Keep track of which base type (B, K, V, or W) is desired in the miniscript_stable
ConsumeStableNode function. This allows aborting early if the constructed node
won't have the right type.
Note that this does not change the fuzzer format; the meaning of inputs in
ConsumeStableNode is unmodified. The only change is that often the fuzzer will
abort early.
The direct motivation is preventing recursing v: wrappers, which are the only
fragment type that does not otherwise increase the overall minimum possible script
size. In a later commit this will be exploited to prevent overly-large scripts from
being constructed.
Check it only once on the top level node.
Running libfuzzer with -runs=0 against the qa-assets corpus (1b9ddc96586769d92b1b62775f397b7f1a63f142).
Without this patch:
miniscript_stable: Done 6616 runs in 118 second(s)
miniscript_smart: Done 13182 runs in 253 second(s)
With this patch:
miniscript_stable: Done 6616 runs in 57 second(s)
miniscript_smart: Done 13182 runs in 124 second(s)
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
This is a "dumb" way of randomly generating a Miniscript node from
fuzzer input. It defines a strict binary encoding and will always generate
a node defined from the encoding without "helping" to create valid nodes.
It will cut through as soon as it encounters an invalid fragment so
hopefully the fuzzer can tend to learn the encoding and generate valid
nodes with a higher probability.
On a valid generated node a number of invariants are checked, especially
around the satisfactions and testing them against the Script
interpreter.
The node generation and testing is modular in order to later introduce
other ways to generate nodes from fuzzer inputs with minimal code.
Co-Authored-By: Pieter Wuille <pieter@wuille.net>
As stated on the website, duplicate keys make it hard to reason about
malleability as a single signature may unlock multiple paths.
We use a custom KeyCompare function instead of operator< to be explicit
about the requirement.
Parse also key hashes using the Key type. Make this target the first of
the 4 Miniscript fuzz targets in a single `miniscript` file.
Co-authored-by: Pieter Wuille <pieter.wuille@gmail.com>
