diff --git a/Cargo.toml b/Cargo.toml index f973284..8bfb9ff 100644 --- a/Cargo.toml +++ b/Cargo.toml @@ -6,3 +6,4 @@ edition = "2021" # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html [dependencies] +crypto_box = "0.8.2" \ No newline at end of file diff --git a/src/bin/client.rs b/src/bin/client.rs index 0c8930b..f298f4c 100644 --- a/src/bin/client.rs +++ b/src/bin/client.rs @@ -1,5 +1,9 @@ use std::io::Write; use std::net::TcpStream; +use crypto_box::{ + aead::{Aead, AeadCore, OsRng}, + SalsaBox, PublicKey, SecretKey +}; fn main() { let port: u32 = 7878; @@ -16,9 +20,67 @@ fn main() { if n == 0 { break; // Beenden bei EOF } - println!("Sending {}", buffer); + // + // Encryption + // + + // Generate a random secret key. + // NOTE: The secret key bytes can be accessed by calling `secret_key.as_bytes()` + let alice_secret_key = SecretKey::generate(&mut OsRng); + + // Get the public key for the secret key we just generated + let alice_public_key_bytes = alice_secret_key.public_key().as_bytes().clone(); + + // Obtain your recipient's public key. + let bob_public_key = PublicKey::from([ + 0xe8, 0x98, 0xc, 0x86, 0xe0, 0x32, 0xf1, 0xeb, + 0x29, 0x75, 0x5, 0x2e, 0x8d, 0x65, 0xbd, 0xdd, + 0x15, 0xc3, 0xb5, 0x96, 0x41, 0x17, 0x4e, 0xc9, + 0x67, 0x8a, 0x53, 0x78, 0x9d, 0x92, 0xc7, 0x54, + ]); + + // Create a `SalsaBox` by performing Diffie-Hellman key agreement between + // the two keys. + let alice_box = SalsaBox::new(&bob_public_key, &alice_secret_key); + + // Get a random nonce to encrypt the message under + let nonce = SalsaBox::generate_nonce(&mut OsRng); + + // Message to encrypt + let plaintext = buffer.trim().as_bytes(); + + // Encrypt the message using the box + let ciphertext = alice_box.encrypt(&nonce, &plaintext[..]).expect("Fehler"); + + println!("Sending {0} as {1:?}", buffer.trim(), plaintext); stream.write(buffer.as_bytes()).unwrap(); - println!("Sent {}, awaiting reply ...", buffer); + + // + // Decryption + // + + // Either side can encrypt or decrypt messages under the Diffie-Hellman key + // they agree upon. The example below shows Bob's side. + let bob_secret_key = SecretKey::from([ + 0xb5, 0x81, 0xfb, 0x5a, 0xe1, 0x82, 0xa1, 0x6f, + 0x60, 0x3f, 0x39, 0x27, 0xd, 0x4e, 0x3b, 0x95, + 0xbc, 0x0, 0x83, 0x10, 0xb7, 0x27, 0xa1, 0x1d, + 0xd4, 0xe7, 0x84, 0xa0, 0x4, 0x4d, 0x46, 0x1b + ]); + + // Deserialize Alice's public key from bytes + let alice_public_key = PublicKey::from(alice_public_key_bytes); + + // Bob can compute the same `SalsaBox` as Alice by performing the + // key agreement operation. + let bob_box = SalsaBox::new(&alice_public_key, &bob_secret_key); + + // Decrypt the message, using the same randomly generated nonce + let decrypted_plaintext = bob_box.decrypt(&nonce, &ciphertext[..]).expect("Fehler"); + let dec_plain_plaintext = std::str::from_utf8(&*decrypted_plaintext).expect("Nö"); + assert_eq!(&plaintext[..], &decrypted_plaintext[..]); + + println!("Sent {0:?} as cypher: {1:?}, decrypted: {2:?}, {3}", plaintext, ciphertext, decrypted_plaintext, dec_plain_plaintext); } Err(error) => { println!("error: {error}");