mirror of
https://github.com/ElementsProject/lightning.git
synced 2024-11-19 01:43:36 +01:00
45533584e2
Get with the modern nomenclature: the pubkey inside a blinded path is called the `path_key` now. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
131 lines
4.3 KiB
C
131 lines
4.3 KiB
C
#ifndef LIGHTNING_COMMON_ONION_MESSAGE_H
|
|
#define LIGHTNING_COMMON_ONION_MESSAGE_H
|
|
#include "config.h"
|
|
#include <ccan/tal/tal.h>
|
|
#include <common/sciddir_or_pubkey.h>
|
|
#include <common/utils.h>
|
|
|
|
struct tlv_onionmsg_tlv;
|
|
struct secret;
|
|
|
|
/* Onion messages are kind of complicated, so read carefully!
|
|
*
|
|
* An onion message is an array of struct tlv_onionmsg_tlv:
|
|
* encrypted struct tlv_encrypted_data_tlv:
|
|
* encrypted_recipient_data
|
|
*
|
|
* The final entry can also have unencrypted fields:
|
|
* struct blinded_path *reply_path;
|
|
* u8 *invoice_request;
|
|
* u8 *invoice;
|
|
* u8 *invoice_error;
|
|
*
|
|
* The struct tlv_encrypted_data_tlv contains the interesting things:
|
|
*
|
|
* Intermediate nodes:
|
|
* short_channel_id/next_node_id (always)
|
|
* next_blinding_override (optional)
|
|
* payment_relay/payment_constraints (required, for payments only)
|
|
* allowed_features (optional)
|
|
*
|
|
* Final nodes:
|
|
* path_id (so it can tell blinded path was correctly used).
|
|
*/
|
|
|
|
/* Low level routines: */
|
|
|
|
/**
|
|
* Stage 0: populate tlv_encrypted_data_tlv[] array.
|
|
* @ctx: tal context
|
|
* @ids: array of pubkeys defining path destinations
|
|
* @scids: optional array of scids: if non-NULL, use this instead of pubkey for
|
|
* next hop values.
|
|
*
|
|
* This simply populates the short_channel_id/next_node_id fields; you will want to
|
|
* add others.
|
|
*/
|
|
struct tlv_encrypted_data_tlv **new_encdata_tlvs(const tal_t *ctx,
|
|
const struct pubkey *ids,
|
|
const struct short_channel_id **scids);
|
|
|
|
/**
|
|
* Stage 1: tlv_encrypted_data_tlv[] -> struct blinded_path.
|
|
* @ctx: tal context
|
|
* @tlvs: tlvs to be encrypted
|
|
* @ids: array of pubkeys.
|
|
*
|
|
* ids[0] needs to be first node id, but rest don't have to be there unless
|
|
* a tlv uses short_channel_id instead of next_node_id.
|
|
*
|
|
* You can turn the first_node_id into an scidd after if you want to.
|
|
*/
|
|
struct blinded_path *blinded_path_from_encdata_tlvs(const tal_t *ctx,
|
|
const struct tlv_encrypted_data_tlv **tlvs,
|
|
const struct pubkey *ids);
|
|
|
|
/**
|
|
* Stage 2: turn struct blinded_path into array of tlv_onionmsg_tlv.
|
|
* @ctx: tal context
|
|
* @bpath: path containing the encrypted blobs.
|
|
*
|
|
* You normally then add payload fields to the final tlv_onionmsg_tlv.
|
|
*/
|
|
struct tlv_onionmsg_tlv **onionmsg_tlvs_from_blinded_path(const tal_t *ctx,
|
|
const struct blinded_path *bpath);
|
|
|
|
/**
|
|
* Stage 3: linearize each struct tlv_onionmsg_tlv into onionmsg_hops
|
|
* @ctx: tal context
|
|
* @bpath: the path (for the pubkeys)
|
|
* @tlvs: the tlvs for each hop.
|
|
*
|
|
* This is the format the sphinx wants to encode the actual onion message.
|
|
*/
|
|
struct sphinx_hop **onionmsg_tlvs_to_hops(const tal_t *ctx,
|
|
const struct blinded_path *bpath,
|
|
const struct tlv_onionmsg_tlv **tlvs);
|
|
|
|
|
|
/* Stage 4: turn into sphinx_hop * into linear onionmsg (e.g. via injectonionmessage,
|
|
* or directly using common/sphinx.c) */
|
|
|
|
/* Higher level helpers. */
|
|
|
|
/**
|
|
* incoming_message_blinded_path - create incoming blinded path for messages.
|
|
* @ctx: context to tallocate off
|
|
* @ids: array of node ids.
|
|
* @scids: optional, if these are set, use these for directions instead of node ids.
|
|
* @path_secret: put this into final entry, so we can verify.
|
|
*/
|
|
struct blinded_path *incoming_message_blinded_path(const tal_t *ctx,
|
|
const struct pubkey *ids,
|
|
const struct short_channel_id **scids,
|
|
const struct secret *path_secret);
|
|
|
|
|
|
/* A ready-to-be-encrypted-and-sent onion message. */
|
|
struct onion_message {
|
|
struct pubkey first_path_key;
|
|
struct sphinx_hop **hops;
|
|
};
|
|
|
|
/**
|
|
* outgoing_message_tlvs - create encrypted blobs to send msg
|
|
* @ctx: context to tallocate off
|
|
* @ids: array of node ids (first is our peer, must be at least one).
|
|
* @scids: optional, if these are set, use these for directions instead of node ids.
|
|
* @their_path: blinded path they told us to use for reply (or NULL)
|
|
* @final_tlv: extra fields to put in final tlv (consumed)
|
|
*
|
|
* If @their_path is set, the final @ids entry must be @their_path->first_node_id.
|
|
* We cannot check this if their_path->first_node_id is not a pubkey, of course.
|
|
*/
|
|
struct onion_message *outgoing_onion_message(const tal_t *ctx,
|
|
const struct pubkey *ids,
|
|
const struct short_channel_id **scids,
|
|
const struct blinded_path *their_path,
|
|
struct tlv_onionmsg_tlv *final_tlv STEALS);
|
|
|
|
#endif /* LIGHTNING_COMMON_ONION_MESSAGE_H */
|