README

functions or class to allow encoding or decoding strings using RFC4648 base32/base16 algorithm. This is a quick polyfill for the proposed RFC around adding an encoding API to PHP

Installation

Composer

composer require bakame-php/aide-base32

System Requirements

You need:

• PHP >= 8.1 but the latest stable version of PHP is recommended

Usage

The package provides a userland base32 encoding and decoding mechanism.

use Encoding\Base32;
use Encoding\DecodingMode;
use Encoding\PaddingMode;

base32_encode(string $data, Base32 $variant = Base32::Ascii, PaddingMode $paddingMode = PaddingMode::VariantControlled): string
base32_decode(string $data, Base32 $variant = Base32::Ascii, DecodingMode $decodingMode = DecodingMode::Strict): string

Parameters:

• $data : the string to encode or decode
• $variant : the base32 alphabet represented as an Enum.
• $paddingMode : the padding mode
• $decodingMode : Strict (follow the RFC) or Forgiving

If the $decodingMode parameter is set to Strict then the base32_decode function will throw

• if encoded sequence length is invalid
• if the input contains character from outside the base64 alphabet.
• if padding is invalid
• if encoded characters do not follow the alphabet lettering.

otherwise listed constraints are silently ignored or discarded.

Examples

<?php

use Encoding\Base16;
use Encoding\Base32;
use Encoding\DecodingMode;
use Encoding\PaddingMode;
use Encoding\TimingMode;
use function Encoding\base16_decode;
use function Encoding\base16_encode;
use function Encoding\base32_decode;
use function Encoding\base32_encode;

base32_encode('Bangui');           // returns 'IJQW4Z3VNE======'
base32_decode('IJQW4Z3VNE======'); // returns 'Bangui'
base32_decode('IJQW4Z083VNE======', decodingMode: DecodingMode::Strict) // throw UnableToDecodeException
base32_encode('Bangui', Base32::Hex, '=');                         // returns '89GMSPRLD4======'
base32_decode('89GMSPRLD4', Base32::Hex, DecodingMode::Forgiving); // returns 'Bangui'
base16_decode("48 65\n6C\t6C\r6F 2C 20 57 6F 72 6C 64 21"); // returns  "Hello, World!"
base16_decode("48 65\n6C\t6C\r6F 2c 20 57 6F 72 6C 64 21", decodingMode: DecodingMode::Forgiving); // returns  "Hello, World!"

By default base16_decode is in TimingMode::Constant.

Caution

Since this is a POV, no real validation check is done on the constant-time decoding for base16.