core-lightning/common/blindedpay.c
Rusty Russell 511e8e6477 common/blindedpay: routines to construct a blinded payment.
Don't shoehorn it into onion_nonfinal_hop() and onion_final_hop(), but
provide an explicit routine "blinded_onion_hops" and an onion helper
"onion_blinded_hop()" for it to call.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2022-10-26 11:29:06 +10:30

41 lines
1.2 KiB
C

#include "config.h"
#include <assert.h>
#include <common/blindedpay.h>
#include <common/bolt12.h>
#include <common/onion.h>
u8 **blinded_onion_hops(const tal_t *ctx,
struct amount_msat final_amount,
u32 final_cltv,
const struct blinded_path *path)
{
u8 **onions = tal_arr(ctx, u8 *, tal_count(path->path));
assert(tal_count(onions) > 0);
for (size_t i = 0; i < tal_count(onions); i++) {
bool first = (i == 0);
bool final = (i == tal_count(onions) - 1);
/* BOLT-route-blinding #4:
* - For every node inside a blinded route:
* - MUST include the `encrypted_data` provided by the
* recipient
* - For the first node in the blinded route:
* - MUST include the `blinding_point` provided by the
* recipient
* - If it is the final node:
* - MUST include `amt_to_forward` and `outgoing_cltv_value`.
* - Otherwise:
* - MUST NOT include `amt_to_forward` and
* `outgoing_cltv_value`.
*/
onions[i] = onion_blinded_hop(onions,
final ? &final_amount : NULL,
final ? &final_cltv : NULL,
path->path[i]->encrypted_recipient_data,
first ? &path->blinding : NULL);
}
return onions;
}