Sop\JWX\JWE\EncryptionAlgorithm\EncryptionAlgorithmFactory

Complexity

Total Complexity

4

Size/Duplication

Total Lines	55
Duplicated Lines	0 %

Test Coverage

Coverage

100%

Importance

Changes

0

2 Methods

Rating	Name	Duplication	Size	Complexity
A	algoByName()	0	8	2
A	algoByHeader()	0	7	2

<?php

declare(strict_types = 1);

namespace Sop\JWX\JWE\EncryptionAlgorithm;

use Sop\JWX\JWA\JWA;
use Sop\JWX\JWE\ContentEncryptionAlgorithm;
use Sop\JWX\JWT\Header\Header;

/**
 * Factory class to construct content encryption algorithm instances.
 */
abstract class EncryptionAlgorithmFactory
{
    /**
     * Mapping from algorithm name to class name.
     *
     * @internal
     *
     * @var array
     */
    const MAP_ALGO_TO_CLASS = [
        JWA::ALGO_A128CBC_HS256 => A128CBCHS256Algorithm::class,
        JWA::ALGO_A192CBC_HS384 => A192CBCHS384Algorithm::class,
        JWA::ALGO_A256CBC_HS512 => A256CBCHS512Algorithm::class,
        JWA::ALGO_A128GCM => A128GCMAlgorithm::class,
        JWA::ALGO_A192GCM => A192GCMAlgorithm::class,
        JWA::ALGO_A256GCM => A256GCMAlgorithm::class,
    ];

    /**
     * Get the content encryption algorithm by algorithm name.
     *
     * @param string $name Algorithm name
     *
     * @throws \UnexpectedValueException if algorithm is not supported
     *
     * @return ContentEncryptionAlgorithm
     */
    public static function algoByName(string $name): ContentEncryptionAlgorithm
    {
        if (!array_key_exists($name, self::MAP_ALGO_TO_CLASS)) {
            throw new \UnexpectedValueException(
                "No content encryption algorithm '{$name}'.");
        }
        $cls = self::MAP_ALGO_TO_CLASS[$name];
        return new $cls();
    }

    /**
     * Get the content encryption algorithm as specified in the given header.
     *
     * @param Header $header Header
     *
     * @throws \UnexpectedValueException If content encryption algorithm
     *                                   parameter is not present or algorithm
     *                                   is not supported
     *
     * @return ContentEncryptionAlgorithm
     */
    public static function algoByHeader(Header $header): ContentEncryptionAlgorithm
    {
        if (!$header->hasEncryptionAlgorithm()) {
            throw new \UnexpectedValueException(
                'No encryption algorithm parameter.');
        }
        return self::algoByName($header->encryptionAlgorithm()->value());
    }
}