Jose\KeyConverter\ECKey

Complexity

Total Complexity

29

Size/Duplication

Total Lines	300
Duplicated Lines	0 %

Coupling/Cohesion

Components	1
Dependencies	10

Importance

Changes	9
Bugs	4	Features	2

19 Methods

Rating	Name	Duplication	Size	Complexity
A	loadPEM()	0	15	3
A	loadJWK()	0	15	2
A	toDER()	0	4	1
A	getOID()	0	9	2
A	getCurve()	0	8	1
A	getSupportedCurves()	0	8	1
A	initPublicKey()	0	12	1
A	initPrivateKey()	0	14	1
A	loadPublicPEM()	0	21	1
A	verifyVersion()	0	5	1
A	getXAndY()	0	14	1
A	getD()	0	6	1
A	loadPrivatePEM()	0	22	1
A	isPrivate()	0	4	1
A	toPublic()	0	9	2
A	__construct()	0	15	4
A	__toString()	0	4	1
A	toArray()	0	4	1
A	toPEM()	0	8	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\KeyConverter;

use Assert\Assertion;
use Base64Url\Base64Url;
use FG\ASN1\ExplicitlyTaggedObject;
use FG\ASN1\Object;
use FG\ASN1\Universal\BitString;
use FG\ASN1\Universal\Integer;
use FG\ASN1\Universal\ObjectIdentifier;
use FG\ASN1\Universal\OctetString;
use FG\ASN1\Universal\Sequence;
use Jose\Object\JWKInterface;

final class ECKey extends Sequence
{
    /**
     * @var bool
     */
    private $private = false;

    /**
     * @var array
     */
    private $values = [];

    /**
     * @param \Jose\Object\JWKInterface|string|array $data
     */
    public function __construct($data)
    {
        parent::__construct();

        if ($data instanceof JWKInterface) {
            $this->loadJWK($data->getAll());
        } elseif (is_array($data)) {
            $this->loadJWK($data);
        } elseif (is_string($data)) {
            $this->loadPEM($data);
        } else {
            throw new \InvalidArgumentException('Unsupported input');
        }
        $this->private = isset($this->values['d']);
    }

    /**
     * @param string $data
     *
     * @throws \Exception
     * @throws \FG\ASN1\Exception\ParserException
     *
     * @return array
     */
    private function loadPEM($data)
    {
        $data = base64_decode(preg_replace('#-.*-|\r|\n#', '', $data));
        $asnObject = Object::fromBinary($data);

        Assertion::isInstanceOf($asnObject, Sequence::class);

        $children = $asnObject->getChildren();

The method getChildren does only exist in FG\ASN1\Construct, but not in FG\ASN1\AbstractString and FG\ASN1\ExplicitlyTaggedObject and FG\ASN1\Universal\Boolean and FG\ASN1\Universal\GeneralizedTime and FG\ASN1\Universal\Integer and FG\ASN1\Universal\NullObject and FG\ASN1\Universal\ObjectIdentifier and FG\ASN1\Universal\OctetString and FG\ASN1\Universal\UTCTime and FG\ASN1\UnknownObject.

        if (4 === count($children)) {
            return $this->loadPrivatePEM($children);
        } elseif (2 === count($children)) {
            return $this->loadPublicPEM($children);
        }
        throw new \Exception('Unable to load the key');
    }

    /**
     * @param array $jwk
     */
    private function loadJWK(array $jwk)
    {
        Assertion::true(array_key_exists('kty', $jwk), 'JWK is not an Elliptic Curve key');
        Assertion::eq($jwk['kty'], 'EC', 'JWK is not an Elliptic Curve key');
        Assertion::true(array_key_exists('crv', $jwk), 'Curve parameter is missing');
        Assertion::true(array_key_exists('x', $jwk), 'Point parameters are missing');
        Assertion::true(array_key_exists('y', $jwk), 'Point parameters are missing');

        $this->values = $jwk;
        if (array_key_exists('d', $jwk)) {
            $this->initPrivateKey();
        } else {
            $this->initPublicKey();
        }
    }

    private function initPublicKey()
    {
        $oid_sequence = new Sequence();
        $oid_sequence->addChild(new ObjectIdentifier('1.2.840.10045.2.1'));
        $oid_sequence->addChild(new ObjectIdentifier($this->getOID($this->values['crv'])));
        $this->addChild($oid_sequence);

        $bits = '04';
        $bits .= bin2hex(Base64Url::decode($this->values['x']));
        $bits .= bin2hex(Base64Url::decode($this->values['y']));
        $this->addChild(new BitString($bits));
    }

    private function initPrivateKey()
    {
        $this->addChild(new Integer(1));
        $this->addChild(new OctetString(bin2hex(Base64Url::decode($this->values['d']))));

        $oid = new ObjectIdentifier($this->getOID($this->values['crv']));
        $this->addChild(new ExplicitlyTaggedObject(0, $oid));

        $bits = '04';
        $bits .= bin2hex(Base64Url::decode($this->values['x']));
        $bits .= bin2hex(Base64Url::decode($this->values['y']));
        $bit = new BitString($bits);
        $this->addChild(new ExplicitlyTaggedObject(1, $bit));
    }

    /**
     * @param array $children
     *
     * @throws \Exception
     *
     * @return array
     */
    private function loadPublicPEM(array $children)
    {
        Assertion::isInstanceOf($children[0], Sequence::class, 'Unsupported key type');

        $sub = $children[0]->getChildren();
        Assertion::isInstanceOf($sub[0], ObjectIdentifier::class, 'Unsupported key type');
        Assertion::eq('1.2.840.10045.2.1', $sub[0]->getContent(), 'Unsupported key type');

        Assertion::isInstanceOf($sub[1], ObjectIdentifier::class, 'Unsupported key type');
        Assertion::isInstanceOf($children[1], BitString::class, 'Unable to load the key');

        $bits = $children[1]->getContent();
        $bits_length = mb_strlen($bits, '8bit');

        Assertion::eq('04', mb_substr($bits, 0, 2, '8bit'), 'Unsupported key type');

        $this->values['kty'] = 'EC';
        $this->values['crv'] = $this->getCurve($sub[1]->getContent());
        $this->values['x'] = Base64Url::encode(hex2bin(mb_substr($bits, 2, ($bits_length - 2) / 2, '8bit')));
        $this->values['y'] = Base64Url::encode(hex2bin(mb_substr($bits, ($bits_length - 2) / 2 + 2, ($bits_length - 2) / 2, '8bit')));
    }

    /**
     * @param \FG\ASN1\Object $children
     */
    private function verifyVersion(Object $children)
    {
        Assertion::isInstanceOf($children, Integer::class, 'Unable to load the key');
        Assertion::eq(1, $children->getContent(), 'Unable to load the key');
    }

    /**
     * @param \FG\ASN1\Object $children
     * @param string|null     $x
     * @param string|null     $y
     */
    private function getXAndY(Object $children, &$x, &$y)
    {
        Assertion::isInstanceOf($children, ExplicitlyTaggedObject::class, 'Unable to load the key');
        Assertion::isArray($children->getContent(), 'Unable to load the key');
        Assertion::isInstanceOf($children->getContent()[0], BitString::class, 'Unable to load the key');

        $bits = $children->getContent()[0]->getContent();
        $bits_length = mb_strlen($bits, '8bit');

        Assertion::eq('04', mb_substr($bits, 0, 2, '8bit'), 'Unsupported key type');

        $x = mb_substr($bits, 2, ($bits_length - 2) / 2, '8bit');
        $y = mb_substr($bits, ($bits_length - 2) / 2 + 2, ($bits_length - 2) / 2, '8bit');
    }

    /**
     * @param \FG\ASN1\Object $children
     *
     * @return string
     */
    private function getD(Object $children)
    {
        Assertion::isInstanceOf($children, '\FG\ASN1\Universal\OctetString', 'Unable to load the key');

        return $children->getContent();
    }

    /**
     * @param array $children
     *
     * @return array
     */
    private function loadPrivatePEM(array $children)
    {
        $this->verifyVersion($children[0]);

        $x = null;
        $y = null;
        $d = $this->getD($children[1]);
        $this->getXAndY($children[3], $x, $y);

        Assertion::isInstanceOf($children[2], ExplicitlyTaggedObject::class, 'Unable to load the key');
        Assertion::isArray($children[2]->getContent(), 'Unable to load the key');
        Assertion::isInstanceOf($children[2]->getContent()[0], ObjectIdentifier::class, 'Unable to load the key');

        $curve = $children[2]->getContent()[0]->getContent();

        $this->private = true;
        $this->values['kty'] = 'EC';
        $this->values['crv'] = $this->getCurve($curve);
        $this->values['d'] = Base64Url::encode(hex2bin($d));
        $this->values['x'] = Base64Url::encode(hex2bin($x));
        $this->values['y'] = Base64Url::encode(hex2bin($y));
    }

    /**
     * @return bool
     */
    public function isPrivate()
    {
        return $this->private;
    }

    /**
     * @param \Jose\KeyConverter\ECKey $private
     *
     * @return \Jose\KeyConverter\ECKey
     */
    public static function toPublic(ECKey $private)
    {
        $data = $private->toArray();
        if (array_key_exists('d', $data)) {
            unset($data['d']);
        }

        return new self($data);
    }

    /**
     * @return string
     */
    public function __toString()
    {
        return $this->toPEM();
    }

    /**
     * @return array
     */
    public function toArray()
    {
        return $this->values;
    }

    /**
     * @return string
     */
    public function toDER()
    {
        return $this->getBinary();
    }

    /**
     * @return string
     */
    public function toPEM()
    {
        $result = '-----BEGIN '.($this->private ? 'EC PRIVATE' : 'PUBLIC').' KEY-----'.PHP_EOL;
        $result .= chunk_split(base64_encode($this->getBinary()), 64, PHP_EOL);
        $result .= '-----END '.($this->private ? 'EC PRIVATE' : 'PUBLIC').' KEY-----'.PHP_EOL;

        return $result;
    }

    /**
     * @param $curve
     *
     * @return string
     */
    private function getOID($curve)
    {
        $curves = $this->getSupportedCurves();
        $oid = array_key_exists($curve, $curves) ? $curves[$curve] : null;

        Assertion::notNull($oid, 'Unsupported curve');

        return $oid;
    }

    /**
     * @param string $oid
     *
     * @return string
     */
    private function getCurve($oid)
    {
        $curves = $this->getSupportedCurves();
        $curve = array_search($oid, $curves, true);
        Assertion::string($curve, 'Unsupported OID');

        return $curve;
    }

    /**
     * @return array
     */
    private function getSupportedCurves()
    {
        return [
            'P-256' => '1.2.840.10045.3.1.7',
            'P-384' => '1.3.132.0.34',
            'P-521' => '1.3.132.0.35',
        ];
    }
}