Sop\JWX\JWK\Parameter\CurveParameter

Complexity

Total Complexity

8

Size/Duplication

Total Lines	114
Duplicated Lines	0 %

Test Coverage

Coverage

100%

Importance

Changes

0

4 Methods

Rating	Name	Duplication	Size	Complexity
A	fromOID()	0	7	2
A	keySizeBits()	0	7	2
A	nameToOID()	0	10	3
A	__construct()	0	3	1

<?php

declare(strict_types = 1);

namespace Sop\JWX\JWK\Parameter;

use Sop\JWX\Parameter\Feature\StringParameterValue;

/**
 * Implements 'Curve' parameter.
 *
 * @see https://tools.ietf.org/html/rfc7518#section-6.2.1.1
 */
class CurveParameter extends JWKParameter
{
    use StringParameterValue;

    /**
     * P-256 Curve.
     *
     * @var string
     */
    const CURVE_P256 = 'P-256';

    /**
     * P-384 Curve.
     *
     * @var string
     */
    const CURVE_P384 = 'P-384';

    /**
     * P-521 Curve.
     *
     * @var string
     */
    const CURVE_P521 = 'P-521';

    /**
     * Mapping from curve OID to curve name.
     *
     * @internal
     *
     * @var array
     */
    const MAP_OID_TO_CURVE = [
        '1.2.840.10045.3.1.7' => self::CURVE_P256,
        '1.3.132.0.34' => self::CURVE_P384,
        '1.3.132.0.35' => self::CURVE_P521,
    ];

    /**
     * Mapping from curve name to bit size.
     *
     * @internal
     *
     * @var array
     */
    const MAP_CURVE_TO_SIZE = [
        self::CURVE_P256 => 256,
        self::CURVE_P384 => 384,
        self::CURVE_P521 => 521,
    ];

    /**
     * Constructor.
     *
     * @param string $curve Curve name
     */
    public function __construct(string $curve)
    {
        parent::__construct(self::PARAM_CURVE, $curve);
    }

    /**
     * Initialize from curve OID.
     *
     * @param string $oid Object identifier in dotted format
     *
     * @throws \UnexpectedValueException If the curve is not supported
     *
     * @return self
     */
    public static function fromOID(string $oid): self
    {
        if (!array_key_exists($oid, self::MAP_OID_TO_CURVE)) {
            throw new \UnexpectedValueException("OID {$oid} not supported.");
        }
        $curve = self::MAP_OID_TO_CURVE[$oid];
        return new self($curve);
    }

    /**
     * Get key size in bits for the curve.
     *
     * @throws \UnexpectedValueException
     *
     * @return int
     */
    public function keySizeBits(): int
    {
        if (!array_key_exists($this->_value, self::MAP_CURVE_TO_SIZE)) {
            throw new \UnexpectedValueException(
                'Curve ' . $this->_value . ' not supported.');
        }
        return self::MAP_CURVE_TO_SIZE[$this->_value];
    }

    /**
     * Get the curve OID by curve name.
     *
     * @param string $name Curve parameter name
     *
     * @throws \UnexpectedValueException If the curve is not supported
     *
     * @return string OID in dotted format
     */
    public static function nameToOID(string $name): string
    {
        static $reverseMap;
        if (!isset($reverseMap)) {
            $reverseMap = array_flip(self::MAP_OID_TO_CURVE);
        }
        if (!isset($reverseMap[$name])) {
            throw new \UnexpectedValueException("Curve {$name} not supported.");
        }
        return $reverseMap[$name];
    }
}