X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fonion_message%2Fpacket.rs;h=3222c08a39263c7d1ab78113f2987e505257059c;hb=59778dac488cff735004671cdefb3f4ac1f920fd;hp=4ab53735ed6f8c9fc132d13dd80fc61628319f35;hpb=950b7d777a3fb129759932f5a4220ece44e94f41;p=rust-lightning diff --git a/lightning/src/onion_message/packet.rs b/lightning/src/onion_message/packet.rs index 4ab53735..510f0ea0 100644 --- a/lightning/src/onion_message/packet.rs +++ b/lightning/src/onion_message/packet.rs @@ -12,31 +12,42 @@ use bitcoin::secp256k1::PublicKey; use bitcoin::secp256k1::ecdh::SharedSecret; -use ln::msgs::DecodeError; -use ln::onion_utils; -use super::blinded_route::{BlindedRoute, ForwardTlvs, ReceiveTlvs}; -use util::chacha20poly1305rfc::{ChaChaPolyReadAdapter, ChaChaPolyWriteAdapter}; -use util::ser::{BigSize, FixedLengthReader, LengthRead, LengthReadable, LengthReadableArgs, Readable, ReadableArgs, Writeable, Writer}; +use crate::blinded_path::BlindedPath; +use crate::blinded_path::message::{ForwardTlvs, NextHop, ReceiveTlvs}; +use crate::blinded_path::utils::Padding; +use crate::ln::msgs::DecodeError; +use crate::ln::onion_utils; +use super::messenger::CustomOnionMessageHandler; +use super::offers::OffersMessage; +use crate::crypto::streams::{ChaChaPolyReadAdapter, ChaChaPolyWriteAdapter}; +use crate::util::logger::Logger; +use crate::util::ser::{BigSize, FixedLengthReader, LengthRead, LengthReadable, LengthReadableArgs, Readable, ReadableArgs, Writeable, Writer}; use core::cmp; -use io::{self, Read}; -use prelude::*; +use crate::io::{self, Read}; +use crate::prelude::*; // Per the spec, an onion message packet's `hop_data` field length should be // SMALL_PACKET_HOP_DATA_LEN if it fits, else BIG_PACKET_HOP_DATA_LEN if it fits. pub(super) const SMALL_PACKET_HOP_DATA_LEN: usize = 1300; pub(super) const BIG_PACKET_HOP_DATA_LEN: usize = 32768; -#[derive(Clone, Debug, PartialEq)] -pub(crate) struct Packet { - pub(super) version: u8, - pub(super) public_key: PublicKey, +/// Packet of hop data for next peer +#[derive(Clone, Debug, Hash, PartialEq, Eq)] +pub struct Packet { + /// Bolt 04 version number + pub version: u8, + /// A random sepc256k1 point, used to build the ECDH shared secret to decrypt hop_data + pub public_key: PublicKey, + /// Encrypted payload for the next hop + // // Unlike the onion packets used for payments, onion message packets can have payloads greater // than 1300 bytes. // TODO: if 1300 ends up being the most common size, optimize this to be: // enum { ThirteenHundred([u8; 1300]), VarLen(Vec) } - pub(super) hop_data: Vec, - pub(super) hmac: [u8; 32], + pub hop_data: Vec, + /// HMAC to verify the integrity of hop_data + pub hmac: [u8; 32], } impl onion_utils::Packet for Packet { @@ -74,7 +85,7 @@ impl LengthReadable for Packet { while read_idx < hop_data_len { let mut read_buffer = [0; READ_BUFFER_SIZE]; let read_amt = cmp::min(hop_data_len - read_idx, READ_BUFFER_SIZE); - r.read_exact(&mut read_buffer[..read_amt]); + r.read_exact(&mut read_buffer[..read_amt])?; hop_data.extend_from_slice(&read_buffer[..read_amt]); read_idx += read_amt; } @@ -92,34 +103,64 @@ impl LengthReadable for Packet { /// Onion message payloads contain "control" TLVs and "data" TLVs. Control TLVs are used to route /// the onion message from hop to hop and for path verification, whereas data TLVs contain the onion /// message content itself, such as an invoice request. -pub(super) enum Payload { +pub(super) enum Payload { /// This payload is for an intermediate hop. Forward(ForwardControlTlvs), /// This payload is for the final hop. Receive { control_tlvs: ReceiveControlTlvs, - reply_path: Option, - // Coming soon: - // message: Message, + reply_path: Option, + message: T, } } -// Coming soon: -// enum Message { -// InvoiceRequest(InvoiceRequest), -// Invoice(Invoice), -// InvoiceError(InvoiceError), -// CustomMessage, -// } +/// The contents of an [`OnionMessage`] as read from the wire. +/// +/// [`OnionMessage`]: crate::ln::msgs::OnionMessage +#[derive(Debug)] +pub enum ParsedOnionMessageContents { + /// A message related to BOLT 12 Offers. + Offers(OffersMessage), + /// A custom onion message specified by the user. + Custom(T), +} + +impl OnionMessageContents for ParsedOnionMessageContents { + /// Returns the type that was used to decode the message payload. + /// + /// This is not exported to bindings users as methods on non-cloneable enums are not currently exportable + fn tlv_type(&self) -> u64 { + match self { + &ParsedOnionMessageContents::Offers(ref msg) => msg.tlv_type(), + &ParsedOnionMessageContents::Custom(ref msg) => msg.tlv_type(), + } + } +} + +impl Writeable for ParsedOnionMessageContents { + fn write(&self, w: &mut W) -> Result<(), io::Error> { + match self { + ParsedOnionMessageContents::Offers(msg) => Ok(msg.write(w)?), + ParsedOnionMessageContents::Custom(msg) => Ok(msg.write(w)?), + } + } +} + +/// The contents of an onion message. +pub trait OnionMessageContents: Writeable + core::fmt::Debug { + /// Returns the TLV type identifying the message contents. MUST be >= 64. + fn tlv_type(&self) -> u64; +} /// Forward control TLVs in their blinded and unblinded form. pub(super) enum ForwardControlTlvs { - /// If we're sending to a blinded route, the node that constructed the blinded route has provided + /// If we're sending to a blinded path, the node that constructed the blinded path has provided /// this hop's control TLVs, already encrypted into bytes. Blinded(Vec), /// If we're constructing an onion message hop through an intermediate unblinded node, we'll need /// to construct the intermediate hop's control TLVs in their unblinded state to avoid encoding - /// them into an intermediate Vec. See [`super::blinded_route::ForwardTlvs`] for more info. + /// them into an intermediate Vec. See [`crate::blinded_path::message::ForwardTlvs`] for more + /// info. Unblinded(ForwardTlvs), } @@ -127,40 +168,42 @@ pub(super) enum ForwardControlTlvs { pub(super) enum ReceiveControlTlvs { /// See [`ForwardControlTlvs::Blinded`]. Blinded(Vec), - /// See [`ForwardControlTlvs::Unblinded`] and [`super::blinded_route::ReceiveTlvs`]. + /// See [`ForwardControlTlvs::Unblinded`] and [`crate::blinded_path::message::ReceiveTlvs`]. Unblinded(ReceiveTlvs), } // Uses the provided secret to simultaneously encode and encrypt the unblinded control TLVs. -impl Writeable for (Payload, [u8; 32]) { +impl Writeable for (Payload, [u8; 32]) { fn write(&self, w: &mut W) -> Result<(), io::Error> { match &self.0 { Payload::Forward(ForwardControlTlvs::Blinded(encrypted_bytes)) => { - encode_varint_length_prefixed_tlv!(w, { - (4, encrypted_bytes, vec_type) + _encode_varint_length_prefixed_tlv!(w, { + (4, *encrypted_bytes, required_vec) }) }, Payload::Receive { - control_tlvs: ReceiveControlTlvs::Blinded(encrypted_bytes), reply_path + control_tlvs: ReceiveControlTlvs::Blinded(encrypted_bytes), reply_path, message, } => { - encode_varint_length_prefixed_tlv!(w, { + _encode_varint_length_prefixed_tlv!(w, { (2, reply_path, option), - (4, encrypted_bytes, vec_type) + (4, *encrypted_bytes, required_vec), + (message.tlv_type(), message, required) }) }, Payload::Forward(ForwardControlTlvs::Unblinded(control_tlvs)) => { let write_adapter = ChaChaPolyWriteAdapter::new(self.1, &control_tlvs); - encode_varint_length_prefixed_tlv!(w, { + _encode_varint_length_prefixed_tlv!(w, { (4, write_adapter, required) }) }, Payload::Receive { - control_tlvs: ReceiveControlTlvs::Unblinded(control_tlvs), reply_path, + control_tlvs: ReceiveControlTlvs::Unblinded(control_tlvs), reply_path, message, } => { let write_adapter = ChaChaPolyWriteAdapter::new(self.1, &control_tlvs); - encode_varint_length_prefixed_tlv!(w, { + _encode_varint_length_prefixed_tlv!(w, { (2, reply_path, option), - (4, write_adapter, required) + (4, write_adapter, required), + (message.tlv_type(), message, required) }) }, } @@ -168,36 +211,69 @@ impl Writeable for (Payload, [u8; 32]) { } } -// Uses the provided secret to simultaneously decode and decrypt the control TLVs. -impl ReadableArgs for Payload { - fn read(mut r: &mut R, encrypted_tlvs_ss: SharedSecret) -> Result { +// Uses the provided secret to simultaneously decode and decrypt the control TLVs and data TLV. +impl ReadableArgs<(SharedSecret, &H, &L)> +for Payload::CustomMessage>> { + fn read(r: &mut R, args: (SharedSecret, &H, &L)) -> Result { + let (encrypted_tlvs_ss, handler, logger) = args; + let v: BigSize = Readable::read(r)?; let mut rd = FixedLengthReader::new(r, v.0); - let mut reply_path: Option = None; + let mut reply_path: Option = None; let mut read_adapter: Option> = None; let rho = onion_utils::gen_rho_from_shared_secret(&encrypted_tlvs_ss.secret_bytes()); - decode_tlv_stream!(&mut rd, { + let mut message_type: Option = None; + let mut message = None; + decode_tlv_stream_with_custom_tlv_decode!(&mut rd, { (2, reply_path, option), - (4, read_adapter, (option: LengthReadableArgs, rho)) + (4, read_adapter, (option: LengthReadableArgs, rho)), + }, |msg_type, msg_reader| { + if msg_type < 64 { return Ok(false) } + // Don't allow reading more than one data TLV from an onion message. + if message_type.is_some() { return Err(DecodeError::InvalidValue) } + + message_type = Some(msg_type); + match msg_type { + tlv_type if OffersMessage::is_known_type(tlv_type) => { + let msg = OffersMessage::read(msg_reader, (tlv_type, logger))?; + message = Some(ParsedOnionMessageContents::Offers(msg)); + Ok(true) + }, + _ => match handler.read_custom_message(msg_type, msg_reader)? { + Some(msg) => { + message = Some(ParsedOnionMessageContents::Custom(msg)); + Ok(true) + }, + None => Ok(false), + }, + } }); rd.eat_remaining().map_err(|_| DecodeError::ShortRead)?; match read_adapter { None => return Err(DecodeError::InvalidValue), Some(ChaChaPolyReadAdapter { readable: ControlTlvs::Forward(tlvs)}) => { + if message_type.is_some() { + return Err(DecodeError::InvalidValue) + } Ok(Payload::Forward(ForwardControlTlvs::Unblinded(tlvs))) }, Some(ChaChaPolyReadAdapter { readable: ControlTlvs::Receive(tlvs)}) => { - Ok(Payload::Receive { control_tlvs: ReceiveControlTlvs::Unblinded(tlvs), reply_path }) + Ok(Payload::Receive { + control_tlvs: ReceiveControlTlvs::Unblinded(tlvs), + reply_path, + message: message.ok_or(DecodeError::InvalidValue)?, + }) }, } } } /// When reading a packet off the wire, we don't know a priori whether the packet is to be forwarded -/// or received. Thus we read a ControlTlvs rather than reading a ForwardControlTlvs or -/// ReceiveControlTlvs directly. -pub(super) enum ControlTlvs { +/// or received. Thus we read a `ControlTlvs` rather than reading a [`ForwardTlvs`] or +/// [`ReceiveTlvs`] directly. Also useful on the encoding side to keep forward and receive TLVs in +/// the same iterator. +pub(crate) enum ControlTlvs { /// This onion message is intended to be forwarded. Forward(ForwardTlvs), /// This onion message is intended to be received. @@ -205,26 +281,29 @@ pub(super) enum ControlTlvs { } impl Readable for ControlTlvs { - fn read(mut r: &mut R) -> Result { - let mut _padding: Option = None; - let mut _short_channel_id: Option = None; - let mut next_node_id: Option = None; - let mut path_id: Option<[u8; 32]> = None; - let mut next_blinding_override: Option = None; - decode_tlv_stream!(&mut r, { + fn read(r: &mut R) -> Result { + _init_and_read_tlv_stream!(r, { (1, _padding, option), - (2, _short_channel_id, option), + (2, short_channel_id, option), (4, next_node_id, option), (6, path_id, option), (8, next_blinding_override, option), }); + let _padding: Option = _padding; + + let next_hop = match (short_channel_id, next_node_id) { + (Some(_), Some(_)) => return Err(DecodeError::InvalidValue), + (Some(scid), None) => Some(NextHop::ShortChannelId(scid)), + (None, Some(pubkey)) => Some(NextHop::NodeId(pubkey)), + (None, None) => None, + }; - let valid_fwd_fmt = next_node_id.is_some() && path_id.is_none(); - let valid_recv_fmt = next_node_id.is_none() && next_blinding_override.is_none(); + let valid_fwd_fmt = next_hop.is_some() && path_id.is_none(); + let valid_recv_fmt = next_hop.is_none() && next_blinding_override.is_none(); let payload_fmt = if valid_fwd_fmt { ControlTlvs::Forward(ForwardTlvs { - next_node_id: next_node_id.unwrap(), + next_hop: next_hop.unwrap(), next_blinding_override, }) } else if valid_recv_fmt { @@ -239,15 +318,11 @@ impl Readable for ControlTlvs { } } -/// Reads padding to the end, ignoring what's read. -pub(crate) struct Padding {} -impl Readable for Padding { - #[inline] - fn read(reader: &mut R) -> Result { - loop { - let mut buf = [0; 8192]; - if reader.read(&mut buf[..])? == 0 { break; } +impl Writeable for ControlTlvs { + fn write(&self, w: &mut W) -> Result<(), io::Error> { + match self { + Self::Forward(tlvs) => tlvs.write(w), + Self::Receive(tlvs) => tlvs.write(w), } - Ok(Self {}) } }