(https://github.com/monero-integrations) * @copyright 2018 * @license MIT * * ============================================================================ * * // Initialize class * $base58 = new base58(); * * // Encode a hexadecimal (base16) string as base58 * $encoded = $base58->encode('0137F8F06C971B168745F562AA107B4D172F336271BC0F9D3B510C14D3460DFB27D8CEBE561E73AC1E11833D5EA40200EB3C82E9C66ACAF1AB1A6BB53C40537C0B7A22160B0E'); * * // Decode * $decoded = $base58->decode('479cG5opa54beQWSyqNoWw5tna9sHUNmMTtiFqLPaUhDevpJ2YLwXAggSx5ePdeFrYF8cdbmVRSmp1Kn3t4Y9kFu7rZ7pFw'); * */ use Exception; class Monero_base58 { static $alphabet = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'; static $encoded_block_sizes = [0, 2, 3, 5, 6, 7, 9, 10, 11]; static $full_block_size = 8; static $full_encoded_block_size = 11; /** * * Convert a hexadecimal string to a binary array * * @param string $hex A hexadecimal string to convert to a binary array * * @return array * */ private function hex_to_bin($hex) { if (gettype($hex) != 'string') { throw new Exception('base58->hex_to_bin(): Invalid input type (must be a string)'); } if (strlen($hex) % 2 != 0) { throw new Exception('base58->hex_to_bin(): Invalid input length (must be even)'); } $res = array_fill(0, strlen($hex) / 2, 0); for ($i = 0; $i < strlen($hex) / 2; $i++) { $res[$i] = intval(substr($hex, $i * 2, $i * 2 + 2 - $i * 2), 16); } return $res; } /** * * Convert a binary array to a hexadecimal string * * @param array $bin A binary array to convert to a hexadecimal string * * @return string * */ private function bin_to_hex($bin) { if (gettype($bin) != 'array') { throw new Exception('base58->bin_to_hex(): Invalid input type (must be an array)'); } $res = []; for ($i = 0; $i < count($bin); $i++) { $res[] = substr('0'.dechex($bin[$i]), -2); } return join($res); } /** * * Convert a string to a binary array * * @param string $str A string to convert to a binary array * * @return array * */ private function str_to_bin($str) { if (gettype($str) != 'string') { throw new Exception('base58->str_to_bin(): Invalid input type (must be a string)'); } $res = array_fill(0, strlen($str), 0); for ($i = 0; $i < strlen($str); $i++) { $res[$i] = ord($str[$i]); } return $res; } /** * * Convert a binary array to a string * * @param array $bin A binary array to convert to a string * * @return string * */ private function bin_to_str($bin) { if (gettype($bin) != 'array') { throw new Exception('base58->bin_to_str(): Invalid input type (must be an array)'); } $res = array_fill(0, count($bin), 0); for ($i = 0; $i < count($bin); $i++) { $res[$i] = chr($bin[$i]); } return preg_replace('/[[:^print:]]/', '', join($res)); // preg_replace necessary to strip errant non-ASCII characters eg. '' } /** * * Convert a UInt8BE (one unsigned big endian byte) array to UInt64 * * @param array $data A UInt8BE array to convert to UInt64 * * @return number * */ private function uint8_be_to_64($data) { if (gettype($data) != 'array') { throw new Exception ('base58->uint8_be_to_64(): Invalid input type (must be an array)'); } $res = 0; $i = 0; switch (9 - count($data)) { case 1: $res = bcadd(bcmul($res, bcpow(2, 8)), $data[$i++]); case 2: $res = bcadd(bcmul($res, bcpow(2, 8)), $data[$i++]); case 3: $res = bcadd(bcmul($res, bcpow(2, 8)), $data[$i++]); case 4: $res = bcadd(bcmul($res, bcpow(2, 8)), $data[$i++]); case 5: $res = bcadd(bcmul($res, bcpow(2, 8)), $data[$i++]); case 6: $res = bcadd(bcmul($res, bcpow(2, 8)), $data[$i++]); case 7: $res = bcadd(bcmul($res, bcpow(2, 8)), $data[$i++]); case 8: $res = bcadd(bcmul($res, bcpow(2, 8)), $data[$i++]); break; default: throw new Exception('base58->uint8_be_to_64: Invalid input length (1 <= count($data) <= 8)'); } return $res; } /** * * Convert a UInt64 (unsigned 64 bit integer) to a UInt8BE array * * @param number $num A UInt64 number to convert to a UInt8BE array * @param integer $size Size of array to return * * @return array * */ private function uint64_to_8_be($num, $size) { if (gettype($num) != ('integer' || 'double')) { throw new Exception ('base58->uint64_to_8_be(): Invalid input type ($num must be a number)'); } if (gettype($size) != 'integer') { throw new Exception ('base58->uint64_to_8_be(): Invalid input type ($size must be an integer)'); } if ($size < 1 || $size > 8) { throw new Exception ('base58->uint64_to_8_be(): Invalid size (1 <= $size <= 8)'); } $res = array_fill(0, $size, 0); for ($i = $size - 1; $i >= 0; $i--) { $res[$i] = bcmod($num, bcpow(2, 8)); $num = bcdiv($num, bcpow(2, 8)); } return $res; } /** * * Convert a hexadecimal (Base16) array to a Base58 string * * @param array $data * @param array $buf * @param number $index * * @return array * */ private function encode_block($data, $buf, $index) { if (gettype($data) != 'array') { throw new Exception('base58->encode_block(): Invalid input type ($data must be an array)'); } if (gettype($buf) != 'array') { throw new Exception('base58->encode_block(): Invalid input type ($buf must be an array)'); } if (gettype($index) != ('integer' || 'double')) { throw new Exception('base58->encode_block(): Invalid input type ($index must be a number)'); } if (count($data) < 1 or count($data) > self::$full_encoded_block_size) { throw new Exception('base58->encode_block(): Invalid input length (1 <= count($data) <= 8)'); } $num = self::uint8_be_to_64($data); $i = self::$encoded_block_sizes[count($data)] - 1; while ($num > 0) { $remainder = bcmod($num, 58); $num = bcdiv($num, 58); $buf[$index + $i] = ord(self::$alphabet[$remainder]); $i--; } return $buf; } /** * * Encode a hexadecimal (Base16) string to Base58 * * @param string $hex A hexadecimal (Base16) string to convert to Base58 * * @return string * */ public function encode($hex) { if (gettype($hex) != 'string') { throw new Exception ('base58->encode(): Invalid input type (must be a string)'); } $data = self::hex_to_bin($hex); if (count($data) == 0) { return ''; } $full_block_count = floor(count($data) / self::$full_block_size); $last_block_size = count($data) % self::$full_block_size; $res_size = $full_block_count * self::$full_encoded_block_size + self::$encoded_block_sizes[$last_block_size]; $res = array_fill(0, $res_size, ord(self::$alphabet[0])); for ($i = 0; $i < $full_block_count; $i++) { $res = self::encode_block(array_slice($data, $i * self::$full_block_size, ($i * self::$full_block_size + self::$full_block_size) - ($i * self::$full_block_size)), $res, $i * self::$full_encoded_block_size); } if ($last_block_size > 0) { $res = self::encode_block(array_slice($data, $full_block_count * self::$full_block_size, $full_block_count * self::$full_block_size + $last_block_size), $res, $full_block_count * self::$full_encoded_block_size); } return self::bin_to_str($res); } /** * * Convert a Base58 input to hexadecimal (Base16) * * @param array $data * @param array $buf * @param integer $index * * @return array * */ private function decode_block($data, $buf, $index) { if (gettype($data) != 'array') { throw new Exception('base58->decode_block(): Invalid input type ($data must be an array)'); } if (gettype($buf) != 'array') { throw new Exception('base58->decode_block(): Invalid input type ($buf must be an array)'); } if (gettype($index) != ('integer' || 'double')) { throw new Exception('base58->decode_block(): Invalid input type ($index must be a number)'); } $res_size = self::index_of(self::$encoded_block_sizes, count($data)); if ($res_size <= 0) { throw new Exception('base58->decode_block(): Invalid input length ($data must be a value from base58::$encoded_block_sizes)'); } $res_num = 0; $order = 1; for ($i = count($data) - 1; $i >= 0; $i--) { $digit = strpos(self::$alphabet, chr($data[$i])); if ($digit < 0) { throw new Exception("base58->decode_block(): Invalid character ($digit \"{$digit}\" not found in base58::$alphabet)"); } $product = bcadd(bcmul($order, $digit), $res_num); if ($product > bcpow(2, 64)) { throw new Exception('base58->decode_block(): Integer overflow ($product exceeds the maximum 64bit integer)'); } $res_num = $product; $order = bcmul($order, 58); } if ($res_size < self::$full_block_size && bcpow(2, 8 * $res_size) <= 0) { throw new Exception('base58->decode_block(): Integer overflow (bcpow(2, 8 * $res_size) exceeds the maximum 64bit integer)'); } $tmp_buf = self::uint64_to_8_be($res_num, $res_size); for ($i = 0; $i < count($tmp_buf); $i++) { $buf[$i + $index] = $tmp_buf[$i]; } return $buf; } /** * * Decode a Base58 string to hexadecimal (Base16) * * @param string $hex A Base58 string to convert to hexadecimal (Base16) * * @return string * */ public function decode($enc) { if (gettype($enc) != 'string') { throw new Exception ('base58->decode(): Invalid input type (must be a string)'); } $enc = self::str_to_bin($enc); if (count($enc) == 0) { return ''; } $full_block_count = floor(bcdiv(count($enc), self::$full_encoded_block_size)); $last_block_size = bcmod(count($enc), self::$full_encoded_block_size); $last_block_decoded_size = self::index_of(self::$encoded_block_sizes, $last_block_size); $data_size = $full_block_count * self::$full_block_size + $last_block_decoded_size; if ($data_size == -1) { return ''; } $data = array_fill(0, $data_size, 0); for ($i = 0; $i <= $full_block_count; $i++) { $data = self::decode_block(array_slice($enc, $i * self::$full_encoded_block_size, ($i * self::$full_encoded_block_size + self::$full_encoded_block_size) - ($i * self::$full_encoded_block_size)), $data, $i * self::$full_block_size); } if ($last_block_size > 0) { $data = self::decode_block(array_slice($enc, $full_block_count * self::$full_encoded_block_size, $full_block_count * self::$full_encoded_block_size + $last_block_size), $data, $full_block_count * self::$full_block_size); } return self::bin_to_hex($data); } /** * * Search an array for a value * Source: https://stackoverflow.com/a/30994678 * * @param array $haystack An array to search * @param string $needle A string to search for *) * @return number The index of the element found (or -1 for no match) * */ private function index_of($haystack, $needle) { if (gettype($haystack) != 'array') { throw new Exception ('base58->decode(): Invalid input type ($haystack must be an array)'); } // if (gettype($needle) != 'string') { // throw new Exception ('base58->decode(): Invalid input type ($needle must be a string)'); // } foreach ($haystack as $key => $value) if ($value === $needle) return $key; return -1; } }