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encrypt.c
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encrypt.c
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/**
* @file: encrypt.c
* @subject: 48430 Embedded C - Assignment 3
* @developers:
* @name: Owen Buckingham@student_id: 12466076
* @name: @student_id:
* @name: @student_id:
* @name: @student_id:
*
* @date: 08-09-2017
*
* @TODO:
*
*/
#include "encrypt.h"
#include <stdlib.h>
/* malloc, free */
#include <string.h>
/* strlen */
/**
* @name encryptFile
* @brief encrypts file
*
* See Header for details
*
*/
char *encryptFile(char plaintext[], int textLen, char password[]) {
/* We use an XOR algorithm to obscure the plaintext. */
/* Loop counters for the plaintext and password. */
int ptext_count, pwcount;
pwcount = 0;
char *output = malloc(sizeof(char)*textLen);
if (output == NULL) {
return NULL;
}
for (ptext_count = 0; ptext_count < textLen; ptext_count++) {
output[ptext_count] = plaintext[ptext_count] ^ password[pwcount];
pwcount++;
if ((size_t)pwcount >= strlen(password)) {
pwcount = 0;
}
}
return output;
}
/**
* @name decryptsFile
* @brief decrypts file
*
* See Header for details
*
*/
char *decryptFile(char encryptText[], int textLen, char password[]) {
return encryptFile(encryptText, textLen, password);
}