Diff: udaes.cpp

Revision:

1:470744ec67c0

Parent:

0:14f07fd5037f

Child:

2:852dbf21ccf6

--- a/udaes.cpp	Mon May 29 03:56:57 2017 +0000
+++ b/udaes.cpp	Tue Jun 13 03:33:09 2017 +0000
@@ -3,48 +3,52 @@
 #include "AES.h"
 #include<cstring>
 
-Serial aespc(USBTX,USBRX);
-AES aes;
+Serial aespc(USBTX,USBRX);             //USB serial pin to print in the console
+AES aes;                               //Object for AES
 const char key[16] = { 0x2B, 0x7E, 0x15, 0x16, 0x28, 0xAE, 0xD2, 0xA6, 0xAB, 0xF7, 0x15, 0x88, 0x09, 0xCF, 0x4F, 0x3C }; //Key used for AES encryption and decryption
 const char iv[16] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F };  //Format used for AES-CBC encryption and decryption
-char message1[16];
-char encackmsg[16]; 
+char message1[16];     //Character array to store the decrypted message
+char encackmsg[16];    //Character array to store the encrypted message
 
+
+//Function to print the hexadecimal ASCII value of the data taking data and its length as parameters
 void printData(const void* data, size_t length)
 {
-    const char* dataBytes = (const char*)data;
-    for (size_t i = 0; i < length; i++) {
+    const char* dataBytes = (const char*)data;   //Casting the data to the character pointers
+    for (size_t i = 0; i < length; i++) {  
         if ((i % 8) == 0)
             printf("\n\t");
-        printf("0x%02X, ", dataBytes[i]);
+        printf("0x%02X, ", dataBytes[i]);       //Print the hexadecimal ASCII value of the respective character
     }
     printf("\n");
 }
 
 
-
+//Function for encryption of data taking char enc[] as a parameter
 char* encryptData(char enc[])
 {
-      printf("\nOriginal message: \"%s\"", enc);                  //Print the message to be encrypted
-     printData(enc, 16);                                         //Print the hexadecimal form of the data
+      printf("\nOriginal message: \"%s\"", enc);                 //Print the message to be encrypted i.e. enc[] 
+     printData(enc, 16);                                         //Print the hexadecimal ASCII form of the data
      aes.setup(key, AES::KEY_128, AES::MODE_CBC, iv);            //Setup the configuration of AES in 128 bit and CBC mode
-     aes.encrypt(enc, encackmsg, 16);                            //Encrypt the given message
+     aes.encrypt(enc, encackmsg, 16);                            //Encrypt the given message and store it in encackmsg
      aes.clear();                                                //clear the AES
-     printf("\nEncrypted message: \"%s\"\n", encackmsg);         //Print the encrypted data
-     printData(encackmsg, sizeof(encackmsg));                    //Print the hexadecimal form of the encrypted data
-     return encackmsg;
+     printf("\nEncrypted message: \"%s\"\n", encackmsg);         //Print the encrypted data stored in encackmsg
+     printData(encackmsg, sizeof(encackmsg));                    //Print the hexadecimal ASCII form of the encackmsg
+     char* encstr=encackmsg;                                     //Store the value of encackmsg in encstr
+     return encstr;                                              //Return encstr
 }
 
 
+//Function for decryption of data taking char dec[] as a parameter
 char* decryptData(char dec[])
 {
-     aespc.printf("\nThe received message is : %s",dec);            //Print the decrypted data to be encrypted
+     //aespc.printf("\nThe received message is : %s",dec);         //Print the decrypted data to be encrypted i.e. dec[]
      aes.setup(key, AES::KEY_128, AES::MODE_CBC, iv);            //Setup the configuration of AES in 128 bit and CBC mode
-     aes.decrypt(dec, message1, 16);                    //Decrypt the given encrypted data
+     aes.decrypt(dec, message1, 16);                    //Decrypt the given encrypted data and store it in message1
      aes.clear();                                                //clear the AES
-     printf("\nDecrypted message: \"%s\"", message1);            //Print the Decrypted data
-     printData(message1, 16);                      //Print the hexadecimal form of the Decrypted data
-     char* decstr=message1;
-     return decstr;
+     printf("\nDecrypted message: \"%s\"", message1);            //Print the Decrypted data stored in message1
+     printData(message1, 16);                      //Print the hexadecimal ASCII form of the message1
+     char* decstr=message1;                                      //Store the value of message1 in decstr
+     return decstr;                                              //Return decstr
 
 }
\ No newline at end of file