vpncloud/src/crypto/sodium.rs

107 lines
3.9 KiB
Rust

use std::mem;
use sodiumoxide::crypto::stream::chacha20::{Key as CryptoKey, Nonce, stream_xor_inplace, gen_nonce,
KEYBYTES, NONCEBYTES};
use sodiumoxide::crypto::auth::hmacsha512256::{Key as AuthKey, Tag, authenticate, verify, TAGBYTES};
use sodiumoxide::crypto::pwhash::{derive_key, SALTBYTES, Salt, HASHEDPASSWORDBYTES,
OPSLIMIT_INTERACTIVE, MEMLIMIT_INTERACTIVE};
use super::super::types::Error;
pub enum Crypto {
None,
ChaCha20HmacSha512256{crypto_key: CryptoKey, auth_key: AuthKey, nonce: Nonce}
}
fn inc_nonce(nonce: Nonce) -> Nonce {
unsafe {
let mut num: u64 = mem::transmute(nonce);
num = num.wrapping_add(1);
mem::transmute(num)
}
}
impl Crypto {
pub fn method(&self) -> u8 {
match self {
&Crypto::None => 0,
&Crypto::ChaCha20HmacSha512256{crypto_key: _, auth_key: _, nonce: _} => 1
}
}
pub fn nonce_bytes(&self) -> usize {
match self {
&Crypto::None => 0,
&Crypto::ChaCha20HmacSha512256{crypto_key: _, auth_key: _, nonce: _} => NONCEBYTES
}
}
pub fn auth_bytes(&self) -> usize {
match self {
&Crypto::None => 0,
&Crypto::ChaCha20HmacSha512256{crypto_key: _, auth_key: _, nonce: _} => TAGBYTES
}
}
pub fn from_shared_key(password: &str) -> Self {
let salt = "vpncloudVPNCLOUDvpncl0udVpnCloud";
assert_eq!(salt.len(), SALTBYTES);
let mut key = [0; HASHEDPASSWORDBYTES];
derive_key(&mut key, password.as_bytes(), &Salt::from_slice(salt.as_bytes()).unwrap(),
OPSLIMIT_INTERACTIVE, MEMLIMIT_INTERACTIVE).unwrap();
let mut crypto_key = CryptoKey([0; KEYBYTES]);
let mut auth_key = AuthKey([0; KEYBYTES]);
for i in 0..KEYBYTES {
crypto_key.0[i] = key[i];
}
for i in 0..KEYBYTES {
auth_key.0[i] = key[KEYBYTES+i];
}
Crypto::ChaCha20HmacSha512256{crypto_key: crypto_key, auth_key: auth_key, nonce: gen_nonce()}
}
pub fn decrypt(&self, mut buf: &mut [u8], nonce: &[u8], hash: &[u8]) -> Result<(), Error> {
match self {
&Crypto::None => unreachable!("This should never be called"),
&Crypto::ChaCha20HmacSha512256{ref crypto_key, ref auth_key, nonce: _} => {
let nonce = Nonce::from_slice(nonce).unwrap();
let hash = Tag::from_slice(hash).unwrap();
stream_xor_inplace(&mut buf, &nonce, crypto_key);
match verify(&hash, &buf, auth_key) {
true => Ok(()),
false => Err(Error::CryptoError("Decryption failed"))
}
}
}
}
pub fn encrypt(&mut self, mut buf: &mut [u8]) -> (Vec<u8>, Vec<u8>) {
match self {
&mut Crypto::None => unreachable!("This should never be called"),
&mut Crypto::ChaCha20HmacSha512256{ref crypto_key, ref auth_key, ref mut nonce} => {
*nonce = inc_nonce(*nonce);
let hash = authenticate(&buf, auth_key);
stream_xor_inplace(&mut buf, nonce, crypto_key);
(nonce.0.iter().map(|v| *v).collect(), hash.0.iter().map(|v| *v).collect())
}
}
}
}
#[test]
fn encrypt_decrypt() {
let mut sender = Crypto::from_shared_key("test");
let receiver = Crypto::from_shared_key("test");
let msg = "HelloWorld0123456789";
let mut buffer: Vec<u8> = msg.bytes().collect();
let (nonce1, hash1) = sender.encrypt(&mut buffer);
assert!(msg.as_bytes() != &buffer as &[u8]);
receiver.decrypt(&mut buffer, &nonce1, &hash1).unwrap();
assert_eq!(msg.as_bytes(), &buffer as &[u8]);
let (nonce2, hash2) = sender.encrypt(&mut buffer);
assert!(nonce1 != nonce2);
assert!(hash1 == hash2);
receiver.decrypt(&mut buffer, &nonce2, &hash2).unwrap();
assert_eq!(msg.as_bytes(), &buffer as &[u8]);
}