Jose\Object\JWKSet

Complexity

Total Complexity

51

Size/Duplication

Total Lines	298
Duplicated Lines	0 %

Coupling/Cohesion

Components	1
Dependencies	3

Importance

Changes	4
Bugs	1	Features	2

24 Methods

Rating	Name	Duplication	Size	Complexity
A	jsonSerialize()	0	4	1
A	count()	0	4	1
A	current()	0	4	2
A	key()	0	4	1
A	next()	0	4	1
A	rewind()	0	4	1
A	valid()	0	4	1
A	__construct()	0	8	3
A	hasKey()	0	4	1
A	getKey()	0	6	1
A	getKeys()	0	4	1
A	addKey()	0	4	1
A	removeKey()	0	6	2
A	countKeys()	0	4	1
A	offsetExists()	0	4	1
A	offsetGet()	0	4	1
A	offsetSet()	0	4	1
A	offsetUnset()	0	4	1
B	selectKey()	0	42	6
B	canKeyBeUsedFor()	0	11	5
A	canKeyBeUsedWithAlgorithm()	0	11	4
A	doesKeySatisfyRestrictions()	0	10	4
B	convertKeyOpsToKeyUse()	0	15	7
A	sortKeys()	0	7	3

<?php

/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2014-2016 Spomky-Labs
 *
 * This software may be modified and distributed under the terms
 * of the MIT license.  See the LICENSE file for details.
 */

namespace Jose\Object;

use Assert\Assertion;

/**
 * Class JWKSet.
 */
final class JWKSet implements JWKSetInterface
{
    /**
     * @var int
     */
    private $position = 0;

    /**
     * @var array
     */
    protected $keys = [];

    public function __construct(array $keys = [])
    {
        if (array_key_exists('keys', $keys)) {
            foreach ($keys['keys'] as $value) {
                $this->addKey(new JWK($value));
            }
        }
    }

    /**
     * {@inheritdoc}
     */
    public function hasKey($index)
    {
        return array_key_exists($index, $this->keys);
    }

    /**
     * {@inheritdoc}
     */
    public function getKey($index)
    {
        Assertion::keyExists($this->keys, $index, 'Undefined index.');

        return $this->keys[$index];
    }

    /**
     * {@inheritdoc}
     */
    public function getKeys()
    {
        return $this->keys;
    }

    /**
     * {@inheritdoc}
     */
    public function addKey(JWKInterface $key)
    {
        $this->keys[] = $key;
    }

    /**
     * {@inheritdoc}
     */
    public function removeKey($key)
    {
        if (isset($this->keys[$key])) {
            unset($this->keys[$key]);
        }
    }

    /**
     * {@inheritdoc}
     */
    public function jsonSerialize()
    {
        return ['keys' => array_values($this->getKeys())];
    }

    /**
     * {@inheritdoc}
     */
    public function count($mode = COUNT_NORMAL)
    {
        return count($this->getKeys(), $mode);
    }

    /**
     * {@inheritdoc}
     */
    public function current()
    {
        return isset($this->keys[$this->position]) ? $this->keys[$this->position] : null;
    }

    /**
     * {@inheritdoc}
     */
    public function key()
    {
        return $this->position;
    }

    /**
     * {@inheritdoc}
     */
    public function next()
    {
        $this->position++;
    }

    /**
     * {@inheritdoc}
     */
    public function rewind()
    {
        $this->position = 0;
    }

    /**
     * {@inheritdoc}
     */
    public function valid()
    {
        return $this->current() instanceof JWKInterface;
    }

    /**
     * {@inheritdoc}
     */
    public function countKeys()
    {
        return count($this->keys);
    }
    /**
     * {@inheritdoc}
     */
    public function offsetExists($offset)
    {
        return $this->hasKey($offset);
    }

    /**
     * {@inheritdoc}
     */
    public function offsetGet($offset)
    {
        return $this->getKey($offset);
    }

    /**
     * {@inheritdoc}
     */
    public function offsetSet($offset, $value)
    {
        $this->addKey($value);
    }

    /**
     * {@inheritdoc}
     */
    public function offsetUnset($offset)
    {
        $this->removeKey($offset);
    }

    /**
     * @param string      $type
     * @param string|null $algorithm
     * @param array       $restrictions
     *
     * @return \Jose\Object\JWKInterface|null
     */
    public function selectKey($type, $algorithm = null, array $restrictions = [])
    {
        Assertion::inArray($type, ['enc', 'sig']);
        Assertion::nullOrString($algorithm);

        $result = [];
        foreach ($this->keys as $key) {
            $ind = 0;
            
            // Check usage
            $can_use = $this->canKeyBeUsedFor($type, $key);
            if (false === $can_use) {
                continue;
            }
            $ind += $can_use;
            
            // Check algorithm
            $alg = $this->canKeyBeUsedWithAlgorithm($algorithm, $key);
            if (false === $alg) {
                continue;
            }
            $ind += $alg;
            
            // Validate restrictions
            if (false === $this->doesKeySatisfyRestrictions($restrictions, $key)) {
                continue;
            }
            
            // Add to the list with trust indicator
            $result[] = ['key' => $key, 'ind' => $ind];
        }

        //Return null if no key
        if (empty($result)) {
            return;
        }

        //Sort by trust indicator
        usort($result, [$this, 'sortKeys']);
        //Return the highest trust indicator (first key)
        return $result[0]['key'];
    }

    /**
     * @param string                    $type
     * @param \Jose\Object\JWKInterface $key
     *
     * @return bool|int
     */
    private function canKeyBeUsedFor($type, JWKInterface $key)
    {
        if ($key->has('use')) {
            return $type === $key->get('use') ? 1 : false;
        }
        if ($key->has('key_ops')) {
            return $type === self::convertKeyOpsToKeyUse($key->get('use')) ? 1 : false;
        }
        
        return 0;
    }

    /**
     * @param null|string               $algorithm
     * @param \Jose\Object\JWKInterface $key
     *
     * @return bool|int
     */
    private function canKeyBeUsedWithAlgorithm($algorithm, JWKInterface $key)
    {
        if (null === $algorithm) {
            return 0;
        }
        if ($key->has('alg')) {
            return $algorithm === $key->get('alg') ? 1 : false;
        }
        
        return 0;
    }

    /**
     * @param array                     $restrictions
     * @param \Jose\Object\JWKInterface $key
     *
     * @return bool
     */
    private function doesKeySatisfyRestrictions(array $restrictions, JWKInterface $key)
    {
        foreach ($restrictions as $k=>$v) {
            if (!$key->has($k) || $v !== $key->get($k)) {
                return false;
            }
        }
        
        return true;
    }

    /**
     * @param string $key_ops
     * 
     * @return string
     */
    private static function convertKeyOpsToKeyUse($key_ops)
    {
        switch ($key_ops) {
            case 'verify':
            case 'sign':
                return 'sig';
            case 'encrypt':
            case 'decrypt':
            case 'wrapKey':
            case 'unwrapKey':
                return 'enc';
            default:
                throw new \InvalidArgumentException(sprintf('Unsupported key operation value "%s"', $key_ops));
        }
    }

    /**
     * @param array $a
     * @param array $b
     *
     * @return int
     */
    public function sortKeys($a, $b)
    {
        if ($a['ind'] === $b['ind']) {
            return 0;
        }
        return ($a['ind'] > $b['ind']) ? -1 : 1;
    }
}