use std::cmp::min;
use cryptoutil::{read_u32_le, write_u32_le};
use mac::{Mac, MacResult};
#[derive(Clone, Copy)]
pub struct Poly1305 {
r : [u32; 5],
h : [u32; 5],
pad : [u32; 4],
leftover : usize,
buffer : [u8; 16],
finalized : bool,
}
impl Poly1305 {
pub fn new(key: &[u8]) -> Poly1305 {
assert!(key.len() == 32);
let mut poly = Poly1305{ r: [0u32; 5], h: [0u32; 5], pad: [0u32; 4], leftover: 0, buffer: [0u8; 16], finalized: false };
poly.r[0] = (read_u32_le(&key[0..4]) ) & 0x3ffffff;
poly.r[1] = (read_u32_le(&key[3..7]) >> 2) & 0x3ffff03;
poly.r[2] = (read_u32_le(&key[6..10]) >> 4) & 0x3ffc0ff;
poly.r[3] = (read_u32_le(&key[9..13]) >> 6) & 0x3f03fff;
poly.r[4] = (read_u32_le(&key[12..16]) >> 8) & 0x00fffff;
poly.pad[0] = read_u32_le(&key[16..20]);
poly.pad[1] = read_u32_le(&key[20..24]);
poly.pad[2] = read_u32_le(&key[24..28]);
poly.pad[3] = read_u32_le(&key[28..32]);
poly
}
fn block(&mut self, m: &[u8]) {
let hibit : u32 = if self.finalized { 0 } else { 1 << 24 };
let r0 = self.r[0];
let r1 = self.r[1];
let r2 = self.r[2];
let r3 = self.r[3];
let r4 = self.r[4];
let s1 = r1 * 5;
let s2 = r2 * 5;
let s3 = r3 * 5;
let s4 = r4 * 5;
let mut h0 = self.h[0];
let mut h1 = self.h[1];
let mut h2 = self.h[2];
let mut h3 = self.h[3];
let mut h4 = self.h[4];
h0 += (read_u32_le(&m[0..4]) ) & 0x3ffffff;
h1 += (read_u32_le(&m[3..7]) >> 2) & 0x3ffffff;
h2 += (read_u32_le(&m[6..10]) >> 4) & 0x3ffffff;
h3 += (read_u32_le(&m[9..13]) >> 6) & 0x3ffffff;
h4 += (read_u32_le(&m[12..16]) >> 8) | hibit;
let d0 = (h0 as u64 * r0 as u64) + (h1 as u64 * s4 as u64) + (h2 as u64 * s3 as u64) + (h3 as u64 * s2 as u64) + (h4 as u64 * s1 as u64);
let mut d1 = (h0 as u64 * r1 as u64) + (h1 as u64 * r0 as u64) + (h2 as u64 * s4 as u64) + (h3 as u64 * s3 as u64) + (h4 as u64 * s2 as u64);
let mut d2 = (h0 as u64 * r2 as u64) + (h1 as u64 * r1 as u64) + (h2 as u64 * r0 as u64) + (h3 as u64 * s4 as u64) + (h4 as u64 * s3 as u64);
let mut d3 = (h0 as u64 * r3 as u64) + (h1 as u64 * r2 as u64) + (h2 as u64 * r1 as u64) + (h3 as u64 * r0 as u64) + (h4 as u64 * s4 as u64);
let mut d4 = (h0 as u64 * r4 as u64) + (h1 as u64 * r3 as u64) + (h2 as u64 * r2 as u64) + (h3 as u64 * r1 as u64) + (h4 as u64 * r0 as u64);
let mut c : u32;
c = (d0 >> 26) as u32; h0 = d0 as u32 & 0x3ffffff;
d1 += c as u64; c = (d1 >> 26) as u32; h1 = d1 as u32 & 0x3ffffff;
d2 += c as u64; c = (d2 >> 26) as u32; h2 = d2 as u32 & 0x3ffffff;
d3 += c as u64; c = (d3 >> 26) as u32; h3 = d3 as u32 & 0x3ffffff;
d4 += c as u64; c = (d4 >> 26) as u32; h4 = d4 as u32 & 0x3ffffff;
h0 += c * 5; c = h0 >> 26; h0 = h0 & 0x3ffffff;
h1 += c;
self.h[0] = h0;
self.h[1] = h1;
self.h[2] = h2;
self.h[3] = h3;
self.h[4] = h4;
}
fn finish(&mut self) {
if self.leftover > 0 {
self.buffer[self.leftover] = 1;
for i in self.leftover+1..16 {
self.buffer[i] = 0;
}
self.finalized = true;
let tmp = self.buffer;
self.block(&tmp);
}
let mut h0 = self.h[0];
let mut h1 = self.h[1];
let mut h2 = self.h[2];
let mut h3 = self.h[3];
let mut h4 = self.h[4];
let mut c : u32;
c = h1 >> 26; h1 = h1 & 0x3ffffff;
h2 += c; c = h2 >> 26; h2 = h2 & 0x3ffffff;
h3 += c; c = h3 >> 26; h3 = h3 & 0x3ffffff;
h4 += c; c = h4 >> 26; h4 = h4 & 0x3ffffff;
h0 += c * 5; c = h0 >> 26; h0 = h0 & 0x3ffffff;
h1 += c;
let mut g0 = h0.wrapping_add(5); c = g0 >> 26; g0 &= 0x3ffffff;
let mut g1 = h1.wrapping_add(c); c = g1 >> 26; g1 &= 0x3ffffff;
let mut g2 = h2.wrapping_add(c); c = g2 >> 26; g2 &= 0x3ffffff;
let mut g3 = h3.wrapping_add(c); c = g3 >> 26; g3 &= 0x3ffffff;
let mut g4 = h4.wrapping_add(c).wrapping_sub(1 << 26);
let mut mask = (g4 >> (32 - 1)).wrapping_sub(1);
g0 &= mask;
g1 &= mask;
g2 &= mask;
g3 &= mask;
g4 &= mask;
mask = !mask;
h0 = (h0 & mask) | g0;
h1 = (h1 & mask) | g1;
h2 = (h2 & mask) | g2;
h3 = (h3 & mask) | g3;
h4 = (h4 & mask) | g4;
h0 = ((h0 ) | (h1 << 26)) & 0xffffffff;
h1 = ((h1 >> 6) | (h2 << 20)) & 0xffffffff;
h2 = ((h2 >> 12) | (h3 << 14)) & 0xffffffff;
h3 = ((h3 >> 18) | (h4 << 8)) & 0xffffffff;
let mut f : u64;
f = h0 as u64 + self.pad[0] as u64 ; h0 = f as u32;
f = h1 as u64 + self.pad[1] as u64 + (f >> 32); h1 = f as u32;
f = h2 as u64 + self.pad[2] as u64 + (f >> 32); h2 = f as u32;
f = h3 as u64 + self.pad[3] as u64 + (f >> 32); h3 = f as u32;
self.h[0] = h0;
self.h[1] = h1;
self.h[2] = h2;
self.h[3] = h3;
}
}
impl Mac for Poly1305 {
fn input(&mut self, data: &[u8]) {
assert!(!self.finalized);
let mut m = data;
if self.leftover > 0 {
let want = min(16 - self.leftover, m.len());
for i in 0..want {
self.buffer[self.leftover+i] = m[i];
}
m = &m[want..];
self.leftover += want;
if self.leftover < 16 {
return;
}
let tmp = self.buffer;
self.block(&tmp);
self.leftover = 0;
}
while m.len() >= 16 {
self.block(&m[0..16]);
m = &m[16..];
}
for i in 0..m.len() {
self.buffer[i] = m[i];
}
self.leftover = m.len();
}
fn reset(&mut self) {
self.h = [0u32; 5];
self.leftover = 0;
self.finalized = false;
}
fn result(&mut self) -> MacResult {
let mut mac = [0u8; 16];
self.raw_result(&mut mac);
MacResult::new(&mac[..])
}
fn raw_result(&mut self, output: &mut [u8]) {
assert!(output.len() >= 16);
if !self.finalized{
self.finish();
}
write_u32_le(&mut output[0..4], self.h[0]);
write_u32_le(&mut output[4..8], self.h[1]);
write_u32_le(&mut output[8..12], self.h[2]);
write_u32_le(&mut output[12..16], self.h[3]);
}
fn output_bytes(&self) -> usize { 16 }
}
#[cfg(test)]
mod test {
use std::iter::repeat;
use poly1305::Poly1305;
use mac::Mac;
fn poly1305(key: &[u8], msg: &[u8], mac: &mut [u8]) {
let mut poly = Poly1305::new(key);
poly.input(msg);
poly.raw_result(mac);
}
#[test]
fn test_nacl_vector() {
let key = [
0xee,0xa6,0xa7,0x25,0x1c,0x1e,0x72,0x91,
0x6d,0x11,0xc2,0xcb,0x21,0x4d,0x3c,0x25,
0x25,0x39,0x12,0x1d,0x8e,0x23,0x4e,0x65,
0x2d,0x65,0x1f,0xa4,0xc8,0xcf,0xf8,0x80,
];
let msg = [
0x8e,0x99,0x3b,0x9f,0x48,0x68,0x12,0x73,
0xc2,0x96,0x50,0xba,0x32,0xfc,0x76,0xce,
0x48,0x33,0x2e,0xa7,0x16,0x4d,0x96,0xa4,
0x47,0x6f,0xb8,0xc5,0x31,0xa1,0x18,0x6a,
0xc0,0xdf,0xc1,0x7c,0x98,0xdc,0xe8,0x7b,
0x4d,0xa7,0xf0,0x11,0xec,0x48,0xc9,0x72,
0x71,0xd2,0xc2,0x0f,0x9b,0x92,0x8f,0xe2,
0x27,0x0d,0x6f,0xb8,0x63,0xd5,0x17,0x38,
0xb4,0x8e,0xee,0xe3,0x14,0xa7,0xcc,0x8a,
0xb9,0x32,0x16,0x45,0x48,0xe5,0x26,0xae,
0x90,0x22,0x43,0x68,0x51,0x7a,0xcf,0xea,
0xbd,0x6b,0xb3,0x73,0x2b,0xc0,0xe9,0xda,
0x99,0x83,0x2b,0x61,0xca,0x01,0xb6,0xde,
0x56,0x24,0x4a,0x9e,0x88,0xd5,0xf9,0xb3,
0x79,0x73,0xf6,0x22,0xa4,0x3d,0x14,0xa6,
0x59,0x9b,0x1f,0x65,0x4c,0xb4,0x5a,0x74,
0xe3,0x55,0xa5,
];
let expected = [
0xf3,0xff,0xc7,0x70,0x3f,0x94,0x00,0xe5,
0x2a,0x7d,0xfb,0x4b,0x3d,0x33,0x05,0xd9,
];
let mut mac = [0u8; 16];
poly1305(&key, &msg, &mut mac);
assert_eq!(&mac[..], &expected[..]);
let mut poly = Poly1305::new(&key);
poly.input(&msg[0..32]);
poly.input(&msg[32..96]);
poly.input(&msg[96..112]);
poly.input(&msg[112..120]);
poly.input(&msg[120..124]);
poly.input(&msg[124..126]);
poly.input(&msg[126..127]);
poly.input(&msg[127..128]);
poly.input(&msg[128..129]);
poly.input(&msg[129..130]);
poly.input(&msg[130..131]);
poly.raw_result(&mut mac);
assert_eq!(&mac[..], &expected[..]);
}
#[test]
fn donna_self_test() {
let wrap_key = [
0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
];
let wrap_msg = [
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
];
let wrap_mac = [
0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
];
let mut mac = [0u8; 16];
poly1305(&wrap_key, &wrap_msg, &mut mac);
assert_eq!(&mac[..], &wrap_mac[..]);
let total_key = [
0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0xff,
0xfe, 0xfd, 0xfc, 0xfb, 0xfa, 0xf9, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00,
];
let total_mac = [
0x64, 0xaf, 0xe2, 0xe8, 0xd6, 0xad, 0x7b, 0xbd,
0xd2, 0x87, 0xf9, 0x7c, 0x44, 0x62, 0x3d, 0x39,
];
let mut tpoly = Poly1305::new(&total_key);
for i in 0..256 {
let key: Vec<u8> = repeat(i as u8).take(32).collect();
let msg: Vec<u8> = repeat(i as u8).take(256).collect();
let mut mac = [0u8; 16];
poly1305(&key[..], &msg[0..i], &mut mac);
tpoly.input(&mac);
}
tpoly.raw_result(&mut mac);
assert_eq!(&mac[..], &total_mac[..]);
}
#[test]
fn test_tls_vectors() {
let key = b"this is 32-byte key for Poly1305";
let msg = [0u8; 32];
let expected = [
0x49, 0xec, 0x78, 0x09, 0x0e, 0x48, 0x1e, 0xc6,
0xc2, 0x6b, 0x33, 0xb9, 0x1c, 0xcc, 0x03, 0x07,
];
let mut mac = [0u8; 16];
poly1305(key, &msg, &mut mac);
assert_eq!(&mac[..], &expected[..]);
let msg = b"Hello world!";
let expected= [
0xa6, 0xf7, 0x45, 0x00, 0x8f, 0x81, 0xc9, 0x16,
0xa2, 0x0d, 0xcc, 0x74, 0xee, 0xf2, 0xb2, 0xf0,
];
poly1305(key, msg, &mut mac);
assert_eq!(&mac[..], &expected[..]);
}
}
#[cfg(all(test, feature = "with-bench"))]
mod bench {
use test::Bencher;
use mac::Mac;
use poly1305::Poly1305;
#[bench]
pub fn poly1305_10(bh: & mut Bencher) {
let mut mac = [0u8; 16];
let key = [0u8; 32];
let bytes = [1u8; 10];
bh.iter( || {
let mut poly = Poly1305::new(&key);
poly.input(&bytes);
poly.raw_result(&mut mac);
});
bh.bytes = bytes.len() as u64;
}
#[bench]
pub fn poly1305_1k(bh: & mut Bencher) {
let mut mac = [0u8; 16];
let key = [0u8; 32];
let bytes = [1u8; 1024];
bh.iter( || {
let mut poly = Poly1305::new(&key);
poly.input(&bytes);
poly.raw_result(&mut mac);
});
bh.bytes = bytes.len() as u64;
}
#[bench]
pub fn poly1305_64k(bh: & mut Bencher) {
let mut mac = [0u8; 16];
let key = [0u8; 32];
let bytes = [1u8; 65536];
bh.iter( || {
let mut poly = Poly1305::new(&key);
poly.input(&bytes);
poly.raw_result(&mut mac);
});
bh.bytes = bytes.len() as u64;
}
}