Add CREATE_CHECK_NAME packet

protocol/src/main/kotlin/org/openrs2/protocol/ProtocolModule.kt

@@ -14,6 +14,7 @@ import org.openrs2.protocol.login.downstream.LoginDownstream
 import org.openrs2.protocol.login.downstream.ServerFullCodec
 import org.openrs2.protocol.login.upstream.CheckWorldSuitabilityCodec
 import org.openrs2.protocol.login.upstream.CreateCheckDateOfBirthCountryCodec
+import org.openrs2.protocol.login.upstream.CreateCheckNameCodec
 import org.openrs2.protocol.login.upstream.InitCrossDomainConnectionCodec
 import org.openrs2.protocol.login.upstream.InitGameConnectionCodec
 import org.openrs2.protocol.login.upstream.InitJaggrabConnectionCodec
@@ -34,6 +35,7 @@ public object ProtocolModule : AbstractModule() {
             InitJs5RemoteConnectionCodec::class.java,
             InitJaggrabConnectionCodec::class.java,
             CreateCheckDateOfBirthCountryCodec::class.java,
+            CreateCheckNameCodec::class.java,
             RequestWorldListCodec::class.java,
             CheckWorldSuitabilityCodec::class.java,
             InitCrossDomainConnectionCodec::class.java

protocol/src/main/kotlin/org/openrs2/protocol/login/upstream/CreateCheckNameCodec.kt

@@ -0,0 +1,23 @@
+package org.openrs2.protocol.login.upstream
+
+import io.netty.buffer.ByteBuf
+import org.openrs2.crypto.StreamCipher
+import org.openrs2.protocol.PacketCodec
+import org.openrs2.util.Base37
+import javax.inject.Singleton
+
+@Singleton
+public class CreateCheckNameCodec : PacketCodec<LoginRequest.CreateCheckName>(
+    type = LoginRequest.CreateCheckName::class.java,
+    opcode = 21,
+    length = 8
+) {
+    override fun decode(input: ByteBuf, cipher: StreamCipher): LoginRequest.CreateCheckName {
+        val username = Base37.decodeLowerCase(input.readLong())
+        return LoginRequest.CreateCheckName(username)
+    }
+
+    override fun encode(input: LoginRequest.CreateCheckName, output: ByteBuf, cipher: StreamCipher) {
+        output.writeLong(Base37.encode(input.username))
+    }
+}

protocol/src/main/kotlin/org/openrs2/protocol/login/upstream/LoginRequest.kt

@@ -11,6 +11,7 @@ public sealed class LoginRequest : Packet {
         public val dateOfBirth: LocalDate,
         public val country: Int
     ) : LoginRequest()
+    public data class CreateCheckName(public val username: String) : LoginRequest()
     public data class RequestWorldList(public val checksum: Int) : LoginRequest()
     public data class CheckWorldSuitability(
         public val build: Int,