`flare.crypto.base64`

flare.crypto.base64 -- RFC 4648 §4 standard base64 encode/decode.

Consolidates three identical near-duplicate encoders: the standard-alphabet base64 implementation lived in three places before -- _b64_encode in flare.http.auth, _base64_encode in flare.ws.client, _b64_encode_srv in flare.ws.server -- each with the same RFC 4648 §4 table and the same chunk-of-3 / pad-tail loop. This module is the single canonical home; the three call sites now import from here.

The URL-safe (RFC 4648 §5, no padding) variant for cookies and JWT lives at :mod:flare.crypto.hmac (:func:base64url_encode / :func:base64url_decode); the two alphabets diverge on + / / vs - / _ and on padding behaviour. The HTTP-side Basic auth header (RFC 7617) and the WebSocket Sec-WebSocket-Accept derivation (RFC 6455 §4.2.2) require the standard alphabet with = padding, which is what this module provides.

Public API

from flare.crypto.base64 import base64_encode, base64_decode

:func:base64_encode(data: Span[UInt8, _]) -> String -- alphabet A-Za-z0-9+/ with = padding to a multiple of 4.
:func:base64_decode(s: String) raises -> List[UInt8] -- inverse; tolerates missing padding, raises on invalid bytes.

Functions

`base64_encode`

def base64_encode(data: Span[UInt8]) -> String

Encode bytes as standard RFC 4648 §4 base64 with = padding.

Alphabet A-Za-z0-9+/. Output length is always a multiple of 4; = is appended so the 2/3 -> 4 round-up is preserved.

Args: data: Input bytes.

`base64_decode`

def base64_decode(s: String) -> List[UInt8]

Decode standard RFC 4648 §4 base64 (with or without =).

Args: s: Encoded string; trailing = characters are tolerated but not required.

Raises Error: When s contains a character outside the base64 alphabet, or its length is otherwise invalid.