/*
* This file is part of "The Java Telnet Application".
*
* (c) Matthias L. Jugel, Marcus Mei�ner 1996-2002. All Rights Reserved.
* The file was changed by Radek Polak to work as midlet in MIDP 1.0
*
* Please visit http://javatelnet.org/ for updates and contact.
*
* --LICENSE NOTICE--
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
* --LICENSE NOTICE--
*/
package ssh.v1;
import ssh.SshIO;
import ssh.SshPacket;
/**
* @author Marcus Meissner
* @version $Id: SshPacket1.java,v 1.1 2006/01/14 01:56:00 karl Exp $
*/
public class SshPacket1 extends SshPacket {
private static final int PHASE_packet_length = 0;
private static final int PHASE_block = 1;
//SSH_RECEIVE_PACKET
private byte[] packet_length_array = new byte[4];
private int packet_length;
private byte[] padding;
private byte[] crc_array = new byte[4];
private byte[] block;
private byte[] decryptedBlock; // decrypted part (Padding + Type + Data + Check)
private int position;
private int phase_packet = PHASE_packet_length;
private SshCrypto crypto;
public SshPacket1() {
}
public SshPacket1( SshCrypto _crypto ) {
/* receiving packet */
crypto = _crypto;
}
public SshPacket1( byte newType ) {
packet_type = newType;
}
/**
* Return the mp-int at the position offset in the data First 2 bytes are
* the number of bits in the integer, msb first (for example, the value
* 0x00012345 would have 17 bits). The value zero has zero bits. It is
* permissible that the number of bits be larger than the real number of
* bits. The number of bits is followed by (bits + 7) / 8 bytes of binary
* data, msb first, giving the value of the integer.
*/
public byte[] getMpInt() {
return getBytes( ( getInt16() + 7 ) / 8 );
}
public void putMpInt( byte [] mpbytes ) {
byte[] xbytes;
int i;
for ( i = 0; ( i < mpbytes.length ) && ( mpbytes[i] == 0 ); i++ )
/* EMPTY */;
xbytes = new byte[mpbytes.length - i];
System.arraycopy( mpbytes, i, xbytes, 0, mpbytes.length - i );
putInt16( xbytes.length * 8 );
putBytes( xbytes );
}
public void putMpInt( BigInteger bi ) {
byte[] mpbytes = bi.toByteArray();
putMpInt( mpbytes );
}
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;
}
private boolean checkCrc() {
byte[] crc_arrayCheck = new byte[4];
long crcCheck;
crcCheck = crc32( decryptedBlock, decryptedBlock.length - 4 );
crc_arrayCheck[3] = (byte) ( crcCheck & 0xff );
crc_arrayCheck[2] = (byte) ( ( crcCheck >> 8 ) & 0xff );
crc_arrayCheck[1] = (byte) ( ( crcCheck >> 16 ) & 0xff );
crc_arrayCheck[0] = (byte) ( ( crcCheck >> 24 ) & 0xff );
/*if ( debug ) {
System.err.println( crc_arrayCheck[3] + " == " + crc_array[3] );
System.err.println( crc_arrayCheck[2] + " == " + crc_array[2] );
System.err.println( crc_arrayCheck[1] + " == " + crc_array[1] );
System.err.println( crc_arrayCheck[0] + " == " + crc_array[0] );
}*/
if ( crc_arrayCheck[3] != crc_array[3] )
return false;
if ( crc_arrayCheck[2] != crc_array[2] )
return false;
if ( crc_arrayCheck[1] != crc_array[1] )
return false;
if ( crc_arrayCheck[0] != crc_array[0] )
return false;
return true;
}
/**
* This table simply represent the results of eight shift/xor operations for
* all combinations of data and CRC register values. In other words, it
* caches all the possible resulting values such that they won't need to be
* computed.
*/
static private long crc32_tab[] = {
0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L, 0x706af48fL, 0xe963a535L, 0x9e6495a3L,
0x0edb8832L, 0x79dcb8a4L, 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L, 0x90bf1d91L,
0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL, 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L,
0x136c9856L, 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L, 0xfa0f3d63L, 0x8d080df5L,
0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L, 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L, 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L,
0x26d930acL, 0x51de003aL, 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L, 0xb8bda50fL,
0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L, 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL,
0x76dc4190L, 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL, 0x9fbfe4a5L, 0xe8b8d433L,
0x7807c9a2L, 0x0f00f934L, 0x9609a88eL, 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL, 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L,
0x65b0d9c6L, 0x12b7e950L, 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L, 0xfbd44c65L,
0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L, 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL,
0x4369e96aL, 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L, 0xaa0a4c5fL, 0xdd0d7cc9L,
0x5005713cL, 0x270241aaL, 0xbe0b1010L, 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L, 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL,
0xedb88320L, 0x9abfb3b6L, 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L, 0x73dc1683L,
0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L, 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L,
0xf00f9344L, 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL, 0x196c3671L, 0x6e6b06e7L,
0xfed41b76L, 0x89d32be0L, 0x10da7a5aL, 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L, 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL,
0xd80d2bdaL, 0xaf0a1b4cL, 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL, 0x4669be79L,
0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L, 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL,
0xc5ba3bbeL, 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L, 0x2cd99e8bL, 0x5bdeae1dL,
0x9b64c2b0L, 0xec63f226L, 0x756aa39cL, 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL, 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L,
0x86d3d2d4L, 0xf1d4e242L, 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L, 0x18b74777L,
0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL, 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L,
0xa00ae278L, 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L, 0x4969474dL, 0x3e6e77dbL,
0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L, 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L, 0xcdd70693L, 0x54de5729L, 0x23d967bfL,
0xb3667a2eL, 0xc4614ab8L, 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL, 0x2d02ef8dL
};
/**
* Compute the crc Cyclic Redundancy Check, with the polynomial 0xedb88320,
* The polynomial is
* X^32+X^26+X^23+X^22+X^16+X^12+X^11+X^10+X^8+X^7+X^5+X^4+X^2+X^1+X^0 We
* take it "backwards" and put the highest-order term in the lowest-order
* bit. The X^32 term is "implied"; the LSB is the X^31 term, etc. The X^0
* term (usually shown as "+1") results in the MSB being 1. so the poly is
* 0x04c11db7 (used for Ethernet) The buf will be the Padding, Packet type,
* and Data fields. The crc is computed before any encryption. R =X^n * M
* rem P M message P polynomial crc R : crc calculated. T(x) = x^n * M(x) +
* R(x) property: T rem P = 0
*/
// Return a 32-bit CRC of the byte using the feedback terms table
static public long crc32( byte[] s, int len ) {
int i;
long crc32val = 0;
for ( i = 0; i < len; i++ ) {
crc32val = crc32_tab[(int) ( ( crc32val ^ s[i] ) & 0xff )] ^ ( crc32val >> 8 );
}
return crc32val;
}
} //class