A User Centric Security Model for Tamper-Resistant Devices

C.2 Online Attestation Mechanism
168 public void p r o c e s s (APDU apdu )throws ISOException {
169 byte [ ] apduBuffer = apdu . g e t B u f f e r ( ) ;
170 i f ( s e l e c t i n g A p p l e t ( ) ) {
171 this . i n i t i a l i s e ( ) ;
172 return ;
173 }
174 i f ( apduBuffer [ ISO7816 .OFFSET_CLA] != CLA) {
175 ISOException . throwIt (SW_CLASSNOTSUPPORTED) ;
176 }
177 r e c e i v i n g B u f f e r = null ;
178 b y t e s L e f t = 0 ;
179 b y t e s L e f t = apdu . getIncomingLength ( ) ;
180 r e c e i v i n g B u f f e r = JCSystem . makeTransientByteArray ( bytesLeft ,
181 JCSystem .MEMORY_TYPE_TRANSIENT_DESELECT) ;
182 readCount = ( short ) ( ( short ) apdu . setIncomingAndReceive ( ) ) ;
183 rCount = 0 ;
184 i f ( b y t e s L e f t > 0) {
185 rCount = U t i l . arrayCopyNonAtomic ( apduBuffer ,
186 ISO7816 .OFFSET_EXT_CDATA, r e c e i v i n g B u f f e r , rCount , readCount ) ;
187 b y t e s L e f t −= readCount ;
188 }
189 while ( b y t e s L e f t > 0) {
190 try {
191 readCount = apdu . r e c e i v e B y t e s ( ( short ) 0) ;
192 rCount = U t i l . arrayCopyNonAtomic ( apduBuffer , ( short ) 0 ,
193 r e c e i v i n g B u f f e r , rCount , readCount ) ;
194 b y t e s L e f t −= readCount ;
195 } catch ( Exception aE) {
196 ISOException . throwIt ( ( short ) 0x7AAA) ;
197 }
198 }
199 byte [ ] c h a l l e n g e = JCSystem . makeTransientByteArray ( ( short ) 128 ,
200 JCSystem .MEMORY_TYPE_TRANSIENT_DESELECT) ;
201 byte [ ] randomnumber = JCSystem . makeTransientByteArray ( ( short ) 128 ,
202 JCSystem .MEMORY_TYPE_TRANSIENT_DESELECT) ;
203 U t i l . arrayCopyNonAtomic ( r e c e i v i n g B u f f e r ,
204 ( short ) 0 , c h a l l e n g e , ( short ) 0 , ( short ) 16) ;
205 U t i l . arrayCopyNonAtomic ( r e c e i v i n g B u f f e r ,
206 ( short ) 16 , randomNumber , ( short ) 0 , ( short ) 16) ;
207 r e s p o n s e B u f f e r = JCSystem . makeTransientByteArray ( ( short ) 128 ,
208 JCSystem .MEMORY_TYPE_TRANSIENT_DESELECT) ;
209 s e l f t e s t P r o c e s s ( ) ;
210 JCSystem . r e q u e s t O b j e c t D e l e t i o n ( ) ;
211 apdu . setOutgoing ( ) ;
212 apdu . setOutgoingLength ( ( short ) r e s p o n s e B u f f e r . l e n g t h ) ;
213 apdu . sendBytesLong ( r e s p o n s e B u f f e r , ( short ) 0 ,
214 ( short ) r e s p o n s e B u f f e r . l e n g t h ) ;
215 JCSystem . r e q u e s t O b j e c t D e l e t i o n ( ) ;
216 }
217
218 void s e l f t e s t P r o c e s s ( ) {
271