Implementing Triple DES on Java card

Hi, here is the implementation of Triple DES on Java card.

 /*  Package handson_crypto_des; import javacard. Framework. *; import javacard. Security. *; import javacardx. crypto. *;/***** class handson *  */   Public   Class Handsoncryptodes Extends  Javacard. Framework. Applet {  //  Globals  Secret ey secret ey; cipher ciphercbc;  Final   Short Dataoffset = (Short  ) Iso7816.offset _ CDATA;  Static   Byte [] Tripplepolicey = {( Byte ) 0x38 ,( Byte ) 0x12 ,( Byte ) 0xa4 ,(  Byte ) 0x19 ,( Byte ) 0xc6 ,( Byte ) 0x3b ,( Byte ) 0xe7 ,( Byte ) 0x71 ,(Byte ) 0x00 ,( Byte ) 0x12 ,( Byte ) 0x00 ,(  Byte ) 0x19 ,( Byte ) 0x80 ,( Byte ) 0x3b ,( Byte ) 0xe7 ,( Byte ) 0x71 ,( Byte ) 0x01 ,( Byte ) 0x12 ,( Byte ) 0x01 ,( Byte ) 0x01 ,( Byte ) 0x01 ,( Byte ) 0x03 ,( Byte ) 0xe7 ,( Byte ) 0x71 };  //  Constructor      Private Handsoncryptodes ( Byte Barray [], Short Boffset, Byte  Blength) {secret ey = (Cipher ey) keybuilder. buildkey (keybuilder. type_des, keybuilder. length_des3_3key, False  ); Ciphercbc = Cipher. getinstance (Cipher. alg_des_cbc_nopad, False  ); Register (barray ,(  Short ) (Boffset + 1 ), Barray [boffset]);}  //  Install      Public   Static   Void Install ( Byte Barray [],Short Boffset, Byte  Blength ){  New  Handsoncryptodes (barray, boffset, blength );}  Public   Void  Process (APDU ){  Byte [] Buf = APDU. getbuffer ();  If  (Selectingapplet ()){  Return ;} Dotrippedes (APDU );}  //  Encdecdes Method  //  Takes an input 24 byte message from the incomming APDU and encrypts it using  //  A des key. It then decrypts the cryptogram using the same des key.  //  Response APDU sends the message (24 bytes) plus cryptogram (24 bytes) plus decrypted message (24 bytes ))      Private   Void  Dotrippedes (APDU ){ Byte A [] = APDU. getbuffer ();  Short Incominglength = ( Short  ) (APDU. setincomingandreceive ());  If (Incominglength! = 24 ) Isoexception. throwit (iso7816.sw _ wrong_length );  //  Perform encryption and append results in APDU Buffer A [] automatically  //  Cipher ey cipher ey = (Cipher ey) keybuilder. buildkey (keybuilder. type_des, keybuilder. length_des3_3key, false ); Secret ey. setkey (tripplepolicey ,( Short ) 0 ); Ciphercbc. INIT (Cipher ey, cipher. mode_encrypt,  New   Byte [] {0, 0, 0, 0, 0, 0 },( Short ) 0 ,( Short ) 8 ); Ciphercbc. dofinal (,(  Short ) Dataoffset, incominglength, ,( Short ) (Dataoffset + 24 ); Ciphercbc. INIT (Cipher ey, cipher. mode_decrypt,  New  Byte [] {0, 0, 0, 0, 0, 0 },( Short ) 0 ,( Short ) 8 ); Ciphercbc. dofinal (,(  Short ) (Dataoffset + 24), incominglength, ,( Short ) (Dataoffset + 48 ));  //  Send results  APDU. setoutgoing (); APDU. setoutgoinglength ((  Short ) 72 ); APDU. sendbyteslong (,( Short ) Dataoffset ,( Short ) 72 );}} 

GP shell script and Output

 Mode_211enable_traceestablish_contextcard_connect -Readernumber 2 * reader name SCM microsystems Inc. scr33x USB Smart Card Reader 0 Select -Aid 01020304050607 Command --> 00a404000701020304050607wrapped command --> 00a404000701020304050607response & Lt; -- 9000 Send_apdu -SC 0-APDU 00aa109180102030405060708090a0b0c0d0e0f101112131415161718 command --> 00aa10000180102030405060708090a0b0c0d0e0f101112131415161718wrapped command --> 00aa213180102030405060708090a0b0c0d0e0f101112131415161718response <-- 0102030405060708090a0b0c0d0e0f101112131415161718 * 3cefff8cfebad556aed ** 98796a03111f15bbcd6adac61058a * 0102030405060708090a0b0c0d0e0f101112131415161718900 0 Card_disconnectrelease_context 

 

 

 

Corresponding Java Representation

 Import Java. Security. generalsecurityexception;  Import  Javax. crypto. cipher;  Import  Javax. crypto. spec. secretkeyspec;  /**  **  @ Author  Amit. Deshpande  */  Public   Class  Tripledes {  Byte [] Staticenc = hexconverter. decodehex ("3812a419c63be7710036919803be771011201010103e771". Tochararray ());  Private   Static Secretkeyspec getkeyspec ( Byte  [] Key ){  If (Key. Length = 16 ){  Byte [] Key24 = New   Byte [24 ]; System. arraycopy (key, 0, key24, 0, 16 ); System. arraycopy (key, 0, key24, 16, 8);  Return   New Secretkeyspec (key24, "desede" );}  Else  {  Return   New Secretkeyspec (key, "desede" );}}  Public   Static   Void  Main (string ARGs []) {tripledes = New Tripledes ();  Try  {Tripledes. tripledes ();}  Catch  (Exception e ){}}  Protected   Void Tripledes () Throws  Generalsecurityexception {cipher Cipher = Cipher. getinstance ("desede/CBC/nopadding" );  Byte [] DATA = hexconverter. decodehex ("0102030405060708090a0b0c0d0e0f101112131415161718". Tochararray (); Java. Security. spec. algorithmparameterspec alspec = New Javax. crypto. spec. ivparameterspec ( New   Byte [] {( Byte ) 0x00 ,( Byte ) 0x00 ,( Byte ) 0x00 ,( Byte ) 0x00 ,(  Byte ) 0x00 ,( Byte ) 0x00 ,( Byte ) 0x00 ,( Byte ) 0x00 }); Cipher. INIT (Cipher. encrypt_mode, getkeyspec (staticenc), alspec );  Byte [] Encrypteddata = Cipher. dofinal (data); system. Out. println ( "Encrypted data:" + Util. printbytes (encrypteddata ));}} 

Java output

 
Encrypted data: * 3cefff8cfebad556aed98796a03111f15bbcd6adac61058a *