A User Centric Security Model for Tamper-Resistant Devices

C.11 Implementation Helper Classes
152 KeyParameter myMacKey = new KeyParameter (MacKey) ;
153 CBCBlockCipherMac myAESMac = new CBCBlockCipherMac ( AESMacEngine ,
154 128) ;
155 ParametersWithIV ivparam = new ParametersWithIV (myMacKey ,
156 I n i t i a l i s a t i o n V e c t o r ) ;
157 myAESMac. i n i t ( ivparam ) ;
158 myAESMac. update ( i n b u f f , i n b u f f O f f s e t , inbuffLength ) ;
159 myAESMac. doFinal ( outbuff , o u t b u f f O f f s e t ) ;
160 }
161 boolean SignatureMethod ( byte [ ] inBuff , int i n B u f f O f f s e t , int
162 inBuffLength , byte [ ] outBuff , int
163 o u t B u f f O f f s e t , Key inKey , short SIGN_MODE)
164 throws InvalidKeyException ,
165 SignatureException {
166 ByteBuffer myTempByteBuffer = ByteBuffer . wrap ( inBuff ,
167 i n B u f f O f f s e t , inBuffLength ) ;
168 i f ( inKey == null && SIGN_MODE == this .SIGN_MODE_GENERATION) {
169 inKey = (Key) this . mySignatureGenerationKey ;
170 } else i f ( inKey == null && SIGN_MODE ==
171 this .SIGN_MODE_VERIFICATION) {
172 inKey = (Key) this . mySignatureVerificationKey ;
173 }
174 switch (SIGN_MODE) {
175 case SIGN_MODE_GENERATION: mySignature . i n i t S i g n ( ( PrivateKey )
176 inKey ) ;
177 mySignature . update ( myTempByteBuffer ) ;
178 mySignature . s i g n ( outBuff , o u t B u f f O f f s e t , 64) ;
179 return true ;
180 case SIGN_MODE_VERIFICATION:
181 mySignature . i n i t V e r i f y ( ( PublicKey ) inKey ) ;
182 mySignature . update ( myTempByteBuffer ) ;
183 return mySignature . v e r i f y ( outBuff , o u t B u f f O f f s e t , 64) ;
184 default :
185 System . out . p r i n t l n ( "ERROR−−−−−−−−−−−−WRONG MODE SELECTION" ) ;
186 }
187 return f a l s e ;
188 }
189 void GenerateDecryption ( byte [ ] i n b u f f , int i n b u f f O f f s e t , int
190 inbuffLength , byte [ ] outbuff , int
191 o u t b u f f O f f s e t , byte [ ] EnKey) throws
192 NoSuchAlgorithmException ,
193 InvalidKeyException ,
194 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 ,
195 NoSuchProviderException ,
196 BadPaddingException , NoSuchPaddingException ,
197 InvalidKeySpecException ,
198 ShortBufferException ,
199 InvalidAlgorithmParameterException {
200 try {
201 IvParameterSpec ivS = new IvParameterSpec ( I n i t i a l i s a t i o n V e c t o r ) ;
202 myAESKey = new SecretKeySpec (EnKey , "AES" ) ;
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