URI: 
       tlnbase: key derivation (WIP) - electrum - Electrum Bitcoin wallet
  HTML git clone https://git.parazyd.org/electrum
   DIR Log
   DIR Files
   DIR Refs
   DIR Submodules
       ---
   DIR commit aa8700d0b3fdffdbcb18ca235d1061a37f2dd23a
   DIR parent 4b8f279d50b4eed374c03da38e1809eb612e2be7
  HTML Author: ThomasV <thomasv@electrum.org>
       Date:   Tue, 17 Apr 2018 11:19:34 +0200
       
       lnbase: key derivation (WIP)
       
       Diffstat:
         M lib/lnbase.py                       |      67 ++++++++++++++++++++++---------
       
       1 file changed, 47 insertions(+), 20 deletions(-)
       ---
   DIR diff --git a/lib/lnbase.py b/lib/lnbase.py
       t@@ -258,6 +258,14 @@ def get_obscured_ctn(ctn, local, remote):
            mask = int.from_bytes(H256(local + remote)[-6:], byteorder="big")
            return ctn ^ mask
        
       +def secret_to_pubkey(secret):
       +    return point_to_ser(SECP256k1.generator * secret)
       +
       +def derive_pubkey(basepoint, per_commitment_point):
       +    p = ser_to_point(basepoint)
       +    p2 = SECP256k1.generator * bitcoin.string_to_number(bitcoin.sha256(per_commitment_point + basepoint))
       +    return point_to_ser(p + p2)
       +
        def overall_weight(num_htlc):
            return 500 + 172 * num_htlc + 224
        
       t@@ -300,11 +308,11 @@ def make_received_htlc(revocation_pubkey, remote_htlcpubkey, local_htlcpubkey, p
        
        
        def make_commitment(ctn, local_funding_pubkey, remote_funding_pubkey, remotepubkey,
       -                    payment_pubkey, remote_payment_pubkey, revocation_pubkey, delayed_pubkey,
       +                    payment_basepoint, remote_payment_basepoint, revocation_pubkey, delayed_pubkey,
                            funding_txid, funding_pos, funding_satoshis,
                            to_local_msat, to_remote_msat, local_feerate, local_delay, htlcs=[]):
            pubkeys = sorted([bh2u(local_funding_pubkey), bh2u(remote_funding_pubkey)])
       -    obs = get_obscured_ctn(ctn, payment_pubkey, remote_payment_pubkey)
       +    obs = get_obscured_ctn(ctn, payment_basepoint, remote_payment_basepoint)
            locktime = (0x20 << 24) + (obs & 0xffffff)
            sequence = (0x80 << 24) + (obs >> 24)
            print_error('locktime', locktime, hex(locktime))
       t@@ -324,13 +332,12 @@ def make_commitment(ctn, local_funding_pubkey, remote_funding_pubkey, remotepubk
            local_script = bytes([opcodes.OP_IF]) + bfh(push_script(bh2u(revocation_pubkey))) + bytes([opcodes.OP_ELSE]) + add_number_to_script(local_delay) \
                           + bytes([opcodes.OP_CSV, opcodes.OP_DROP]) + bfh(push_script(bh2u(delayed_pubkey))) + bytes([opcodes.OP_ENDIF, opcodes.OP_CHECKSIG])
            local_address = bitcoin.redeem_script_to_address('p2wsh', bh2u(local_script))
       -    fee = local_feerate * overall_weight(0) // 1000
       +    fee = local_feerate * overall_weight(len(htlcs)) // 1000
            local_amount = to_local_msat // 1000 - fee
            remote_address = bitcoin.pubkey_to_address('p2wpkh', bh2u(remotepubkey))
            remote_amount = to_remote_msat // 1000
            to_local = (bitcoin.TYPE_ADDRESS, local_address, local_amount)
            to_remote = (bitcoin.TYPE_ADDRESS, remote_address, remote_amount)
       -    # no htlc for the moment
            c_outputs = [to_local, to_remote]
            for script, msat_amount in htlcs:
                c_outputs += [(bitcoin.TYPE_ADDRESS, bitcoin.redeem_script_to_address('p2wsh', bh2u(script)), msat_amount // 1000)]
       t@@ -639,14 +646,23 @@ class Peer(PrintError):
            @aiosafe
            async def channel_establishment_flow(self, wallet, config):
                await self.initialized
       -        keys = get_unused_keys()
                temp_channel_id = os.urandom(32)
       +
       +        keys = get_unused_keys()
                funding_pubkey, funding_privkey = next(keys)
       -        revocation_pubkey, revocation_privkey = next(keys)
       -        htlc_pubkey, htlc_privkey = next(keys)
       -        payment_pubkey, payment_privkey = next(keys)
       -        delayed_pubkey, delayed_privkey = next(keys)
       +        revocation_basepoint, revocation_privkey = next(keys)
       +        htlc_basepoint, htlc_privkey = next(keys)
       +        payment_basepoint, payment_privkey = next(keys)
       +        delayed_payment_basepoint, delayed_privkey = next(keys)
       +
                funding_satoshis = 20000
       +        base_secret = 0x000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f
       +        per_commitment_secret = 0x1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100
       +        base_point = secret_to_pubkey(base_secret)
       +        print('base_point', binascii.hexlify(base_point))
       +        per_commitment_point = secret_to_pubkey(per_commitment_secret)
       +        print('per_commitment_point', binascii.hexlify(per_commitment_point))
       +
                msg = gen_msg(
                    "open_channel",
                    temporary_channel_id=temp_channel_id,
       t@@ -654,30 +670,41 @@ class Peer(PrintError):
                    funding_satoshis=funding_satoshis,
                    max_accepted_htlcs=5,
                    funding_pubkey=funding_pubkey,
       -            revocation_basepoint=revocation_pubkey,
       -            htlc_basepoint=htlc_pubkey,
       -            payment_basepoint=payment_pubkey,
       -            delayed_payment_basepoint=delayed_pubkey,
       -            first_per_commitment_point=next(keys)[0]
       +            revocation_basepoint=revocation_basepoint,
       +            htlc_basepoint=htlc_basepoint,
       +            payment_basepoint=payment_basepoint,
       +            delayed_payment_basepoint=delayed_payment_basepoint,
       +            first_per_commitment_point=per_commitment_point
                )
                self.channel_accepted[temp_channel_id] = asyncio.Future()
                self.send_message(msg)
                try:
       -            accept_channel = await self.channel_accepted[temp_channel_id]
       +            payload = await self.channel_accepted[temp_channel_id]
                finally:
                    del self.channel_accepted[temp_channel_id]
       -        remote_funding_pubkey = accept_channel["funding_pubkey"]
       -        pubkeys = sorted([bh2u(funding_pubkey), bh2u(remote_pubkey)])
       +        remote_funding_pubkey = payload["funding_pubkey"]
       +        pubkeys = sorted([bh2u(funding_pubkey), bh2u(remote_funding_pubkey)])
                redeem_script = transaction.multisig_script(pubkeys, 2)
                funding_address = bitcoin.redeem_script_to_address('p2wsh', redeem_script)
                funding_output = (bitcoin.TYPE_ADDRESS, funding_address, funding_satoshis)
                funding_tx = wallet.mktx([funding_output], None, config, 1000)
                funding_index = funding_tx.outputs().index(funding_output)
       -        remote_payment_pubkey = accept_channel['payment_basepoint']
       +        remote_payment_basepoint = payload['payment_basepoint']
       +        localpubkey = derive_pubkey(payment_basepoint, per_commitment_point)
       +        self.print_error('localpubkey', binascii.hexlify(localpubkey))
       +        revocation_pubkey = derive_pubkey(revocation_basepoint, per_commitment_point)
       +        self.print_error('revocation_pubkey', binascii.hexlify(revocation_pubkey))
       +        local_delayedpubkey = derive_pubkey(delayed_payment_basepoint, per_commitment_point)
       +        self.print_error('local_delayedpubkey', binascii.hexlify(local_delayedpubkey))
       +        remotepubkey = derive_pubkey(remote_payment_basepoint, per_commitment_point)
       +        self.print_error('remotepubkey', binascii.hexlify(remotepubkey))
       +        ctn = 0
                c_tx = make_commitment(
       -            0,
       +            ctn,
                    funding_pubkey, remote_funding_pubkey,
       -            payment_pubkey, remote_payment_pubkey, revocation_pubkey, delayed_pubkey,
       +            remotepubkey,
       +            payment_basepoint, remote_payment_basepoint,
       +            revocation_pubkey, local_delayedpubkey,
                    funding_tx.txid(), funding_index, funding_satoshis,
                    funding_satoshis*1000, 0, 20000, 144)
                c_tx.sign({bh2u(funding_pubkey): (funding_privkey, True)})