Library for verifying digital signatures using RSA-2048 and SHA-256 on ESP32 and ESP8266
- Download the Library as ZIP files
- Launch the Arduino IDE on your computer.
- Import the Library: Go to "Sketch" in the menu bar and navigate to "Include Library" > "Add .ZIP Library...". This will open a file dialog.
- Locate the Library ZIP File: In the file dialog, navigate to the location where you downloaded the library ZIP file and select it. Click the "Open" button to import the library.
The example signatureVerification demonstrates the process of verifying a digital signature using a public key and the SHA256 hash algorithm. It provides instructions for key generation, signing a file, and creating the necessary signature array for inclusion in an Arduino sketch.
By following these instructions, Bob will be able to verify if a message is indeed coming from Alice by using her public key. This ensures the authenticity and integrity of the message, as only Alice's private key can produce a valid signature that can be verified using her public key.
Alice generate the private key:
- openssl genrsa -out priv_key.pem 2048 and the corresponding public key:
- openssl rsa -in priv_key_2048.pem -pubout > rsa_key_2048.pub sign the SHA256 hash with the private key:
- openssl dgst -sign priv_key_2048.pem -keyform PEM -sha256 -out textSigned.sign -binary Alice.txt create the array with the signature:
- xxd -i textSigned.sign > textSigned.h