public static function decodeHex($hex)
{
if (!is_string($hex) || !ctype_xdigit($hex) && '0x' != substr($hex, 0, 2)) {
throw new \Exception('Argument must be a string of hex digits.');
}
$hex = strtolower($hex);
// if it has a prefix of 0x this needs to be trimed
if (substr($hex, 0, 2) == '0x') {
$hex = substr($hex, 2);
}
$hexLen = strlen($hex);
for ($dec = '0', $i = 0; $i < $hexLen; $i++) {
$current = strpos(self::HEX_CHARS, $hex[$i]);
$dec = Math::add(Math::mul($dec, 16), $current);
}
return $dec;
} /**
* Encodes $data into BASE-58 format
*
* @param string $data
*
* @return string
*/
public static function encode($data)
{
if (strlen($data) % 2 != 0 || strlen($data) == 0) {
throw new \Exception('Invalid Length');
}
$code_string = self::BASE58_CHARS;
$x = Util::decodeHex($data);
$output_string = '';
while (Math::cmp($x, '0') > 0) {
$q = Math::div($x, 58);
$r = Math::mod($x, 58);
$output_string .= substr($code_string, intval($r), 1);
$x = $q;
}
for ($i = 0; $i < strlen($data) && substr($data, $i, 2) == '00'; $i += 2) {
$output_string .= substr($code_string, 0, 1);
}
$output_string = strrev($output_string);
return $output_string;
}