Encryption

Recipe	Crates	Categories
Use the RSA Algorithm

Encryption transforms readable data (plaintext) into an unreadable format (ciphertext) to protect its confidentiality. Decryption reverses this process, restoring the original plaintext from the ciphertext using a secret key.

Use the RSA Algorithm

RSA (Rivest-Shamir-Adleman) is one of the most widely used public-key cryptosystems for secure data transmission. It relies on the mathematical properties of prime numbers to generate a pair of keys: a public key and a private key. The public key is used to encrypt data, which can only be decrypted by the corresponding private key, ensuring that only the intended recipient can access the information.

rsa⮳ is a pure Rust RSA implementation. It allows you to generate RSA key pairs (public and private keys), encrypt data with the public key, and decrypt data with the corresponding private key. The crate also supports digital signatures, enabling you to sign data with the private key and verify the signature with the public key. rsa⮳ offers various functionalities for working with RSA keys, including loading and saving keys in different formats (like PEM), and provides implementations of different padding schemes (like PKCS#1 v1.5 padding and PSS padding).

// Operating System's Random Number Generator
use rand::rngs::OsRng;
// Encryption using PKCS#1 v1.5 padding.
use rsa::Pkcs1v15Encrypt;
use rsa::RsaPrivateKey;
use rsa::RsaPublicKey;

// RSA encryption and decryption
//
// In this example, we
// - generate a 2048-bit RSA private key using `RsaPrivateKey::new`.
// - derive the corresponding public key using `RsaPublicKey::from`.
// - encrypt a message to be encrypted using the public key with
// `PaddingScheme::new_pkcs1v15_encrypt`.
// - decrypt the message using the private key with the same padding scheme.
//
// Read the security section of https://docs.rs/rsa/

fn main() {
    // Define the message to be encrypted
    let message = b"Secret message";
    println!(
        "Original message: {:?}",
        String::from_utf8(message.to_vec()).unwrap()
    );

    // Generate a 2048-bit private key
    let mut rng = OsRng;
    let bits = 2048;
    let private_key =
        RsaPrivateKey::new(&mut rng, bits).expect("failed to generate a key");

    // Derive the public key from the private key
    let public_key = RsaPublicKey::from(&private_key);

    // Encrypt the message using the public key
    let encrypted_message = public_key
        .encrypt(&mut rng, Pkcs1v15Encrypt, &message[..])
        .expect("failed to encrypt");

    println!("Encrypted message: {:?}", encrypted_message);

    // Decrypt the message using the private key
    let decrypted_message = private_key
        .decrypt(Pkcs1v15Encrypt, &encrypted_message)
        .expect("failed to decrypt");

    assert_eq!(message.to_vec(), decrypted_message);

    println!(
        "Decrypted message: {:?}",
        String::from_utf8(decrypted_message).unwrap()
    );
}