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|
use std::net::TcpStream;
use std::time::Duration;
use std::io::{Read, Write};
use std::cmp;
use crypto::digest::Digest;
use crypto::blake2b::Blake2b;
use sodiumoxide::crypto::stream::*;
use rand::{OsRng, Rng};
use protobuf::Message;
use protobuf::parse_from_bytes;
use integer_encoding::{VarIntReader, VarIntWriter};
use errors::*;
use network_msgs::*;
use metadata_msgs::Index;
#[derive(Debug)]
pub enum DatNetMessage {
Feed(Feed),
Handshake(Handshake),
Info(Info),
Have(Have),
Unhave(Unhave),
Want(Want),
Unwant(Unwant),
Request(Request),
Cancel(Cancel),
Data(Data),
}
fn msg_code(msg: &DatNetMessage) -> u8 {
match msg {
&DatNetMessage::Feed(_) => 0,
&DatNetMessage::Handshake(_) => 1,
&DatNetMessage::Info(_) => 2,
&DatNetMessage::Have(_) => 3,
&DatNetMessage::Unhave(_) => 4,
&DatNetMessage::Want(_) => 5,
&DatNetMessage::Unwant(_) => 6,
&DatNetMessage::Request(_) => 7,
&DatNetMessage::Cancel(_) => 8,
&DatNetMessage::Data(_) => 9,
}
}
fn msg_sugar(msg: &DatNetMessage) -> &Message {
match msg {
&DatNetMessage::Feed(ref m) => m,
&DatNetMessage::Handshake(ref m) => m,
&DatNetMessage::Info(ref m) => m,
&DatNetMessage::Have(ref m) => m,
&DatNetMessage::Unhave(ref m) => m,
&DatNetMessage::Want(ref m) => m,
&DatNetMessage::Unwant(ref m) => m,
&DatNetMessage::Request(ref m) => m,
&DatNetMessage::Cancel(ref m) => m,
&DatNetMessage::Data(ref m) => m,
}
}
/// This helper is pretty slow/inefficient; lots of copying memory
fn bytewise_stream_xor_ic_inplace(buf: &mut [u8], byte_offset: u64, nonce: &Nonce, key: &Key) {
let mut offset = byte_offset;
// We may have a partial-64-byte-block to finish encrypting first
let partial_offset: usize = (offset % 64) as usize;
let partial_len: usize = cmp::min(64 - partial_offset, buf.len());
if partial_len != 0 {
let mut partial = vec![0; 64];
for i in 0..partial_len {
partial[partial_offset + i] = buf[i];
}
let partial_enc = stream_xor_ic(&partial, offset / 64, &nonce, &key);
offset += partial_len as u64;
for i in 0..partial_len {
buf[i] = partial_enc[partial_offset + i];
}
}
if buf.len() > partial_len {
let main_enc = stream_xor_ic(&buf[partial_len..], offset / 64, &nonce, &key);
//offset += main_enc.len() as u64;
for i in 0..main_enc.len() {
buf[partial_len + i] = main_enc[i];
}
}
}
#[test]
fn test_bsxii_short() {
let nonce = gen_nonce();
let key = gen_key();
for size in [10, 100, 1234].iter() {
let mut a = vec![7; *size];
let mut b = vec![7; *size];
let c = vec![7; *size];
assert_eq!(a, b);
bytewise_stream_xor_ic_inplace(&mut a, 0, &nonce, &key);
bytewise_stream_xor_ic_inplace(&mut b, 0, &nonce, &key);
assert_eq!(a, b);
assert_ne!(a, c);
bytewise_stream_xor_ic_inplace(&mut a, 0, &nonce, &key);
assert_eq!(a, c);
}
}
#[test]
fn test_bsxii_continued() {
let nonce = gen_nonce();
let key = gen_key();
let mut a = vec![7; 1234];
let mut b = vec![7; 1234];
let c = vec![7; 1234];
assert_eq!(a, b);
bytewise_stream_xor_ic_inplace(&mut a[0..10], 0, &nonce, &key);
bytewise_stream_xor_ic_inplace(&mut a[10..20], 10, &nonce, &key);
bytewise_stream_xor_ic_inplace(&mut b[0..20], 0, &nonce, &key);
assert_eq!(a, b);
bytewise_stream_xor_ic_inplace(&mut a[20..50], 20, &nonce, &key);
bytewise_stream_xor_ic_inplace(&mut a[50..500], 50, &nonce, &key);
bytewise_stream_xor_ic_inplace(&mut b[20..500], 20, &nonce, &key);
assert_ne!(a, c);
assert_eq!(a, b);
bytewise_stream_xor_ic_inplace(&mut a[500..1234], 500, &nonce, &key);
bytewise_stream_xor_ic_inplace(&mut a, 0, &nonce, &key);
assert_eq!(a, c);
}
// TODO: move to lib.rs?
pub fn make_discovery_key(key: &[u8]) -> Vec<u8> {
// calculate discovery key
let mut discovery_key = [0; 32];
let mut hash = Blake2b::new_keyed(32, key);
hash.input(&"hypercore".as_bytes());
hash.result(&mut discovery_key);
discovery_key.to_vec()
}
/// Represents a bi-directional connection to a network peer
///
/// Spec says nonce is 32 bytes, by dat implementation (hypercore-protocol) is 24 bytes.
pub struct DatConnection {
id: [u8; 32],
remote_id: [u8; 32],
tcp: TcpStream,
live: bool,
key: Key,
discovery_key: [u8; 32],
data_key: [u8; 32],
data_discovery_key: [u8; 32],
tx_nonce: Nonce,
tx_offset: u64,
rx_nonce: Nonce,
rx_offset: u64,
}
impl Read for DatConnection {
/// Encrypted TCP read (after connection initialized). Uses XOR of an XSalsa20 stream, using
/// block offsets.
fn read(&mut self, buf: &mut [u8]) -> ::std::io::Result<usize> {
let len = self.tcp.read(buf)?;
bytewise_stream_xor_ic_inplace(&mut buf[0..len], self.rx_offset, &self.rx_nonce, &self.key);
self.rx_offset += len as u64;
Ok(len)
}
}
impl Write for DatConnection {
/// Encrypted write to complement `read()`.
fn write(&mut self, buf: &[u8]) -> ::std::io::Result<usize> {
// Don't mutate what we've been passed
let mut enc = vec![0; buf.len()];
enc.copy_from_slice(buf);
bytewise_stream_xor_ic_inplace(&mut enc, self.tx_offset, &self.tx_nonce, &self.key);
self.tx_offset += enc.len() as u64;
self.tcp.write(&enc)
}
fn flush(&mut self) -> ::std::io::Result<()> {
self.tcp.flush()
}
}
impl DatConnection {
pub fn connect(host_port: &str, key: &[u8], live: bool) -> Result<DatConnection> {
let timeout = Duration::new(7, 0);
let tx_nonce = gen_nonce();
let mut local_id = [0; 32];
let mut rng = OsRng::new()?;
rng.fill_bytes(&mut local_id);
let mut dk = [0; 32];
dk.copy_from_slice(&make_discovery_key(key)[0..32]);
// Connect to server
info!("Connecting to {}", host_port);
// TODO: timeout on connect (socketaddr dance)
let tcp = TcpStream::connect(host_port)?;
tcp.set_read_timeout(Some(timeout))?;
tcp.set_write_timeout(Some(timeout))?;
let mut dc = DatConnection {
id: local_id,
tcp,
live,
remote_id: [0; 32],
key: Key::from_slice(key).unwrap(), // TODO:
discovery_key: dk,
data_key: [0; 32],
data_discovery_key: [0; 32],
tx_nonce: tx_nonce,
tx_offset: 0,
rx_nonce: gen_nonce(), // dummy
rx_offset: 0,
};
// Exchange feed
dc.tcp.set_nodelay(true)?; // Faster handshake
let mut feed_msg = Feed::new();
feed_msg.set_discoveryKey(dc.discovery_key.to_vec());
feed_msg.set_nonce((tx_nonce[0..24]).to_vec());
dc.send_feed(&feed_msg)?;
// read feed
let registration = dc.recv_feed()?;
if registration.get_discoveryKey()[0..32] != dk[..] {
bail!("Remote peer not sharing same discovery key");
}
let rn = registration.get_nonce();
dc.rx_nonce = Nonce::from_slice(&rn).unwrap();
// send handshake
let mut handshake_msg = Handshake::new();
handshake_msg.set_live(dc.live);
handshake_msg.set_id(dc.id.to_vec());
dc.send_msg(&DatNetMessage::Handshake(handshake_msg), false)?;
// read handshake
let (was_content, msg) = dc.recv_msg()?;
if was_content {
bail!("Expected metadata msg, not content");
}
if let DatNetMessage::Handshake(handshake) = msg {
// TODO: more satisfying way to do this copy
let hid = handshake.get_id();
for i in 0..32 {
dc.remote_id[i] = hid[i];
}
} else {
bail!("Expected Handshake message, got something else");
}
// TODO: read data feed here?
// Fetch and configure key for data feed
dc.get_data_key()?;
// Send (encrypted) Feed message for data feed
let mut feed_msg = Feed::new();
feed_msg.set_discoveryKey(dc.data_discovery_key.to_vec());
dc.send_msg(&DatNetMessage::Feed(feed_msg), true)?;
dc.tcp.set_nodelay(false)?; // Back to normal
Ok(dc)
}
fn send_msg(&mut self, dnm: &DatNetMessage, is_content: bool) -> Result<()> {
let header_int: u8 = (is_content as u8) << 4 | (msg_code(dnm) & 0x0F);
let msg: &Message = msg_sugar(dnm);
let total_message_size = (msg.compute_size() as usize) + 1;
trace!(
"SEND total_len={} header={} is_content={} type={:?}",
total_message_size,
header_int,
is_content,
&dnm
);
// send both header varints, and data
self.write_varint(total_message_size as u64)?;
self.write_varint(header_int as u32)?;
match dnm {
&DatNetMessage::Feed(ref m) => m.write_to_writer(self)?,
&DatNetMessage::Handshake(ref m) => m.write_to_writer(self)?,
&DatNetMessage::Info(ref m) => m.write_to_writer(self)?,
&DatNetMessage::Have(ref m) => m.write_to_writer(self)?,
&DatNetMessage::Unhave(ref m) => m.write_to_writer(self)?,
&DatNetMessage::Want(ref m) => m.write_to_writer(self)?,
&DatNetMessage::Unwant(ref m) => m.write_to_writer(self)?,
&DatNetMessage::Request(ref m) => m.write_to_writer(self)?,
&DatNetMessage::Cancel(ref m) => m.write_to_writer(self)?,
&DatNetMessage::Data(ref m) => m.write_to_writer(self)?,
}
Ok(())
}
fn recv_msg(&mut self) -> Result<(bool, DatNetMessage)> {
let total_len: u64 = self.read_varint()?;
let header: u8 = self.read_varint()?;
let is_content = (header & (1 << 4)) != 0;
trace!(
"RECV total_len={} header={} is_content={}",
total_len,
header,
is_content
);
if header > 0x1F {
bail!("Invalid header received: {}", header);
}
let msg_len = (total_len - 1) as usize;
let mut buf = vec![0; msg_len];
self.read_exact(&mut buf[0..msg_len])?;
let dnm = match header & 0x0F {
0 => DatNetMessage::Feed(parse_from_bytes::<Feed>(&mut buf)?),
1 => DatNetMessage::Handshake(parse_from_bytes::<Handshake>(&mut buf)?),
2 => DatNetMessage::Info(parse_from_bytes::<Info>(&mut buf)?),
3 => DatNetMessage::Have(parse_from_bytes::<Have>(&mut buf)?),
4 => DatNetMessage::Unhave(parse_from_bytes::<Unhave>(&mut buf)?),
5 => DatNetMessage::Want(parse_from_bytes::<Want>(&mut buf)?),
6 => DatNetMessage::Unwant(parse_from_bytes::<Unwant>(&mut buf)?),
7 => DatNetMessage::Request(parse_from_bytes::<Request>(&mut buf)?),
8 => DatNetMessage::Cancel(parse_from_bytes::<Cancel>(&mut buf)?),
9 => DatNetMessage::Data(parse_from_bytes::<Data>(&mut buf)?),
other => bail!("Unimplemented message type received: {}", other),
};
trace!("\twas: {:?}", &dnm);
Ok((is_content, dnm))
}
/// Special unencrypted variant of `send_msg()`, used only during initial connection
/// establishment (eg, to check metadata discovery key and exchange nonces). After the
/// connection is initialized, send Feed messages as normal to add extra feeds.
fn send_feed(&mut self, reg: &Feed) -> Result<()> {
// TODO: refactor this to take discovery key and nonce directly
let header_int: u8 = 0;
let total_message_size = (reg.compute_size() as usize) + 1;
trace!(
"SEND total_len={} header={} msg={:?}",
total_message_size,
header_int,
reg
);
self.tcp.write_varint(total_message_size as u64)?;
self.tcp.write_varint(header_int as u32)?;
reg.write_to_writer(&mut self.tcp)?;
Ok(())
}
/// Receive complement to `send_feed()`.
fn recv_feed(&mut self) -> Result<Feed> {
// TODO: refactor this to return discovery key and nonce directly
let total_len: u64 = self.tcp.read_varint()?;
let header: u8 = self.tcp.read_varint()?;
if header != 0 {
bail!("Invalid Feed header received");
}
trace!("RECV total_len={} header={}", total_len, header);
let msg_len = (total_len - 1) as usize;
let mut buf = vec![0; msg_len];
self.tcp.read_exact(&mut buf[0..msg_len])?;
let reg = parse_from_bytes::<Feed>(&mut buf)?;
trace!("\twas: {:?}", reg);
Ok(reg)
}
pub fn get_data_key(&mut self) -> Result<()> {
// Info: downloading, not uploading
let mut im = Info::new();
im.set_uploading(false);
im.set_downloading(true);
self.send_msg(&DatNetMessage::Info(im), false)?;
// Have: nothing (so far)
let mut hm = Have::new();
hm.set_start(0);
hm.set_length(0);
self.send_msg(&DatNetMessage::Have(hm), false)?;
// UnHave: still nothing
let mut uhm = Unhave::new();
uhm.set_start(0);
self.send_msg(&DatNetMessage::Unhave(uhm), false)?;
// Want: just the first element
let mut wm = Want::new();
wm.set_start(0);
wm.set_length(1);
self.send_msg(&DatNetMessage::Want(wm), false)?;
// listen for Have
loop {
let (was_content, msg) = self.recv_msg()?;
if was_content {
continue;
}
if let DatNetMessage::Have(_) = msg {
break;
} else {
info!("Expected Have message, got: {:?}", &msg);
continue;
}
}
// Request
let mut rm = Request::new();
rm.set_index(0);
self.send_msg(&DatNetMessage::Request(rm), false)?;
loop {
let (was_content, msg) = self.recv_msg()?;
if was_content {
info!("Expected other message channel");
continue;
}
if let DatNetMessage::Data(dm) = msg {
info!("Got metadata: {}", dm.get_index());
if dm.get_index() == 0 {
let index_msg = parse_from_bytes::<Index>(&mut dm.get_value())?;
if index_msg.get_field_type() == "hyperdrive" {
let data_key = index_msg.get_content();
if data_key.len() != 32 {
bail!("Received data key had wrong length: {}", data_key.len());
}
info!("Got data discovery key");
self.data_key.copy_from_slice(&data_key[0..32]);
self.data_discovery_key
.copy_from_slice(&make_discovery_key(data_key)[0..32]);
return Ok(());
} else {
bail!("non-hyperdrive Index type: {}", index_msg.get_field_type());
}
}
} else {
info!("Expected Data message, got: {:?}", &msg);
continue;
}
}
}
pub fn receive_all(&mut self, is_content: bool, length: u64) -> Result<()> {
// Info: downloading, not uploading
let mut im = Info::new();
im.set_uploading(false);
im.set_downloading(true);
self.send_msg(&DatNetMessage::Info(im), is_content)?;
// Have: nothing (so far)
let mut hm = Have::new();
hm.set_start(0);
hm.set_length(0);
self.send_msg(&DatNetMessage::Have(hm), is_content)?;
// UnHave: still nothing
let mut uhm = Unhave::new();
uhm.set_start(0);
self.send_msg(&DatNetMessage::Unhave(uhm), is_content)?;
// Want: everything
let mut wm = Want::new();
wm.set_start(0);
self.send_msg(&DatNetMessage::Want(wm), is_content)?;
// Request / Data loop
for i in 0..length {
let mut rm = Request::new();
rm.set_index(i);
self.send_msg(&DatNetMessage::Request(rm), is_content)?;
loop {
let (was_content, msg) = self.recv_msg()?;
if was_content != is_content {
info!("Expected other message channel");
continue;
}
if let DatNetMessage::Data(dm) = msg {
info!("Got content: {}", dm.get_index());
break;
} else {
info!("Expected Data message, got: {:?}", &msg);
continue;
}
}
}
Ok(())
}
}
|