optimizations

AES.cpp

@@ -369,11 +369,13 @@ byte AES::cbc_encrypt (byte * plain, byte * cipher, int n_block, byte iv [N_BLOC
   return SUCCESS ;
 }
 
+/******************************************************************************/
+
 byte AES::cbc_encrypt (byte * plain, byte * cipher, int n_block)
 {
   while (n_block--)
     {
-      xor_block (iv, plain) ;
+	  xor_block (iv, plain) ;
       if (encrypt (iv, iv) != SUCCESS)
         return FAILURE ;
       copy_n_bytes (cipher, iv, N_BLOCK) ;
@@ -424,6 +426,24 @@ byte AES::cbc_decrypt (byte * cipher, byte * plain, int n_block, byte iv [N_BLOC
   return SUCCESS ;
 }
 
+/******************************************************************************/
+
+byte AES::cbc_decrypt (byte * cipher, byte * plain, int n_block)
+{   
+  while (n_block--)
+    {
+      byte tmp [N_BLOCK] ;
+      copy_n_bytes (tmp, cipher, N_BLOCK) ;
+      if (decrypt (cipher, plain) != SUCCESS)
+        return FAILURE ;
+      xor_block (plain, iv) ;
+      copy_n_bytes (iv, tmp, N_BLOCK) ;
+      plain  += N_BLOCK ;
+      cipher += N_BLOCK;
+    }
+  return SUCCESS ;
+}
+
 /*****************************************************************************/
 
 void AES::set_IV(unsigned long long int IVCl){
@@ -527,10 +547,20 @@ void AES::printArray(byte output[],int sizel)
 }
 
 
+/******************************************************************************/
+
+void AES::do_aes_encrypt(byte *plain,int size_p,byte *cipher,byte *key, int bits, byte ivl [N_BLOCK]){
+	calc_size_n_pad(size_p);
+	byte plain_p[get_size()];
+	padPlaintext(plain,plain_p);
+	int blocks = get_size() / N_BLOCK;
+	set_key (key, bits) ;
+	cbc_encrypt (plain_p, cipher, blocks, ivl);
+}
+
 /******************************************************************************/
 
 void AES::do_aes_encrypt(byte *plain,int size_p,byte *cipher,byte *key, int bits){
-	iv_inc();
 	calc_size_n_pad(size_p);
 	byte plain_p[get_size()];
 	padPlaintext(plain,plain_p);
@@ -541,13 +571,22 @@ void AES::do_aes_encrypt(byte *plain,int size_p,byte *cipher,byte *key, int bits
 
 /******************************************************************************/
 
-void AES::do_aes_dencrypt(byte *cipher,int size_c,byte *plain,byte *key, int bits, byte ivl [N_BLOCK]){
+void AES::do_aes_decrypt(byte *cipher,int size_c,byte *plain,byte *key, int bits, byte ivl [N_BLOCK]){
 	set_size(size_c);
 	int blocks = size_c / N_BLOCK;
 	set_key (key, bits);
 	cbc_decrypt (cipher,plain, blocks, ivl);
 }
 
+/******************************************************************************/
+
+void AES::do_aes_decrypt(byte *cipher,int size_c,byte *plain,byte *key, int bits){
+	set_size(size_c);
+	int blocks = size_c / N_BLOCK;
+	set_key (key, bits);
+	cbc_decrypt (cipher,plain, blocks);
+}
+
 
 /******************************************************************************/
 
@@ -556,4 +595,4 @@ double AES::millis(){
 	gettimeofday(&tv, NULL);
 	return (tv.tv_sec + 0.000001 * tv.tv_usec);
 }
-#endif
+#endif

AES.h

@@ -139,6 +139,16 @@ class AES
 	 *
 	 */
 	byte cbc_decrypt (byte * cipher, byte * plain, int n_block, byte iv [N_BLOCK]) ;
+
+	/** CBC decrypt a number of blocks (input and return an IV) 
+	 *  
+	 *  @param *cipher Pointer, points to the ciphertext that will be created.
+	 *  @param *plain Pointer, points to the plaintex.
+	 *  @param n_block integer, indicated the number of blocks to be ciphered.
+	 *  @Return 0 if SUCCESS or -1 if FAILURE
+	 *
+	 */
+	byte cbc_decrypt (byte * cipher, byte * plain, int n_block) ;
 
 	/** Sets IV (initialization vector) and IVC (IV counter).
 	 *  This function changes the ivc and iv variables needed for AES.
@@ -229,6 +239,18 @@ class AES
 	*/
 	void printArray(byte output[],int sizel);
 
+	/** User friendly implementation of AES-CBC encryption.
+	 * 
+	 * @param *plain pointer to the plaintext
+	 * @param size_p size of the plaintext
+	 * @param *cipher pointer to the ciphertext
+	 * @param *key pointer to the key that will be used.
+	 * @param bits bits of the encryption/decrpytion
+	 * @param ivl[N_BLOCK] the initialization vector IV that will be used for encryption.
+	 * @note The key will be stored in class variable.
+	 */
+	void do_aes_encrypt(byte *plain,int size_p,byte *cipher,byte *key, int bits, byte ivl [N_BLOCK]);
+
 	/** User friendly implementation of AES-CBC encryption.
 	 * 
 	 * @param *plain pointer to the plaintext
@@ -250,7 +272,18 @@ class AES
 	 * @param ivl[N_BLOCK] the initialization vector IV that will be used for decryption.
 	 * @note The key will be stored in class variable.
 	 */
-	void do_aes_dencrypt(byte *cipher,int size_c,byte *plain,byte *key, int bits, byte ivl [N_BLOCK]);
+	void do_aes_decrypt(byte *cipher,int size_c,byte *plain,byte *key, int bits, byte ivl [N_BLOCK]);
+
+	/** User friendly implementation of AES-CBC decryption.
+	 * 
+	 * @param *cipher pointer to the ciphertext
+	 * @param size_c size of the ciphertext
+	 * @param *plain pointer to the plaintext
+	 * @param *key pointer to the key that will be used.
+	 * @param bits bits of the encryption/decrpytion
+	 * @note The key will be stored in class variable.
+	 */
+	void do_aes_decrypt(byte *cipher,int size_c,byte *plain,byte *key, int bits);
 
 	#if defined(AES_LINUX)
 		/**

examples/aes/aes.pde

@@ -3,18 +3,18 @@
 
 AES aes ;
 
-byte key[] = "01234567899876543210012345678998";
+byte *key = (unsigned char*)"0123456789010123";
 
-byte plain[] = "TESTTESTTESTTESTTESTTESTTESTTESTTESTTEST";
+byte plain[] = "Add NodeAdd NodeAdd NodeAdd NodeAdd Node";
 
 //real iv = iv x2 ex: 01234567 = 0123456701234567
-unsigned long long int my_iv = 01234567;
+unsigned long long int my_iv = 36753562;
 
 void setup ()
 {
   Serial.begin (57600) ;
   printf_begin();
-  delay(1000);
+  delay(500);
   printf("\n===testng mode\n") ;
 
 //  otfly_test () ;
@@ -29,20 +29,31 @@ void loop ()
 
 void prekey (int bits)
 {
+  aes.iv_inc();
   byte iv [N_BLOCK] ;
-  byte plain_p[sizeof(plain) + (N_BLOCK - (sizeof(plain) % 16)) - 1];
-  byte cipher[sizeof(plain_p)];
-  aes.do_aes_encrypt(plain,sizeof(plain),cipher,key,bits);
+  byte plain_p[48];
+  byte cipher [48] ;
+  byte check [48] ;
+  unsigned long ms = micros ();
+  aes.set_IV(my_iv);
   aes.get_IV(iv);
-  aes.do_aes_dencrypt(cipher,aes.get_size(),plain_p,key,bits,iv);
-  //normally u have sizeof(cipher) but if its in the same sketch you cannot determin it dynamically
-
+  aes.do_aes_encrypt(plain,41,cipher,key,bits,iv);
+  Serial.print("Encryption took: ");
+  Serial.println(micros() - ms);
+  ms = micros ();
+  aes.set_IV(my_iv);
+  aes.get_IV(iv);
+  aes.do_aes_decrypt(cipher,48,check,key,bits,iv);
+  Serial.print("Decryption took: ");
+  Serial.println(micros() - ms);
   printf("\n\nPLAIN :");
-  aes.printArray(plain);
+  aes.printArray(plain,(bool)true);
   printf("\nCIPHER:");
-  aes.printArray(cipher);
-  printf("\nPlain2:");
-  aes.printArray(plain_p);
+  aes.printArray(cipher,(bool)false);
+  printf("\nCHECK :");
+  aes.printArray(check,(bool)true);
+  printf("\nIV    :");
+  aes.printArray(iv,16);
   printf("\n============================================================\n");
 }