connectbot/sshlib

package com.trilead.ssh2.packets;

import java.io.IOException;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;

/**
 * Packet format described here:
 * https://tools.ietf.org/html/draft-ietf-curdle-ssh-ext-info-15#section-2.3
 */
public class PacketExtInfo
{
    private byte[] payload;

    private final Map<String, String> extNameToValue;

    public byte[] getPayload()
    {
        if (payload == null)
        {
            TypesWriter tw = new TypesWriter();
            tw.writeByte(Packets.SSH_MSG_EXT_INFO);
            tw.writeUINT32(extNameToValue.size());
            for (Entry<String, String> nameAndValue : extNameToValue.entrySet())
            {
                tw.writeString(nameAndValue.getKey());
                tw.writeString(nameAndValue.getValue());
            }
            payload = tw.getBytes();
        }
        return payload;
    }

    public Map<String, String> getExtNameToValue()
    {
        return extNameToValue;
    }

    public PacketExtInfo(byte[] payload, int off, int len) throws IOException
    {
        this.payload = new byte[len];
        System.arraycopy(payload, off, this.payload, 0, len);

        TypesReader tr = new TypesReader(payload, off, len);
        int packet_type = tr.readByte();
        if (packet_type != Packets.SSH_MSG_EXT_INFO)
        {
            throw new IOException("This is not a SSH_MSG_EXT_INFO! ("
                    + packet_type + ")");
        }

        // Type has dynamic number of fields
        // First int tells us how many pairs to expect
        int numExtensions = tr.readUINT32();
        if (numExtensions >= 1024) {
            throw new IOException("Too many entries in ext info packet");
        }

        Map<String, String> extNameToValue_ = new HashMap<>(numExtensions);
        for (int i = 0; i < numExtensions; i++)
        {
            String name = tr.readString();
            String value = tr.readString();
            extNameToValue_.put(name, value);
        }
        extNameToValue = Collections.unmodifiableMap(extNameToValue_);

        if (tr.remain() != 0)
        {
            throw new IOException("Padding in SSH_MSG_EXT_INFO packet!");
        }
    }

    public PacketExtInfo(Map<String, String> extNameToValue)
    {
        this.extNameToValue = Collections.unmodifiableMap(new HashMap<>(extNameToValue));
    }
}