self::ASN1_MAX_SINGLE_BYTE ? self::ASN1_LENGTH_2BYTES : ''; $bin = hex2bin( self::ASN1_SEQUENCE .$lengthPrefix.dechex($totalLength) .self::ASN1_INTEGER.dechex($lengthR).$pointR .self::ASN1_INTEGER.dechex($lengthS).$pointS ); if (false === $bin) { throw new InvalidArgumentException('Unable to convert into ASN.1'); } return $bin; } public static function fromAsn1(string $signature, int $length): string { $message = bin2hex($signature); $position = 0; if (self::ASN1_SEQUENCE !== self::readAsn1Content($message, $position, self::BYTE_SIZE)) { throw new InvalidArgumentException('Invalid data. Should start with a sequence.'); } // @phpstan-ignore-next-line if (self::ASN1_LENGTH_2BYTES === self::readAsn1Content($message, $position, self::BYTE_SIZE)) { $position += self::BYTE_SIZE; } $pointR = self::retrievePositiveInteger(self::readAsn1Integer($message, $position)); $pointS = self::retrievePositiveInteger(self::readAsn1Integer($message, $position)); $bin = hex2bin(str_pad($pointR, $length, '0', STR_PAD_LEFT).str_pad($pointS, $length, '0', STR_PAD_LEFT)); if (false === $bin) { throw new InvalidArgumentException('Unable to convert from ASN.1'); } return $bin; } private static function octetLength(string $data): int { return intdiv(mb_strlen($data, '8bit'), self::BYTE_SIZE); } private static function preparePositiveInteger(string $data): string { if (mb_substr($data, 0, self::BYTE_SIZE, '8bit') > self::ASN1_BIG_INTEGER_LIMIT) { return self::ASN1_NEGATIVE_INTEGER.$data; } while ( self::ASN1_NEGATIVE_INTEGER === mb_substr($data, 0, self::BYTE_SIZE, '8bit') && mb_substr($data, 2, self::BYTE_SIZE, '8bit') <= self::ASN1_BIG_INTEGER_LIMIT ) { $data = mb_substr($data, 2, null, '8bit'); } return $data; } private static function readAsn1Content(string $message, int &$position, int $length): string { $content = mb_substr($message, $position, $length, '8bit'); $position += $length; return $content; } private static function readAsn1Integer(string $message, int &$position): string { if (self::ASN1_INTEGER !== self::readAsn1Content($message, $position, self::BYTE_SIZE)) { throw new InvalidArgumentException('Invalid data. Should contain an integer.'); } $length = (int) hexdec(self::readAsn1Content($message, $position, self::BYTE_SIZE)); return self::readAsn1Content($message, $position, $length * self::BYTE_SIZE); } private static function retrievePositiveInteger(string $data): string { while ( self::ASN1_NEGATIVE_INTEGER === mb_substr($data, 0, self::BYTE_SIZE, '8bit') && mb_substr($data, 2, self::BYTE_SIZE, '8bit') > self::ASN1_BIG_INTEGER_LIMIT ) { $data = mb_substr($data, 2, null, '8bit'); } return $data; } }