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#![allow(unsafe_code)]
use {aead, c, error, polyfill};
use core;
const CHACHA20_KEY_LEN: usize = 256 / 8;
const POLY1305_STATE_LEN: usize = 256;
const POLY1305_KEY_LEN: usize = 32;
pub static CHACHA20_POLY1305: aead::Algorithm = aead::Algorithm {
key_len: CHACHA20_KEY_LEN,
init: init,
seal: chacha20_poly1305_seal,
open: chacha20_poly1305_open,
};
fn chacha20_poly1305_seal(ctx: &[u64; aead::KEY_CTX_BUF_ELEMS],
nonce: &[u8; aead::NONCE_LEN], in_out: &mut [u8],
tag_out: &mut [u8; aead::TAG_LEN], ad: &[u8])
-> Result<(), error::Unspecified> {
seal(chacha20_poly1305_update, ctx, nonce, in_out, tag_out, ad)
}
fn chacha20_poly1305_open(ctx: &[u64; aead::KEY_CTX_BUF_ELEMS],
nonce: &[u8; aead::NONCE_LEN], in_out: &mut [u8],
in_prefix_len: usize,
tag_out: &mut [u8; aead::TAG_LEN], ad: &[u8])
-> Result<(), error::Unspecified> {
open(chacha20_poly1305_update, ctx, nonce, in_out, in_prefix_len, tag_out,
ad)
}
fn chacha20_poly1305_update(state: &mut [u8; POLY1305_STATE_LEN], ad: &[u8],
ciphertext: &[u8]) {
fn update_padded_16(state: &mut [u8; POLY1305_STATE_LEN], data: &[u8]) {
poly1305_update(state, data);
if data.len() % 16 != 0 {
static PADDING: [u8; 16] = [0u8; 16];
poly1305_update(state, &PADDING[..PADDING.len() - (data.len() % 16)])
}
}
update_padded_16(state, ad);
update_padded_16(state, ciphertext);
poly1305_update_length(state, ad.len());
poly1305_update_length(state, ciphertext.len());
}
pub static CHACHA20_POLY1305_OLD: aead::Algorithm = aead::Algorithm {
key_len: CHACHA20_KEY_LEN,
init: init,
seal: chacha20_poly1305_old_seal,
open: chacha20_poly1305_old_open,
};
fn chacha20_poly1305_old_seal(ctx: &[u64; aead::KEY_CTX_BUF_ELEMS],
nonce: &[u8; aead::NONCE_LEN], in_out: &mut [u8],
tag_out: &mut [u8; aead::TAG_LEN], ad: &[u8])
-> Result<(), error::Unspecified> {
seal(chacha20_poly1305_update_old, ctx, nonce, in_out, tag_out, ad)
}
fn chacha20_poly1305_old_open(ctx: &[u64; aead::KEY_CTX_BUF_ELEMS],
nonce: &[u8; aead::NONCE_LEN], in_out: &mut [u8],
in_prefix_len: usize,
tag_out: &mut [u8; aead::TAG_LEN], ad: &[u8])
-> Result<(), error::Unspecified> {
open(chacha20_poly1305_update_old, ctx, nonce, in_out, in_prefix_len,
tag_out, ad)
}
fn chacha20_poly1305_update_old(state: &mut [u8; POLY1305_STATE_LEN],
ad: &[u8], ciphertext: &[u8]) {
poly1305_update(state, ad);
poly1305_update_length(state, ad.len());
poly1305_update(state, ciphertext);
poly1305_update_length(state, ciphertext.len());
}
pub fn init(ctx_buf: &mut [u8], key: &[u8]) -> Result<(), error::Unspecified> {
ctx_buf[..key.len()].copy_from_slice(key);
Ok(())
}
fn seal(update: UpdateFn, ctx: &[u64; aead::KEY_CTX_BUF_ELEMS],
nonce: &[u8; aead::NONCE_LEN], in_out: &mut [u8],
tag_out: &mut [u8; aead::TAG_LEN], ad: &[u8])
-> Result<(), error::Unspecified> {
let chacha20_key = try!(ctx_as_key(ctx));
let mut counter = make_counter(1, nonce);
debug_assert!(core::mem::align_of_val(chacha20_key) >= 4);
debug_assert!(core::mem::align_of_val(&counter) >= 4);
unsafe {
GFp_ChaCha20_ctr32(in_out.as_mut_ptr(), in_out.as_ptr(), in_out.len(),
chacha20_key, &counter);
}
counter[0] = 0;
aead_poly1305(update, tag_out, chacha20_key, &counter, ad, in_out);
Ok(())
}
fn open(update: UpdateFn, ctx: &[u64; aead::KEY_CTX_BUF_ELEMS],
nonce: &[u8; aead::NONCE_LEN], in_out: &mut [u8], in_prefix_len: usize,
tag_out: &mut [u8; aead::TAG_LEN], ad: &[u8])
-> Result<(), error::Unspecified> {
let chacha20_key = try!(ctx_as_key(ctx));
let mut counter = make_counter(0, nonce);
{
let ciphertext = &in_out[in_prefix_len..];
aead_poly1305(update, tag_out, chacha20_key, &counter, ad, ciphertext);
}
counter[0] = 1;
debug_assert!(core::mem::align_of_val(chacha20_key) >= 4);
debug_assert!(core::mem::align_of_val(&counter) >= 4);
unsafe {
if cfg!(any(target_arch = "arm", target_arch = "x86")) &&
in_prefix_len != 0 {
GFp_ChaCha20_ctr32(in_out[in_prefix_len..].as_mut_ptr(),
in_out[in_prefix_len..].as_ptr(),
in_out.len() - in_prefix_len, chacha20_key,
&counter);
core::ptr::copy(in_out[in_prefix_len..].as_ptr(),
in_out.as_mut_ptr(), in_out.len() - in_prefix_len);
} else {
GFp_ChaCha20_ctr32(in_out.as_mut_ptr(),
in_out[in_prefix_len..].as_ptr(),
in_out.len() - in_prefix_len, chacha20_key,
&counter);
}
}
Ok(())
}
fn ctx_as_key(ctx: &[u64; aead::KEY_CTX_BUF_ELEMS])
-> Result<&[u32; CHACHA20_KEY_LEN / 4], error::Unspecified> {
slice_as_array_ref!(
&polyfill::slice::u64_as_u32(ctx)[..(CHACHA20_KEY_LEN / 4)],
CHACHA20_KEY_LEN / 4)
}
#[inline]
fn make_counter(counter: u32, nonce: &[u8; aead::NONCE_LEN]) -> [u32; 4] {
use polyfill::slice::u32_from_le_u8;
[counter.to_le(),
u32_from_le_u8(slice_as_array_ref!(&nonce[0..4], 4).unwrap()),
u32_from_le_u8(slice_as_array_ref!(&nonce[4..8], 4).unwrap()),
u32_from_le_u8(slice_as_array_ref!(&nonce[8..12], 4).unwrap())]
}
type UpdateFn = fn(state: &mut [u8; POLY1305_STATE_LEN], ad: &[u8],
ciphertext: &[u8]);
fn aead_poly1305(update: UpdateFn, tag_out: &mut [u8; aead::TAG_LEN],
chacha20_key: &[u32; CHACHA20_KEY_LEN / 4],
counter: &[u32; 4], ad: &[u8], ciphertext: &[u8]) {
debug_assert_eq!(counter[0], 0);
let mut poly1305_key = [0u8; POLY1305_KEY_LEN];
debug_assert!(core::mem::align_of_val(chacha20_key) >= 4);
debug_assert!(core::mem::align_of_val(&counter) >= 4);
unsafe {
GFp_ChaCha20_ctr32(poly1305_key.as_mut_ptr(), poly1305_key.as_ptr(),
POLY1305_KEY_LEN, chacha20_key, &counter);
}
let mut ctx = [0u8; POLY1305_STATE_LEN];
poly1305_init(&mut ctx, &poly1305_key);
update(&mut ctx, ad, ciphertext);
poly1305_finish(&mut ctx, tag_out);
}
fn poly1305_update_length(ctx: &mut [u8; POLY1305_STATE_LEN], len: usize) {
let mut j = len;
let mut length_bytes = [0u8; 8];
for b in &mut length_bytes {
*b = j as u8;
j >>= 8;
}
poly1305_update(ctx, &length_bytes);
}
#[inline(always)]
fn poly1305_init(state: &mut [u8; POLY1305_STATE_LEN],
key: &[u8; POLY1305_KEY_LEN]) {
unsafe {
GFp_poly1305_init(state, key)
}
}
#[inline(always)]
fn poly1305_finish(state: &mut [u8; POLY1305_STATE_LEN],
tag_out: &mut [u8; aead::TAG_LEN]) {
unsafe {
GFp_poly1305_finish(state, tag_out)
}
}
#[inline(always)]
fn poly1305_update(state: &mut [u8; POLY1305_STATE_LEN], in_: &[u8]) {
unsafe {
GFp_poly1305_update(state, in_.as_ptr(), in_.len())
}
}
extern {
fn GFp_ChaCha20_ctr32(out: *mut u8, in_: *const u8, in_len: c::size_t,
key: &[u32; CHACHA20_KEY_LEN / 4],
counter: &[u32; 4]);
fn GFp_poly1305_init(state: &mut [u8; POLY1305_STATE_LEN],
key: &[u8; POLY1305_KEY_LEN]);
fn GFp_poly1305_finish(state: &mut [u8; POLY1305_STATE_LEN],
mac: &mut [u8; aead::TAG_LEN]);
fn GFp_poly1305_update(state: &mut [u8; POLY1305_STATE_LEN],
in_: *const u8, in_len: c::size_t);
}
#[cfg(test)]
mod tests {
use {aead, c, polyfill, test};
use super::{GFp_ChaCha20_ctr32, CHACHA20_KEY_LEN, make_counter};
bssl_test!(test_poly1305, bssl_poly1305_test_main);
#[test]
pub fn test_chacha20_poly1305() {
aead::tests::test_aead(&aead::CHACHA20_POLY1305,
"crypto/cipher/test/chacha20_poly1305_tests.txt");
}
#[test]
pub fn test_chacha20_poly1305_old() {
aead::tests::test_aead(&aead::CHACHA20_POLY1305_OLD,
"crypto/cipher/test/chacha20_poly1305_old_tests.txt");
}
#[test]
pub fn test_poly1305_state_len() {
assert_eq!((super::POLY1305_STATE_LEN + 255) / 256,
(GFp_POLY1305_STATE_LEN + 255) / 256);
}
#[test]
pub fn chacha20_tests() {
test::from_file("src/aead/chacha_tests.txt", |section, test_case| {
assert_eq!(section, "");
let key_bytes = test_case.consume_bytes("Key");
let mut key = [0u32; CHACHA20_KEY_LEN / 4];
for ki in 0..(CHACHA20_KEY_LEN / 4) {
let kb =
slice_as_array_ref!(&key_bytes[ki * 4..][..4], 4).unwrap();
key[ki] = polyfill::slice::u32_from_le_u8(kb);
}
let ctr = test_case.consume_usize("Ctr");
let nonce_bytes = test_case.consume_bytes("Nonce");
let nonce = slice_as_array_ref!(&nonce_bytes,
aead::NONCE_LEN).unwrap();
let ctr = make_counter(ctr as u32, &nonce);
let input = test_case.consume_bytes("Input");
let output = test_case.consume_bytes("Output");
let mut in_out_buf = vec![0u8; input.len() + 276];
for len in 0..(input.len() + 1) {
chacha20_test_case_inner(&key, &ctr, &input[..len],
&output[..len], len, &mut in_out_buf);
}
Ok(())
});
}
fn chacha20_test_case_inner(key: &[u32; CHACHA20_KEY_LEN / 4],
ctr: &[u32; 4], input: &[u8], expected: &[u8],
len: usize, in_out_buf: &mut [u8]) {
unsafe {
GFp_ChaCha20_ctr32(in_out_buf.as_mut_ptr(), input[..len].as_ptr(),
len, key, &ctr);
}
assert_eq!(&in_out_buf[..len], expected);
let max_offset =
if cfg!(any(target_arch = "x86", target_arch = "arm")) {
0
} else {
259
};
for alignment in 0..16 {
for offset in 0..(max_offset + 1) {
in_out_buf[alignment+offset..][..len].copy_from_slice(input);
unsafe {
GFp_ChaCha20_ctr32(in_out_buf[alignment..].as_mut_ptr(),
in_out_buf[alignment + offset..].as_ptr(),
len, key, ctr);
assert_eq!(&in_out_buf[alignment..][..len], expected);
}
}
}
}
extern {
static GFp_POLY1305_STATE_LEN: c::size_t;
}
}