feat: Implement address parsing from plain Yggdrasil NodeID

app/src/main/java/io/github/chronosx88/yggdrasil/address/NodeID.java

@@ -0,0 +1,45 @@
+package io.github.chronosx88.yggdrasil.address;
+
+import androidx.annotation.NonNull;
+
+public class NodeID {
+    public static final short NODEID_LENGTH = 64; // SHA512 size
+    private byte[] bytes;
+
+    public NodeID(String hex) {
+        bytes = Utils.hexToBytes(hex);
+    }
+
+    public byte[] getBytes() {
+        return bytes;
+    }
+
+    @NonNull
+    @Override
+    public String toString() {
+        return Utils.bytesToHex(bytes);
+    }
+
+    private static class Utils {
+        private static final char[] HEX_ARRAY = "0123456789ABCDEF".toCharArray();
+        private static String bytesToHex(byte[] bytes) {
+            char[] hexChars = new char[bytes.length * 2];
+            for (int j = 0; j < bytes.length; j++) {
+                int v = bytes[j] & 0xFF;
+                hexChars[j * 2] = HEX_ARRAY[v >>> 4];
+                hexChars[j * 2 + 1] = HEX_ARRAY[v & 0x0F];
+            }
+            return new String(hexChars);
+        }
+
+        private static byte[] hexToBytes(String s) {
+            int len = s.length();
+            byte[] data = new byte[len / 2];
+            for (int i = 0; i < len; i += 2) {
+                data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4)
+                        + Character.digit(s.charAt(i+1), 16));
+            }
+            return data;
+        }
+    }
+}

app/src/main/java/io/github/chronosx88/yggdrasil/address/YggAddress.java

@@ -0,0 +1,54 @@
+package io.github.chronosx88.yggdrasil.address;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.util.ArrayList;
+import java.util.List;
+
+public class YggAddress {
+    private static final short IPV6_ADDRESS_LENGTH = 16; // represents an IPv6 address in the yggdrasil address range.
+    private static final short IPV6_SUBNET_LENGTH = 16; // represents an IPv6 /64 subnet in the yggdrasil subnet range.
+
+    private byte[] addressBytes;
+    private InetAddress address;
+
+    public YggAddress(NodeID nodeID) {
+        addressBytes = new byte[IPV6_ADDRESS_LENGTH];
+        List<Byte> temp = new ArrayList<>();
+        boolean done = false;
+        byte ones = 0;
+        byte bits = 0;
+        byte nBits = 0;
+        for(int idx = 0; idx < 8 * nodeID.getBytes().length; idx++) {
+            byte bit = (byte) ((nodeID.getBytes()[idx/8] & (0x80 >> (byte)(idx%8))) >> (byte)(7-(idx%8)));
+            if(!done && bit != 0) {
+                ones++;
+                continue;
+            }
+            if(!done && bit == 0) {
+                done = true;
+                continue;
+            }
+            bits = (byte) ((bits << 1) | bit);
+            nBits++;
+            if(nBits == 8) {
+                nBits = 0;
+                temp.add(bits);
+            }
+        }
+
+        byte[] prefix = getPrefix();
+        System.arraycopy(prefix, 0, addressBytes, 0, prefix.length);
+        addressBytes[prefix.length] = ones;
+        System.arraycopy(temp.toArray(new Byte[0]), 0, addressBytes, prefix.length+1, temp.size());
+        try {
+            address = InetAddress.getByAddress(addressBytes);
+        } catch (UnknownHostException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public static byte[] getPrefix() {
+        return new byte[]{0x02};
+    }
+}