1 files changed, 118 insertions, 0 deletions
diff --git a/crypto/src/tls/HeartbeatMessage.cs b/crypto/src/tls/HeartbeatMessage.cs
new file mode 100644
index 000000000..9e5c7d14e
--- /dev/null
+++ b/crypto/src/tls/HeartbeatMessage.cs
@@ -0,0 +1,118 @@
+using System;
+using System.IO;
+
+using Org.BouncyCastle.Utilities;
+using Org.BouncyCastle.Utilities.IO;
+
+namespace Org.BouncyCastle.Tls
+{
+    public sealed class HeartbeatMessage
+    {
+        public static HeartbeatMessage Create(TlsContext context, short type, byte[] payload)
+        {
+            return Create(context, type, payload, 16);
+        }
+
+        public static HeartbeatMessage Create(TlsContext context, short type, byte[] payload, int paddingLength)
+        {
+            byte[] padding = context.NonceGenerator.GenerateNonce(paddingLength);
+
+            return new HeartbeatMessage(type, payload, padding);
+        }
+
+        private readonly short m_type;
+        private readonly byte[] m_payload;
+        private readonly byte[] m_padding;
+
+        public HeartbeatMessage(short type, byte[] payload, byte[] padding)
+        {
+            if (!HeartbeatMessageType.IsValid(type))
+                throw new ArgumentException("not a valid HeartbeatMessageType value", "type");
+            if (null == payload || payload.Length >= (1 << 16))
+                throw new ArgumentException("must have length < 2^16", "payload");
+            if (null == padding || padding.Length < 16)
+                throw new ArgumentException("must have length >= 16", "padding");
+
+            this.m_type = type;
+            this.m_payload = payload;
+            this.m_padding = padding;
+        }
+
+        public int PaddingLength
+        {
+            /*
+             * RFC 6520 4. The padding of a received HeartbeatMessage message MUST be ignored
+             */
+            get { return m_padding.Length; }
+        }
+
+        public byte[] Payload
+        {
+            get { return m_payload; }
+        }
+
+        public short Type
+        {
+            get { return m_type; }
+        }
+
+        /// <summary>Encode this <see cref="HeartbeatMessage"/> to a <see cref="Stream"/>.</summary>
+        /// <param name="output">the <see cref="Stream"/> to encode to.</param>
+        /// <exception cref="IOException"/>
+        public void Encode(Stream output)
+        {
+            TlsUtilities.WriteUint8(m_type, output);
+
+            TlsUtilities.CheckUint16(m_payload.Length);
+            TlsUtilities.WriteUint16(m_payload.Length, output);
+            output.Write(m_payload, 0, m_payload.Length);
+
+            output.Write(m_padding, 0, m_padding.Length);
+        }
+
+        /// <summary>Parse a <see cref="HeartbeatMessage"/> from a <see cref="Stream"/>.</summary>
+        /// <param name="input">the <see cref="Stream"/> to parse from.</param>
+        /// <returns>a <see cref="HeartbeatMessage"/> object.</returns>
+        /// <exception cref="IOException"/>
+        public static HeartbeatMessage Parse(Stream input)
+        {
+            short type = TlsUtilities.ReadUint8(input);
+            if (!HeartbeatMessageType.IsValid(type))
+                throw new TlsFatalAlert(AlertDescription.illegal_parameter);
+
+            int payload_length = TlsUtilities.ReadUint16(input);
+            byte[] payloadBuffer = Streams.ReadAll(input);
+
+            byte[] payload = GetPayload(payloadBuffer, payload_length);
+            if (null == payload)
+            {
+                /*
+                 * RFC 6520 4. If the payload_length of a received HeartbeatMessage is too large, the received
+                 * HeartbeatMessage MUST be discarded silently.
+                 */
+                return null;
+            }
+
+            byte[] padding = GetPadding(payloadBuffer, payload_length);
+
+            return new HeartbeatMessage(type, payload, padding);
+        }
+
+        private static byte[] GetPayload(byte[] payloadBuffer, int payloadLength)
+        {
+            /*
+             * RFC 6520 4. The padding_length MUST be at least 16.
+             */
+            int maxPayloadLength = payloadBuffer.Length - 16;
+            if (payloadLength > maxPayloadLength)
+                return null;
+
+            return Arrays.CopyOf(payloadBuffer, payloadLength);
+        }
+
+        private static byte[] GetPadding(byte[] payloadBuffer, int payloadLength)
+        {
+            return TlsUtilities.CopyOfRangeExact(payloadBuffer, payloadLength, payloadBuffer.Length);
+        }
+    }
+}