private static function JWT::signatureFromDER in Auth0 Single Sign On 8.2

Encodes signature from a DER object.

Parameters

string $der binary signature in DER format:

int $keySize the number of bits in the key:

Return value

string the signature

1 call to JWT::signatureFromDER()

JWT::sign in vendor/firebase/php-jwt/src/JWT.php

Sign a string with a given key and algorithm.

File

vendor/firebase/php-jwt/src/JWT.php, line 454

Class

JWT

JSON Web Token implementation, based on this spec: https://tools.ietf.org/html/rfc7519

Namespace

Firebase\JWT

Code

private static function signatureFromDER($der, $keySize) {

  // OpenSSL returns the ECDSA signatures as a binary ASN.1 DER SEQUENCE
  list($offset, $_) = self::readDER($der);
  list($offset, $r) = self::readDER($der, $offset);
  list($offset, $s) = self::readDER($der, $offset);

  // Convert r-value and s-value from signed two's compliment to unsigned
  // big-endian integers
  $r = \ltrim($r, "\0");
  $s = \ltrim($s, "\0");

  // Pad out r and s so that they are $keySize bits long
  $r = \str_pad($r, $keySize / 8, "\0", STR_PAD_LEFT);
  $s = \str_pad($s, $keySize / 8, "\0", STR_PAD_LEFT);
  return $r . $s;
}