throw new IOException("SSH_MSG_CHANNEL_OPEN_FAILURE message has wrong size (" + msglen + ")");
TypesReader tr = new TypesReader(msg, 0, msglen);
tr.readByte(); // skip packet type
int id = tr.readUINT32(); /* sender channel */
Channel c = getChannel(id);
if (c == null)
throw new IOException("Unexpected SSH_MSG_CHANNEL_OPEN_FAILURE message for non-existent channel " + id);