Add PendingOutboundPayment::InvoiceReceived
[rust-lightning] / lightning / src / ln / onion_utils.rs
index 31f1d5064fe1fdba3dadf30b735c105a02efdf7f..8fdbdefef6592766b52b9ad0cf142e55ad045990 100644 (file)
@@ -91,25 +91,39 @@ pub(super) fn gen_pad_from_shared_secret(shared_secret: &[u8]) -> [u8; 32] {
        Hmac::from_engine(hmac).into_inner()
 }
 
-pub(crate) fn next_hop_packet_pubkey<T: secp256k1::Signing + secp256k1::Verification>(secp_ctx: &Secp256k1<T>, packet_pubkey: PublicKey, packet_shared_secret: &[u8; 32]) -> Result<PublicKey, secp256k1::Error> {
+/// Calculates a pubkey for the next hop, such as the next hop's packet pubkey or blinding point.
+pub(crate) fn next_hop_pubkey<T: secp256k1::Signing + secp256k1::Verification>(
+       secp_ctx: &Secp256k1<T>, curr_pubkey: PublicKey, shared_secret: &[u8]
+) -> Result<PublicKey, secp256k1::Error> {
        let blinding_factor = {
                let mut sha = Sha256::engine();
-               sha.input(&packet_pubkey.serialize()[..]);
-               sha.input(packet_shared_secret);
+               sha.input(&curr_pubkey.serialize()[..]);
+               sha.input(shared_secret);
                Sha256::from_engine(sha).into_inner()
        };
 
-       packet_pubkey.mul_tweak(secp_ctx, &Scalar::from_be_bytes(blinding_factor).unwrap())
+       curr_pubkey.mul_tweak(secp_ctx, &Scalar::from_be_bytes(blinding_factor).unwrap())
 }
 
 // can only fail if an intermediary hop has an invalid public key or session_priv is invalid
 #[inline]
-pub(super) fn construct_onion_keys_callback<T: secp256k1::Signing, FType: FnMut(SharedSecret, [u8; 32], PublicKey, &RouteHop, usize)> (secp_ctx: &Secp256k1<T>, path: &Vec<RouteHop>, session_priv: &SecretKey, mut callback: FType) -> Result<(), secp256k1::Error> {
+pub(super) fn construct_onion_keys_callback<T, FType>(
+       secp_ctx: &Secp256k1<T>, path: &Path, session_priv: &SecretKey, mut callback: FType
+) -> Result<(), secp256k1::Error>
+where
+       T: secp256k1::Signing,
+       FType: FnMut(SharedSecret, [u8; 32], PublicKey, Option<&RouteHop>, usize)
+{
        let mut blinded_priv = session_priv.clone();
        let mut blinded_pub = PublicKey::from_secret_key(secp_ctx, &blinded_priv);
 
-       for (idx, hop) in path.iter().enumerate() {
-               let shared_secret = SharedSecret::new(&hop.pubkey, &blinded_priv);
+       let unblinded_hops_iter = path.hops.iter().map(|h| (&h.pubkey, Some(h)));
+       let blinded_pks_iter = path.blinded_tail.as_ref()
+               .map(|t| t.hops.iter()).unwrap_or([].iter())
+               .skip(1) // Skip the intro node because it's included in the unblinded hops
+               .map(|h| (&h.blinded_node_id, None));
+       for (idx, (pubkey, route_hop_opt)) in unblinded_hops_iter.chain(blinded_pks_iter).enumerate() {
+               let shared_secret = SharedSecret::new(pubkey, &blinded_priv);
 
                let mut sha = Sha256::engine();
                sha.input(&blinded_pub.serialize()[..]);
@@ -121,7 +135,7 @@ pub(super) fn construct_onion_keys_callback<T: secp256k1::Signing, FType: FnMut(
                blinded_priv = blinded_priv.mul_tweak(&Scalar::from_be_bytes(blinding_factor).unwrap())?;
                blinded_pub = PublicKey::from_secret_key(secp_ctx, &blinded_priv);
 
-               callback(shared_secret, blinding_factor, ephemeral_pubkey, hop, idx);
+               callback(shared_secret, blinding_factor, ephemeral_pubkey, route_hop_opt, idx);
        }
 
        Ok(())
@@ -131,7 +145,9 @@ pub(super) fn construct_onion_keys_callback<T: secp256k1::Signing, FType: FnMut(
 pub(super) fn construct_onion_keys<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, path: &Path, session_priv: &SecretKey) -> Result<Vec<OnionKeys>, secp256k1::Error> {
        let mut res = Vec::with_capacity(path.hops.len());
 
-       construct_onion_keys_callback(secp_ctx, &path.hops, session_priv, |shared_secret, _blinding_factor, ephemeral_pubkey, _, _| {
+       construct_onion_keys_callback(secp_ctx, &path, session_priv,
+               |shared_secret, _blinding_factor, ephemeral_pubkey, _, _|
+       {
                let (rho, mu) = gen_rho_mu_from_shared_secret(shared_secret.as_ref());
 
                res.push(OnionKeys {
@@ -380,15 +396,22 @@ pub(super) fn build_first_hop_failure_packet(shared_secret: &[u8], failure_type:
        encrypt_failure_packet(shared_secret, &failure_packet.encode()[..])
 }
 
+pub(crate) struct DecodedOnionFailure {
+       pub(crate) network_update: Option<NetworkUpdate>,
+       pub(crate) short_channel_id: Option<u64>,
+       pub(crate) payment_retryable: bool,
+       #[cfg(test)]
+       pub(crate) onion_error_code: Option<u16>,
+       #[cfg(test)]
+       pub(crate) onion_error_data: Option<Vec<u8>>,
+}
+
 /// Process failure we got back from upstream on a payment we sent (implying htlc_source is an
 /// OutboundRoute).
-/// Returns update, a boolean indicating that the payment itself failed, the short channel id of
-/// the responsible channel, and the error code.
 #[inline]
 pub(super) fn process_onion_failure<T: secp256k1::Signing, L: Deref>(
        secp_ctx: &Secp256k1<T>, logger: &L, htlc_source: &HTLCSource, mut packet_decrypted: Vec<u8>
-) -> (Option<NetworkUpdate>, Option<u64>, bool, Option<u16>, Option<Vec<u8>>)
-where L::Target: Logger {
+) -> DecodedOnionFailure where L::Target: Logger {
        let (path, session_priv, first_hop_htlc_msat) = if let &HTLCSource::OutboundRoute {
                ref path, ref session_priv, ref first_hop_htlc_msat, ..
        } = htlc_source {
@@ -400,10 +423,28 @@ where L::Target: Logger {
        let mut error_packet_ret = None;
        let mut is_from_final_node = false;
 
+       const BADONION: u16 = 0x8000;
+       const PERM: u16 = 0x4000;
+       const NODE: u16 = 0x2000;
+       const UPDATE: u16 = 0x1000;
+
        // Handle packed channel/node updates for passing back for the route handler
-       construct_onion_keys_callback(secp_ctx, &path.hops, session_priv, |shared_secret, _, _, route_hop, route_hop_idx| {
+       construct_onion_keys_callback(secp_ctx, &path, session_priv,
+               |shared_secret, _, _, route_hop_opt, route_hop_idx|
+       {
                if res.is_some() { return; }
 
+               let route_hop = match route_hop_opt {
+                       Some(hop) => hop,
+                       None => {
+                               // Got an error from within a blinded route.
+                               error_code_ret = Some(BADONION | PERM | 24); // invalid_onion_blinding
+                               error_packet_ret = Some(vec![0; 32]);
+                               is_from_final_node = false;
+                               return
+                       },
+               };
+
                let amt_to_forward = htlc_msat - route_hop.fee_msat;
                htlc_msat = amt_to_forward;
 
@@ -415,8 +456,8 @@ where L::Target: Logger {
                chacha.process(&packet_decrypted, &mut decryption_tmp[..]);
                packet_decrypted = decryption_tmp;
 
-               // The failing hop includes either the inbound channel to the recipient or the outbound
-               // channel from the current hop (i.e., the next hop's inbound channel).
+               // The failing hop includes either the inbound channel to the recipient or the outbound channel
+               // from the current hop (i.e., the next hop's inbound channel).
                is_from_final_node = route_hop_idx + 1 == path.hops.len();
                let failing_route_hop = if is_from_final_node { route_hop } else { &path.hops[route_hop_idx + 1] };
 
@@ -432,8 +473,8 @@ where L::Target: Logger {
                let error_code_slice = match err_packet.failuremsg.get(0..2) {
                        Some(s) => s,
                        None => {
-                               // Useless packet that we can't use but it passed HMAC, so it
-                               // definitely came from the peer in question
+                               // Useless packet that we can't use but it passed HMAC, so it definitely came from the peer
+                               // in question
                                let network_update = Some(NetworkUpdate::NodeFailure {
                                        node_id: route_hop.pubkey,
                                        is_permanent: true,
@@ -443,10 +484,6 @@ where L::Target: Logger {
                                return
                        }
                };
-               const BADONION: u16 = 0x8000;
-               const PERM: u16 = 0x4000;
-               const NODE: u16 = 0x2000;
-               const UPDATE: u16 = 0x1000;
 
                let error_code = u16::from_be_bytes(error_code_slice.try_into().expect("len is 2"));
                error_code_ret = Some(error_code);
@@ -454,8 +491,7 @@ where L::Target: Logger {
 
                let (debug_field, debug_field_size) = errors::get_onion_debug_field(error_code);
 
-               // indicate that payment parameter has failed and no need to
-               // update Route object
+               // indicate that payment parameter has failed and no need to update Route object
                let payment_failed = match error_code & 0xff {
                        15|16|17|18|19|23 => true,
                        _ => false,
@@ -465,14 +501,13 @@ where L::Target: Logger {
                let mut short_channel_id = None;
 
                if error_code & BADONION == BADONION {
-                       // If the error code has the BADONION bit set, always blame the channel
-                       // from the node "originating" the error to its next hop. The
-                       // "originator" is ultimately actually claiming that its counterparty
-                       // is the one who is failing the HTLC.
-                       // If the "originator" here isn't lying we should really mark the
-                       // next-hop node as failed entirely, but we can't be confident in that,
-                       // as it would allow any node to get us to completely ban one of its
-                       // counterparties. Instead, we simply remove the channel in question.
+                       // If the error code has the BADONION bit set, always blame the channel from the node
+                       // "originating" the error to its next hop. The "originator" is ultimately actually claiming
+                       // that its counterparty is the one who is failing the HTLC.
+                       // If the "originator" here isn't lying we should really mark the next-hop node as failed
+                       // entirely, but we can't be confident in that, as it would allow any node to get us to
+                       // completely ban one of its counterparties. Instead, we simply remove the channel in
+                       // question.
                        network_update = Some(NetworkUpdate::ChannelFailure {
                                short_channel_id: failing_route_hop.short_channel_id,
                                is_permanent: true,
@@ -551,6 +586,8 @@ where L::Target: Logger {
                                                                        msg: chan_update,
                                                                })
                                                        } else {
+                                                               // The node in question intentionally encoded a 0-length channel update. This is
+                                                               // likely due to https://github.com/ElementsProject/lightning/issues/6200.
                                                                network_update = Some(NetworkUpdate::ChannelFailure {
                                                                        short_channel_id: route_hop.short_channel_id,
                                                                        is_permanent: false,
@@ -579,16 +616,15 @@ where L::Target: Logger {
                                short_channel_id = Some(route_hop.short_channel_id);
                        }
                } else if payment_failed {
-                       // Only blame the hop when a value in the HTLC doesn't match the
-                       // corresponding value in the onion.
+                       // Only blame the hop when a value in the HTLC doesn't match the corresponding value in the
+                       // onion.
                        short_channel_id = match error_code & 0xff {
                                18|19 => Some(route_hop.short_channel_id),
                                _ => None,
                        };
                } else {
-                       // We can't understand their error messages and they failed to
-                       // forward...they probably can't understand our forwards so its
-                       // really not worth trying any further.
+                       // We can't understand their error messages and they failed to forward...they probably can't
+                       // understand our forwards so it's really not worth trying any further.
                        network_update = Some(NetworkUpdate::NodeFailure {
                                node_id: route_hop.pubkey,
                                is_permanent: true,
@@ -605,12 +641,24 @@ where L::Target: Logger {
                        log_info!(logger, "Onion Error[from {}: {}({:#x})] {}", route_hop.pubkey, title, error_code, description);
                }
        }).expect("Route that we sent via spontaneously grew invalid keys in the middle of it?");
-       if let Some((channel_update, short_channel_id, payment_retryable)) = res {
-               (channel_update, short_channel_id, payment_retryable, error_code_ret, error_packet_ret)
+       if let Some((network_update, short_channel_id, payment_retryable)) = res {
+               DecodedOnionFailure {
+                       network_update, short_channel_id, payment_retryable,
+                       #[cfg(test)]
+                       onion_error_code: error_code_ret,
+                       #[cfg(test)]
+                       onion_error_data: error_packet_ret
+               }
        } else {
                // only not set either packet unparseable or hmac does not match with any
                // payment not retryable only when garbage is from the final node
-               (None, None, !is_from_final_node, None, None)
+               DecodedOnionFailure {
+                       network_update: None, short_channel_id: None, payment_retryable: !is_from_final_node,
+                       #[cfg(test)]
+                       onion_error_code: None,
+                       #[cfg(test)]
+                       onion_error_data: None
+               }
        }
 }
 
@@ -734,12 +782,12 @@ impl HTLCFailReason {
 
        pub(super) fn decode_onion_failure<T: secp256k1::Signing, L: Deref>(
                &self, secp_ctx: &Secp256k1<T>, logger: &L, htlc_source: &HTLCSource
-       ) -> (Option<NetworkUpdate>, Option<u64>, bool, Option<u16>, Option<Vec<u8>>)
-       where L::Target: Logger {
+       ) -> DecodedOnionFailure where L::Target: Logger {
                match self.0 {
                        HTLCFailReasonRepr::LightningError { ref err } => {
                                process_onion_failure(secp_ctx, logger, &htlc_source, err.data.clone())
                        },
+                       #[allow(unused)]
                        HTLCFailReasonRepr::Reason { ref failure_code, ref data, .. } => {
                                // we get a fail_malformed_htlc from the first hop
                                // TODO: We'd like to generate a NetworkUpdate for temporary
@@ -747,7 +795,15 @@ impl HTLCFailReason {
                                // generally ignores its view of our own channels as we provide them via
                                // ChannelDetails.
                                if let &HTLCSource::OutboundRoute { ref path, .. } = htlc_source {
-                                       (None, Some(path.hops[0].short_channel_id), true, Some(*failure_code), Some(data.clone()))
+                                       DecodedOnionFailure {
+                                               network_update: None,
+                                               payment_retryable: true,
+                                               short_channel_id: Some(path.hops[0].short_channel_id),
+                                               #[cfg(test)]
+                                               onion_error_code: Some(*failure_code),
+                                               #[cfg(test)]
+                                               onion_error_data: Some(data.clone()),
+                                       }
                                } else { unreachable!(); }
                        }
                }
@@ -951,7 +1007,7 @@ mod tests {
                                                short_channel_id: 0, fee_msat: 0, cltv_expiry_delta: 0 // We fill in the payloads manually instead of generating them from RouteHops.
                                        },
                        ], blinded_tail: None }],
-                       payment_params: None,
+                       route_params: None,
                };
 
                let onion_keys = super::construct_onion_keys(&secp_ctx, &route.paths[0], &get_test_session_key()).unwrap();