From f34a9e00ed839663297c4d9ee48ef01e734d05f8 Mon Sep 17 00:00:00 2001
From: Peter Dettman <peter.dettman@bouncycastle.org>
Date: Fri, 14 Apr 2023 15:57:32 +0700
Subject: Add and use DtlsRecordCallback

---
 crypto/src/tls/DtlsRecordLayer.cs | 29 ++++++++++++++++++-----------
 crypto/src/tls/DtlsTransport.cs   | 26 ++++++++++++++++++++++----
 2 files changed, 40 insertions(+), 15 deletions(-)

diff --git a/crypto/src/tls/DtlsRecordLayer.cs b/crypto/src/tls/DtlsRecordLayer.cs
index 82fc3db64..a61688cb0 100644
--- a/crypto/src/tls/DtlsRecordLayer.cs
+++ b/crypto/src/tls/DtlsRecordLayer.cs
@@ -278,7 +278,7 @@ namespace Org.BouncyCastle.Tls
         }
 
         /// <exception cref="IOException"/>
-        internal int Receive(byte[] buf, int off, int len, int waitMillis, Action recordCallback)
+        internal int Receive(byte[] buf, int off, int len, int waitMillis, DtlsRecordCallback recordCallback)
         {
 #if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
             return Receive(buf.AsSpan(off, len), waitMillis, recordCallback);
@@ -348,7 +348,7 @@ namespace Org.BouncyCastle.Tls
         }
 
         /// <exception cref="IOException"/>
-        internal int ReceivePending(byte[] buf, int off, int len, Action recordCallback)
+        internal int ReceivePending(byte[] buf, int off, int len, DtlsRecordCallback recordCallback)
         {
 #if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
             return ReceivePending(buf.AsSpan(off, len), recordCallback);
@@ -380,7 +380,7 @@ namespace Org.BouncyCastle.Tls
         }
 
         /// <exception cref="IOException"/>
-        internal int Receive(Span<byte> buffer, int waitMillis, Action recordCallback)
+        internal int Receive(Span<byte> buffer, int waitMillis, DtlsRecordCallback recordCallback)
         {
             long currentTimeMillis = DateTimeUtilities.CurrentUnixMs();
 
@@ -446,7 +446,7 @@ namespace Org.BouncyCastle.Tls
         }
 
         /// <exception cref="IOException"/>
-        internal int ReceivePending(Span<byte> buffer, Action recordCallback)
+        internal int ReceivePending(Span<byte> buffer, DtlsRecordCallback recordCallback)
         {
             if (m_recordQueue.Available > 0)
             {
@@ -677,9 +677,10 @@ namespace Org.BouncyCastle.Tls
         // TODO Include 'currentTimeMillis' as an argument, use with Timeout, resetHeartbeat
         /// <exception cref="IOException"/>
 #if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
-        private int ProcessRecord(int received, byte[] record, Span<byte> buffer, Action recordCallback)
+        private int ProcessRecord(int received, byte[] record, Span<byte> buffer, DtlsRecordCallback recordCallback)
 #else
-        private int ProcessRecord(int received, byte[] record, byte[] buf, int off, int len, Action recordCallback)
+        private int ProcessRecord(int received, byte[] record, byte[] buf, int off, int len,
+            DtlsRecordCallback recordCallback)
 #endif
         {
             // NOTE: received < 0 (timeout) is covered by this first case
@@ -823,13 +824,19 @@ namespace Org.BouncyCastle.Tls
              */
             if (recordCallback != null)
             {
-                // TODO Make the callback more general than just peer address update
-                if (ContentType.tls12_cid == recordType &&
-                    isLatestConfirmed &&
-                    recordEpoch == m_readEpoch)
+                var flags = DtlsRecordFlags.None;
+
+                if (recordEpoch == m_readEpoch && isLatestConfirmed)
+                {
+                    flags |= DtlsRecordFlags.IsNewest;
+                }
+
+                if (ContentType.tls12_cid == recordType)
                 {
-                    recordCallback();
+                    flags |= DtlsRecordFlags.UsesConnectionID;
                 }
+
+                recordCallback(flags);
             }
 
             switch (decoded.contentType)
diff --git a/crypto/src/tls/DtlsTransport.cs b/crypto/src/tls/DtlsTransport.cs
index b452b8c89..2e928e761 100644
--- a/crypto/src/tls/DtlsTransport.cs
+++ b/crypto/src/tls/DtlsTransport.cs
@@ -4,6 +4,20 @@ using System.Net.Sockets;
 
 namespace Org.BouncyCastle.Tls
 {
+    [Flags]
+    public enum DtlsRecordFlags
+    {
+        None = 0,
+
+        /// <summary>The record is newer (by epoch and sequence number) than any record received previously.</summary>
+        IsNewest = 1,
+
+        /// <summary>The record includes the (valid) connection ID (RFC 9146) for this connection.</summary>
+        UsesConnectionID = 2,
+    }
+
+    public delegate void DtlsRecordCallback(DtlsRecordFlags flags);
+
     public class DtlsTransport
         : DatagramTransport
     {
@@ -34,8 +48,9 @@ namespace Org.BouncyCastle.Tls
             return Receive(buf, off, len, waitMillis, null);
         }
 
+        // TODO[api] Add to DatagramTransport (with a default null parameter)
         /// <exception cref="IOException"/>
-        public virtual int Receive(byte[] buf, int off, int len, int waitMillis, Action recordCallback)
+        public virtual int Receive(byte[] buf, int off, int len, int waitMillis, DtlsRecordCallback recordCallback)
         {
             if (null == buf)
                 throw new ArgumentNullException("buf");
@@ -92,8 +107,9 @@ namespace Org.BouncyCastle.Tls
 #endif
         }
 
+        // TODO[api] Add to DatagramTransport
         /// <exception cref="IOException"/>
-        public virtual int ReceivePending(byte[] buf, int off, int len, Action recordCallback = null)
+        public virtual int ReceivePending(byte[] buf, int off, int len, DtlsRecordCallback recordCallback = null)
         {
             if (null == buf)
                 throw new ArgumentNullException("buf");
@@ -154,8 +170,9 @@ namespace Org.BouncyCastle.Tls
             return Receive(buffer, waitMillis, null);
         }
 
+        // TODO[api] Add to DatagramTransport (with a default null parameter)
         /// <exception cref="IOException"/>
-        public virtual int Receive(Span<byte> buffer, int waitMillis, Action recordCallback)
+        public virtual int Receive(Span<byte> buffer, int waitMillis, DtlsRecordCallback recordCallback)
         {
             if (waitMillis < 0)
                 throw new ArgumentException("cannot be negative", nameof(waitMillis));
@@ -201,8 +218,9 @@ namespace Org.BouncyCastle.Tls
             }
         }
 
+        // TODO[api] Add to DatagramTransport
         /// <exception cref="IOException"/>
-        public virtual int ReceivePending(Span<byte> buffer, Action recordCallback = null)
+        public virtual int ReceivePending(Span<byte> buffer, DtlsRecordCallback recordCallback = null)
         {
             try
             {
-- 
cgit 1.4.1