/**
* Determines if the address is valid.
*
* @return true if the address is valid.
*/
public static boolean isValid(@Nullable final String value) {
if (value == null) {
return false;
}
// this check should prevent leading and trailing whitespace
if (NUM_DECODED_BYTES_LENGTH != value.length()) {
return false;
}
final byte[] encodedBytes;
try {
encodedBytes = Base32Encoder.getBytes(value);
} catch (final IllegalArgumentException e) {
return false;
}
if (NUM_ENCODED_BYTES_LENGTH != encodedBytes.length) {
return false;
}
if (AppConstants.NETWORK_VERSION.get() != encodedBytes[0]) {
return false;
}
final int checksumStartIndex = NUM_ENCODED_BYTES_LENGTH - NUM_CHECKSUM_BYTES;
final byte[] versionPrefixedHash = Arrays.copyOfRange(encodedBytes, 0, checksumStartIndex);
final byte[] addressChecksum =
Arrays.copyOfRange(
encodedBytes, checksumStartIndex, checksumStartIndex + NUM_CHECKSUM_BYTES);
final byte[] calculatedChecksum = generateChecksum(versionPrefixedHash);
return Arrays.equals(addressChecksum, calculatedChecksum);
}
private static String generateEncoded(final byte version, final byte[] publicKey) {
// step 1: sha3 hash of the public key
final byte[] sha3PublicKeyHash = Hashes.sha3_256(publicKey);
// step 2: ripemd160 hash of (1)
final byte[] ripemd160StepOneHash = Hashes.ripemd160(sha3PublicKeyHash);
// step 3: store version byte in front of (2)
final byte[] versionPrefixedRipemd160Hash =
ArrayUtils.concat(new byte[] {version}, ripemd160StepOneHash);
// step 4: get the checksum of (3)
final byte[] stepThreeChecksum = generateChecksum(versionPrefixedRipemd160Hash);
// step 5: concatenate (3) and (4)
final byte[] concatStepThreeAndStepSix =
ArrayUtils.concat(versionPrefixedRipemd160Hash, stepThreeChecksum);
// step 6: base32 encode (5)
return Base32Encoder.getString(concatStepThreeAndStepSix);
}