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//! Declare traits to be implemented by types that describe a place
//! that Tor can connect to, directly or indirectly.
use derive_deftly::derive_deftly_adhoc;
use itertools::Itertools;
use safelog::Redactable;
use std::{
fmt,
iter::FusedIterator,
net::{IpAddr, SocketAddr},
};
use tor_llcrypto::pk;
use crate::{ChannelMethod, RelayIdRef, RelayIdType, RelayIdTypeIter};
#[cfg(feature = "pt-client")]
use crate::PtTargetAddr;
/// Legacy implementation helper for HasRelayIds.
///
/// Previously, we assumed that everything had these two identity types, which
/// is not an assumption we want to keep making in the future.
pub trait HasRelayIdsLegacy {
/// Return the ed25519 identity for this relay.
fn ed_identity(&self) -> &pk::ed25519::Ed25519Identity;
/// Return the RSA identity for this relay.
fn rsa_identity(&self) -> &pk::rsa::RsaIdentity;
}
/// An object containing information about a relay's identity keys.
/// This trait has a fairly large number of methods, most of which you're not
/// actually expected to implement. The only one that you need to provide is
/// [`identity`](HasRelayIds::identity).
pub trait HasRelayIds {
/// Return the identity of this relay whose type is `key_type`, or None if
/// the relay has no such identity.
/// (Currently all relays have all recognized identity types, but we might
/// implement or deprecate an identity type in the future.)
fn identity(&self, key_type: RelayIdType) -> Option<RelayIdRef<'_>>;
/// Return an iterator over all of the identities held by this object.
fn identities(&self) -> RelayIdIter<'_, Self> {
RelayIdIter {
info: self,
next_key: RelayIdType::all_types(),
/// Return the ed25519 identity for this relay if it has one.
fn ed_identity(&self) -> Option<&pk::ed25519::Ed25519Identity> {
self.identity(RelayIdType::Ed25519)
.map(RelayIdRef::unwrap_ed25519)
/// Return the RSA identity for this relay if it has one.
fn rsa_identity(&self) -> Option<&pk::rsa::RsaIdentity> {
self.identity(RelayIdType::Rsa).map(RelayIdRef::unwrap_rsa)
/// Check whether the provided Id is a known identity of this relay.
/// Remember that a given set of identity keys may be incomplete: some
/// objects that represent a relay have only a subset of the relay's
/// identities. Therefore, a "true" answer means that the relay has this
/// identity, but a "false" answer could mean that the relay has a
/// different identity of this type, or that it has _no_ known identity of
/// this type.
fn has_identity(&self, id: RelayIdRef<'_>) -> bool {
self.identity(id.id_type()).map(|my_id| my_id == id) == Some(true)
/// Return true if this object has any known identity.
fn has_any_identity(&self) -> bool {
RelayIdType::all_types().any(|id_type| self.identity(id_type).is_some())
/// Return true if this object has exactly the same relay IDs as `other`.
//
// TODO: Once we make it so particular identity key types are optional, we
// should add a note saying that this function is usually not what you want
// for many cases, since you might want to know "could this be the same
// relay" vs "is this definitely the same relay."
// NOTE: We don't make this an `Eq` method, since we want to make callers
// choose carefully among this method, `has_all_relay_ids_from`, and any
// similar methods we add in the future.
#[allow(clippy::nonminimal_bool)] // rust-clippy/issues/12627
fn same_relay_ids<T: HasRelayIds + ?Sized>(&self, other: &T) -> bool {
// We use derive-deftly to iterate over the id types, rather than strum
// Empirically, with rustc 1.77.0-beta.5, this arranges that
// <tor_netdir::Relay as HasRelayIds>::same_relay_ids
// compiles to the same asm (on amd64) as the open-coded inherent
// tor_netdir::Relay::has_same_relay_ids
// The problem with the strum approach seems to be that the compiler doesn't inline
// <RelayIdTypeIter as Iterator>::next
// and unroll the loop.
// Adding `#[inline]` and even `#[inline(always)]` to the strum output didn't help.
// When `next()` isn't inlined and the loop unrolled,
// the compiler can't inline the matching on the id type,
// and generate the obvious simple function.
// Empirically, the same results with non-inlined next() and non-unrolled loop,
// were obtained with:
// - a simpler hand-coded Iterator struct
// - that hand-coded Iterator struct locally present in tor-netdir,
// - using `<[RelayIdType; ] as IntoIterator>`
// I experimented to see if this was a general problem with `strum`'s iterator.
// In a smaller test program the compiler *does* unroll and inline.
// I suspect that the compiler is having trouble with the complexities
// of disentangling `HasLegacyRelayIds` and/or comparing `Option<RelayIdRef>`.
// TODO: do we want to replace RelayIdType::all_types with derive-deftly
// in RelayIdIter, has_all_relay_ids_from, has_any_relay_id_from, etc.?
// If so, search this crate for all_types.
derive_deftly_adhoc! {
RelayIdType:
$(
self.identity($vtype) == other.identity($vtype) &&
)
true
/// Return true if this object has every relay ID that `other` does.
/// (It still returns true if there are some IDs in this object that are not
/// present in `other`.)
fn has_all_relay_ids_from<T: HasRelayIds + ?Sized>(&self, other: &T) -> bool {
RelayIdType::all_types().all(|key_type| {
match (self.identity(key_type), other.identity(key_type)) {
// If we both have the same key for this type, great.
(Some(mine), Some(theirs)) if mine == theirs => true,
// Uh oh. They do have a key for his type, but it's not ours.
(_, Some(_theirs)) => false,
// If they don't care what we have for this type, great.
(_, None) => true,
})
/// Return true if this object has any relay ID that `other` has.
/// This is symmetrical:
/// it returns true if the two objects have any overlap in their identities.
fn has_any_relay_id_from<T: HasRelayIds + ?Sized>(&self, other: &T) -> bool {
RelayIdType::all_types()
.filter_map(|key_type| Some((self.identity(key_type)?, other.identity(key_type)?)))
.any(|(self_id, other_id)| self_id == other_id)
/// Compare this object to another HasRelayIds.
/// Objects are sorted by Ed25519 identities, with ties decided by RSA
/// identities. An absent identity of a given type is sorted before a
/// present identity of that type.
/// If additional identities are added in the future, they may taken into
/// consideration before _or_ after the current identity types.
fn cmp_by_relay_ids<T: HasRelayIds + ?Sized>(&self, other: &T) -> std::cmp::Ordering {
for key_type in RelayIdType::all_types() {
let ordering = Ord::cmp(&self.identity(key_type), &other.identity(key_type));
if ordering.is_ne() {
return ordering;
std::cmp::Ordering::Equal
/// Return a reference to this object suitable for formatting its
/// [`HasRelayIds`] members.
fn display_relay_ids(&self) -> DisplayRelayIds<'_, Self> {
DisplayRelayIds { inner: self }
impl<T: HasRelayIdsLegacy> HasRelayIds for T {
fn identity(&self, key_type: RelayIdType) -> Option<RelayIdRef<'_>> {
match key_type {
RelayIdType::Rsa => Some(self.rsa_identity().into()),
RelayIdType::Ed25519 => Some(self.ed_identity().into()),
/// A helper type used to format the [`RelayId`](crate::RelayId)s in a
/// [`HasRelayIds`].
#[derive(Clone)]
pub struct DisplayRelayIds<'a, T: HasRelayIds + ?Sized> {
/// The HasRelayIds that we're displaying.
inner: &'a T,
// Redactable must implement Debug.
impl<'a, T: HasRelayIds + ?Sized> fmt::Debug for DisplayRelayIds<'a, T> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("DisplayRelayIds").finish_non_exhaustive()
impl<'a, T: HasRelayIds + ?Sized> DisplayRelayIds<'a, T> {
/// Helper: output `self` in a possibly redacted way.
fn fmt_impl(&self, f: &mut fmt::Formatter<'_>, redact: bool) -> fmt::Result {
let mut iter = self.inner.identities();
if let Some(ident) = iter.next() {
write!(f, "{}", ident.maybe_redacted(redact))?;
if redact {
return Ok(());
for ident in iter {
write!(f, " {}", ident.maybe_redacted(redact))?;
Ok(())
impl<'a, T: HasRelayIds + ?Sized> fmt::Display for DisplayRelayIds<'a, T> {
self.fmt_impl(f, false)
impl<'a, T: HasRelayIds + ?Sized> Redactable for DisplayRelayIds<'a, T> {
fn display_redacted(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.fmt_impl(f, true)
/// An iterator over all of the relay identities held by a [`HasRelayIds`]
pub struct RelayIdIter<'a, T: HasRelayIds + ?Sized> {
/// The object holding the keys
info: &'a T,
/// The next key type to yield
next_key: RelayIdTypeIter,
impl<'a, T: HasRelayIds + ?Sized> Iterator for RelayIdIter<'a, T> {
type Item = RelayIdRef<'a>;
fn next(&mut self) -> Option<Self::Item> {
for key_type in &mut self.next_key {
if let Some(key) = self.info.identity(key_type) {
return Some(key);
None
// RelayIdIter is fused since next_key is fused.
impl<'a, T: HasRelayIds + ?Sized> FusedIterator for RelayIdIter<'a, T> {}
/// An object that represents a host on the network which may have known IP addresses.
pub trait HasAddrs {
/// Return the addresses listed for this server.
/// NOTE that these addresses are not necessarily ones that we should
/// connect to directly! They can be useful for telling where a server is
/// located, or whether it is "close" to another server, but without knowing
/// the associated protocols you cannot use these to launch a connection.
/// Also, for some servers, we may not actually have any relevant addresses;
/// in that case, the returned slice is empty.
/// To see how to _connect_ to a relay, use [`HasChanMethod::chan_method`]
// TODO: This is a questionable API. I'd rather return an iterator
// of addresses or references to addresses, but both of those options
// make defining the right associated types rather tricky.
fn addrs(&self) -> impl Iterator<Item = SocketAddr>;
impl<T: HasAddrs> HasAddrs for &T {
fn addrs(&self) -> impl Iterator<Item = SocketAddr> {
// Be explicit about the type here so that we don't end up in an infinite loop by accident.
<T as HasAddrs>::addrs(self)
/// An object that can be connected to via [`ChannelMethod`]s.
pub trait HasChanMethod {
/// Return the known ways to contact this
// TODO: See notes on HasAddrs above.
// TODO: I don't like having this return a new ChannelMethod, but I
// don't see a great alternative. Let's revisit that.-nickm.
fn chan_method(&self) -> ChannelMethod;
/// Implement `HasChanMethods` for an object with `HasAddr` whose addresses
/// _all_ represent a host we can connect to by a direct Tor connection at its
/// IP addresses.
pub trait DirectChanMethodsHelper: HasAddrs {}
impl<D: DirectChanMethodsHelper> HasChanMethod for D {
fn chan_method(&self) -> ChannelMethod {
ChannelMethod::Direct(self.addrs().collect_vec())
/// Information about a Tor relay used to connect to it.
/// Anything that implements 'ChanTarget' can be used as the
/// identity of a relay for the purposes of launching a new
/// channel.
pub trait ChanTarget: HasRelayIds + HasAddrs + HasChanMethod {
/// [`ChanTarget`]-specific members.
/// The display format is not exhaustive, but tries to give enough
/// information to identify which channel target we're talking about.
fn display_chan_target(&self) -> DisplayChanTarget<'_, Self>
where
Self: Sized,
{
DisplayChanTarget { inner: self }
/// Return true if we think all addresses are allowed to be used for a relay outgoing channel.
/// If no address are found, true is returned.
/// NOTE: The set of RFCs checked here are not expected to change over time and so this should
/// be a check that yields the same result regardless of the Rust library version. HOWEVER, it
/// doesn't mean that each relay/client on the network uses the same set of checks.
fn all_addrs_allowed_for_outgoing_channels(&self) -> bool {
self.addrs().all(|addr| match addr.ip() {
IpAddr::V4(v4) => {
!(v4.is_loopback() // RFC 1122 (127.0.0.0/8)
|| v4.is_private() // RFC1918
|| v4.is_unspecified() // 0.0.0.0
|| v4.is_documentation() // RFC 5737
|| v4.is_multicast() // RFC 5771 (224.0.0.0/4)
|| v4.is_link_local()) // RFC 3927 (169.254.0.0/16)
IpAddr::V6(v6) => {
!(v6.is_loopback() // RFC 4291 (::1)
|| v6.is_multicast() // RFC 4291 (ff00::/8)
|| v6.is_unspecified() // RFC 4291 (::)
|| v6.is_unique_local() // RFC 4193 (fc00::/7)
|| v6.is_unicast_link_local()) // RFC 4291 (2001:db8::/32, fe80::/10)
/// Return true iff all addresses' ports are non-zero, or there are no addresses.
fn has_all_nonzero_port(&self) -> bool {
self.addrs().all(|addr| addr.port() != 0)
/// Information about a Tor relay used to extend a circuit to it.
/// Anything that implements 'CircTarget' can be used as the
/// identity of a relay for the purposes of extending a circuit.
pub trait CircTarget: ChanTarget {
/// Return a new vector of encoded link specifiers for this relay.
/// Note that, outside of this method, nothing in Arti should be re-ordering
/// the link specifiers returned by this method. It is this method's
/// responsibility to return them in the correct order.
/// The default implementation for this method builds a list of link
/// specifiers from this object's identities and IP addresses, and sorts
/// them into the order specified in tor-spec to avoid implementation
/// fingerprinting attacks.
// of link specifiers, but that's not so easy to do, since it seems
// doing so correctly would require default associated types.
fn linkspecs(&self) -> tor_bytes::EncodeResult<Vec<crate::EncodedLinkSpec>> {
let mut result: Vec<_> = self.identities().map(|id| id.to_owned().into()).collect();
#[allow(irrefutable_let_patterns)]
if let ChannelMethod::Direct(addrs) = self.chan_method() {
result.extend(addrs.into_iter().map(crate::LinkSpec::from));
crate::LinkSpec::sort_by_type(&mut result[..]);
result.into_iter().map(|ls| ls.encode()).collect()
/// Return the ntor onion key for this relay
fn ntor_onion_key(&self) -> &pk::curve25519::PublicKey;
/// Return the subprotocols implemented by this relay.
fn protovers(&self) -> &tor_protover::Protocols;
/// A reference to a ChanTarget that implements Display using a hopefully useful
/// format.
#[derive(Debug, Clone)]
pub struct DisplayChanTarget<'a, T> {
/// The ChanTarget that we're formatting.
impl<'a, T: ChanTarget> DisplayChanTarget<'a, T> {
/// helper: output `self` in a possibly redacted way.
write!(f, "[")?;
// We look at the chan_method() (where we would connect to) rather than
// the addrs() (where the relay is, nebulously, "located"). This lets us
// give a less surprising description.
match self.inner.chan_method() {
ChannelMethod::Direct(v) if v.is_empty() => write!(f, "?")?,
ChannelMethod::Direct(v) if v.len() == 1 => {
write!(f, "{}", v[0].maybe_redacted(redact))?;
ChannelMethod::Direct(v) => write!(f, "{}+", v[0].maybe_redacted(redact))?,
ChannelMethod::Pluggable(target) => {
match target.addr() {
PtTargetAddr::None => {}
other => write!(f, "{} ", other.maybe_redacted(redact))?,
write!(f, "via {}", target.transport())?;
// This deliberately doesn't include the PtTargetSettings, since
// they can be large, and they're typically unnecessary.
write!(f, " ")?;
self.inner.display_relay_ids().fmt_impl(f, redact)?;
write!(f, "]")
impl<'a, T: ChanTarget> fmt::Display for DisplayChanTarget<'a, T> {
impl<'a, T: ChanTarget + fmt::Debug> safelog::Redactable for DisplayChanTarget<'a, T> {
fn debug_redacted(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "ChanTarget({:?})", self.redacted().to_string())
#[cfg(test)]
mod test {
// @@ begin test lint list maintained by maint/add_warning @@
#![allow(clippy::bool_assert_comparison)]
#![allow(clippy::clone_on_copy)]
#![allow(clippy::dbg_macro)]
#![allow(clippy::mixed_attributes_style)]
#![allow(clippy::print_stderr)]
#![allow(clippy::print_stdout)]
#![allow(clippy::single_char_pattern)]
#![allow(clippy::unwrap_used)]
#![allow(clippy::unchecked_time_subtraction)]
#![allow(clippy::useless_vec)]
#![allow(clippy::needless_pass_by_value)]
#![allow(clippy::string_slice)] // See arti#2571
//! <!-- @@ end test lint list maintained by maint/add_warning @@ -->
use super::*;
use crate::RelayIds;
use hex_literal::hex;
use std::net::IpAddr;
use tor_llcrypto::pk::{self, ed25519::Ed25519Identity, rsa::RsaIdentity};
struct Example {
addrs: Vec<SocketAddr>,
ed_id: pk::ed25519::Ed25519Identity,
rsa_id: pk::rsa::RsaIdentity,
ntor: pk::curve25519::PublicKey,
pv: tor_protover::Protocols,
impl HasAddrs for Example {
self.addrs.iter().copied()
impl DirectChanMethodsHelper for Example {}
impl HasRelayIdsLegacy for Example {
fn ed_identity(&self) -> &pk::ed25519::Ed25519Identity {
&self.ed_id
fn rsa_identity(&self) -> &pk::rsa::RsaIdentity {
&self.rsa_id
impl ChanTarget for Example {}
impl CircTarget for Example {
fn ntor_onion_key(&self) -> &pk::curve25519::PublicKey {
&self.ntor
fn protovers(&self) -> &tor_protover::Protocols {
&self.pv
/// Return an `Example` object, for use in tests below.
fn example() -> Example {
Example {
addrs: vec![
"127.0.0.1:99".parse::<SocketAddr>().unwrap(),
"[::1]:909".parse::<SocketAddr>().unwrap(),
],
ed_id: pk::ed25519::PublicKey::from_bytes(&hex!(
"fc51cd8e6218a1a38da47ed00230f058
0816ed13ba3303ac5deb911548908025"
))
.unwrap()
.into(),
rsa_id: pk::rsa::RsaIdentity::from_bytes(&hex!(
"1234567890abcdef12341234567890abcdef1234"
.unwrap(),
ntor: pk::curve25519::PublicKey::from(hex!(
"e6db6867583030db3594c1a424b15f7c
726624ec26b3353b10a903a6d0ab1c4c"
)),
pv: tor_protover::Protocols::default(),
#[test]
fn test_linkspecs() {
let ex = example();
let specs = ex
.linkspecs()
.into_iter()
.map(|ls| ls.parse())
.collect::<Result<Vec<_>, _>>()
.unwrap();
assert_eq!(4, specs.len());
use crate::ls::LinkSpec;
assert_eq!(
specs[0],
LinkSpec::OrPort("127.0.0.1".parse::<IpAddr>().unwrap(), 99)
);
specs[1],
LinkSpec::RsaId(
pk::rsa::RsaIdentity::from_bytes(&hex!("1234567890abcdef12341234567890abcdef1234"))
specs[2],
LinkSpec::Ed25519Id(
pk::ed25519::PublicKey::from_bytes(&hex!(
.into()
specs[3],
LinkSpec::OrPort("::1".parse::<IpAddr>().unwrap(), 909)
fn cmp_by_ids() {
use std::cmp::Ordering;
fn b(ed: Option<Ed25519Identity>, rsa: Option<RsaIdentity>) -> RelayIds {
let mut b = RelayIds::builder();
if let Some(ed) = ed {
b.ed_identity(ed);
if let Some(rsa) = rsa {
b.rsa_identity(rsa);
b.build().unwrap()
// Assert that v is strictly ascending.
fn assert_sorted(v: &[RelayIds]) {
for slice in v.windows(2) {
assert_eq!(slice[0].cmp_by_relay_ids(&slice[1]), Ordering::Less);
assert_eq!(slice[1].cmp_by_relay_ids(&slice[0]), Ordering::Greater);
assert_eq!(slice[0].cmp_by_relay_ids(&slice[0]), Ordering::Equal);
let ed1 = hex!("0a54686973206973207468652043656e7472616c205363727574696e697a6572").into();
let ed2 = hex!("6962696c69747920746f20656e666f72636520616c6c20746865206c6177730a").into();
let ed3 = hex!("73736564207965740a497420697320616c736f206d7920726573706f6e736962").into();
let rsa1 = hex!("2e2e2e0a4974206973206d7920726573706f6e73").into();
let rsa2 = hex!("5468617420686176656e2774206265656e207061").into();
let rsa3 = hex!("696c69747920746f20616c65727420656163680a").into();
assert_sorted(&[
b(Some(ed1), None),
b(Some(ed2), None),
b(Some(ed3), None),
b(Some(ed3), Some(rsa1)),
]);
b(Some(ed1), Some(rsa3)),
b(Some(ed2), Some(rsa2)),
b(Some(ed3), Some(rsa2)),
b(Some(ed1), Some(rsa1)),
b(Some(ed1), Some(rsa2)),
b(None, Some(rsa1)),
b(None, Some(rsa2)),
b(None, Some(rsa3)),
fn compare_id_sets() {
// TODO somehow nicely unify these repeated predefined examples
let rsa2 = RsaIdentity::from(hex!("5468617420686176656e2774206265656e207061"));
let both1 = RelayIds::builder()
.ed_identity(ed1)
.rsa_identity(rsa1)
.build()
let mixed = RelayIds::builder()
.rsa_identity(rsa2)
let ed1 = RelayIds::builder().ed_identity(ed1).build().unwrap();
let rsa1 = RelayIds::builder().rsa_identity(rsa1).build().unwrap();
let rsa2 = RelayIds::builder().rsa_identity(rsa2).build().unwrap();
fn chk_equal(v: &impl HasRelayIds) {
assert!(v.same_relay_ids(v));
assert!(v.has_all_relay_ids_from(v));
assert!(v.has_any_relay_id_from(v));
fn chk_strict_subset(bigger: &impl HasRelayIds, smaller: &impl HasRelayIds) {
assert!(!bigger.same_relay_ids(smaller));
assert!(bigger.has_all_relay_ids_from(smaller));
assert!(bigger.has_any_relay_id_from(smaller));
assert!(!smaller.same_relay_ids(bigger));
assert!(!smaller.has_all_relay_ids_from(bigger));
assert!(smaller.has_any_relay_id_from(bigger));
fn chk_nontrivially_overlapping_one_way(a: &impl HasRelayIds, b: &impl HasRelayIds) {
assert!(!a.same_relay_ids(b));
assert!(!a.has_all_relay_ids_from(b));
assert!(a.has_any_relay_id_from(b));
fn chk_nontrivially_overlapping(a: &impl HasRelayIds, b: &impl HasRelayIds) {
chk_nontrivially_overlapping_one_way(a, b);
chk_nontrivially_overlapping_one_way(b, a);
chk_equal(&ed1);
chk_equal(&rsa1);
chk_equal(&both1);
chk_strict_subset(&both1, &ed1);
chk_strict_subset(&both1, &rsa1);
chk_strict_subset(&mixed, &ed1);
chk_strict_subset(&mixed, &rsa2);
chk_nontrivially_overlapping(&both1, &mixed);
fn display() {
let e1 = example();
e1.display_chan_target().to_string(),
"[127.0.0.1:99+ ed25519:/FHNjmIYoaONpH7QAjDwWAgW7RO6MwOsXeuRFUiQgCU \
$1234567890abcdef12341234567890abcdef1234]"
use crate::PtTarget;
let rsa = hex!("234461644a6f6b6523436f726e794f6e4d61696e").into();
let mut b = crate::OwnedChanTarget::builder();
b.ids().rsa_identity(rsa);
let e2 = b
.method(ChannelMethod::Pluggable(PtTarget::new(
"obfs4".parse().unwrap(),
"127.0.0.1:99".parse().unwrap(),
)))
e2.to_string(),
"[127.0.0.1:99 via obfs4 $234461644a6f6b6523436f726e794f6e4d61696e]"
fn has_id() {
assert!(example().has_any_identity());
assert!(!RelayIds::empty().has_any_identity());