest way and constant time.
-    return _decode(s + "=" * (4 - (len(s) % 4)))
+    return _decode(s + -len(s) % 4 * "=", altchars=b"-_", validate=validate)
+
+
+def enc_lines(data: bytes, length: int = 76, sep="\n") -> str:
+    """Base64 encode bytes to a URL-safe string split into lines.
+
+    Returns a string with newlines inserted after every `length` characters.
+    The value should be a multiple of 4 for best compatibility with other systems.
+    """
+    s = enc(data)
+    return sep.join([s[i : i + length] for i in range(0, len(s), length)])
+
+
+def dec_lines(s: str) -> bytes:
+    """Decode standard or urlsafe Base64 from a multiline string.
+
+    All whitespace is ignored to allow formatted input.
+    Raises binascii.Error (ValueError) on other invalid characters.
+    """
+    return dec("".join(s.split()))

pyproject.toml

@@ -1,7 +1,7 @@
 [project]
 name = "base64url"
-version = "1.0.0"
-description = "Base64 encoding without Python's base64 flaws. No padding, str types."
+version = "1.1.0"
+description = "Base64 encoding without Python's base64 flaws. Output urlsafe without padding, as str. Decodes any variant with or without padding, with validation."
 readme = "README.md"
 requires-python = ">=3.8"
 dependencies = []

test_base64url.py

@@ -0,0 +1,206 @@
+"""Tests for base64url module."""
+
+import binascii
+
+import pytest
+
+import base64url
+
+
+class TestEnc:
+    """Tests for enc() function."""
+
+    def test_empty(self):
+        assert base64url.enc(b"") == ""
+
+    def test_single_byte(self):
+        assert base64url.enc(b"\x00") == "AA"
+
+    def test_no_padding_needed(self):
+        # 3 bytes encodes to 4 chars, no padding
+        assert base64url.enc(b"abc") == "YWJj"
+
+    def test_one_padding_stripped(self):
+        # 2 bytes encodes to 3 chars + 1 padding
+        assert base64url.enc(b"ab") == "YWI"
+        assert "=" not in base64url.enc(b"ab")
+
+    def test_two_padding_stripped(self):
+        # 1 byte encodes to 2 chars + 2 padding
+        assert base64url.enc(b"a") == "YQ"
+        assert "=" not in base64url.enc(b"a")
+
+    def test_urlsafe_chars(self):
+        # Bytes that produce + and / in standard Base64 should use - and _
+        # 0xfb -> standard: +, urlsafe: -
+        # 0xff -> standard: /, urlsafe: _
+        data = b"\xfb\xff\xfe"
+        result = base64url.enc(data)
+        assert "+" not in result
+        assert "/" not in result
+        assert "-" in result or "_" in result
+
+    def test_all_bytes(self):
+        # Verify all byte values encode/decode correctly
+        data = bytes(range(256))
+        encoded = base64url.enc(data)
+        assert "+" not in encoded
+        assert "/" not in encoded
+        assert "=" not in encoded
+
+
+class TestDec:
+    """Tests for dec() function."""
+
+    def test_empty(self):
+        assert base64url.dec("") == b""
+
+    def test_single_byte(self):
+        assert base64url.dec("AA") == b"\x00"
+
+    def test_without_padding(self):
+        assert base64url.dec("YWJj") == b"abc"
+        assert base64url.dec("YWI") == b"ab"
+        assert base64url.dec("YQ") == b"a"
+
+    def test_with_padding(self):
+        # Padding should be optional
+        assert base64url.dec("YWI=") == b"ab"
+        assert base64url.dec("YQ==") == b"a"
+
+    def test_urlsafe_chars(self):
+        # Should accept - instead of +, _ instead of /
+        assert base64url.dec("--__") == base64url.dec("++//")
+
+    def test_standard_base64_chars(self):
+        # Should also accept standard Base64 with + and /
+        assert base64url.dec("++//") == b"\xfb\xef\xff"
+
+    def test_mixed_chars(self):
+        # Mix of standard and urlsafe should work
+        assert base64url.dec("+-/_") is not None
+
+    def test_invalid_char_raises(self):
+        # Invalid characters should raise binascii.Error
+        with pytest.raises(binascii.Error):
+            base64url.dec("!!!!")
+
+    def test_invalid_char_in_middle_raises(self):
+        with pytest.raises(binascii.Error):
+            base64url.dec("YW!j")
+
+    def test_whitespace_raises(self):
+        # Whitespace should not be silently ignored
+        with pytest.raises(binascii.Error):
+            base64url.dec("YW Jj")
+
+    def test_newline_raises(self):
+        with pytest.raises(binascii.Error):
+            base64url.dec("YWJj\n")
+
+
+class TestRoundtrip:
+    """Tests for enc/dec roundtrip."""
+
+    def test_empty_roundtrip(self):
+        assert base64url.dec(base64url.enc(b"")) == b""
+
+    def test_hello_roundtrip(self):
+        assert base64url.dec(base64url.enc(b"hello")) == b"hello"
+
+    def test_binary_roundtrip(self):
+        data = bytes(range(256))
+        assert base64url.dec(base64url.enc(data)) == data
+
+    def test_various_lengths(self):
+        # Test lengths 0-20 to cover all padding scenarios
+        for i in range(21):
+            data = bytes(range(i))
+            assert base64url.dec(base64url.enc(data)) == data
+
+    def test_random_bytes(self):
+        import os
+
+        for _ in range(10):
+            data = os.urandom(100)
+            assert base64url.dec(base64url.enc(data)) == data
+
+
+class TestEncLines:
+    """Tests for enc_lines() function."""
+
+    def test_empty(self):
+        assert base64url.enc_lines(b"") == ""
+
+    def test_short_no_wrap(self):
+        # Short data fits on one line
+        result = base64url.enc_lines(b"hello", length=76)
+        assert "\n" not in result
+        assert result == "aGVsbG8"
+
+    def test_wrapping(self):
+        # 60 bytes -> 80 base64 chars, should wrap at 76
+        data = b"x" * 60
+        result = base64url.enc_lines(data, length=76)
+        lines = result.split("\n")
+        assert len(lines) == 2
+        assert len(lines[0]) == 76
+        assert len(lines[1]) == 4
+
+    def test_custom_line_length(self):
+        data = b"hello world"
+        result = base64url.enc_lines(data, length=4)
+        lines = result.split("\n")
+        assert all(len(line) <= 4 for line in lines)
+
+    def test_exact_multiple(self):
+        # 6 bytes -> 8 base64 chars, exactly 2 lines of 4
+        data = b"abcdef"
+        result = base64url.enc_lines(data, length=4)
+        lines = result.split("\n")
+        assert len(lines) == 2
+        assert all(len(line) == 4 for line in lines)
+
+
+class TestDecLines:
+    """Tests for dec_lines() function."""
+
+    def test_empty(self):
+        assert base64url.dec_lines("") == b""
+
+    def test_single_line(self):
+        assert base64url.dec_lines("aGVsbG8") == b"hello"
+
+    def test_multiline(self):
+        multiline = "aGVs\nbG8"
+        assert base64url.dec_lines(multiline) == b"hello"
+
+    def test_spaces(self):
+        spaced = "aGVs bG8"
+        assert base64url.dec_lines(spaced) == b"hello"
+
+    def test_tabs(self):
+        tabbed = "aGVs\tbG8"
+        assert base64url.dec_lines(tabbed) == b"hello"
+
+    def test_mixed_whitespace(self):
+        mixed = "  aGVs\n\t  bG8  \n"
+        assert base64url.dec_lines(mixed) == b"hello"
+
+    def test_crlf(self):
+        crlf = "aGVs\r\nbG8"
+        assert base64url.dec_lines(crlf) == b"hello"
+
+
+class TestLinesRoundtrip:
+    """Tests for enc_lines/dec_lines roundtrip."""
+
+    def test_roundtrip(self):
+        data = bytes(range(256))
+        assert base64url.dec_lines(base64url.enc_lines(data)) == data
+
+    def test_roundtrip_various_line_lengths(self):
+        data = b"hello world" * 10
+        for line_length in [4, 16, 64, 76, 100]:
+            encoded = base64url.enc_lines(data, length=line_length)
+            assert base64url.dec_lines(encoded) == data