55 lines
2.2 KiB
Markdown
55 lines
2.2 KiB
Markdown
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# esp32-Encrypt
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This little example project will focus on how to cipher or decipher data with AES-128 in ECB mode, on the Arduino core running on the ESP32. Based on the examples mentioned on [techtutorialsx.com](https://techtutorialsx.com/2018/05/10/esp32-arduino-decrypt-aes-128-in-ecb-mode/) and [github.com](https://github.com/suculent/thinx-aes-lib) i have created the class Cipher to encrypt and decrypt a whole string with variable length. To store the result on the internal storage of the ESP32, the class CSPIFFS is quite helpfull to achieve this aim.
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Here is a little arduino console output picture to visualize project achievements:
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<p align="center"><img width="95%" src="demo.png"></p>
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## Quick start
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To use my created class, you only have to include the [Cipher.h](./src/Cipher.h) file in your current Arduino sketch and create an object of it. Now you have to set a secure cipher key to encrypt your data (in this example a simple string). The encryption result can be stored in a string with calling the function encryptString(). Decrypting the encrypted data can be achieved by using the decryptString() function.
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``` bash
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#include "Cipher.h"
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Cipher * cipher = new Cipher();
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void setup() {
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char * key = "abcdefghijklmnop";
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cipher->setKey(key);
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String data = "ESP32 AES128bit Encryption example";
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String cipherString = cipher->encryptString(data);
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String decipheredString = cipher->decryptString(cipherString);
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}
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void loop() {
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}
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```
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## Using the internal storage for saving purposes
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If you want to save the encrypted string on the internal storage (e.g use case of a secure config file), you have to include the [SPIFFSTest.h](./src/SPIFFSTest.h). Storing and loading the content form Spiffs is now very easly. You just have to call the method writeFile() to save a string in a file and the method getFile() to load the content of a file into an string which will be used to decrypt.
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``` bash
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#include "SPIFFSTest.h"
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...
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CSPIFFS mSpiffs;
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void setup() {
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SPIFFS.begin(true);
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...
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mSpiffs.writeFile(SPIFFS, "/test.txt", cipher->encryptString(data) );
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String decipheredString = cipher->decryptString(mSpiffs.getFile(SPIFFS, "/test.txt"));
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}
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void loop() {
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}
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```
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