ch.ethz.ssh2
Class DHGexParameters

java.lang.Object
  extended by ch.ethz.ssh2.DHGexParameters

public class DHGexParameters
extends java.lang.Object

A DHGexParameters object can be used to specify parameters for the diffie-hellman group exchange.

Depending on which constructor is used, either the use of a SSH_MSG_KEX_DH_GEX_REQUEST or SSH_MSG_KEX_DH_GEX_REQUEST_OLD can be forced.

Version:
$Id: DHGexParameters.java,v 1.3 2006/09/20 12:51:37 cplattne Exp $
Author:
Christian Plattner, plattner@inf.ethz.ch
See Also:
Connection.setDHGexParameters(DHGexParameters)

Field Summary
private static int MAX_ALLOWED
           
private  int max_group_len
           
private static int MIN_ALLOWED
           
private  int min_group_len
           
private  int pref_group_len
           
 
Constructor Summary
DHGexParameters()
          Same as calling DHGexParameters(1024, 1024, 4096).
DHGexParameters(int pref_group_len)
          This constructor can be used to force the sending of a SSH_MSG_KEX_DH_GEX_REQUEST_OLD request.
DHGexParameters(int min_group_len, int pref_group_len, int max_group_len)
          This constructor can be used to force the sending of a SSH_MSG_KEX_DH_GEX_REQUEST request.
 
Method Summary
 int getMax_group_len()
          Get the maximum group length.
 int getMin_group_len()
          Get the minimum group length.
 int getPref_group_len()
          Get the preferred group length.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

min_group_len

private final int min_group_len

pref_group_len

private final int pref_group_len

max_group_len

private final int max_group_len

MIN_ALLOWED

private static final int MIN_ALLOWED
See Also:
Constant Field Values

MAX_ALLOWED

private static final int MAX_ALLOWED
See Also:
Constant Field Values
Constructor Detail

DHGexParameters

public DHGexParameters()
Same as calling DHGexParameters(1024, 1024, 4096). This is also the default used by the Connection class.


DHGexParameters

public DHGexParameters(int pref_group_len)
This constructor can be used to force the sending of a SSH_MSG_KEX_DH_GEX_REQUEST_OLD request. Internally, the minimum and maximum group lengths will be set to zero.

Parameters:
pref_group_len - has to be >= 1024 and <= 8192

DHGexParameters

public DHGexParameters(int min_group_len,
                       int pref_group_len,
                       int max_group_len)
This constructor can be used to force the sending of a SSH_MSG_KEX_DH_GEX_REQUEST request.

Note: older OpenSSH servers don't understand this request, in which case you should use the DHGexParameters(int) constructor.

All values have to be >= 1024 and <= 8192. Furthermore, min_group_len <= pref_group_len <= max_group_len.

Parameters:
min_group_len -
pref_group_len -
max_group_len -
Method Detail

getMax_group_len

public int getMax_group_len()
Get the maximum group length.

Returns:
the maximum group length, may be zero if SSH_MSG_KEX_DH_GEX_REQUEST_OLD should be requested

getMin_group_len

public int getMin_group_len()
Get the minimum group length.

Returns:
minimum group length, may be zero if SSH_MSG_KEX_DH_GEX_REQUEST_OLD should be requested

getPref_group_len

public int getPref_group_len()
Get the preferred group length.

Returns:
the preferred group length