:: :: /- *btc-wallet-store /+ bip32, btc, bp=btc-provider =, secp:crypto =+ ecc=secp256k1 |% ++ defaults |% ++ max-gap 20 ++ confs 6 -- :: ++ num-confs |= [last-block=@ud =utxo:btc] ?: =(0 height.utxo) 0 (add 1 (sub last-block height.utxo)) :: ++ from-xpub |= [=xpub:btc =fprint:btc scan-to=(unit scon) max-gap=(unit @ud) confs=(unit @ud)] ^- walt :* xpub fprint (from-extended:bip32 (trip xpub)) (xpub-type:btc xpub) *wach [0 0] %.n (fall scan-to *scon) (fall max-gap max-gap:defaults) (fall confs confs:defaults) == :: txb: transaction builder helpers :: ++ txb |_ t=txbu ++ value ^- [in=sats out=sats] :- %+ roll %+ turn txis.t |=(=txi value.utxo.txi) add %+ roll (turn txos.t |=(=txo value.txo)) add :: ++ fee =/ [in=sats out=sats] value (sub in out) :: ++ add-output |= =txo ^- txbu t(txos [txo txos.t]) :: +to-psbt: returns a based 64 PSBT if :: - txinfo is present :: - all inputs have an associated rawtx :: ++ to-psbt ^- (unit (list bytc)) :: ^- (unit base64:psbt:btc) ?~ txinfo.t ~ =/ ins=(list in:psbt:btc) %+ murn txis.t |= =txi ?~ ur.txi ~ `[utxo.txi u.ur.txi hdkey.txi] ?: (lth (lent ins) (lent txis.t)) ~ =/ outs=(list out:psbt:btc) %+ turn txos.t |=(=txo [address.txo hk.txo]) :- ~ %: encode:pbt:btc rawtx.u.txinfo.t txid.u.txinfo.t ins outs == -- :: wad: door for processing walts (wallets) :: parameterized on a walt and it's chyg account :: ++ wad |_ [w=walt =chyg] ++ pubkey |= =idx:btc ^- bytc:btc =/ pk=@ux %- compress-point:ecc pub:(derive-public:(derive-public:wilt.w (@ chyg)) idx) [(met 3 pk) pk] :: ++ hdkey |= =idx:btc ^- hdkey:btc [fprint.w (~(pubkey wad w chyg) idx) bipt.w chyg idx] :: ++ mk-address |= =idx:btc ^- address:btc ?: ?=(%84 bipt.w) (need (encode-pubkey:bech32:btc %main dat:(pubkey idx))) ~|("legacy addresses not supported yet " !!) :: +nixt-address: used to get change addresses :: - gets the current next available address :: - doesn't bump nixt-address if it's unused :: - if used, fall back to gen-address and make a new one :: ++ nixt-address ^- (trel address:btc idx:btc walt) =/ addr (mk-address nixt-idx) ~| "lib/btc-wallet-store: get-next-address: nixt shouldn't be blank" =/ =addi (~(got by wach.w) addr) ?. used.addi [addr nixt-idx w] gen-address :: :: +gen-address: :: - generates the next available address :: - watches it (using update address) :: ++ gen-address ^- (trel address:btc idx:btc walt) =/ addr (mk-address nixt-idx) :* addr nixt-idx %+ update-address addr [%.n chyg nixt-idx *(set utxo:btc)] == :: +update-address :: - insert a new address :: - update "nixt" free address if this one was it :: - watch the new nixt :: ++ update-address |= [a=address:btc =addi] ^- walt ?> =(chyg chyg.addi) ?> =(a (mk-address idx.addi)) =? w (is-nixt addi) bump-nixt w(wach (~(put by wach.w) a addi)) :: ++ is-nixt |= =addi ^- ? ?: ?=(%0 chyg.addi) =(idx.addi p.nixt.w) =(idx.addi q.nixt.w) ++ nixt-idx ?:(?=(%0 chyg) p.nixt.w q.nixt.w) :: +bump-nixt: return wallet with bumped nixt :: - find next unused address :: - watches that address :: - crashes if max-index is passed :: ++ bump-nixt |^ ^- walt =/ new-idx=idx:btc +(nixt-idx) |- ?> (lte new-idx max-index) =+ addr=(mk-address new-idx) =/ =addi %+ ~(gut by wach.w) addr [%.n chyg new-idx *(set utxo:btc)] ?. used.addi %= w nixt (set-nixt new-idx) wach (~(put by wach.w) addr addi) == $(new-idx +(new-idx)) :: ++ set-nixt |= =idx:btc ^- nixt ?:(?=(%0 chyg) [idx q.nixt.w] [p.nixt.w idx]) -- -- :: sut: door to select utxos :: ++ sut |_ [w=walt eny=@uvJ last-block=@ud payee=(unit ship) =feyb txos=(list txo)] ++ meta-weight 10 ++ output-weight 31 ++ n-txos (lent txos) :: ++ target-value ^- sats %+ roll (turn txos |=(=txo value.txo)) |=([a=sats b=sats] (add a b)) :: ++ base-weight |= num-txos=@ud ^- vbytes %+ add meta-weight (mul num-txos output-weight) :: ++ input-weight ^- vbytes ?. ?=(%84 bipt.w) ~|("Only bech32 wallets supported" !!) 102 :: ++ min-tx-fee ^- sats %+ mul feyb (add (base-weight 1) input-weight) :: ++ total-vbytes |= selected=(list input) ^- vbytes %+ add (base-weight n-txos) (mul input-weight (lent selected)) :: value of an input after fee :: 0 if net is <= 0 :: ++ net-value |= val=sats ^- sats =/ cost (mul input-weight feyb) ?: (lte val cost) 0 (sub val cost) :: :: +spendable: whether utxo has enough confs to spend :: ++ spendable |= =utxo:btc ^- ? (gte (num-confs last-block utxo) confs.w) :: +with-change: :: - choose UTXOs, if there are enough :: - return txbu and amount of change (if any) :: ++ with-change ^- [tb=(unit txbu) chng=(unit sats)] =+ tb=select-utxos ?~ tb [~ ~] =+ fee=~(fee txb u.tb) =/ costs=sats :: cost of this tx + sending another %+ add min-tx-fee (mul feyb vbytes.u.tb) ?. (gth fee costs) [tb ~] :- tb `(sub fee costs) :: Uses naive random selection. Should switch to branch-and-bound later. :: ++ select-utxos |^ ^- (unit txbu) =/ is=(unit (list input)) %- single-random-draw %- zing (turn ~(val by wach.w) to-inputs) ?~(is ~ `(inputs-to-txbu u.is)) :: ++ to-inputs |= =addi ^- (list input) %+ turn ~(tap in utxos.addi) |=(=utxo:btc [utxo chyg.addi idx.addi]) :: ++ inputs-to-txbu |= is=(list input) ^- txbu :* (gen-req-id:bp eny) ~ xpub.w payee (total-vbytes is) %+ turn is |= i=input [utxo.i ~ (~(hdkey wad w chyg.i) idx.i)] txos == -- :: single-random-draw :: randomly choose utxos until target is hit :: only use an input if its net-value > 0 :: ++ single-random-draw |= is=(list input) ^- (unit (list input)) =/ rng ~(. og eny) =/ target (add target-value (mul feyb (base-weight n-txos))) :: add base fees to target =| [select=(list input) total=sats:btc] |- ?: =(~ is) ~ =^ n rng (rads:rng (lent is)) =/ i=input (snag n is) =/ net-val (net-value value.utxo.i) =? select ?&((spendable utxo.i) (gth net-val 0)) [i select] :: select if net-value > 0 =/ new-total (add total net-val) ?: (gte new-total target) `select %= $ is (oust [n 1] is) total new-total == :: -- --