In Tapscript MINIMALIF is a consensus rule, so we can rely on the fact
that the `DUP IF [X] ENDIF` will always put an exact 1 on the stack upon
satisfaction.
It is the equivalent of multi() but for Tapscript, using CHECKSIGADD
instead of CHECKMULTISIG.
It shares the same properties as multi() but for 'n', since a threshold
multi_a() may have an empty vector as the top element of its
satisfaction. It could also have the 'o' property when it only has a
single key, but in this case a 'pk()' is always preferable anyways.
6c7a17a8e0 psbt: support externally provided preimages for Miniscript satisfaction (Antoine Poinsot)
840a396029 qa: add a "smart" Miniscript fuzz target (Antoine Poinsot)
17e3547241 qa: add a fuzz target generating random nodes from a binary encoding (Antoine Poinsot)
611e12502a qa: functional test Miniscript signing with key and timelocks (Antoine Poinsot)
d57b7f2021 refactor: make descriptors in Miniscript functional test more readable (Antoine Poinsot)
0a8fc9e200 wallet: check solvability using descriptor in AvailableCoins (Antoine Poinsot)
560e62b1e2 script/sign: signing support for Miniscripts with hash preimage challenges (Antoine Poinsot)
a2f81b6a8f script/sign: signing support for Miniscript with timelocks (Antoine Poinsot)
61c6d1a844 script/sign: basic signing support for Miniscript descriptors (Antoine Poinsot)
4242c1c521 Align 'e' property of or_d and andor with website spec (Pieter Wuille)
f5deb41780 Various additional explanations of the satisfaction logic from Pieter (Pieter Wuille)
22c5b00345 miniscript: satisfaction support (Antoine Poinsot)
Pull request description:
This makes the Miniscript descriptors solvable.
Note this introduces signing support for much more complex scripts than the wallet was previously able to solve, and the whole tooling isn't provided for a complete Miniscript integration in the wallet. Particularly, the PSBT<->Miniscript integration isn't entirely covered in this PR.
ACKs for top commit:
achow101:
ACK 6c7a17a8e0
sipa:
utACK 6c7a17a8e0 (to the extent that it's not my own code).
Tree-SHA512: a71ec002aaf66bd429012caa338fc58384067bcd2f453a46e21d381ed1bacc8e57afb9db57c0fb4bf40de43b30808815e9ebc0ae1fbd9e61df0e7b91a17771cc
The 'Fragment' type was previously named 'Nodetype'. For clarity, name
the variables the same.
-BEGIN VERIFY SCRIPT-
sed -i 's/nodetype/fragment/g' src/script/miniscript.*
-END VERIFY SCRIPT-
Co-authored-by: Pieter Wuille <pieter.wuille@gmail.com>
The value it leaves on the stack depends on the last element on the
stack. However, we can't make sure this element is OP_1 (which would
give us the 'u' property) without the MINIMALIF rule.
MINIMALIF is only policy for P2WSH, therefore giving 'd:' the 'u'
property breaks consensus soundness: it makes it possible (by consensus
but not policy) for instance to satisfy a thresh() without satisfying
at least k of its subs.
This bug was found and reported by Andrew Poelstra.
More information about Miniscript can be found at https://bitcoin.sipa.be/miniscript/ (the
website source is hosted at https://github.com/sipa/miniscript/).
This commit defines all fragments, their composition, parsing from
string representation and conversion to Script.
Co-Authored-By: Antoine Poinsot <darosior@protonmail.com>
Co-Authored-By: Sanket Kanjalkar <sanket1729@gmail.com>
Co-Authored-By: Samuel Dobson <dobsonsa68@gmail.com>
