Ticket verification works!

NPTicket.Test/LbpSigningKey.cs

@@ -0,0 +1,9 @@
+using NPTicket.Verification.Keys;
+
+namespace NPTicket.Test;
+
+public class LbpSigningKey : PsnSigningKey
+{
+    public override string CurveX => "39c62d061d4ee35c5f3f7531de0af3cf918346526edac727";
+    public override string CurveY => "a5d578b55113e612bf1878d4cc939d61a41318403b5bdf86";
+}

NPTicket.Test/Program.cs

@@ -1,13 +1,13 @@
 using System.Text.Json;
 using NPTicket;
+using NPTicket.Test;
 using NPTicket.Verification;
-using NPTicket.Verification.Keys;
 
 byte[] ticketData = await File.ReadAllBytesAsync(string.Join(' ', args));
 Ticket ticket = Ticket.ReadFromBytes(ticketData);
 
 Console.WriteLine(JsonSerializer.Serialize(ticket));
 
-TicketVerifier verifier = new(ticketData, ticket, RpcnSigningKey.Instance);
+TicketVerifier verifier = new(ticketData, ticket, new LbpSigningKey());
 Console.WriteLine(JsonSerializer.Serialize(verifier));
 Console.WriteLine(verifier.IsTicketValid());

NPTicket/Reader/TicketReader.cs

@@ -34,11 +34,11 @@ internal ushort ReadTicketHeader()
 
     internal TicketDataSection ReadTicketSectionHeader()
     {
+        long position = this.BaseStream.Position;
+
         this.ReadByte(); // Skip first byte of type (which is a short)
-
         TicketDataSectionType type = (TicketDataSectionType)this.ReadByte();
         ushort length = this.ReadUInt16();
-        long position = this.BaseStream.Position;
 
         return new TicketDataSection(type, length, position);
     }

NPTicket/Verification/ITicketSigningKey.cs

@@ -7,6 +7,7 @@ public interface ITicketSigningKey
 {
     string HashAlgorithm { get; }
     string CurveTable { get; }
+    TicketSignatureMessageType MessageType { get; }
     string CurveX { get; }
     string CurveY { get; }
 }

NPTicket/Verification/Keys/PsnSigningKey.cs

@@ -4,6 +4,7 @@ public abstract class PsnSigningKey : ITicketSigningKey
 {
     public string HashAlgorithm => "SHA-1";
     public string CurveTable => "secp192r1";
+    public TicketSignatureMessageType MessageType => TicketSignatureMessageType.Ticket;
     public abstract string CurveX { get; }
     public abstract string CurveY { get; }
 }

NPTicket/Verification/Keys/RpcnSigningKey.cs

@@ -10,6 +10,7 @@ private RpcnSigningKey() {}
 
     public string HashAlgorithm => "SHA-224";
     public string CurveTable => "secp224k1";
+    public TicketSignatureMessageType MessageType => TicketSignatureMessageType.Body;
     public string CurveX => "b07bc0f0addb97657e9f389039e8d2b9c97dc2a31d3042e7d0479b93";
     public string CurveY => "d81c42b0abdf6c42191a31e31f93342f8f033bd529c2c57fdb5a0a7d";
 }

NPTicket/Verification/TicketSignatureMessageType.cs

@@ -0,0 +1,7 @@
+namespace NPTicket.Verification;
+
+public enum TicketSignatureMessageType : byte
+{
+    Ticket = 0,
+    Body = 1,
+}

NPTicket/Verification/TicketVerifier.cs

@@ -1,3 +1,4 @@
+using Org.BouncyCastle.Asn1;
 using Org.BouncyCastle.Asn1.X9;
 using Org.BouncyCastle.Crypto;
 using Org.BouncyCastle.Crypto.Parameters;
@@ -9,12 +10,14 @@ namespace NPTicket.Verification;
 
 public class TicketVerifier
 {
+    private readonly TicketSignatureMessageType _messageType;
     private readonly Ticket _ticket;
     private readonly byte[] _ticketData;
     private readonly ISigner _signer;
 
     public TicketVerifier(byte[] ticketData, Ticket ticket, ITicketSigningKey key)
     {
+        this._messageType = key.MessageType;
         this._ticketData = ticketData;
         this._ticket = ticket;
 
@@ -26,10 +29,49 @@ public TicketVerifier(byte[] ticketData, Ticket ticket, ITicketSigningKey key)
         this._signer = SignerUtilities.GetSigner(key.HashAlgorithm + "withECDSA");
         this._signer.Init(false, publicKey);
     }
+
+    // https://github.com/LBPUnion/ProjectLighthouse/blob/80cfb24d6f72ecdf45c8389b29a89fd1c13d0a96/ProjectLighthouse/Tickets/Signature/TicketSignatureVerifier.cs#L30
+    // Sometimes psn signatures have one or two extra empty bytes
+    // This is slow but it's better than carelessly chopping 0's
+    private static byte[] TrimSignature(byte[] signature)
+    {
+        for (int i = 0; i <= 2; i++)
+        {
+            try
+            {
+                Asn1Object.FromByteArray(signature);
+                break;
+            }
+            catch
+            {
+                signature = signature.SkipLast(1).ToArray();
+            }
+        }
+
+        return signature;
+    }
 
     public bool IsTicketValid()
     {
-        this._signer.BlockUpdate(this._ticketData, this._ticket.BodySection.Position, this._ticket.BodySection.Length);
-        return this._signer.VerifySignature(this._ticketData);
+        int inOff;
+        int inLen;
+
+        switch (this._messageType)
+        {
+            case TicketSignatureMessageType.Body:
+                inOff = this._ticket.BodySection.Position;
+                inLen = this._ticket.BodySection.Length + 4;
+                break;
+            case TicketSignatureMessageType.Ticket:
+                inOff = 0;
+                inLen = this._ticketData.Length - this._ticket.SignatureData.Length;
+                break;
+            default:
+                throw new NotImplementedException(this._messageType.ToString());
+        }
+
+        this._signer.BlockUpdate(this._ticketData, inOff, inLen);
+
+        return this._signer.VerifySignature(TrimSignature(this._ticket.SignatureData));
     }
 }