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;
}
public int addPayload(byte[] buff, int boffset, int length) {
// byte newbuf[] = null;
int boffsetend = boffset + length;
while (boffset < boffsetend) {
switch (phase_packet) {
// 4 bytes
// Packet length: 32 bit unsigned integer
// gives the length of the packet, not including the length
// field
// and padding. maximum is 262144 bytes.
case PHASE_packet_length:
packet_length_array[position++] = buff[boffset++];
if (position >= 4) {
packet_length =
(packet_length_array[3] & 0xff)
+ ((packet_length_array[2] & 0xff) << 8)
+ ((packet_length_array[1] & 0xff) << 16)
+ ((packet_length_array[0] & 0xff) << 24);
position = 0;
phase_packet++;
if (packet_length > 262144) {
throw new IllegalStateException("SshPacket1: Invalid packet_length " + packet_length);
}
int block_length = 8 * (packet_length / 8 + 1);
block = new byte[block_length];
// System.out.println( "PACKET LENGTH " + packet_length + " BLOCK LENGTH " +
// block_length );
}
break; // switch (phase_packet)
// 8*(packet_length/8 +1) bytes
case PHASE_block:
if (block.length > position) {
if (boffset < boffsetend) {
int amount = boffsetend - boffset;
if (amount > block.length - position) amount = block.length - position;
System.arraycopy(buff, boffset, block, position, amount);
boffset += amount;
position += amount;
}
}
if (position == block.length) { // the block is complete
int blockOffset = 0;
// padding
int padding_length = (int) (8 - (packet_length % 8));
padding = new byte[padding_length];
if (crypto != null) decryptedBlock = crypto.decrypt(block);
else decryptedBlock = block;
if (decryptedBlock.length != padding_length + packet_length) {
throw new IllegalStateException("SshPacket1: invalid decrypted packet length");
}
for (int i = 0; i < padding.length; i++) padding[i] = decryptedBlock[blockOffset++];
// packet type
packet_type = decryptedBlock[blockOffset++];
byte[] data;
// data
if (packet_length > 5) {
data = new byte[packet_length - 5];
System.arraycopy(decryptedBlock, blockOffset, data, 0, packet_length - 5);
blockOffset += packet_length - 5;
} else data = null;
putData(data);
// crc
for (int i = 0; i < crc_array.length; i++) crc_array[i] = decryptedBlock[blockOffset++];
if (!checkCrc()) {
throw new IllegalStateException("SshPacket1: CRC wrong in received packet!");
}
return boffset;
}
break;
}
}
return boffset;
}
