//! Creating blinded paths and related utilities live here.
+pub mod payment;
pub(crate) mod message;
pub(crate) mod utils;
use bitcoin::secp256k1::{self, PublicKey, Secp256k1, SecretKey};
-use crate::sign::EntropySource;
use crate::ln::msgs::DecodeError;
+use crate::offers::invoice::BlindedPayInfo;
+use crate::sign::EntropySource;
use crate::util::ser::{Readable, Writeable, Writer};
use crate::io;
pub blinded_hops: Vec<BlindedHop>,
}
-/// Used to construct the blinded hops portion of a blinded path. These hops cannot be identified
-/// by outside observers and thus can be used to hide the identity of the recipient.
+/// An encrypted payload and node id corresponding to a hop in a payment or onion message path, to
+/// be encoded in the sender's onion packet. These hops cannot be identified by outside observers
+/// and thus can be used to hide the identity of the recipient.
#[derive(Clone, Debug, Hash, PartialEq, Eq)]
pub struct BlindedHop {
- /// The blinded node id of this hop in a blinded path.
+ /// The blinded node id of this hop in a [`BlindedPath`].
pub blinded_node_id: PublicKey,
- /// The encrypted payload intended for this hop in a blinded path.
+ /// The encrypted payload intended for this hop in a [`BlindedPath`].
// The node sending to this blinded path will later encode this payload into the onion packet for
// this hop.
pub encrypted_payload: Vec<u8>,
blinded_hops: message::blinded_hops(secp_ctx, node_pks, &blinding_secret).map_err(|_| ())?,
})
}
+
+ /// Create a one-hop blinded path for a payment.
+ pub fn one_hop_for_payment<ES: EntropySource, T: secp256k1::Signing + secp256k1::Verification>(
+ payee_node_id: PublicKey, payee_tlvs: payment::ReceiveTlvs, entropy_source: &ES,
+ secp_ctx: &Secp256k1<T>
+ ) -> Result<(BlindedPayInfo, Self), ()> {
+ // This value is not considered in pathfinding for 1-hop blinded paths, because it's intended to
+ // be in relation to a specific channel.
+ let htlc_maximum_msat = u64::max_value();
+ Self::new_for_payment(
+ &[], payee_node_id, payee_tlvs, htlc_maximum_msat, entropy_source, secp_ctx
+ )
+ }
+
+ /// Create a blinded path for a payment, to be forwarded along `intermediate_nodes`.
+ ///
+ /// Errors if:
+ /// * a provided node id is invalid
+ /// * [`BlindedPayInfo`] calculation results in an integer overflow
+ /// * any unknown features are required in the provided [`ForwardTlvs`]
+ ///
+ /// [`ForwardTlvs`]: crate::blinded_path::payment::ForwardTlvs
+ // TODO: make all payloads the same size with padding + add dummy hops
+ pub(crate) fn new_for_payment<ES: EntropySource, T: secp256k1::Signing + secp256k1::Verification>(
+ intermediate_nodes: &[payment::ForwardNode], payee_node_id: PublicKey,
+ payee_tlvs: payment::ReceiveTlvs, htlc_maximum_msat: u64, entropy_source: &ES,
+ secp_ctx: &Secp256k1<T>
+ ) -> Result<(BlindedPayInfo, Self), ()> {
+ let blinding_secret_bytes = entropy_source.get_secure_random_bytes();
+ let blinding_secret = SecretKey::from_slice(&blinding_secret_bytes[..]).expect("RNG is busted");
+
+ let blinded_payinfo = payment::compute_payinfo(intermediate_nodes, &payee_tlvs, htlc_maximum_msat)?;
+ Ok((blinded_payinfo, BlindedPath {
+ introduction_node_id: intermediate_nodes.first().map_or(payee_node_id, |n| n.node_id),
+ blinding_point: PublicKey::from_secret_key(secp_ctx, &blinding_secret),
+ blinded_hops: payment::blinded_hops(
+ secp_ctx, intermediate_nodes, payee_node_id, payee_tlvs, &blinding_secret
+ ).map_err(|_| ())?,
+ }))
+ }
}
impl Writeable for BlindedPath {