public byte[] getPayLoad(SshCrypto crypto) {
byte[] data = getData();
// packet length
if (data != null) packet_length = data.length + 5;
else packet_length = 5;
packet_length_array[3] = (byte) (packet_length & 0xff);
packet_length_array[2] = (byte) ((packet_length >> 8) & 0xff);
packet_length_array[1] = (byte) ((packet_length >> 16) & 0xff);
packet_length_array[0] = (byte) ((packet_length >> 24) & 0xff);
// padding
padding = new byte[(8 - (packet_length % 8))];
if (crypto == null) {
for (int i = 0; i < padding.length; i++) padding[i] = 0;
} else {
for (int i = 0; i < padding.length; i++) padding[i] = SshIO.getNotZeroRandomByte();
}
// Compute the crc of [ Padding, Packet type, Data ]
block = new byte[packet_length + padding.length];
System.arraycopy(padding, 0, block, 0, padding.length);
int offset = padding.length;
block[offset++] = getType();
if (packet_length > 5) {
System.arraycopy(data, 0, block, offset, data.length);
offset += data.length;
}
long crc = crc32(block, offset);
crc_array[3] = (byte) (crc & 0xff);
crc_array[2] = (byte) ((crc >> 8) & 0xff);
crc_array[1] = (byte) ((crc >> 16) & 0xff);
crc_array[0] = (byte) ((crc >> 24) & 0xff);
System.arraycopy(crc_array, 0, block, offset, 4);
// encrypt
if (crypto != null) block = crypto.encrypt(block);
byte[] full = new byte[block.length + 4];
System.arraycopy(packet_length_array, 0, full, 0, 4);
System.arraycopy(block, 0, full, 4, block.length);
return full;
}
