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>
Normal output is suitable for feeding to devtools/onion, but for python tests
we want something simpler.
Ideally, we'd simply generate blinded paths in pyln.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
e.g.
$ PUBKEY1=0266e4598d1d3c415f572a8488830b60f7e744ed9235eb0b1ba93283b315c03518
$ PRIVKEY1=41bfd2660762506c9933ade59f1debf7e6495b10c14a92dbcd2d623da2507d3d
$ PUBKEY2=022d223620a359a47ff7f7ac447c85c46c923da53389221a0054c11c1e3ca31d59
$ PRIVKEY1=c4a813f81ffdca1da6864db81795ad2d320add274452cafa1fb2ac2d07d062bd
# First line is blinding, second is contents and nodeids for onion.
$ ./devtools/blindedpath create $PUBKEY1 $PUBKEY2
03f006a18d5653c4edf5391ff23a61f03ff83d237e880ee61187fa9f379a028e0a
0266e4598d1d3c415f572a8488830b60f7e744ed9235eb0b1ba93283b315c03518/350633c340f28bc69cbc86f568b7b9e99fa41eb581452d066fcd70dd53c43ace14d034eebfbe472a2b9901b11c268d2cc2034a77928a 0326f31ff78e584461420e5026fe72374af2ef853e65c47a3f2406348b7c6c0911/00
# Generate the onion
$ /devtools/onion generate 0266e4598d1d3c415f572a8488830b60f7e744ed9235eb0b1ba93283b315c03518/350633c340f28bc69cbc86f568b7b9e99fa41eb581452d066fcd70dd53c43ace14d034eebfbe472a2b9901b11c268d2cc2034a77928a 0326f31ff78e584461420e5026fe72374af2ef853e65c47a3f2406348b7c6c0911/00 > /tmp/onion.dat
# First node unwraps it, gives next blinding and onion
$ ./devtools/blindedpath --first-node unwrap $PRIVKEY1 `cat /tmp/onion.dat` 03f006a18d5653c4edf5391ff23a61f03ff83d237e880ee61187fa9f379a028e0a
Contents: 04210326f31ff78e584461420e5026fe72374af2ef853e65c47a3f2406348b7c6c0911
Next blinding: 021295ce94fcadc42c3e5187a12dd80122214c8f9da61635163cddb63282f1ee9b
Next onion: 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
# Feed that onion and blinding to second node
$ ./devtools/blindedpath unwrap $PRIVKEY2 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 021295ce94fcadc42c3e5187a12dd80122214c8f9da61635163cddb63282f1ee9b
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Header from folded patch 'fixup':
fixup! devtool/blindedpath: primitive tool to make blinded onions.
On decode, don't mess with op.ephemeralkey, since it will be used to derive
the next hop.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Rusty Russell