+++ /dev/null
-// ring has a garbage API so its use is avoided, but rust-crypto doesn't have RFC-variant poly1305
-// Instead, we steal rust-crypto's implementation and tweak it to match the RFC.
-
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-// This is a port of Andrew Moons poly1305-donna
-// https://github.com/floodyberry/poly1305-donna
-
-#[cfg(not(feature = "fuzztarget"))]
-mod real_chachapoly {
- use crypto::aead::{AeadEncryptor,AeadDecryptor};
- use crypto::chacha20::ChaCha20;
- use crypto::symmetriccipher::SynchronousStreamCipher;
- use crypto::poly1305::Poly1305;
- use crypto::mac::Mac;
- use crypto::util::fixed_time_eq;
-
- use util::byte_utils;
-
- #[derive(Clone, Copy)]
- pub struct ChaCha20Poly1305RFC {
- cipher : ChaCha20,
- mac: Poly1305,
- finished: bool,
- data_len: usize,
- aad_len: u64,
- }
-
- impl ChaCha20Poly1305RFC {
- #[inline]
- fn pad_mac_16(mac: &mut Poly1305, len: usize) {
- if len % 16 != 0 {
- mac.input(&[0; 16][0..16 - (len % 16)]);
- }
- }
- pub fn new(key: &[u8], nonce: &[u8], aad: &[u8]) -> ChaCha20Poly1305RFC {
- assert!(key.len() == 16 || key.len() == 32);
- assert!(nonce.len() == 12);
-
- // Ehh, I'm too lazy to *also* tweak ChaCha20 to make it RFC-compliant
- assert!(nonce[0] == 0 && nonce[1] == 0 && nonce[2] == 0 && nonce[3] == 0);
-
- let mut cipher = ChaCha20::new(key, &nonce[4..]);
- let mut mac_key = [0u8; 64];
- let zero_key = [0u8; 64];
- cipher.process(&zero_key, &mut mac_key);
-
- let mut mac = Poly1305::new(&mac_key[..32]);
- mac.input(aad);
- ChaCha20Poly1305RFC::pad_mac_16(&mut mac, aad.len());
-
- ChaCha20Poly1305RFC {
- cipher: cipher,
- mac: mac,
- finished: false,
- data_len: 0,
- aad_len: aad.len() as u64,
- }
- }
- }
-
- impl AeadEncryptor for ChaCha20Poly1305RFC {
- fn encrypt(&mut self, input: &[u8], output: &mut [u8], out_tag: &mut [u8]) {
- assert!(input.len() == output.len());
- assert!(self.finished == false);
- self.cipher.process(input, output);
- self.data_len += input.len();
- self.mac.input(output);
- ChaCha20Poly1305RFC::pad_mac_16(&mut self.mac, self.data_len);
- self.finished = true;
- self.mac.input(&byte_utils::le64_to_array(self.aad_len));
- self.mac.input(&byte_utils::le64_to_array(self.data_len as u64));
- self.mac.raw_result(out_tag);
- }
- }
-
- impl AeadDecryptor for ChaCha20Poly1305RFC {
- fn decrypt(&mut self, input: &[u8], output: &mut [u8], tag: &[u8]) -> bool {
- assert!(input.len() == output.len());
- assert!(self.finished == false);
-
- self.finished = true;
-
- self.mac.input(input);
-
- self.data_len += input.len();
- ChaCha20Poly1305RFC::pad_mac_16(&mut self.mac, self.data_len);
- self.mac.input(&byte_utils::le64_to_array(self.aad_len));
- self.mac.input(&byte_utils::le64_to_array(self.data_len as u64));
-
- let mut calc_tag = [0u8; 16];
- self.mac.raw_result(&mut calc_tag);
- if fixed_time_eq(&calc_tag, tag) {
- self.cipher.process(input, output);
- true
- } else {
- false
- }
- }
- }
-}
-#[cfg(not(feature = "fuzztarget"))]
-pub use self::real_chachapoly::ChaCha20Poly1305RFC;
-
-#[cfg(feature = "fuzztarget")]
-mod fuzzy_chachapoly {
- use crypto::aead::{AeadEncryptor,AeadDecryptor};
-
- #[derive(Clone, Copy)]
- pub struct ChaCha20Poly1305RFC {
- tag: [u8; 16],
- finished: bool,
- }
- impl ChaCha20Poly1305RFC {
- pub fn new(key: &[u8], nonce: &[u8], _aad: &[u8]) -> ChaCha20Poly1305RFC {
- assert!(key.len() == 16 || key.len() == 32);
- assert!(nonce.len() == 12);
-
- // Ehh, I'm too lazy to *also* tweak ChaCha20 to make it RFC-compliant
- assert!(nonce[0] == 0 && nonce[1] == 0 && nonce[2] == 0 && nonce[3] == 0);
-
- let mut tag = [0; 16];
- tag.copy_from_slice(&key[0..16]);
-
- ChaCha20Poly1305RFC {
- tag,
- finished: false,
- }
- }
- }
-
- impl AeadEncryptor for ChaCha20Poly1305RFC {
- fn encrypt(&mut self, input: &[u8], output: &mut [u8], out_tag: &mut [u8]) {
- assert!(input.len() == output.len());
- assert!(self.finished == false);
-
- output.copy_from_slice(&input);
- out_tag.copy_from_slice(&self.tag);
- self.finished = true;
- }
- }
-
- impl AeadDecryptor for ChaCha20Poly1305RFC {
- fn decrypt(&mut self, input: &[u8], output: &mut [u8], tag: &[u8]) -> bool {
- assert!(input.len() == output.len());
- assert!(self.finished == false);
-
- if tag[..] != self.tag[..] { return false; }
- output.copy_from_slice(input);
- self.finished = true;
- true
- }
- }
-}
-#[cfg(feature = "fuzztarget")]
-pub use self::fuzzy_chachapoly::ChaCha20Poly1305RFC;