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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);
}
}
}
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