Collaboration diagram for Firebase\JWT\JWK:

Static Public Member Functions
static	parseKeySet (array $jwks, string $defaultAlg=null)
	Parse a set of JWK keys. More...

static	parseKey (array $jwk, string $defaultAlg=null)
	Parse a JWK key. More...

Static Private Member Functions
static	createPemFromCrvAndXYCoordinates (string $crv, string $x, string $y)
	Converts the EC JWK values to pem format. More...

static	createPemFromModulusAndExponent (string $n, string $e)
	Create a public key represented in PEM format from RSA modulus and exponent information. More...

static	encodeLength (int $length)
	DER-encode the length. More...

static	encodeDER (int $type, string $value)
	Encodes a value into a DER object. More...

static	encodeOID (string $oid)
	Encodes a string into a DER-encoded OID. More...

Private Attributes
const	OID = '1.2.840.10045.2.1'

const	ASN1_OBJECT_IDENTIFIER = 0x06

const	ASN1_SEQUENCE = 0x10

const	ASN1_BIT_STRING = 0x03

const	EC_CURVES

const	OKP_SUBTYPES

Detailed Description

Definition at line 21 of file JWK.php.

Member Function Documentation

◆ createPemFromCrvAndXYCoordinates()

static Firebase\JWT\JWK::createPemFromCrvAndXYCoordinates	(	string	$crv,
		string	$x,
		string	$y
	)

staticprivate

Converts the EC JWK values to pem format.

Parameters

string	$crv	The EC curve (only P-256 & P-384 is supported)
string	$x	The EC x-coordinate
string	$y	The EC y-coordinate

Returns: string

Definition at line 191 of file JWK.php.

                                                                                               : string
    {
        $pem =
            self::encodeDER(
                self::ASN1_SEQUENCE,
                self::encodeDER(
                    self::ASN1_SEQUENCE,
                    self::encodeDER(
                        self::ASN1_OBJECT_IDENTIFIER,
                        self::encodeOID(self::OID)
                    )
                    . self::encodeDER(
                        self::ASN1_OBJECT_IDENTIFIER,
                        self::encodeOID(self::EC_CURVES[$crv])
                    )
                ) .
                self::encodeDER(
                    self::ASN1_BIT_STRING,
                    \chr(0x00) . \chr(0x04)
                    . JWT::urlsafeB64Decode($x)
                    . JWT::urlsafeB64Decode($y)
                )
            );
 
        return sprintf(
            "-----BEGIN PUBLIC KEY-----\n%s\n-----END PUBLIC KEY-----\n",
            wordwrap(base64_encode($pem), 64, "\n", true)
        );
    }

References Firebase\JWT\JWK\encodeDER(), and Firebase\JWT\JWT\urlsafeB64Decode().

Referenced by Firebase\JWT\JWK\parseKey().

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◆ createPemFromModulusAndExponent()

static Firebase\JWT\JWK::createPemFromModulusAndExponent	(	string	$n,
		string	$e
	)

staticprivate

Create a public key represented in PEM format from RSA modulus and exponent information.

Parameters

string	$n	The RSA modulus encoded in Base64
string	$e	The RSA exponent encoded in Base64

Returns: string The RSA public key represented in PEM format

@uses encodeLength

Definition at line 231 of file JWK.php.

     : string {
        $mod = JWT::urlsafeB64Decode($n);
        $exp = JWT::urlsafeB64Decode($e);
 
        $modulus = \pack('Ca*a*', 2, self::encodeLength(\strlen($mod)), $mod);
        $publicExponent = \pack('Ca*a*', 2, self::encodeLength(\strlen($exp)), $exp);
 
        $rsaPublicKey = \pack(
            'Ca*a*a*',
            48,
            self::encodeLength(\strlen($modulus) + \strlen($publicExponent)),
            $modulus,
            $publicExponent
        );
 
        // sequence(oid(1.2.840.113549.1.1.1), null)) = rsaEncryption.
        $rsaOID = \pack('H*', '300d06092a864886f70d0101010500'); // hex version of MA0GCSqGSIb3DQEBAQUA
        $rsaPublicKey = \chr(0) . $rsaPublicKey;
        $rsaPublicKey = \chr(3) . self::encodeLength(\strlen($rsaPublicKey)) . $rsaPublicKey;
 
        $rsaPublicKey = \pack(
            'Ca*a*',
            48,
            self::encodeLength(\strlen($rsaOID . $rsaPublicKey)),
            $rsaOID . $rsaPublicKey
        );
 
        return "-----BEGIN PUBLIC KEY-----\r\n" .
            \chunk_split(\base64_encode($rsaPublicKey), 64) .
            '-----END PUBLIC KEY-----';
    }

Referenced by Firebase\JWT\JWK\parseKey().

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◆ encodeDER()

static Firebase\JWT\JWK::encodeDER	(	int	$type,
		string	$value
	)

staticprivate

Encodes a value into a DER object.

Also defined in Firebase\JWT\JWT

Parameters

int	$type	DER tag
string	$value	the value to encode

Returns: string the encoded object

Definition at line 294 of file JWK.php.

                                                               : string
    {
        $tag_header = 0;
        if ($type === self::ASN1_SEQUENCE) {
            $tag_header |= 0x20;
        }
 
        // Type
        $der = \chr($tag_header | $type);
 
        // Length
        $der .= \chr(\strlen($value));
 
        return $der . $value;
    }

References $type.

Referenced by Firebase\JWT\JWK\createPemFromCrvAndXYCoordinates().

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◆ encodeLength()

static Firebase\JWT\JWK::encodeLength ( int $length )

staticprivate

DER-encode the length.

DER supports lengths up to (2**8)**127, however, we'll only support lengths up to (2**8)**4. See X.690 paragraph 8.1.3 for more information.

Parameters

int $length

Returns: string

Definition at line 275 of file JWK.php.

                                                     : string
    {
        if ($length <= 0x7F) {
            return \chr($length);
        }
 
        $temp = \ltrim(\pack('N', $length), \chr(0));
 
        return \pack('Ca*', 0x80 | \strlen($temp), $temp);
    }

◆ encodeOID()

static Firebase\JWT\JWK::encodeOID ( string $oid )

staticprivate

Encodes a string into a DER-encoded OID.

Parameters

string $oid the OID string

Returns: string the binary DER-encoded OID

Definition at line 316 of file JWK.php.

                                                  : string
    {
        $octets = explode('.', $oid);
 
        // Get the first octet
        $first = (int) array_shift($octets);
        $second = (int) array_shift($octets);
        $oid = \chr($first * 40 + $second);
 
        // Iterate over subsequent octets
        foreach ($octets as $octet) {
            if ($octet == 0) {
                $oid .= \chr(0x00);
                continue;
            }
            $bin = '';
 
            while ($octet) {
                $bin .= \chr(0x80 | ($octet & 0x7f));
                $octet >>= 7;
            }
            $bin[0] = $bin[0] & \chr(0x7f);
 
            // Convert to big endian if necessary
            if (pack('V', 65534) == pack('L', 65534)) {
                $oid .= strrev($bin);
            } else {
                $oid .= $bin;
            }
        }
 
        return $oid;
    }

References ILIAS\Repository\int().

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◆ parseKey()

static Firebase\JWT\JWK::parseKey	(	array	$jwk,
		string	$defaultAlg = `null`
	)

static

Parse a JWK key.

Parameters

	array<mixed>	$jwk An individual JWK
string	$defaultAlg	The algorithm for the Key object if "alg" is not set in the JSON Web Key Set

Returns: Key The key object for the JWK

Exceptions

InvalidArgumentException	Provided JWK is empty
UnexpectedValueException	Provided JWK was invalid
DomainException	OpenSSL failure

@uses createPemFromModulusAndExponent

Definition at line 96 of file JWK.php.

                                                                          : ?Key
    {
        if (empty($jwk)) {
            throw new InvalidArgumentException('JWK must not be empty');
        }
 
        if (!isset($jwk['kty'])) {
            throw new UnexpectedValueException('JWK must contain a "kty" parameter');
        }
 
        if (!isset($jwk['alg'])) {
            if (\is_null($defaultAlg)) {
                // The "alg" parameter is optional in a KTY, but an algorithm is required
                // for parsing in this library. Use the $defaultAlg parameter when parsing the
                // key set in order to prevent this error.
                // @see https://datatracker.ietf.org/doc/html/rfc7517#section-4.4
                throw new UnexpectedValueException('JWK must contain an "alg" parameter');
            }
            $jwk['alg'] = $defaultAlg;
        }
 
        switch ($jwk['kty']) {
            case 'RSA':
                if (!empty($jwk['d'])) {
                    throw new UnexpectedValueException('RSA private keys are not supported');
                }
                if (!isset($jwk['n']) || !isset($jwk['e'])) {
                    throw new UnexpectedValueException('RSA keys must contain values for both "n" and "e"');
                }
 
                $pem = self::createPemFromModulusAndExponent($jwk['n'], $jwk['e']);
                $publicKey = \openssl_pkey_get_public($pem);
                if (false === $publicKey) {
                    throw new DomainException(
                        'OpenSSL error: ' . \openssl_error_string()
                    );
                }
                return new Key($publicKey, $jwk['alg']);
            case 'EC':
                if (isset($jwk['d'])) {
                    // The key is actually a private key
                    throw new UnexpectedValueException('Key data must be for a public key');
                }
 
                if (empty($jwk['crv'])) {
                    throw new UnexpectedValueException('crv not set');
                }
 
                if (!isset(self::EC_CURVES[$jwk['crv']])) {
                    throw new DomainException('Unrecognised or unsupported EC curve');
                }
 
                if (empty($jwk['x']) || empty($jwk['y'])) {
                    throw new UnexpectedValueException('x and y not set');
                }
 
                $publicKey = self::createPemFromCrvAndXYCoordinates($jwk['crv'], $jwk['x'], $jwk['y']);
                return new Key($publicKey, $jwk['alg']);
            case 'OKP':
                if (isset($jwk['d'])) {
                    // The key is actually a private key
                    throw new UnexpectedValueException('Key data must be for a public key');
                }
 
                if (!isset($jwk['crv'])) {
                    throw new UnexpectedValueException('crv not set');
                }
 
                if (empty(self::OKP_SUBTYPES[$jwk['crv']])) {
                    throw new DomainException('Unrecognised or unsupported OKP key subtype');
                }
 
                if (empty($jwk['x'])) {
                    throw new UnexpectedValueException('x not set');
                }
 
                // This library works internally with EdDSA keys (Ed25519) encoded in standard base64.
                $publicKey = JWT::convertBase64urlToBase64($jwk['x']);
                return new Key($publicKey, $jwk['alg']);
            default:
                break;
        }
 
        return null;
    }

References Firebase\JWT\JWK\createPemFromCrvAndXYCoordinates(), and Firebase\JWT\JWK\createPemFromModulusAndExponent().

Referenced by Firebase\JWT\CachedKeySet\offsetGet(), and ILIAS\LTI\ToolProvider\Jwt\FirebaseClient\parseKeySet().

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◆ parseKeySet()

static Firebase\JWT\JWK::parseKeySet	(	array	$jwks,
		string	$defaultAlg = `null`
	)

static

Parse a set of JWK keys.

Parameters

	array<mixed>	$jwks The JSON Web Key Set as an associative array
string	$defaultAlg	The algorithm for the Key object if "alg" is not set in the JSON Web Key Set

Returns: array<string, Key> An associative array of key IDs (kid) to Key objects

Exceptions

InvalidArgumentException	Provided JWK Set is empty
UnexpectedValueException	Provided JWK Set was invalid
DomainException	OpenSSL failure

@uses parseKey

Definition at line 55 of file JWK.php.

                                                                              : array
    {
        $keys = [];
 
        if (!isset($jwks['keys'])) {
            throw new UnexpectedValueException('"keys" member must exist in the JWK Set');
        }
 
        if (empty($jwks['keys'])) {
            throw new InvalidArgumentException('JWK Set did not contain any keys');
        }
 
        foreach ($jwks['keys'] as $k => $v) {
            $kid = isset($v['kid']) ? $v['kid'] : $k;
            if ($key = self::parseKey($v, $defaultAlg)) {
                $keys[(string) $kid] = $key;
            }
        }
 
        if (0 === \count($keys)) {
            throw new UnexpectedValueException('No supported algorithms found in JWK Set');
        }
 
        return $keys;
    }

References ILIAS\LTI\ToolProvider\$key, $keys, and ILIAS\LTI\ToolProvider\$kid.

Referenced by ilObjLTIConsumerGUI\saveContentSelection().

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Field Documentation

◆ ASN1_BIT_STRING

const Firebase\JWT\JWK::ASN1_BIT_STRING = 0x03

private

Definition at line 26 of file JWK.php.

◆ ASN1_OBJECT_IDENTIFIER

const Firebase\JWT\JWK::ASN1_OBJECT_IDENTIFIER = 0x06

private

Definition at line 24 of file JWK.php.

◆ ASN1_SEQUENCE

const Firebase\JWT\JWK::ASN1_SEQUENCE = 0x10

private

Definition at line 25 of file JWK.php.

◆ EC_CURVES

const Firebase\JWT\JWK::EC_CURVES

private

Initial value:

= [
        'P-256' => '1.2.840.10045.3.1.7', 
        'secp256k1' => '1.3.132.0.10', 
        'P-384' => '1.3.132.0.34', 
        
    ]

Definition at line 27 of file JWK.php.

◆ OID

const Firebase\JWT\JWK::OID = '1.2.840.10045.2.1'

private

Definition at line 23 of file JWK.php.

◆ OKP_SUBTYPES

const Firebase\JWT\JWK::OKP_SUBTYPES

private

Initial value:

= [
        'Ed25519' => true, 
    ]

Definition at line 36 of file JWK.php.

The documentation for this class was generated from the following file:

Services/LTI/src/Firebase/JWK.php

Static Public Member Functions

Static Private Member Functions

Private Attributes

Detailed Description

Member Function Documentation

◆ createPemFromCrvAndXYCoordinates()

◆ createPemFromModulusAndExponent()

◆ encodeDER()

◆ encodeLength()

◆ encodeOID()

◆ parseKey()

◆ parseKeySet()

Field Documentation

◆ ASN1_BIT_STRING

◆ ASN1_OBJECT_IDENTIFIER

◆ ASN1_SEQUENCE

◆ EC_CURVES

◆ OID

◆ OKP_SUBTYPES