Bitcoin/address validation: Difference between revisions
Content deleted Content added
m Add initial dart implementation of btc address validation |
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Line 417:
"1AGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW62iz": not Bitcoin version 0.
"1AGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW62izz": too long Bitcoin address.</pre>
=={{header|Dart}}==
This requires [https://pub.dev/packages/crypto Crypto package] to compile.
<lang dart>
import 'package:crypto/crypto.dart';
class Bitcoin {
final String ALPHABET =
"123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
List<int> bigIntToByteArray(BigInt data) {
String str;
bool neg = false;
if (data < BigInt.zero) {
str = (~data).toRadixString(16);
neg = true;
} else str = data.toRadixString(16);
int p = 0;
int len = str.length;
int blen = (len + 1) ~/ 2;
int boff = 0;
List bytes;
if (neg) {
if (len & 1 == 1) {
p = -1;
}
int byte0 = ~int.parse(str.substring(0, p + 2), radix: 16);
if (byte0 < -128) byte0 += 256;
if (byte0 >= 0) {
boff = 1;
bytes = new List<int>(blen + 1);
bytes[0] = -1;
bytes[1] = byte0;
} else {
bytes = new List<int>(blen);
bytes[0] = byte0;
}
for (int i = 1; i < blen; ++i) {
int byte = ~int.parse(str.substring(p + (i << 1), p + (i << 1) + 2),
radix: 16);
if (byte < -128) byte += 256;
bytes[i + boff] = byte;
}
} else {
if (len & 1 == 1) {
p = -1;
}
int byte0 = int.parse(str.substring(0, p + 2), radix: 16);
if (byte0 > 127) byte0 -= 256;
if (byte0 < 0) {
boff = 1;
bytes = new List<int>(blen + 1);
bytes[0] = 0;
bytes[1] = byte0;
} else {
bytes = new List<int>(blen);
bytes[0] = byte0;
}
for (int i = 1; i < blen; ++i) {
int byte =
int.parse(str.substring(p + (i << 1), p + (i << 1) + 2), radix: 16);
if (byte > 127) byte -= 256;
bytes[i + boff] = byte;
}
}
return bytes;
}
List<int> arrayCopy(bytes, srcOffset, result, destOffset, bytesLength) {
for (int i = srcOffset; i < bytesLength; i++) {
result[destOffset + i] = bytes[i];
}
return result;
}
List<int> decodeBase58To25Bytes(String input) {
BigInt number = BigInt.zero;
for (String t in input.split('')) {
int p = ALPHABET.indexOf(t);
if (p == (-1))
return null;
number = number * (BigInt.from(58)) + (BigInt.from(p));
}
List<int> result = new List<int>(24);
List<int> numBytes = bigIntToByteArray(number);
return arrayCopy(
numBytes, 0, result, result.length - numBytes.length, numBytes.length);
}
validateAddress(String address) {
List<int> decoded = new List.from(decodeBase58To25Bytes(address));
List<int> temp = new List<int>.from(decoded);
temp.insert(0, 0);
List<int> hash1 = sha256.convert(temp.sublist(0, 21)).bytes;
List<int> hash2 = sha256.convert(hash1).bytes;
if (hash2[0] != decoded[20] ||
hash2[1] != decoded[21] ||
hash2[2] != decoded[22] ||
hash2[3] != decoded[23]) return false;
return true;
}
}
</lang>
{{out}}
<pre>"1BNGaR29FmfAqidXmD9HLwsGv9p5WVvvhq" true
"1BNGaR29FmfAqidXmD9HLws" false
</pre>
=={{header|Delphi}}==
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