urbit/lib/btc.hoon
timlucmiptev 8df6ac81f2 btc fixes
2021-05-26 18:30:14 -07:00

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/- sur=btc
^?
=< [sur .]
=, sur
|%
++ xpub-type
|= =xpub
^- bipt
=/ prefix=tape (scag 4 (trip xpub))
?: =("xpub" prefix) %bip44
?: =("ypub" prefix) %bip49
?: =("zpub" prefix) %bip84
~|("invalid xpub: {<xpub>}" !!)
:: +flip-byts: flip endianness while preserving lead/trail zeroes
::
++ flip-byts
|= b=btc-byts
%- to-byts:buffer
%- flop
%- from-byts:buffer b
:: big endian sha256: input and output are both MSB first (big endian)
::
++ sha256
|= =byts ^- hash256
:: if there are leading 0s, lshift by their amount after flip to little endian to preserve
=/ pad=@ (sub wid.byts (met 3 dat.byts))
=/ little-endian=@
(lsh [3 pad] (swp 3 dat.byts))
%- hash256
:- 32
%+ swp 3
(shay wid.byts little-endian)
::
++ dsha256
|= =byts
(sha256 (sha256 byts))
::
++ hash-160
|= pubkey=@ux ^- hash160
=, ripemd:crypto
%- hash160
:- 20
%- ripemd-160
%- sha256 [(met 3 pubkey) pubkey]
::
++ to-script-pubkey
|= script=^buffer ^- ^buffer
%- zing
:~ ~[0x19 0x76 0xa9 0x14]
script
~[0x88 0xac]
==
++ address-to-script-pubkey
|= =address ^- ^buffer
=/ hex=byts
?- -.address
%bech32
(to-hex:bech32 address)
%legacy
=/ h=@ux (@ux +.address)
[(met 3 h) h]
==
?. =(wid.hex 20)
~|("Only 20-byte addresses supported" !!)
(to-script-pubkey (from-byts:buffer hex))
:: arms to handle BIP174 PSBTs
::
++ psbt
|%
:: +create: make base64 cord of PSBT
::
++ create
|= [=rawtx =txid inputs=(list in:^psbt) outputs=(list out:^psbt)]
^- cord
:: TODO
:: make global map
:: turn each input and output into a map (or ~)
:: put the 0x0 separator between all
:: parse to hex
:: encode as base64!
*cord
::
++ hd-path
|= [pubkey=btc-byts =target:^psbt =hdkey]
^- keyval:^psbt
=/ k=btc-byts
%- to-byts:buffer
?- target
%input
[0x6 (from-byts:buffer pubkey)]
::
%output
[0x2 (from-byts:buffer pubkey)]
==
=/ bip ?- bipt.hdkey
%bip84 0x54
%bip49 0x31
%bip44 0x2c
==
=/ hdpath=^buffer
%+ weld
:~ bip 0x0 0x0 0x80
0x0 0x0 0x0 0x80
0x0 0x0 0x0 0x80
`@ux`chyg.hdkey 0x0 0x0 0x0
==
(from-atom-le:buffer (met 3 idx.hdkey) idx.hdkey)
:- k
%- concat-as-byts:buffer
:~ (from-byts:buffer fprint.hdkey)
hdpath
==
::
++ parse
|= psbt-base64=cord
^- (list map:^psbt)
=/ todo=^buffer
%+ slag 5 (to-buffer psbt-base64)
=| acc=(list map:^psbt)
=| m=map:^psbt
|-
?~ todo (snoc acc m)
:: 0x0: map separator
?: =(0x0 i.todo)
$(acc (snoc acc m), m *map:^psbt, todo t.todo)
=+ [kv rest]=(next-keyval todo)
$(m (snoc m kv), todo rest)
:: +get-txid: extract txid from a valid PSBT
::
++ get-txid
|= psbt-base64=cord
^- txid
=/ tx=btc-byts
%- raw-tx
%+ slag 5
(to-buffer psbt-base64)
=/ hash=btc-byts
%- flip-byts
%- sha256
%- sha256
tx
?> ?=(%32 -.hash)
hash
:: +raw-tx: extract hex transaction
:: looks for key 0x0 in global map
:: crashes if tx not in buffer
::
++ raw-tx
|= b=^buffer
|- ^- btc-byts
?~ b !!
?: =(0x0 i.b) !!
=+ nk=(next-keyval b)
?: =(0x0 dat.key.kv.nk)
val.kv.nk
$(b rest.nk)
:: +next-keyval: returns next key-val in a PSBT map
:: input buffer head must be a map key length
::
++ next-keyval
|= b=^buffer
^- [kv=keyval:^psbt rest=^buffer]
=+ klen=(snag 0 b)
=+ k=(swag [1 klen] b)
=+ vlen=(snag (add 1 klen) b)
=+ v=(swag [(add 2 klen) vlen] b)
=+ len=(add 2 (add klen vlen))
?> ?=([^ ^] [k v])
:_ (slag len b)
:- (to-byts:buffer k)
(to-byts:buffer v)
::
++ to-buffer
|= psbt-base64=cord
^- ^buffer
~| "Invalid PSBT"
=+ p=(de:base64:mimes:html psbt-base64)
?~ p !!
=/ bigend=@ux (swp 3 q.u.p)
(from-byts:buffer [(met 3 bigend) bigend])
--
:: buffer: byte buffer utilities
:: list of @ux that is big endian for hashing purposes
:: used to preserve 0s when concatenating byte sequences
::
++ buffer
|%
++ from-byts
|= =byts ^- ^buffer
=/ b=(list @ux)
(flop (rip 3 dat.byts))
=/ pad=@ (sub wid.byts (lent b))
(weld (reap pad 0x0) b)
:: converts an atom to a little endian buffer with wid length (trailing 0s)
:: atom 1 with wid=4 becomes ~[0x1 0x0 0x0 0x0]
:: 0xff11 with wid=8 becomes ~[0x11 0xff 0x0 0x0 0x0 0x0 0x0 0x0]
::
++ from-atom-le
|= [wid=@ a=@] ^- ^buffer
=/ b=(list @ux) (rip 3 a)
=/ pad=@ (sub wid (lent b))
(weld b (reap pad 0x0))
::
++ to-byts
|= b=^buffer ^- byts
[(lent b) (rep 3 (flop b))]
::
++ concat-as-byts
|= bs=(list ^buffer) ^- byts
%- to-byts (zing bs)
--
:: Converts a list of bits to a list of n-bit numbers
:: input-bits should be big-endian
::
++ bits
|%
:: rip atom a with num-bits. Preserve leading 0s, big endian
:: returns a list of bits
::
++ zeros-brip
|= [num-bits=@ a=@]
^- (list @)
=/ bits=(list @) (flop (rip 0 a))
=/ pad=@ (sub num-bits (lent bits))
(weld (reap pad 0) bits)
:: +convert: list of bits to a list of atoms each with bitwidth d(est)
::
++ convert
|= [d=@ bits=(list @)]
^- (list @)
=| ret=(list @)
|- ?~ bits ret
=/ dest-bits (scag d ((list @) bits))
:: left-shift the "missing" number of bits
=/ num=@
%+ lsh [0 (sub d (lent dest-bits))]
(rep 0 (flop dest-bits))
$(ret (snoc ret num), bits (slag d ((list @) bits)))
:: Converts e.g. ~[0 0 31 31 31 31 0 0] in base32 (5 bitwidth)
:: to ~[0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0]
::
++ from-digits
|= [bitwidth=@ digits=(list @)]
^- (list @)
%- zing
%+ turn digits
|= d=@ (zeros-brip bitwidth d)
:: converts 40 bits: ~[0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0]
:: to 0x3fff.fc00 when cast to hex
::
++ to-atom
|= bits=(list @)
^- @
%+ rep 0
%- flop bits
--
::
++ bech32
|%
++ prefixes
^- (map network tape)
(my [[%main "bc"] [%testnet "tb"] ~])
++ charset "qpzry9x8gf2tvdw0s3jn54khce6mua7l"
+$ raw-decoded [hrp=tape data=(list @) checksum=(list @)]
:: below is a port of: https://github.com/bitcoinjs/bech32/blob/master/index.js
::
++ polymod
|= values=(list @)
|^ ^- @
=/ gen=(list @ux)
~[0x3b6a.57b2 0x2650.8e6d 0x1ea1.19fa 0x3d42.33dd 0x2a14.62b3]
=/ chk=@ 1
|- ?~ values chk
=/ top (rsh [0 25] chk)
=. chk
(mix i.values (lsh [0 5] (dis chk 0x1ff.ffff)))
$(values t.values, chk (update-chk chk top gen))
::
++ update-chk
|= [chk=@ top=@ gen=(list @ux)]
=/ is (gulf 0 4)
|- ?~ is chk
?: =(1 (dis 1 (rsh [0 i.is] top)))
$(is t.is, chk (mix chk (snag i.is gen)))
$(is t.is)
--
::
++ expand-hrp
|= hrp=tape
^- (list @)
=/ front (turn hrp |=(p=@tD (rsh [0 5] p)))
=/ back (turn hrp |=(p=@tD (dis 31 p)))
(zing ~[front ~[0] back])
::
++ verify-checksum
|= [hrp=tape data-and-checksum=(list @)]
^- ?
%+ |=([a=@ b=@] =(a b))
1
%- polymod
(weld (expand-hrp hrp) data-and-checksum)
::
++ checksum
|= [hrp=tape data=(list @)]
^- (list @)
:: xor 1 with the polymod
=/ pmod=@
%+ mix 1
%- polymod
(zing ~[(expand-hrp hrp) data (reap 6 0)])
%+ turn (gulf 0 5)
|=(i=@ (dis 31 (rsh [0 (mul 5 (sub 5 i))] pmod)))
::
++ charset-to-value
|= c=@tD
^- (unit @)
(find ~[c] charset)
++ value-to-charset
|= value=@
^- (unit @tD)
?: (gth value 31) ~
`(snag value charset)
::
++ is-valid
|= [bech=tape last-1-pos=@] ^- ?
?& ?|(=((cass bech) bech) =((cuss bech) bech)) :: to upper or to lower is same as bech
(gte last-1-pos 1)
(lte (add last-1-pos 7) (lent bech))
(lte (lent bech) 90)
(levy bech |=(c=@tD (gte c 33)))
(levy bech |=(c=@tD (lte c 126)))
==
:: data should be 5bit words
::
++ encode-raw
|= [hrp=tape data=(list @)]
^- bech32-address
=/ combined=(list @)
(weld data (checksum hrp data))
:- %bech32
%- crip
(zing ~[hrp "1" (tape (murn combined value-to-charset))])
++ decode-raw
|= b=bech32-address
^- (unit raw-decoded)
=/ bech (cass (trip +.b)) :: to lowercase
=/ pos (flop (fand "1" bech))
?~ pos ~
=/ last-1=@ i.pos
?. (is-valid bech last-1) :: check bech32 validity (not segwit validity or checksum)
~
=/ hrp (scag last-1 bech)
=/ encoded-data-and-checksum=(list @)
(slag +(last-1) bech)
=/ data-and-checksum=(list @)
%+ murn encoded-data-and-checksum
charset-to-value
?. =((lent encoded-data-and-checksum) (lent data-and-checksum)) :: ensure all were in CHARSET
~
?. (verify-checksum hrp data-and-checksum)
~
=/ checksum-pos (sub (lent data-and-checksum) 6)
`[hrp (scag checksum-pos data-and-checksum) (slag checksum-pos data-and-checksum)]
:: goes from a bech32 address to hex. Returns byts to preserve leading 0s
::
++ to-hex
|= b=bech32-address ^- hash
=/ d=(unit raw-decoded) (decode-raw b)
?~ d ~|("Invalid bech32 address" !!)
=/ bs=(list @)
(from-digits:bits 5 (slag 1 data.u.d))
=/ byt-len=@ (div (lent bs) 8)
?. =(0 (mod (lent bs) 8))
~|("Invalid bech32 address: not 8bit" !!)
?. ?|(?=(%20 byt-len) ?=(%32 byt-len))
~|("Invalid bech32 address: must be 20 (P2WPKH) or 32 (P2WSH) bytes" !!)
%- hash
[byt-len (to-atom:bits bs)]
:: pubkey is the 33 byte ECC compressed public key
::
++ encode-pubkey
|= [=network pubkey=@ux]
^- (unit bech32-address)
?. =(33 (met 3 pubkey))
~|('pubkey must be a 33 byte ECC compressed public key' !!)
=/ prefix (~(get by prefixes) network)
?~ prefix ~
:- ~
%+ encode-raw u.prefix
[0 (convert:bits 5 (zeros-brip:bits 160 dat:(hash-160 pubkey)))]
++ encode-hash-160
|= [=network h160=byts]
^- (unit bech32-address)
=/ prefix (~(get by prefixes) network)
?~ prefix ~
:- ~
%+ encode-raw u.prefix
[0 (convert:bits 5 (zeros-brip:bits 160 dat.h160))]
--
::
--