exchange_deposit_address.dart

Lines 1–49

import 'package:crypto/crypto.dart'; const _base58 = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'; /// Normalize only addresses explicitly associated with the TRON network./// https://developers.tron.network/docs/encodingString? exchangeDepositAddress(int? chain, String value) {  final address = value.trim();  if (address.isEmpty) return null;  if (chain != -200) return address;  var hex = address.startsWith('0x') ? address.substring(2) : address;  if (RegExp(r'^[0-9a-fA-F]{40}$').hasMatch(hex)) hex = '41$hex';  if (RegExp(r'^41[0-9a-fA-F]{40}$').hasMatch(hex)) {    final bytes = [      for (var i = 0; i < hex.length; i += 2)        int.parse(hex.substring(i, i + 2), radix: 16),    ];    final checksum = sha256.convert(sha256.convert(bytes).bytes).bytes.take(4);    var number = BigInt.zero;    for (final byte in [...bytes, ...checksum]) {      number = (number << 8) | BigInt.from(byte);    }    var encoded = '';    while (number > BigInt.zero) {      encoded = _base58[(number % BigInt.from(58)).toInt()] + encoded;      number ~/= BigInt.from(58);    }    return encoded;  }  if (address.length != 34 || !address.startsWith('T')) return null;  var number = BigInt.zero;  for (final char in address.split('')) {    final digit = _base58.indexOf(char);    if (digit < 0) return null;    number = number * BigInt.from(58) + BigInt.from(digit);  }  final bytes = <int>[];  while (number > BigInt.zero) {    bytes.insert(0, (number & BigInt.from(255)).toInt());    number >>= 8;  }  if (bytes.length != 25 || bytes.first != 0x41) return null;  final checksum =      sha256.convert(sha256.convert(bytes.sublist(0, 21)).bytes).bytes;  for (var i = 0; i < 4; i++) {    if (bytes[21 + i] != checksum[i]) return null;  }  return address;}