view src/com/trilead/ssh2/DHGexParameters.java @ 316:6b424bb783a2
ganymed
add ecdsa key support everywhere
author
Carl Byington <carl@five-ten-sg.com>
date
Wed, 30 Jul 2014 16:39:13 -0700 (2014-07-30)
parents
0ce5cc452d02
children
line source
+ −
+ − package com.trilead.ssh2;
+ −
+ − /**
+ − * A <code>DHGexParameters</code> object can be used to specify parameters for
+ − * the diffie-hellman group exchange.
+ − * <p>
+ − * Depending on which constructor is used, either the use of a
+ − * <code>SSH_MSG_KEX_DH_GEX_REQUEST</code> or <code>SSH_MSG_KEX_DH_GEX_REQUEST_OLD</code>
+ − * can be forced.
+ − *
+ − * @see Connection#setDHGexParameters(DHGexParameters)
+ − * @author Christian Plattner, plattner@trilead.com
+ − * @version $Id: DHGexParameters.java,v 1.1 2007/10/15 12:49:56 cplattne Exp $
+ − */
+ −
+ − public class DHGexParameters {
+ − private final int min_group_len;
+ − private final int pref_group_len;
+ − private final int max_group_len;
+ −
+ − private static final int MIN_ALLOWED = 1024;
+ − private static final int MAX_ALLOWED = 8192;
+ −
+ − /**
+ − * Same as calling {@link #DHGexParameters(int, int, int) DHGexParameters(1024, 1024, 4096)}.
+ − * This is also the default used by the Connection class.
+ − *
+ − */
+ − public DHGexParameters() {
+ − this(1024, 1024, 4096);
+ − }
+ −
+ − /**
+ − * This constructor can be used to force the sending of a
+ − * <code>SSH_MSG_KEX_DH_GEX_REQUEST_OLD</code> request.
+ − * Internally, the minimum and maximum group lengths will
+ − * be set to zero.
+ − *
+ − * @param pref_group_len has to be >= 1024 and <= 8192
+ − */
+ − public DHGexParameters(int pref_group_len) {
+ − if ((pref_group_len < MIN_ALLOWED) || (pref_group_len > MAX_ALLOWED))
+ − throw new IllegalArgumentException("pref_group_len out of range!");
+ −
+ − this.pref_group_len = pref_group_len;
+ − this.min_group_len = 0;
+ − this.max_group_len = 0;
+ − }
+ −
+ − /**
+ − * This constructor can be used to force the sending of a
+ − * <code>SSH_MSG_KEX_DH_GEX_REQUEST</code> request.
+ − * <p>
+ − * Note: older OpenSSH servers don't understand this request, in which
+ − * case you should use the {@link #DHGexParameters(int)} constructor.
+ − * <p>
+ − * All values have to be >= 1024 and <= 8192. Furthermore,
+ − * min_group_len <= pref_group_len <= max_group_len.
+ − *
+ − * @param min_group_len
+ − * @param pref_group_len
+ − * @param max_group_len
+ − */
+ − public DHGexParameters(int min_group_len, int pref_group_len, int max_group_len) {
+ − if ((min_group_len < MIN_ALLOWED) || (min_group_len > MAX_ALLOWED))
+ − throw new IllegalArgumentException("min_group_len out of range!");
+ −
+ − if ((pref_group_len < MIN_ALLOWED) || (pref_group_len > MAX_ALLOWED))
+ − throw new IllegalArgumentException("pref_group_len out of range!");
+ −
+ − if ((max_group_len < MIN_ALLOWED) || (max_group_len > MAX_ALLOWED))
+ − throw new IllegalArgumentException("max_group_len out of range!");
+ −
+ − if ((pref_group_len < min_group_len) || (pref_group_len > max_group_len))
+ − throw new IllegalArgumentException("pref_group_len is incompatible with min and max!");
+ −
+ − if (max_group_len < min_group_len)
+ − throw new IllegalArgumentException("max_group_len must not be smaller than min_group_len!");
+ −
+ − this.min_group_len = min_group_len;
+ − this.pref_group_len = pref_group_len;
+ − this.max_group_len = max_group_len;
+ − }
+ −
+ − /**
+ − * Get the maximum group length.
+ − *
+ − * @return the maximum group length, may be <code>zero</code> if
+ − * SSH_MSG_KEX_DH_GEX_REQUEST_OLD should be requested
+ − */
+ − public int getMax_group_len() {
+ − return max_group_len;
+ − }
+ −
+ − /**
+ − * Get the minimum group length.
+ − *
+ − * @return minimum group length, may be <code>zero</code> if
+ − * SSH_MSG_KEX_DH_GEX_REQUEST_OLD should be requested
+ − */
+ − public int getMin_group_len() {
+ − return min_group_len;
+ − }
+ −
+ − /**
+ − * Get the preferred group length.
+ − *
+ − * @return the preferred group length
+ − */
+ − public int getPref_group_len() {
+ − return pref_group_len;
+ − }
+ − }