You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
312 lines
8.4 KiB
312 lines
8.4 KiB
#include "common/onion.h"
|
|
#include <assert.h>
|
|
#include <ccan/array_size/array_size.h>
|
|
#include <common/sphinx.h>
|
|
#include <wire/gen_onion_wire.h>
|
|
|
|
/* BOLT #4:
|
|
*
|
|
* ## Legacy `hop_data` payload format
|
|
*
|
|
* The `hop_data` format is identified by a single `0x00`-byte length,
|
|
* for backward compatibility. Its payload is defined as:
|
|
*
|
|
* 1. type: `hop_data` (for `realm` 0)
|
|
* 2. data:
|
|
* * [`short_channel_id`:`short_channel_id`]
|
|
* * [`u64`:`amt_to_forward`]
|
|
* * [`u32`:`outgoing_cltv_value`]
|
|
* * [`12*byte`:`padding`]
|
|
*/
|
|
static u8 *make_v0_hop(const tal_t *ctx,
|
|
const struct short_channel_id *scid,
|
|
struct amount_msat forward, u32 outgoing_cltv)
|
|
{
|
|
const u8 padding[] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
|
0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
|
|
/* Prepend 0 byte for realm */
|
|
u8 *buf = tal_arrz(ctx, u8, 1);
|
|
towire_short_channel_id(&buf, scid);
|
|
towire_u64(&buf, forward.millisatoshis); /* Raw: low-level serializer */
|
|
towire_u32(&buf, outgoing_cltv);
|
|
towire(&buf, padding, ARRAY_SIZE(padding));
|
|
assert(tal_bytelen(buf) == 1 + 32);
|
|
return buf;
|
|
}
|
|
|
|
static u8 *make_tlv_hop(const tal_t *ctx,
|
|
const struct tlv_tlv_payload *tlv)
|
|
{
|
|
/* We can't have over 64k anyway */
|
|
u8 *tlvs = tal_arr(ctx, u8, 3);
|
|
|
|
towire_tlv_payload(&tlvs, tlv);
|
|
|
|
switch (bigsize_put(tlvs, tal_bytelen(tlvs) - 3)) {
|
|
case 1:
|
|
/* Move over two unused bytes */
|
|
memmove(tlvs + 1, tlvs + 3, tal_bytelen(tlvs) - 3);
|
|
tal_resize(&tlvs, tal_bytelen(tlvs) - 2);
|
|
return tlvs;
|
|
case 3:
|
|
return tlvs;
|
|
}
|
|
abort();
|
|
}
|
|
|
|
u8 *onion_nonfinal_hop(const tal_t *ctx,
|
|
bool use_tlv,
|
|
const struct short_channel_id *scid,
|
|
struct amount_msat forward,
|
|
u32 outgoing_cltv)
|
|
{
|
|
if (use_tlv) {
|
|
struct tlv_tlv_payload *tlv = tlv_tlv_payload_new(tmpctx);
|
|
struct tlv_tlv_payload_amt_to_forward tlv_amt;
|
|
struct tlv_tlv_payload_outgoing_cltv_value tlv_cltv;
|
|
struct tlv_tlv_payload_short_channel_id tlv_scid;
|
|
|
|
/* BOLT #4:
|
|
*
|
|
* The writer:
|
|
*...
|
|
* - For every node:
|
|
* - MUST include `amt_to_forward` and `outgoing_cltv_value`.
|
|
* - For every non-final node:
|
|
* - MUST include `short_channel_id`
|
|
* - MUST NOT include `payment_data`
|
|
*/
|
|
tlv_amt.amt_to_forward = forward.millisatoshis; /* Raw: TLV convert */
|
|
tlv_cltv.outgoing_cltv_value = outgoing_cltv;
|
|
tlv_scid.short_channel_id = *scid;
|
|
tlv->amt_to_forward = &tlv_amt;
|
|
tlv->outgoing_cltv_value = &tlv_cltv;
|
|
tlv->short_channel_id = &tlv_scid;
|
|
|
|
return make_tlv_hop(ctx, tlv);
|
|
} else {
|
|
return make_v0_hop(ctx, scid, forward, outgoing_cltv);
|
|
}
|
|
}
|
|
|
|
u8 *onion_final_hop(const tal_t *ctx,
|
|
bool use_tlv,
|
|
struct amount_msat forward,
|
|
u32 outgoing_cltv,
|
|
struct amount_msat total_msat,
|
|
const struct secret *payment_secret)
|
|
{
|
|
/* These go together! */
|
|
if (!payment_secret)
|
|
assert(amount_msat_eq(total_msat, forward));
|
|
|
|
if (use_tlv) {
|
|
struct tlv_tlv_payload *tlv = tlv_tlv_payload_new(tmpctx);
|
|
struct tlv_tlv_payload_amt_to_forward tlv_amt;
|
|
struct tlv_tlv_payload_outgoing_cltv_value tlv_cltv;
|
|
struct tlv_tlv_payload_payment_data tlv_pdata;
|
|
|
|
/* BOLT #4:
|
|
*
|
|
* The writer:
|
|
*...
|
|
* - For every node:
|
|
* - MUST include `amt_to_forward` and `outgoing_cltv_value`.
|
|
*...
|
|
* - For the final node:
|
|
* - MUST NOT include `short_channel_id`
|
|
* - if the recipient provided `payment_secret`:
|
|
* - MUST include `payment_data`
|
|
* - MUST set `payment_secret` to the one provided
|
|
* - MUST set `total_msat` to the total amount it will send
|
|
*/
|
|
tlv_amt.amt_to_forward = forward.millisatoshis; /* Raw: TLV convert */
|
|
tlv_cltv.outgoing_cltv_value = outgoing_cltv;
|
|
tlv->amt_to_forward = &tlv_amt;
|
|
tlv->outgoing_cltv_value = &tlv_cltv;
|
|
|
|
if (payment_secret) {
|
|
tlv_pdata.payment_secret = *payment_secret;
|
|
tlv_pdata.total_msat = total_msat.millisatoshis; /* Raw: TLV convert */
|
|
tlv->payment_data = &tlv_pdata;
|
|
}
|
|
return make_tlv_hop(ctx, tlv);
|
|
} else {
|
|
static struct short_channel_id all_zero_scid;
|
|
/* No payment secrets in legacy format. */
|
|
if (payment_secret)
|
|
return NULL;
|
|
return make_v0_hop(ctx, &all_zero_scid, forward, outgoing_cltv);
|
|
}
|
|
}
|
|
|
|
/* Returns true if valid, and fills in type. */
|
|
static bool pull_payload_length(const u8 **cursor,
|
|
size_t *max,
|
|
enum onion_payload_type *type,
|
|
size_t *len)
|
|
{
|
|
/* *len will incorporate bytes we read from cursor */
|
|
const u8 *start = *cursor;
|
|
|
|
/* BOLT #4:
|
|
*
|
|
* The `length` field determines both the length and the format of the
|
|
* `hop_payload` field; the following formats are defined:
|
|
*/
|
|
*len = fromwire_bigsize(cursor, max);
|
|
if (!cursor)
|
|
return false;
|
|
|
|
/* BOLT #4:
|
|
* - Legacy `hop_data` format, identified by a single `0x00` byte for
|
|
* length. In this case the `hop_payload_length` is defined to be 32
|
|
* bytes.
|
|
*/
|
|
if (*len == 0) {
|
|
if (type)
|
|
*type = ONION_V0_PAYLOAD;
|
|
assert(*cursor - start == 1);
|
|
*len = 1 + 32;
|
|
return true;
|
|
}
|
|
|
|
/* BOLT #4:
|
|
* - `tlv_payload` format, identified by any length over `1`. In this
|
|
* case the `hop_payload_length` is equal to the numeric value of
|
|
* `length`.
|
|
*/
|
|
if (*len > 1) {
|
|
/* It's still invalid if it claims to be too long! */
|
|
if (*len > ROUTING_INFO_SIZE - HMAC_SIZE)
|
|
return false;
|
|
|
|
if (type)
|
|
*type = ONION_TLV_PAYLOAD;
|
|
*len += (*cursor - start);
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
size_t onion_payload_length(const u8 *raw_payload, size_t len,
|
|
bool *valid,
|
|
enum onion_payload_type *type)
|
|
{
|
|
size_t max = len, payload_len;
|
|
*valid = pull_payload_length(&raw_payload, &max, type, &payload_len);
|
|
|
|
/* If it's not valid, copy the entire thing. */
|
|
if (!*valid)
|
|
return len;
|
|
|
|
return payload_len;
|
|
}
|
|
|
|
struct onion_payload *onion_decode(const tal_t *ctx,
|
|
const struct route_step *rs,
|
|
u64 *failtlvtype,
|
|
size_t *failtlvpos)
|
|
{
|
|
struct onion_payload *p = tal(ctx, struct onion_payload);
|
|
const u8 *cursor = rs->raw_payload;
|
|
size_t max = tal_bytelen(cursor), len;
|
|
struct tlv_tlv_payload *tlv;
|
|
|
|
if (!pull_payload_length(&cursor, &max, &p->type, &len))
|
|
return tal_free(p);
|
|
|
|
switch (p->type) {
|
|
case ONION_V0_PAYLOAD:
|
|
p->type = ONION_V0_PAYLOAD;
|
|
p->forward_channel = tal(p, struct short_channel_id);
|
|
fromwire_short_channel_id(&cursor, &max, p->forward_channel);
|
|
p->amt_to_forward = fromwire_amount_msat(&cursor, &max);
|
|
p->outgoing_cltv = fromwire_u32(&cursor, &max);
|
|
p->payment_secret = NULL;
|
|
|
|
if (rs->nextcase == ONION_FORWARD) {
|
|
p->total_msat = NULL;
|
|
} else {
|
|
/* BOLT #4:
|
|
* - if it is the final node:
|
|
* - MUST treat `total_msat` as if it were equal to
|
|
* `amt_to_forward` if it is not present. */
|
|
p->total_msat = tal_dup(p, struct amount_msat,
|
|
&p->amt_to_forward);
|
|
}
|
|
|
|
/* If they somehow got an invalid onion this far, fail. */
|
|
if (!cursor)
|
|
return tal_free(p);
|
|
return p;
|
|
|
|
case ONION_TLV_PAYLOAD:
|
|
tlv = tlv_tlv_payload_new(p);
|
|
if (!fromwire_tlv_payload(&cursor, &max, tlv))
|
|
goto fail;
|
|
|
|
if (!tlv_payload_is_valid(tlv, failtlvpos)) {
|
|
*failtlvtype = tlv->fields[*failtlvpos].numtype;
|
|
goto fail;
|
|
}
|
|
|
|
/* BOLT #4:
|
|
*
|
|
* The reader:
|
|
* - MUST return an error if `amt_to_forward` or
|
|
* `outgoing_cltv_value` are not present.
|
|
*/
|
|
if (!tlv->amt_to_forward || !tlv->outgoing_cltv_value)
|
|
goto fail;
|
|
|
|
amount_msat_from_u64(&p->amt_to_forward,
|
|
tlv->amt_to_forward->amt_to_forward);
|
|
p->outgoing_cltv = tlv->outgoing_cltv_value->outgoing_cltv_value;
|
|
|
|
/* BOLT #4:
|
|
*
|
|
* The writer:
|
|
*...
|
|
* - For every non-final node:
|
|
* - MUST include `short_channel_id`
|
|
*/
|
|
if (rs->nextcase == ONION_FORWARD) {
|
|
if (!tlv->short_channel_id)
|
|
goto fail;
|
|
p->forward_channel = tal(p, struct short_channel_id);
|
|
*p->forward_channel
|
|
= tlv->short_channel_id->short_channel_id;
|
|
p->total_msat = NULL;
|
|
} else {
|
|
p->forward_channel = NULL;
|
|
/* BOLT #4:
|
|
* - if it is the final node:
|
|
* - MUST treat `total_msat` as if it were equal to
|
|
* `amt_to_forward` if it is not present. */
|
|
p->total_msat = tal_dup(p, struct amount_msat,
|
|
&p->amt_to_forward);
|
|
}
|
|
|
|
p->payment_secret = NULL;
|
|
|
|
if (tlv->payment_data) {
|
|
p->payment_secret = tal_dup(p, struct secret,
|
|
&tlv->payment_data->payment_secret);
|
|
tal_free(p->total_msat);
|
|
p->total_msat = tal(p, struct amount_msat);
|
|
p->total_msat->millisatoshis /* Raw: tu64 on wire */
|
|
= tlv->payment_data->total_msat;
|
|
}
|
|
tal_free(tlv);
|
|
return p;
|
|
}
|
|
|
|
/* You said it was a valid type! */
|
|
abort();
|
|
fail:
|
|
tal_free(tlv);
|
|
tal_free(p);
|
|
return NULL;
|
|
}
|
|
|