class="kw">package com.hypixel.hytale.server.core.io.ice;

class="kw">import java.net.InetAddress;
class="kw">import java.net.InetSocketAddress;
class="kw">import java.net.UnknownHostException;
class="kw">import java.nio.ByteBuffer;
class="kw">import java.nio.charset.StandardCharsets;
class="kw">import java.security.GeneralSecurityException;
class="kw">import java.security.MessageDigest;
class="kw">import java.security.SecureRandom;
class="kw">import java.util.ArrayList;
class="kw">import java.util.List;
class="kw">import java.util.zip.CRC32;
class="kw">import javax.annotation.Nonnull;
class="kw">import javax.annotation.Nullable;
class="kw">import javax.crypto.Mac;
class="kw">import javax.crypto.spec.SecretKeySpec;

class="kw">public class="kw">final class StunMessage {
   class="kw">public class="kw">static class="kw">final int MAGIC_COOKIE = 554869826;
   class="kw">public class="kw">static class="kw">final int HEADER_LENGTH = 20;
   class="kw">public class="kw">static class="kw">final int TRANSACTION_ID_LENGTH = 12;
   class="kw">public class="kw">static class="kw">final int BINDING_REQUEST = 1;
   class="kw">public class="kw">static class="kw">final int BINDING_INDICATION = 17;
   class="kw">public class="kw">static class="kw">final int BINDING_RESPONSE = 257;
   class="kw">public class="kw">static class="kw">final int BINDING_ERROR_RESPONSE = 273;
   class="kw">public class="kw">static class="kw">final int ATTR_MAPPED_ADDRESS = 1;
   class="kw">public class="kw">static class="kw">final int ATTR_USERNAME = 6;
   class="kw">public class="kw">static class="kw">final int ATTR_MESSAGE_INTEGRITY = 8;
   class="kw">public class="kw">static class="kw">final int ATTR_ERROR_CODE = 9;
   class="kw">public class="kw">static class="kw">final int ATTR_XOR_MAPPED_ADDRESS = 32;
   class="kw">public class="kw">static class="kw">final int ATTR_PRIORITY = 36;
   class="kw">public class="kw">static class="kw">final int ATTR_USE_CANDIDATE = 37;
   class="kw">public class="kw">static class="kw">final int ATTR_FINGERPRINT = 32808;
   class="kw">public class="kw">static class="kw">final int ATTR_ICE_CONTROLLED = 32809;
   class="kw">public class="kw">static class="kw">final int ATTR_ICE_CONTROLLING = 32810;
   class="kw">public class="kw">static class="kw">final int MESSAGE_INTEGRITY_LENGTH = 24;
   class="kw">public class="kw">static class="kw">final int FINGERPRINT_LENGTH = 8;
   class="kw">public class="kw">static class="kw">final int FINGERPRINT_XOR = 1398035790;
   class="kw">private class="kw">static class="kw">final int MAX_ATTRIBUTES = 64;
   class="kw">private class="kw">static class="kw">final SecureRandom RANDOM = new SecureRandom();
   class="kw">private class="kw">static class="kw">final ThreadLocal<Mac> HMAC_SHA1 = ThreadLocal.withInitial(StunMessage::createHmacSha1);
   class="kw">private class="kw">final int messageType;
   class="kw">private class="kw">final byte[] transactionId;
   class="kw">private class="kw">final List<StunMessage.Attribute> attributes = new ArrayList<>();

   class="kw">public StunMessage(int var1, @Nonnull byte[] var2) {
      if (var2.length != 12) {
         throw new IllegalArgumentException("Transaction ID must be 12 bytes");
      }

      this.messageType = var1;
      this.transactionId = var2;
   }

   class="kw">public class="kw">static StunMessage request() {
      byte[] var0 = new byte[12];
      RANDOM.nextBytes(var0);
      class="kw">return new StunMessage(1, var0);
   }

   class="kw">public class="kw">static StunMessage response(@Nonnull byte[] var0) {
      class="kw">return new StunMessage(257, var0);
   }

   class="kw">public class="kw">static StunMessage errorResponse(@Nonnull byte[] var0, int var1, @Nonnull String var2) {
      byte[] var3 = var2.getBytes(StandardCharsets.UTF_8);
      byte[] var4 = new byte[4 + var3.length];
      var4[2] = (byte)(var1 / 100);
      var4[3] = (byte)(var1 % 100);
      System.arraycopy(var3, 0, var4, 4, var3.length);
      StunMessage var5 = new StunMessage(273, var0);
      var5.attributes.add(new StunMessage.Attribute(9, var4));
      class="kw">return var5;
   }

   class="kw">public int getMessageType() {
      class="kw">return this.messageType;
   }

   class="kw">public byte[] getTransactionId() {
      class="kw">return this.transactionId;
   }

   class="kw">public boolean isRequest() {
      class="kw">return this.messageType == 1;
   }

   class="kw">public boolean isResponse() {
      class="kw">return this.messageType == 257;
   }

   @Nullable
   class="kw">public byte[] getAttribute(int var1) {
      for (StunMessage.Attribute var3 : this.attributes) {
         if (var3.type() == var1) {
            class="kw">return var3.value();
         }
      }

      class="kw">return null;
   }

   class="kw">public boolean hasAttribute(int var1) {
      class="kw">return this.getAttribute(var1) != null;
   }

   @Nullable
   class="kw">public String getUsername() {
      byte[] var1 = this.getAttribute(6);
      class="kw">return var1 == null ? null : new String(var1, StandardCharsets.UTF_8);
   }

   class="kw">public long getPriority() {
      byte[] var1 = this.getAttribute(36);
      class="kw">return var1 != null && var1.length >= 4 ? Integer.toUnsignedLong(ByteBuffer.wrap(var1).getInt()) : 0L;
   }

   @Nullable
   class="kw">public InetSocketAddress getMappedAddress() {
      byte[] var1 = this.getAttribute(32);
      if (var1 != null) {
         class="kw">return decodeMappedAddress(var1, true, this.transactionId);
      }

      var1 = this.getAttribute(1);
      class="kw">return var1 == null ? null : decodeMappedAddress(var1, false, this.transactionId);
   }

   class="kw">public void addAttribute(int var1, @Nonnull byte[] var2) {
      this.attributes.add(new StunMessage.Attribute(var1, var2));
   }

   class="kw">public void addUsername(@Nonnull String var1) {
      this.addAttribute(6, var1.getBytes(StandardCharsets.UTF_8));
   }

   class="kw">public void addPriority(long var1) {
      byte[] var3 = new byte[4];
      ByteBuffer.wrap(var3).putInt((int)var1);
      this.addAttribute(36, var3);
   }

   class="kw">public void addUseCandidate() {
      this.addAttribute(37, new byte[0]);
   }

   class="kw">public void addIceRole(boolean var1, long var2) {
      byte[] var4 = new byte[8];
      ByteBuffer.wrap(var4).putLong(var2);
      this.addAttribute(var1 ? 32810 : 32809, var4);
   }

   class="kw">public void addXorMappedAddress(@Nonnull InetSocketAddress var1) {
      byte[] var2 = var1.getAddress().getAddress();
      byte[] var3 = new byte[4 + var2.length];
      var3[0] = 0;
      var3[1] = (byte)(var2.length == 4 ? 1 : 2);
      int var4 = var1.getPort() ^ 8466;
      var3[2] = (byte)(var4 >>> 8);
      var3[3] = (byte)var4;
      byte[] var5 = createXorMask(var2.length, this.transactionId);

      for (int var6 = 0; var6 < var2.length; var6++) {
         var3[4 + var6] = (byte)(var2[var6] ^ var5[var6]);
      }

      this.addAttribute(32, var3);
   }

   class="kw">public void appendMessageIntegrity(@Nonnull byte[] var1) {
      byte[] var2 = hmacSha1(var1, this.serializeWithReserved(24));
      this.attributes.add(new StunMessage.Attribute(8, var2));
   }

   class="kw">public void appendFingerprint() {
      CRC32 var1 = new CRC32();
      var1.update(this.serializeWithReserved(8));
      byte[] var2 = new byte[4];
      ByteBuffer.wrap(var2).putInt((int)(var1.getValue() ^ Integer.toUnsignedLong(1398035790)));
      this.attributes.add(new StunMessage.Attribute(32808, var2));
   }

   class="kw">public class="kw">static boolean verifyMessageIntegrity(@Nonnull byte[] var0, int var1, @Nonnull byte[] var2) {
      class="kw">return var1 >= 0 && var1 <= var0.length ? verifyMessageIntegrity(ByteBuffer.wrap(var0, 0, var1), var2) : false;
   }

   class="kw">public class="kw">static boolean verifyMessageIntegrity(@Nonnull ByteBuffer var0, @Nonnull byte[] var1) {
      ByteBuffer var2 = var0.slice();
      int var3 = findAttribute(var2, 8);
      if (var3 < 0) {
         class="kw">return false;
      }

      int var4 = readUnsignedShort(var2, var3 + 2);
      if (var4 != 20) {
         class="kw">return false;
      }

      int var5 = var3 - 20 + 24;
      Mac var6 = initializeHmacSha1(var1);
      var6.update(var2.get(0));
      var6.update(var2.get(1));
      var6.update((byte)(var5 >>> 8));
      var6.update((byte)var5);
      ByteBuffer var7 = var2.duplicate();
      var7.position(4);
      var7.limit(var3);
      var6.update(var7);
      byte[] var8 = var6.doFinal();
      byte[] var9 = new byte[20];
      ByteBuffer var10 = var2.duplicate();
      var10.position(var3 + 4);
      var10.get(var9);
      class="kw">return MessageDigest.isEqual(var8, var9);
   }

   class="kw">public byte[] toBytes() {
      int var1 = 0;

      for (StunMessage.Attribute var3 : this.attributes) {
         var1 += serializedLength(var3.value().length);
      }

      ByteBuffer var7 = ByteBuffer.allocate(20 + var1);
      var7.putShort((short)this.messageType);
      var7.putShort((short)var1);
      var7.putInt(554869826);
      var7.put(this.transactionId);

      for (StunMessage.Attribute var4 : this.attributes) {
         var7.putShort((short)var4.type());
         var7.putShort((short)var4.value().length);
         var7.put(var4.value());
         int var5 = (4 - var4.value().length % 4) % 4;

         for (int var6 = 0; var6 < var5; var6++) {
            var7.put((byte)0);
         }
      }

      class="kw">return var7.array();
   }

   @Nullable
   class="kw">public class="kw">static StunMessage parse(@Nonnull byte[] var0, int var1) {
      class="kw">return var1 >= 0 && var1 <= var0.length ? parse(ByteBuffer.wrap(var0, 0, var1)) : null;
   }

   @Nullable
   class="kw">public class="kw">static StunMessage parse(@Nonnull ByteBuffer var0) {
      ByteBuffer var1 = var0.slice();
      int var2 = var1.remaining();
      if (var2 < 20) {
         class="kw">return null;
      }

      int var3 = readUnsignedShort(var1, 0);
      if ((var3 & 49152) != 0) {
         class="kw">return null;
      }

      int var4 = readUnsignedShort(var1, 2);
      if (var4 % 4 != 0) {
         class="kw">return null;
      }

      if (20 + var4 != var2) {
         class="kw">return null;
      }

      if (var1.getInt(4) != 554869826) {
         class="kw">return null;
      }

      byte[] var5 = new byte[12];
      ByteBuffer var6 = var1.duplicate();
      var6.position(8);
      var6.get(var5);
      StunMessage var7 = new StunMessage(var3, var5);
      int var8 = 20;
      int var9 = 20 + var4;

      while (var8 + 4 <= var9) {
         if (var7.attributes.size() >= 64) {
            class="kw">return null;
         }

         int var10 = readUnsignedShort(var1, var8);
         int var11 = readUnsignedShort(var1, var8 + 2);
         if (var8 + 4 + var11 > var9) {
            class="kw">return null;
         }

         byte[] var12 = new byte[var11];
         ByteBuffer var13 = var1.duplicate();
         var13.position(var8 + 4);
         var13.get(var12);
         var7.attributes.add(new StunMessage.Attribute(var10, var12));
         var8 += serializedLength(var11);
         if (var10 == 8) {
            break;
         }
      }

      class="kw">return var7;
   }

   class="kw">public class="kw">static boolean looksLikeStun(@Nonnull byte[] var0, int var1) {
      class="kw">return var1 >= 0 && var1 <= var0.length ? looksLikeStun(ByteBuffer.wrap(var0, 0, var1)) : false;
   }

   class="kw">public class="kw">static boolean looksLikeStun(@Nonnull ByteBuffer var0) {
      ByteBuffer var1 = var0.slice();
      int var2 = var1.remaining();
      if (var2 < 20) {
         class="kw">return false;
      }

      if ((var1.get(0) & 192) != 0) {
         class="kw">return false;
      }

      if (var1.getInt(4) != 554869826) {
         class="kw">return false;
      }

      int var3 = readUnsignedShort(var1, 2);
      class="kw">return var3 % 4 == 0 && 20 + var3 == var2;
   }

   class="kw">private byte[] serializeWithReserved(int var1) {
      byte[] var2 = this.toBytes();
      writeUnsignedShort(var2, 2, var2.length - 20 + var1);
      class="kw">return var2;
   }

   class="kw">private class="kw">static int serializedLength(int var0) {
      class="kw">return 4 + var0 + (4 - var0 % 4) % 4;
   }

   class="kw">private class="kw">static int findAttribute(ByteBuffer var0, int var1) {
      int var2 = var0.remaining();
      if (var2 < 20) {
         class="kw">return -1;
      }

      int var3 = 20 + readUnsignedShort(var0, 2);
      if (var3 > var2) {
         class="kw">return -1;
      }

      int var4 = 20;

      while (var4 + 4 <= var3) {
         int var5 = readUnsignedShort(var0, var4);
         int var6 = readUnsignedShort(var0, var4 + 2);
         if (var4 + 4 + var6 > var3) {
            class="kw">return -1;
         }

         if (var5 == var1) {
            class="kw">return var4;
         }

         var4 += serializedLength(var6);
      }

      class="kw">return -1;
   }

   class="kw">private class="kw">static byte[] hmacSha1(byte[] var0, byte[] var1) {
      class="kw">return initializeHmacSha1(var0).doFinal(var1);
   }

   class="kw">private class="kw">static Mac initializeHmacSha1(byte[] var0) {
      try {
         Mac var1 = HMAC_SHA1.get();
         var1.init(new SecretKeySpec(var0, "HmacSHA1"));
         class="kw">return var1;
      } catch (GeneralSecurityException var2) {
         throw new IllegalStateException("HmacSHA1 is required for STUN message integrity", var2);
      }
   }

   class="kw">private class="kw">static Mac createHmacSha1() {
      try {
         class="kw">return Mac.getInstance("HmacSHA1");
      } catch (GeneralSecurityException var1) {
         throw new IllegalStateException("HmacSHA1 is required for STUN message integrity", var1);
      }
   }

   @Nullable
   class="kw">private class="kw">static InetSocketAddress decodeMappedAddress(byte[] var0, boolean var1, byte[] var2) {
      if (var0.length < 4) {
         class="kw">return null;
      }

      int var3 = class="kw">switch (var0[1] & 0xFF) {
         case 1 -> 4;
         case 2 -> 16;
         class="kw">default -> -1;
      };
      if (var0.length != 4 + var3) {
         class="kw">return null;
      }

      int var4 = readUnsignedShort(var0, 2);
      byte[] var5 = new byte[var3];
      System.arraycopy(var0, 4, var5, 0, var3);
      if (var1) {
         var4 ^= 8466;
         byte[] var6 = createXorMask(var3, var2);

         for (int var7 = 0; var7 < var3; var7++) {
            var5[var7] ^= var6[var7];
         }
      }

      try {
         class="kw">return new InetSocketAddress(InetAddress.getByAddress(var5), var4);
      } catch (UnknownHostException var8) {
         class="kw">return null;
      }
   }

   class="kw">private class="kw">static byte[] createXorMask(int var0, byte[] var1) {
      byte[] var2 = new byte[var0];
      ByteBuffer.wrap(var2).putInt(554869826);
      if (var0 > 4) {
         System.arraycopy(var1, 0, var2, 4, 12);
      }

      class="kw">return var2;
   }

   class="kw">private class="kw">static int readUnsignedShort(byte[] var0, int var1) {
      class="kw">return (var0[var1] & 0xFF) << 8 | var0[var1 + 1] & 0xFF;
   }

   class="kw">private class="kw">static int readUnsignedShort(ByteBuffer var0, int var1) {
      class="kw">return (var0.get(var1) & 0xFF) << 8 | var0.get(var1 + 1) & 0xFF;
   }

   class="kw">private class="kw">static void writeUnsignedShort(byte[] var0, int var1, int var2) {
      var0[var1] = (byte)(var2 >>> 8);
      var0[var1 + 1] = (byte)var2;
   }

   class="kw">public record Attribute(int type, byte[] value) {
      class="kw">public Attribute {
      }
   }
}