Port of non-blocking TLS API from Java

8 files changed, 665 insertions, 29 deletions

diff --git a/crypto/crypto.csproj b/crypto/crypto.csproj
index 7f4131f4e..df7df9f5a 100644
--- a/crypto/crypto.csproj
+++ b/crypto/crypto.csproj
@@ -4469,6 +4469,11 @@
                     BuildAction = "Compile"
                 />
                 <File
+                    RelPath = "src\crypto\tls\ByteQueueStream.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
                     RelPath = "src\crypto\tls\CertChainType.cs"
                     SubType = "Code"
                     BuildAction = "Compile"
@@ -11615,6 +11620,11 @@
                     BuildAction = "Compile"
                 />
                 <File
+                    RelPath = "test\src\crypto\tls\test\ByteQueueStreamTest.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
                     RelPath = "test\src\crypto\tls\test\DtlsProtocolTest.cs"
                     SubType = "Code"
                     BuildAction = "Compile"
@@ -11705,6 +11715,11 @@
                     BuildAction = "Compile"
                 />
                 <File
+                    RelPath = "test\src\crypto\tls\test\TlsProtocolNonBlockingTest.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
                     RelPath = "test\src\crypto\tls\test\TlsPskProtocolTest.cs"
                     SubType = "Code"
                     BuildAction = "Compile"
diff --git a/crypto/src/crypto/tls/ByteQueueStream.cs b/crypto/src/crypto/tls/ByteQueueStream.cs
new file mode 100644
index 000000000..bf603e006
--- /dev/null
+++ b/crypto/src/crypto/tls/ByteQueueStream.cs
@@ -0,0 +1,114 @@
+using System;
+using System.IO;
+
+namespace Org.BouncyCastle.Crypto.Tls
+{
+    public class ByteQueueStream
+        : Stream
+    {
+        private readonly ByteQueue buffer;
+
+        public ByteQueueStream()
+        {
+            this.buffer = new ByteQueue();
+        }
+
+        public virtual int Available
+        {
+            get { return buffer.Available; }
+        }
+
+        public override bool CanRead
+        {
+            get { return true; }
+        }
+
+        public override bool CanSeek
+        {
+            get { return false; }
+        }
+
+        public override bool CanWrite
+        {
+            get { return true; }
+        }
+
+        public override void Close()
+        {
+        }
+
+        public override void Flush()
+        {
+        }
+
+        public override long Length
+        {
+            get { throw new NotSupportedException(); }
+        }
+
+        public virtual int Peek(byte[] buf)
+        {
+            int bytesToRead = System.Math.Min(buffer.Available, buf.Length);
+            buffer.Read(buf, 0, bytesToRead, 0);
+            return bytesToRead;
+        }
+
+        public override long Position
+        {
+            get { throw new NotSupportedException(); }
+            set { throw new NotSupportedException(); }
+        }
+
+        public virtual int Read(byte[] buf)
+        {
+            return Read(buf, 0, buf.Length);
+        }
+
+        public override int Read(byte[] buf, int off, int len)
+        {
+            int bytesToRead = System.Math.Min(buffer.Available, len);
+            buffer.RemoveData(buf, off, bytesToRead, 0);
+            return bytesToRead;
+        }
+
+        public override int ReadByte()
+        {
+            if (buffer.Available == 0)
+                return -1;
+
+            return buffer.RemoveData(1, 0)[0] & 0xFF;
+        }
+
+        public override long Seek(long offset, SeekOrigin origin)
+        {
+            throw new NotSupportedException();
+        }
+
+        public override void SetLength(long value)
+        {
+            throw new NotSupportedException();
+        }
+
+        public virtual int Skip(int n)
+        {
+            int bytesToSkip = System.Math.Min(buffer.Available, n);
+            buffer.RemoveData(bytesToSkip);
+            return bytesToSkip;
+        }
+
+        public virtual void Write(byte[] buf)
+        {
+            buffer.AddData(buf, 0, buf.Length);
+        }
+
+        public override void Write(byte[] buf, int off, int len)
+        {
+            buffer.AddData(buf, off, len);
+        }
+
+        public override void WriteByte(byte b)
+        {
+            buffer.AddData(new byte[]{ b }, 0, 1);
+        }
+    }
+}
diff --git a/crypto/src/crypto/tls/RecordStream.cs b/crypto/src/crypto/tls/RecordStream.cs
index db5b158bc..6f3fc41c6 100644
--- a/crypto/src/crypto/tls/RecordStream.cs
+++ b/crypto/src/crypto/tls/RecordStream.cs
@@ -8,6 +8,11 @@ namespace Org.BouncyCastle.Crypto.Tls
     {
         private const int DEFAULT_PLAINTEXT_LIMIT = (1 << 14);
 
+        internal const int TLS_HEADER_SIZE = 5;
+        internal const int TLS_HEADER_TYPE_OFFSET = 0;
+        internal const int TLS_HEADER_VERSION_OFFSET = 1;
+        internal const int TLS_HEADER_LENGTH_OFFSET = 3;
+
         private TlsProtocol mHandler;
         private Stream mInput;
         private Stream mOutput;
@@ -116,11 +121,11 @@ namespace Org.BouncyCastle.Crypto.Tls
 
         internal virtual bool ReadRecord()
         {
-            byte[] recordHeader = TlsUtilities.ReadAllOrNothing(5, mInput);
+            byte[] recordHeader = TlsUtilities.ReadAllOrNothing(TLS_HEADER_SIZE, mInput);
             if (recordHeader == null)
                 return false;
 
-            byte type = TlsUtilities.ReadUint8(recordHeader, 0);
+            byte type = TlsUtilities.ReadUint8(recordHeader, TLS_HEADER_TYPE_OFFSET);
 
             /*
              * RFC 5246 6. If a TLS implementation receives an unexpected record type, it MUST send an
@@ -130,13 +135,13 @@ namespace Org.BouncyCastle.Crypto.Tls
 
             if (!mRestrictReadVersion)
             {
-                int version = TlsUtilities.ReadVersionRaw(recordHeader, 1);
+                int version = TlsUtilities.ReadVersionRaw(recordHeader, TLS_HEADER_VERSION_OFFSET);
                 if ((version & 0xffffff00) != 0x0300)
                     throw new TlsFatalAlert(AlertDescription.illegal_parameter);
             }
             else
             {
-                ProtocolVersion version = TlsUtilities.ReadVersion(recordHeader, 1);
+                ProtocolVersion version = TlsUtilities.ReadVersion(recordHeader, TLS_HEADER_VERSION_OFFSET);
                 if (mReadVersion == null)
                 {
                     mReadVersion = version;
@@ -147,7 +152,7 @@ namespace Org.BouncyCastle.Crypto.Tls
                 }
             }
 
-            int length = TlsUtilities.ReadUint16(recordHeader, 3);
+            int length = TlsUtilities.ReadUint16(recordHeader, TLS_HEADER_LENGTH_OFFSET);
             byte[] plaintext = DecodeAndVerify(type, mInput, length);
             mHandler.ProcessRecord(type, plaintext, 0, plaintext.Length);
             return true;
@@ -247,11 +252,11 @@ namespace Org.BouncyCastle.Crypto.Tls
              */
             CheckLength(ciphertext.Length, mCiphertextLimit, AlertDescription.internal_error);
 
-            byte[] record = new byte[ciphertext.Length + 5];
-            TlsUtilities.WriteUint8(type, record, 0);
-            TlsUtilities.WriteVersion(mWriteVersion, record, 1);
-            TlsUtilities.WriteUint16(ciphertext.Length, record, 3);
-            Array.Copy(ciphertext, 0, record, 5, ciphertext.Length);
+            byte[] record = new byte[ciphertext.Length + TLS_HEADER_SIZE];
+            TlsUtilities.WriteUint8(type, record, TLS_HEADER_TYPE_OFFSET);
+            TlsUtilities.WriteVersion(mWriteVersion, record, TLS_HEADER_VERSION_OFFSET);
+            TlsUtilities.WriteUint16(ciphertext.Length, record, TLS_HEADER_LENGTH_OFFSET);
+            Array.Copy(ciphertext, 0, record, TLS_HEADER_SIZE, ciphertext.Length);
             mOutput.Write(record, 0, record.Length);
             mOutput.Flush();
         }
diff --git a/crypto/src/crypto/tls/TlsClientProtocol.cs b/crypto/src/crypto/tls/TlsClientProtocol.cs
index 7b8439acc..14c1cf4a4 100644
--- a/crypto/src/crypto/tls/TlsClientProtocol.cs
+++ b/crypto/src/crypto/tls/TlsClientProtocol.cs
@@ -21,21 +21,56 @@ namespace Org.BouncyCastle.Crypto.Tls
         protected CertificateStatus mCertificateStatus = null;
         protected CertificateRequest mCertificateRequest = null;
 
+        /**
+         * Constructor for blocking mode.
+         * @param stream The bi-directional stream of data to/from the server
+         * @param secureRandom Random number generator for various cryptographic functions
+         */
         public TlsClientProtocol(Stream stream, SecureRandom secureRandom)
-            :   base(stream, secureRandom)
+            : base(stream, secureRandom)
         {
         }
 
+        /**
+         * Constructor for blocking mode.
+         * @param input The stream of data from the server
+         * @param output The stream of data to the server
+         * @param secureRandom Random number generator for various cryptographic functions
+         */
         public TlsClientProtocol(Stream input, Stream output, SecureRandom secureRandom)
-            :   base(input, output, secureRandom)
+            : base(input, output, secureRandom)
+        {
+        }
+
+        /**
+         * Constructor for non-blocking mode.<br>
+         * <br>
+         * When data is received, use {@link #offerInput(java.nio.ByteBuffer)} to
+         * provide the received ciphertext, then use
+         * {@link #readInput(byte[], int, int)} to read the corresponding cleartext.<br>
+         * <br>
+         * Similarly, when data needs to be sent, use
+         * {@link #offerOutput(byte[], int, int)} to provide the cleartext, then use
+         * {@link #readOutput(byte[], int, int)} to get the corresponding
+         * ciphertext.
+         * 
+         * @param secureRandom
+         *            Random number generator for various cryptographic functions
+         */
+        public TlsClientProtocol(SecureRandom secureRandom)
+            : base(secureRandom)
         {
         }
 
         /**
-         * Initiates a TLS handshake in the role of client
+         * Initiates a TLS handshake in the role of client.<br>
+         * <br>
+         * In blocking mode, this will not return until the handshake is complete.
+         * In non-blocking mode, use {@link TlsPeer#NotifyHandshakeComplete()} to
+         * receive a callback when the handshake is complete.
          *
          * @param tlsClient The {@link TlsClient} to use for the handshake.
-         * @throws IOException If handshake was not successful.
+         * @throws IOException If in blocking mode and handshake was not successful.
          */
         public virtual void Connect(TlsClient tlsClient)
         {
@@ -71,7 +106,7 @@ namespace Org.BouncyCastle.Crypto.Tls
             SendClientHelloMessage();
             this.mConnectionState = CS_CLIENT_HELLO;
 
-            CompleteHandshake();
+            BlockForHandshake();
         }
 
         protected override void CleanupHandshake()
@@ -116,6 +151,7 @@ namespace Org.BouncyCastle.Crypto.Tls
                 this.mConnectionState = CS_CLIENT_FINISHED;
                 this.mConnectionState = CS_END;
 
+                CompleteHandshake();
                 return;
             }
 
@@ -208,6 +244,8 @@ namespace Org.BouncyCastle.Crypto.Tls
                     ProcessFinishedMessage(buf);
                     this.mConnectionState = CS_SERVER_FINISHED;
                     this.mConnectionState = CS_END;
+
+                    CompleteHandshake();
                     break;
                 }
                 default:
diff --git a/crypto/src/crypto/tls/TlsProtocol.cs b/crypto/src/crypto/tls/TlsProtocol.cs
index 8eb7beb3f..7acc34d3c 100644
--- a/crypto/src/crypto/tls/TlsProtocol.cs
+++ b/crypto/src/crypto/tls/TlsProtocol.cs
@@ -72,6 +72,10 @@ namespace Org.BouncyCastle.Crypto.Tls
         protected bool mAllowCertificateStatus = false;
         protected bool mExpectSessionTicket = false;
 
+        protected bool mBlocking = true;
+        protected ByteQueueStream mInputBuffers = null;
+        protected ByteQueueStream mOutputBuffer = null;
+
         public TlsProtocol(Stream stream, SecureRandom secureRandom)
             :   this(stream, stream, secureRandom)
         {
@@ -83,6 +87,15 @@ namespace Org.BouncyCastle.Crypto.Tls
             this.mSecureRandom = secureRandom;
         }
 
+        public TlsProtocol(SecureRandom secureRandom)
+        {
+            this.mBlocking = false;
+            this.mInputBuffers = new ByteQueueStream();
+            this.mOutputBuffer = new ByteQueueStream();
+            this.mRecordStream = new RecordStream(this, mInputBuffers, mOutputBuffer);
+            this.mSecureRandom = secureRandom;
+        }
+
         protected abstract TlsContext Context { get; }
 
         internal abstract AbstractTlsContext ContextAdmin { get; }
@@ -140,13 +153,10 @@ namespace Org.BouncyCastle.Crypto.Tls
             this.mExpectSessionTicket = false;
         }
 
-        protected virtual void CompleteHandshake()
+        protected virtual void BlockForHandshake()
         {
-            try
+            if (mBlocking)
             {
-                /*
-                 * We will now read data, until we have completed the handshake.
-                 */
                 while (this.mConnectionState != CS_END)
                 {
                     if (this.mClosed)
@@ -156,7 +166,13 @@ namespace Org.BouncyCastle.Crypto.Tls
 
                     SafeReadRecord();
                 }
+            }
+        }
 
+        protected virtual void CompleteHandshake()
+        {
+            try
+            {
                 this.mRecordStream.FinaliseHandshake();
 
                 this.mSplitApplicationDataRecords = !TlsUtilities.IsTlsV11(Context);
@@ -168,7 +184,10 @@ namespace Org.BouncyCastle.Crypto.Tls
                 {
                     this.mAppDataReady = true;
 
-                    this.mTlsStream = new TlsStream(this);
+                    if (mBlocking)
+                    {
+                        this.mTlsStream = new TlsStream(this);
+                    }
                 }
 
                 if (this.mTlsSession != null)
@@ -573,9 +592,156 @@ namespace Org.BouncyCastle.Crypto.Tls
         }
 
         /// <summary>The secure bidirectional stream for this connection</summary>
+        /// <remarks>Only allowed in blocking mode.</remarks>
         public virtual Stream Stream
         {
-            get { return this.mTlsStream; }
+            get
+            {
+                if (!mBlocking)
+                    throw new InvalidOperationException("Cannot use Stream in non-blocking mode! Use OfferInput()/OfferOutput() instead.");
+                return this.mTlsStream;
+            }
+        }
+
+        /**
+         * Offer input from an arbitrary source. Only allowed in non-blocking mode.<br>
+         * <br>
+         * After this method returns, the input buffer is "owned" by this object. Other code
+         * must not attempt to do anything with it.<br>
+         * <br>
+         * This method will decrypt and process all records that are fully available.
+         * If only part of a record is available, the buffer will be retained until the
+         * remainder of the record is offered.<br>
+         * <br>
+         * If any records containing application data were processed, the decrypted data
+         * can be obtained using {@link #readInput(byte[], int, int)}. If any records
+         * containing protocol data were processed, a response may have been generated.
+         * You should always check to see if there is any available output after calling
+         * this method by calling {@link #getAvailableOutputBytes()}.
+         * @param input The input buffer to offer
+         * @throws IOException If an error occurs while decrypting or processing a record
+         */
+        public virtual void OfferInput(byte[] input)
+        {
+            if (mBlocking)
+                throw new InvalidOperationException("Cannot use OfferInput() in blocking mode! Use Stream instead.");
+            if (mClosed)
+                throw new IOException("Connection is closed, cannot accept any more input");
+
+            mInputBuffers.Write(input);
+
+            // loop while there are enough bytes to read the length of the next record
+            while (mInputBuffers.Available >= RecordStream.TLS_HEADER_SIZE)
+            {
+                byte[] header = new byte[RecordStream.TLS_HEADER_SIZE];
+                mInputBuffers.Peek(header);
+
+                int totalLength = TlsUtilities.ReadUint16(header, RecordStream.TLS_HEADER_LENGTH_OFFSET) + RecordStream.TLS_HEADER_SIZE;
+                if (mInputBuffers.Available < totalLength)
+                {
+                    // not enough bytes to read a whole record
+                    break;
+                }
+
+                SafeReadRecord();
+            }
+        }
+
+        /**
+         * Gets the amount of received application data. A call to {@link #readInput(byte[], int, int)}
+         * is guaranteed to be able to return at least this much data.<br>
+         * <br>
+         * Only allowed in non-blocking mode.
+         * @return The number of bytes of available application data
+         */
+        public virtual int GetAvailableInputBytes()
+        {
+            if (mBlocking)
+                throw new InvalidOperationException("Cannot use GetAvailableInputBytes() in blocking mode! Use ApplicationDataAvailable() instead.");
+
+            return ApplicationDataAvailable();
+        }
+
+        /**
+         * Retrieves received application data. Use {@link #getAvailableInputBytes()} to check
+         * how much application data is currently available. This method functions similarly to
+         * {@link InputStream#read(byte[], int, int)}, except that it never blocks. If no data
+         * is available, nothing will be copied and zero will be returned.<br>
+         * <br>
+         * Only allowed in non-blocking mode.
+         * @param buffer The buffer to hold the application data
+         * @param offset The start offset in the buffer at which the data is written
+         * @param length The maximum number of bytes to read
+         * @return The total number of bytes copied to the buffer. May be less than the
+         *          length specified if the length was greater than the amount of available data.
+         */
+        public virtual int ReadInput(byte[] buffer, int offset, int length)
+        {
+            if (mBlocking)
+                throw new InvalidOperationException("Cannot use ReadInput() in blocking mode! Use Stream instead.");
+
+            return ReadApplicationData(buffer, offset, System.Math.Min(length, ApplicationDataAvailable()));
+        }
+
+        /**
+         * Offer output from an arbitrary source. Only allowed in non-blocking mode.<br>
+         * <br>
+         * After this method returns, the specified section of the buffer will have been
+         * processed. Use {@link #readOutput(byte[], int, int)} to get the bytes to
+         * transmit to the other peer.<br>
+         * <br>
+         * This method must not be called until after the handshake is complete! Attempting
+         * to call it before the handshake is complete will result in an exception.
+         * @param buffer The buffer containing application data to encrypt
+         * @param offset The offset at which to begin reading data
+         * @param length The number of bytes of data to read
+         * @throws IOException If an error occurs encrypting the data, or the handshake is not complete
+         */
+        public virtual void OfferOutput(byte[] buffer, int offset, int length)
+        {
+            if (mBlocking)
+                throw new InvalidOperationException("Cannot use OfferOutput() in blocking mode! Use Stream instead.");
+            if (!mAppDataReady)
+                throw new IOException("Application data cannot be sent until the handshake is complete!");
+
+            WriteData(buffer, offset, length);
+        }
+
+        /**
+         * Gets the amount of encrypted data available to be sent. A call to
+         * {@link #readOutput(byte[], int, int)} is guaranteed to be able to return at
+         * least this much data.<br>
+         * <br>
+         * Only allowed in non-blocking mode.
+         * @return The number of bytes of available encrypted data
+         */
+        public virtual int GetAvailableOutputBytes()
+        {
+            if (mBlocking)
+                throw new InvalidOperationException("Cannot use GetAvailableOutputBytes() in blocking mode! Use Stream instead.");
+
+            return mOutputBuffer.Available;
+        }
+
+        /**
+         * Retrieves encrypted data to be sent. Use {@link #getAvailableOutputBytes()} to check
+         * how much encrypted data is currently available. This method functions similarly to
+         * {@link InputStream#read(byte[], int, int)}, except that it never blocks. If no data
+         * is available, nothing will be copied and zero will be returned.<br>
+         * <br>
+         * Only allowed in non-blocking mode.
+         * @param buffer The buffer to hold the encrypted data
+         * @param offset The start offset in the buffer at which the data is written
+         * @param length The maximum number of bytes to read
+         * @return The total number of bytes copied to the buffer. May be less than the
+         *          length specified if the length was greater than the amount of available data.
+         */
+        public virtual int ReadOutput(byte[] buffer, int offset, int length)
+        {
+            if (mBlocking)
+                throw new InvalidOperationException("Cannot use ReadOutput() in blocking mode! Use Stream instead.");
+
+            return mOutputBuffer.Read(buffer, offset, length);
         }
 
         /**
@@ -764,7 +930,7 @@ namespace Org.BouncyCastle.Crypto.Tls
             mRecordStream.Flush();
         }
 
-        protected internal virtual bool IsClosed
+        public virtual bool IsClosed
         {
             get { return mClosed; }
         }
diff --git a/crypto/src/crypto/tls/TlsServerProtocol.cs b/crypto/src/crypto/tls/TlsServerProtocol.cs
index b73cb5a30..27f7a1dfd 100644
--- a/crypto/src/crypto/tls/TlsServerProtocol.cs
+++ b/crypto/src/crypto/tls/TlsServerProtocol.cs
@@ -22,21 +22,57 @@ namespace Org.BouncyCastle.Crypto.Tls
         protected short mClientCertificateType = -1;
         protected TlsHandshakeHash mPrepareFinishHash = null;
 
+        /**
+         * Constructor for blocking mode.
+         * @param stream The bi-directional stream of data to/from the client
+         * @param output The stream of data to the client
+         * @param secureRandom Random number generator for various cryptographic functions
+         */
         public TlsServerProtocol(Stream stream, SecureRandom secureRandom)
-            :   base(stream, secureRandom)
+            : base(stream, secureRandom)
         {
         }
 
+        /**
+         * Constructor for blocking mode.
+         * @param input The stream of data from the client
+         * @param output The stream of data to the client
+         * @param secureRandom Random number generator for various cryptographic functions
+         */
         public TlsServerProtocol(Stream input, Stream output, SecureRandom secureRandom)
-            :   base(input, output, secureRandom)
+            : base(input, output, secureRandom)
+        {
+        }
+
+        /**
+         * Constructor for non-blocking mode.<br>
+         * <br>
+         * When data is received, use {@link #offerInput(java.nio.ByteBuffer)} to
+         * provide the received ciphertext, then use
+         * {@link #readInput(byte[], int, int)} to read the corresponding cleartext.<br>
+         * <br>
+         * Similarly, when data needs to be sent, use
+         * {@link #offerOutput(byte[], int, int)} to provide the cleartext, then use
+         * {@link #readOutput(byte[], int, int)} to get the corresponding
+         * ciphertext.
+         * 
+         * @param secureRandom
+         *            Random number generator for various cryptographic functions
+         */
+        public TlsServerProtocol(SecureRandom secureRandom)
+            : base(secureRandom)
         {
         }
 
         /**
-         * Receives a TLS handshake in the role of server
+         * Receives a TLS handshake in the role of server.<br>
+         * <br>
+         * In blocking mode, this will not return until the handshake is complete.
+         * In non-blocking mode, use {@link TlsPeer#notifyHandshakeComplete()} to
+         * receive a callback when the handshake is complete.
          *
-         * @param mTlsServer
-         * @throws IOException If handshake was not successful.
+         * @param tlsServer
+         * @throws IOException If in blocking mode and handshake was not successful.
          */
         public virtual void Accept(TlsServer tlsServer)
         {
@@ -60,7 +96,7 @@ namespace Org.BouncyCastle.Crypto.Tls
 
             this.mRecordStream.SetRestrictReadVersion(false);
 
-            CompleteHandshake();
+            BlockForHandshake();
         }
 
         protected override void CleanupHandshake()
@@ -329,6 +365,8 @@ namespace Org.BouncyCastle.Crypto.Tls
                     SendFinishedMessage();
                     this.mConnectionState = CS_SERVER_FINISHED;
                     this.mConnectionState = CS_END;
+
+                    CompleteHandshake();
                     break;
                 }
                 default:
diff --git a/crypto/test/src/crypto/tls/test/ByteQueueStreamTest.cs b/crypto/test/src/crypto/tls/test/ByteQueueStreamTest.cs
new file mode 100644
index 000000000..1d68a5215
--- /dev/null
+++ b/crypto/test/src/crypto/tls/test/ByteQueueStreamTest.cs
@@ -0,0 +1,134 @@
+using System;
+
+using NUnit.Framework;
+
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Crypto.Tls.Tests
+{
+    [TestFixture]
+    public class ByteQueueStreamTest
+    {
+        [Test]
+        public void TestAvailable()
+        {
+            ByteQueueStream input = new ByteQueueStream();
+
+            // buffer is empty
+            Assert.AreEqual(0, input.Available);
+
+            // after adding once
+            input.Write(new byte[10]);
+            Assert.AreEqual(10, input.Available);
+
+            // after adding more than once
+            input.Write(new byte[5]);
+            Assert.AreEqual(15, input.Available);
+
+            // after reading a single byte
+            input.ReadByte();
+            Assert.AreEqual(14, input.Available);
+
+            // after reading into a byte array
+            input.Read(new byte[4]);
+            Assert.AreEqual(10, input.Available);
+
+            input.Close(); // so compiler doesn't whine about a resource leak
+        }
+
+        [Test]
+        public void TestSkip()
+        {
+            ByteQueueStream input = new ByteQueueStream();
+
+            // skip when buffer is empty
+            Assert.AreEqual(0, input.Skip(10));
+
+            // skip equal to available
+            input.Write(new byte[2]);
+            Assert.AreEqual(2, input.Skip(2));
+            Assert.AreEqual(0, input.Available);
+
+            // skip less than available
+            input.Write(new byte[10]);
+            Assert.AreEqual(5, input.Skip(5));
+            Assert.AreEqual(5, input.Available);
+
+            // skip more than available
+            Assert.AreEqual(5, input.Skip(20));
+            Assert.AreEqual(0, input.Available);
+
+            input.Close();// so compiler doesn't whine about a resource leak
+        }
+
+        [Test]
+        public void TestRead()
+        {
+            ByteQueueStream input = new ByteQueueStream();
+            input.Write(new byte[] { 0x01, 0x02 });
+            input.Write(new byte[]{ 0x03 });
+
+            Assert.AreEqual(0x01, input.ReadByte());
+            Assert.AreEqual(0x02, input.ReadByte());
+            Assert.AreEqual(0x03, input.ReadByte());
+            Assert.AreEqual(-1, input.ReadByte());
+
+            input.Close(); // so compiler doesn't whine about a resource leak
+        }
+
+        [Test]
+        public void TestReadArray()
+        {
+            ByteQueueStream input = new ByteQueueStream();
+            input.Write(new byte[] { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06 });
+
+            byte[] buffer = new byte[5];
+
+            // read less than available into specified position
+            Assert.AreEqual(1, input.Read(buffer, 2, 1));
+            AssertArrayEquals(new byte[]{ 0x00, 0x00, 0x01, 0x00, 0x00 }, buffer);
+
+            // read equal to available
+            Assert.AreEqual(5, input.Read(buffer));
+            AssertArrayEquals(new byte[]{ 0x02, 0x03, 0x04, 0x05, 0x06 }, buffer);
+
+            // read more than available
+            input.Write(new byte[]{ 0x01, 0x02, 0x03 });
+            Assert.AreEqual(3, input.Read(buffer));
+            AssertArrayEquals(new byte[]{ 0x01, 0x02, 0x03, 0x05, 0x06 }, buffer);
+
+            input.Close(); // so compiler doesn't whine about a resource leak
+        }
+
+        [Test]
+        public void TestPeek()
+        {
+            ByteQueueStream input = new ByteQueueStream();
+
+            byte[] buffer = new byte[5];
+
+            // peek more than available
+            Assert.AreEqual(0, input.Peek(buffer));
+            AssertArrayEquals(new byte[]{ 0x00, 0x00, 0x00, 0x00, 0x00 }, buffer);
+
+            // peek less than available
+            input.Write(new byte[]{ 0x01, 0x02, 0x03, 0x04, 0x05, 0x06 });
+            Assert.AreEqual(5, input.Peek(buffer));
+            AssertArrayEquals(new byte[]{ 0x01, 0x02, 0x03, 0x04, 0x05 }, buffer);
+            Assert.AreEqual(6, input.Available);
+
+            // peek equal to available
+            input.ReadByte();
+            Assert.AreEqual(5, input.Peek(buffer));
+            AssertArrayEquals(new byte[]{ 0x02, 0x03, 0x04, 0x05, 0x06 }, buffer);
+            Assert.AreEqual(5, input.Available);
+
+            input.Close(); // so compiler doesn't whine about a resource leak
+        }
+
+        private static void AssertArrayEquals(byte[] a, byte[] b)
+        {
+            Assert.IsTrue(Arrays.AreEqual(a, b));
+        }
+    }
+}
diff --git a/crypto/test/src/crypto/tls/test/TlsProtocolNonBlockingTest.cs b/crypto/test/src/crypto/tls/test/TlsProtocolNonBlockingTest.cs
new file mode 100644
index 000000000..5fe0f32ad
--- /dev/null
+++ b/crypto/test/src/crypto/tls/test/TlsProtocolNonBlockingTest.cs
@@ -0,0 +1,126 @@
+using System;
+using System.IO;
+
+using NUnit.Framework;
+
+using Org.BouncyCastle.Security;
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Crypto.Tls.Tests
+{
+    [TestFixture]
+    public class TlsProtocolNonBlockingTest
+    {
+        [Test]
+        public void TestClientServerFragmented()
+        {
+            // tests if it's really non-blocking when partial records arrive
+            DoTestClientServer(true);
+        }
+
+        [Test]
+        public void TestClientServerNonFragmented()
+        {
+            DoTestClientServer(false);
+        }
+
+        private static void DoTestClientServer(bool fragment)
+        {
+            SecureRandom secureRandom = new SecureRandom();
+
+            TlsClientProtocol clientProtocol = new TlsClientProtocol(secureRandom);
+            TlsServerProtocol serverProtocol = new TlsServerProtocol(secureRandom);
+
+            clientProtocol.Connect(new MockTlsClient(null));
+            serverProtocol.Accept(new MockTlsServer());
+
+            // pump handshake
+            bool hadDataFromServer = true;
+            bool hadDataFromClient = true;
+            while (hadDataFromServer || hadDataFromClient)
+            {
+                hadDataFromServer = PumpData(serverProtocol, clientProtocol, fragment);
+                hadDataFromClient = PumpData(clientProtocol, serverProtocol, fragment);
+            }
+
+            // send data in both directions
+            byte[] data = new byte[1024];
+            secureRandom.NextBytes(data);
+            WriteAndRead(clientProtocol, serverProtocol, data, fragment);
+            WriteAndRead(serverProtocol, clientProtocol, data, fragment);
+
+            // close the connection
+            clientProtocol.Close();
+            PumpData(clientProtocol, serverProtocol, fragment);
+            CheckClosed(serverProtocol);
+            CheckClosed(clientProtocol);
+        }
+
+        private static void WriteAndRead(TlsProtocol writer, TlsProtocol reader, byte[] data, bool fragment)
+        {
+            int dataSize = data.Length;
+            writer.OfferOutput(data, 0, dataSize);
+            PumpData(writer, reader, fragment);
+
+            Assert.AreEqual(dataSize, reader.GetAvailableInputBytes());
+            byte[] readData = new byte[dataSize];
+            reader.ReadInput(readData, 0, dataSize);
+            AssertArrayEquals(data, readData);
+        }
+
+        private static bool PumpData(TlsProtocol from, TlsProtocol to, bool fragment)
+        {
+            int byteCount = from.GetAvailableOutputBytes();
+            if (byteCount == 0)
+            {
+                return false;
+            }
+
+            if (fragment)
+            {
+                while (from.GetAvailableOutputBytes() > 0)
+                {
+                    byte[] buffer = new byte[1];
+                    from.ReadOutput(buffer, 0, 1);
+                    to.OfferInput(buffer);
+                }
+            }
+            else
+            {
+                byte[] buffer = new byte[byteCount];
+                from.ReadOutput(buffer, 0, buffer.Length);
+                to.OfferInput(buffer);
+            }
+
+            return true;
+        }
+
+        private static void CheckClosed(TlsProtocol protocol)
+        {
+            Assert.IsTrue(protocol.IsClosed);
+
+            try
+            {
+                protocol.OfferInput(new byte[10]);
+                Assert.Fail("Input was accepted after close");
+            }
+            catch (IOException e)
+            {
+            }
+
+            try
+            {
+                protocol.OfferOutput(new byte[10], 0, 10);
+                Assert.Fail("Output was accepted after close");
+            }
+            catch (IOException e)
+            {
+            }
+        }
+
+        private static void AssertArrayEquals(byte[] a, byte[] b)
+        {
+            Assert.IsTrue(Arrays.AreEqual(a, b));
+        }
+    }
+}