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macro_rules! stream_module (($stream_name:ident,
$xor_name:ident,
$xor_ic_name:ident,
$keybytes:expr,
$noncebytes:expr) => (
#[cfg(not(feature = "std"))] use prelude::*;
use libc::c_ulonglong;
use randombytes::randombytes_into;
/// Number of bytes in a `Key`.
pub const KEYBYTES: usize = $keybytes;
/// Number of bytes in a `Nonce`.
pub const NONCEBYTES: usize = $noncebytes;
new_type! {
/// `Key` for symmetric encryption
///
/// When a `Key` goes out of scope its contents
/// will be zeroed out
secret Key(KEYBYTES);
}
new_type! {
/// `Nonce` for symmetric encryption
nonce Nonce(NONCEBYTES);
}
/// `gen_key()` randomly generates a key for symmetric encryption
///
/// THREAD SAFETY: `gen_key()` is thread-safe provided that you have
/// called `sodiumoxide::init()` once before using any other function
/// from sodiumoxide.
pub fn gen_key() -> Key {
let mut key = [0; KEYBYTES];
randombytes_into(&mut key);
Key(key)
}
/// `stream()` produces a `len`-byte stream `c` as a function of a
/// secret key `k` and a nonce `n`.
pub fn stream(len: usize,
n: &Nonce,
k: &Key) -> Vec<u8> {
unsafe {
let mut c = vec![0u8; len];
$stream_name(c.as_mut_ptr(),
c.len() as c_ulonglong,
n.0.as_ptr(),
k.0.as_ptr());
c
}
}
/// `stream_xor()` encrypts a message `m` using a secret key `k` and a nonce `n`.
/// The `stream_xor()` function returns the ciphertext `c`.
///
/// `stream_xor()` guarantees that the ciphertext has the same length as the plaintext,
/// and is the plaintext xor the output of `stream()`.
/// Consequently `stream_xor()` can also be used to decrypt.
pub fn stream_xor(m: &[u8],
n: &Nonce,
k: &Key) -> Vec<u8> {
unsafe {
let mut c = vec![0u8; m.len()];
$xor_name(c.as_mut_ptr(),
m.as_ptr(),
m.len() as c_ulonglong,
n.0.as_ptr(),
k.0.as_ptr());
c
}
}
/// `stream_xor_inplace()` encrypts a message `m` using a secret key `k` and a nonce `n`.
/// The `stream_xor_inplace()` function encrypts the message in place.
///
/// `stream_xor_inplace()` guarantees that the ciphertext has the same length as
/// the plaintext, and is the plaintext xor the output of `stream_inplace()`.
/// Consequently `stream_xor_inplace()` can also be used to decrypt.
pub fn stream_xor_inplace(m: &mut [u8],
n: &Nonce,
k: &Key) {
unsafe {
$xor_name(m.as_mut_ptr(),
m.as_ptr(),
m.len() as c_ulonglong,
n.0.as_ptr(),
k.0.as_ptr());
}
}
/// `stream_xor_ic()` encrypts a message `m` using a secret key `k` and a nonce `n`,
/// it is similar to `stream_xor()` but allows the caller to set the value of the initial
/// block counter `ic`.
///
/// `stream_xor()` guarantees that the ciphertext has the same length as the plaintext,
/// and is the plaintext xor the output of `stream()`.
/// Consequently `stream_xor()` can also be used to decrypt.
pub fn stream_xor_ic(m: &[u8],
n: &Nonce,
ic: u64,
k: &Key) -> Vec<u8> {
unsafe {
let mut c = vec![0u8; m.len()];
$xor_ic_name(c.as_mut_ptr(),
m.as_ptr(),
m.len() as c_ulonglong,
n.0.as_ptr(),
ic as u64,
k.0.as_ptr());
c
}
}
/// `stream_xor_ic_inplace()` encrypts a message `m` using a secret key `k` and a nonce `n`,
/// it is similar to `stream_xor_inplace()` but allows the caller to set the value of the initial
/// block counter `ic`.
/// The `stream_xor_ic_inplace()` function encrypts the message in place.
///
/// `stream_xor_ic_inplace()` guarantees that the ciphertext has the same length as
/// the plaintext, and is the plaintext xor the output of `stream_inplace()`.
/// Consequently `stream_xor_ic_inplace()` can also be used to decrypt.
pub fn stream_xor_ic_inplace(m: &mut [u8],
n: &Nonce,
ic: u64,
k: &Key) {
unsafe {
$xor_ic_name(m.as_mut_ptr(),
m.as_ptr(),
m.len() as c_ulonglong,
n.0.as_ptr(),
ic as u64,
k.0.as_ptr());
}
}
#[cfg(test)]
mod test_m {
use super::*;
use crypto::nonce::gen_random_nonce;
#[test]
fn test_encrypt_decrypt() {
use randombytes::randombytes;
for i in 0..1024usize {
let k = gen_key();
let n = gen_random_nonce();
let m = randombytes(i);
let c = stream_xor(&m, &n, &k);
let m2 = stream_xor(&c, &n, &k);
assert!(m == m2);
}
}
#[test]
fn test_stream_xor() {
use randombytes::randombytes;
for i in 0..1024usize {
let k = gen_key();
let n = gen_random_nonce();
let m = randombytes(i);
let mut c = m.clone();
let s = stream(c.len(), &n, &k);
for (e, v) in c.iter_mut().zip(s.iter()) {
*e ^= *v;
}
let c2 = stream_xor(&m, &n, &k);
assert!(c == c2);
}
}
#[test]
fn test_stream_xor_inplace() {
use randombytes::randombytes;
for i in 0..1024usize {
let k = gen_key();
let n = gen_random_nonce();
let mut m = randombytes(i);
let mut c = m.clone();
let s = stream(c.len(), &n, &k);
for (e, v) in c.iter_mut().zip(s.iter()) {
*e ^= *v;
}
stream_xor_inplace(&mut m, &n, &k);
assert!(c == m);
}
}
#[test]
fn test_stream_xor_ic_same() {
use randombytes::randombytes;
for i in 0..1024usize {
let k = gen_key();
let n = gen_random_nonce();
let m = randombytes(i);
let c = stream_xor(&m, &n, &k);
let c_ic = stream_xor_ic(&m, &n, 0, &k);
assert_eq!(c, c_ic);
}
}
#[test]
fn test_stream_xor_ic_inplace() {
use randombytes::randombytes;
for i in 0..1024usize {
let k = gen_key();
let n = gen_random_nonce();
for j in 0..10 {
let mut m = randombytes(i);
let c = stream_xor_ic(&m, &n, j, &k);
stream_xor_ic_inplace(&mut m, &n, j, &k);
assert_eq!(m, c);
}
}
}
#[cfg(feature = "serde")]
#[test]
fn test_serialisation() {
use test_utils::round_trip;
for _ in 0..1024usize {
let k = gen_key();
let n: Nonce = gen_random_nonce();
round_trip(k);
round_trip(n);
}
}
}
#[cfg(feature = "benchmarks")]
#[cfg(test)]
mod bench_m {
extern crate test;
use super::*;
const BENCH_SIZES: [usize; 14] = [0, 1, 2, 4, 8, 16, 32, 64,
128, 256, 512, 1024, 2048, 4096];
#[bench]
fn bench_stream(b: &mut test::Bencher) {
let k = gen_key();
let n = gen_random_nonce();
b.iter(|| {
for size in BENCH_SIZES.iter() {
stream(*size, &n, &k);
}
});
}
}
));