A User Centric Security Model for Tamper-Resistant Devices

C.11 Implementation Helper Classes
203 myAESCipher = Cipher . g e t I n s t a n c e ( "AES/CBC/NoPadding" ) ;
204 myAESCipher . i n i t ( Cipher .DECRYPT_MODE, myAESKey, ivS ) ;
205 myAESCipher . doFinal ( i n b u f f , i n b u f f O f f s e t , inbuffLength , outbuff ,
206 o u t b u f f O f f s e t ) ;
207 } catch ( I l l e g a l B l o c k S i z e E x c e p t i o n ce ) {
208 System . out . p r i n t l n ( " Error at l i k e n 140 : " + ce . getMessage ( ) +
209 "\ nInput Length " + inbuffLength ) ;
210 }
211 }
212 void GenerateEncryption ( byte [ ] i n b u f f , int i n b u f f O f f s e t , int
213 inbuffLength , byte [ ] outbuff , int
214 o u t b u f f O f f s e t , byte [ ] EnKey) throws
215 NoSuchAlgorithmException ,
216 InvalidKeyException ,
217 I l l e g a l B l o c k S i z e E x c e p t i o n ,
218 NoSuchProviderException ,
219 BadPaddingException , NoSuchPaddingException ,
220 InvalidKeySpecException ,
221 ShortBufferException ,
222 InvalidAlgorithmParameterException {
223 IvParameterSpec ivS = new IvParameterSpec ( I n i t i a l i s a t i o n V e c t o r ) ;
224 myAESKey = new SecretKeySpec (EnKey , "AES" ) ;
225 myAESCipher = Cipher . g e t I n s t a n c e ( "AES/CBC/NoPadding" ) ;
226 myAESCipher . i n i t ( Cipher .ENCRYPT_MODE, myAESKey, ivS ) ;
227 myAESCipher . doFinal ( i n b u f f , i n b u f f O f f s e t , inbuffLength , outbuff ,
228 o u t b u f f O f f s e t ) ;
229 }
230 public P r o t o c o l H e l p e r C l a s s ( ) {
231 S e c u r i t y . addProvider (new
232 org . b o u n c y c a s t l e . j c e . p r o v i d e r . BouncyCastleProvider ( ) ) ;
233 }
234 public PublicKey getPublicKey ( ) {
235 return this . mySignatureVerificationKey ;
236 }
237 public byte [ ] getRandomNumber ( ) {
238 try {
239 myRNG = SecureRandom . g e t I n s t a n c e ( "SHA1PRNG" ) ;
240 myRNG. nextBytes ( this . ServiceProviderRandom ) ;
241 } catch ( Exception cE ) {
242 System . out . p r i n t l n (
243 " Error ? : P r o t o c o l H e l p e r C l a s s . getRandomNumber :
" + cE . getMessage ( ) ) ;
244 }
245 return this . ServiceProviderRandom ;
246 }
247 public s t a t i c S t r i n g byteToString ( byte [ ] inArray ) {
248 byte [ ] HEX_CHAR_TABLE = {
249 ( byte ) ' 0 ' , ( byte ) ' 1 ' , ( byte ) ' 2 ' , ( byte ) ' 3 ' , ( byte ) ' 4 ' , ( byte )
250 ' 5 ' , ( byte ) ' 6 ' , ( byte ) ' 7 ' , ( byte ) ' 8 ' , ( byte ) ' 9 ' , ( byte ) ' a ' ,
251 ( byte ) ' b ' , ( byte ) ' c ' , ( byte ) ' d ' , ( byte ) ' e ' , ( byte ) ' f '
252 } ;
438