Files
status-keycard-java/lib/src/main/java/im/status/keycard/applet/Metadata.java
T

107 lines
2.4 KiB
Java

package im.status.keycard.applet;
import java.io.ByteArrayOutputStream;
import java.nio.charset.Charset;
import java.util.SortedSet;
import java.util.TreeSet;
public class Metadata {
private String cardName;
private SortedSet<Long> wallets;
public static Metadata fromData(byte[] data) {
int version = (data[0] & 0xe0) >> 5;
if (version != 1) {
throw new RuntimeException("Invalid version");
}
int namelen = (data[0] & 0x1f);
int off = 1;
String cardName = new String(data, off, namelen, Charset.forName("US-ASCII"));
off += namelen;
SortedSet<Long> set = new TreeSet<>();
while(off < data.length) {
int[] start = TinyBERTLV.readNum(data, off);
int[] count = TinyBERTLV.readNum(data, start[1]);
off = count[1];
long s = start[0] & 0xffffffffl;
buildRange(set, s, (s + count[0]));
}
return new Metadata(cardName, set);
}
private static void buildRange(SortedSet<Long> set, long start, long end) {
for (long i = start; i <= end; i++) {
set.add(i);
}
}
Metadata(String cardName, SortedSet<Long> wallets) {
this.cardName = cardName;
this.wallets = wallets;
}
public Metadata(String cardName) {
this(cardName, new TreeSet<>());
}
public String getCardName() {
return cardName;
}
public void setCardName(String cardName) {
if (cardName.length() > 20) {
throw new IllegalArgumentException("card name too long");
}
this.cardName = cardName;
}
public SortedSet<Long> getWallets() {
return wallets;
}
public void addWallet(long w) {
this.wallets.add(w);
}
public void removeWallet(long w) {
this.wallets.remove(w);
}
public byte[] toByteArray() {
ByteArrayOutputStream os = new ByteArrayOutputStream();
byte[] name = this.cardName.getBytes(Charset.forName("US-ASCII"));
os.write(0x20 | name.length);
os.write(name, 0, name.length);
if (wallets.isEmpty()) {
return os.toByteArray();
}
long start = wallets.first();
int len = 0;
for (Long w : wallets.tailSet(start + 1)) {
if (w == (start + len + 1)) {
len++;
} else {
TinyBERTLV.writeNum(os, (int) start);
TinyBERTLV.writeNum(os, len);
len = 0;
start = w;
}
}
TinyBERTLV.writeNum(os, (int) start);
TinyBERTLV.writeNum(os, len);
return os.toByteArray();
}
}