common/onion is going to need to use this for the case where it finds a blinding
seed inside the TLV. But how it does ecdh is daemon-specific.
We already had this problem for devtools/gossipwith, which supplied a
special hsm_do_ecdh(). This just makes it more general.
So we create a generic ecdh() interface, with a specific implementation
which subdaemons and lightningd can use.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
For messages, we use the onion but payload lengths 0 and 1 aren't special.
Create a flag to disable that logic.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is in preparation for messages, which want this as their assocdata.
Plus, it's a bit cleaner rather than creating a tmp tal array.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Expands the interface to play with onions a bit more. Potentially a bit
slower due to allocations, but that's a small price to pay. It also allows us
to avoid serializing a compressed onion to `u8*` if we process it right away.
Also implements a way to decompress an onion using the devtools/onion tool
Changelog-Added: devtools: The `onion` tool can now generate, compress and decompress onions for rendez-vous routing
Generally I prefer structures over u8, since the size is enforced at
runtime; and in several places we were doing conversions as the code
using Sphinx does treat struct secret as type of the secret.
Note that passing an array is the same as passing the address, so
changing from 'u8 secret[32]' to 'struct secret secret' means various
'secret' parameters change to '&secret'. Technically, '&secret' also
would have worked before, since '&' is a noop on array, but that's
always seemed a bit weird.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Now "raw_payload" is always the complete string (including realm or length
bytes at the front).
This has several effects:
1. We can receive an decrypt an onion which is grossly malformed.
2. We can still hand this to the htlc_accepted hook.
3. We then fail it unless the htlc_accepted accepts it manually.
4. The createonion API now takes the raw payload, and does not know
anything about "style".
The only caveat is that the sphinx code needs to know the payload
length: we have a call for that, which simply tells it to copy the
entire onion (and treat us as the final node) if it's invalid.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Also pulls in a new onion error (mpp_timeout). We change our
route_step_decode_end() to always return the total_msat and optional
secret.
We check total_amount (to prohibit mpp), but we do nothing with
secret for now other than hand it to the htlc_accepted hook.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Simplifying some operations, erroring in some cases and moving to global
defines for constants.
Suggested-by: Rusty Russell <@rustyrussell>
Signed-off-by: Christian Decker <decker.christian@gmail.com>
The `runtest` command takes a JSON onion spec, creates the onion and decodes
it with the provided private keys. It is fully configurable and can be used
for the test-vectors in the spec.
Signed-off-by: Christian Decker <decker.christian@gmail.com>
This was a mismatch between the go tool and this test tool so far. Just
aligning the tools to allows for easier testing.
Signed-off-by: Christian Decker <decker.christian@gmail.com>
This is just taking the existing serialization code and repackaging it in a
more useful form.
Signed-off-by: Christian Decker <decker.christian@gmail.com>
This is also required for actually creating usable onions. For the moment,
due to API limitations, we only let them set realm 0.
Note that the privkey parsing was broken, requiring an additional two
hex digits, overflowing the buffer, and were ignored.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Add odd-length string can never be valid hex!
In addition, don't try to print the next hop if there isn't one, but
always print the (raw) payload.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We need to do it in various places, but we shouldn't do it lightly:
the primitives are there to help us get overflow handling correct.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
As a side-effect of using amount_msat in gossipd/routing.c, we explicitly
handle overflows and don't need to pre-prune ridiculous-fee channels.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Rusty Russell
Christian Decker
Richard Myers
practicalswift