protected int check2048(Class c, int _max) throws Exception {
DH dh = (com.jcraft.jsch.DH) (c.newInstance());
dh.init();
byte[] foo = new byte[257];
foo[1] = (byte) 0xdd;
foo[256] = 0x73;
dh.setP(foo);
byte[] bar = {(byte) 0x02};
dh.setG(bar);
try {
dh.getE();
_max = 2048;
} catch (Exception e) {
}
return _max;
}
public void init(Session session, byte[] V_S, byte[] V_C, byte[] I_S, byte[] I_C)
throws Exception {
this.session = session;
this.V_S = V_S;
this.V_C = V_C;
this.I_S = I_S;
this.I_C = I_C;
try {
Class c = Class.forName(session.getConfig(hash));
sha = (HASH) (c.newInstance());
sha.init();
} catch (Exception e) {
System.err.println(e);
}
buf = new Buffer();
packet = new Packet(buf);
try {
Class c = Class.forName(session.getConfig("dh"));
// Since JDK8, SunJCE has lifted the keysize restrictions
// from 1024 to 2048 for DH.
preferred = max = check2048(c, max);
dh = (com.jcraft.jsch.DH) (c.newInstance());
dh.init();
} catch (Exception e) {
throw e;
}
packet.reset();
buf.putByte((byte) SSH_MSG_KEX_DH_GEX_REQUEST);
buf.putInt(min);
buf.putInt(preferred);
buf.putInt(max);
session.write(packet);
if (JSch.getLogger().isEnabled(Logger.INFO)) {
JSch.getLogger()
.log(
Logger.INFO,
"SSH_MSG_KEX_DH_GEX_REQUEST(" + min + "<" + preferred + "<" + max + ") sent");
JSch.getLogger().log(Logger.INFO, "expecting SSH_MSG_KEX_DH_GEX_GROUP");
}
state = SSH_MSG_KEX_DH_GEX_GROUP;
}
