Crate miniscript
source · [−]Expand description
Miniscript and Output Descriptors
Introduction
Bitcoin Script
In Bitcoin, spending policies are defined and enforced by means of a stack-based programming language known as Bitcoin Script. While this language appears to be designed with tractable analysis in mind (e.g. there are no looping or jumping constructions), in practice this is extremely difficult. As a result, typical wallet software supports only a small set of script templates, cannot interoperate with other similar software, and each wallet contains independently written ad-hoc manually verified code to handle these templates. Users who require more complex spending policies, or who want to combine signing infrastructure which was not explicitly designed to work together, are simply out of luck.
Miniscript
Miniscript is an alternative to Bitcoin Script which eliminates these problems. It can be efficiently and simply encoded as Script to ensure that it works on the Bitcoin blockchain, but its design is very different. Essentially, a Miniscript is a monotone function (tree of ANDs, ORs and thresholds) of signature requirements, hash preimage requirements, and timelocks.
A full description of Miniscript is available here.
Miniscript also admits a more human-readable encoding.
Output Descriptors
While spending policies in Bitcoin are entirely defined by Script; there are multiple ways of embedding these Scripts in transaction outputs; for example, P2SH or Segwit v0. These different embeddings are expressed by Output Descriptors, which are described here
Examples
Deriving an address from a descriptor
use std::str::FromStr;
let desc = miniscript::Descriptor::<bitcoin::PublicKey>::from_str("\
sh(wsh(or_d(\
c:pk_k(020e0338c96a8870479f2396c373cc7696ba124e8635d41b0ea581112b67817261),\
c:pk_k(0250863ad64a87ae8a2fe83c1af1a8403cb53f53e486d8511dad8a04887e5b2352)\
)))\
").unwrap();
// Derive the P2SH address
assert_eq!(
desc.address(bitcoin::Network::Bitcoin).unwrap().to_string(),
"3CJxbQBfWAe1ZkKiGQNEYrioV73ZwvBWns"
);
// Check whether the descriptor is safe. This checks whether all spend paths are accessible in
// the Bitcoin network. It may be possible that some of the spend paths require more than 100
// elements in Wsh scripts or they contain a combination of timelock and heightlock.
assert!(desc.sanity_check().is_ok());
// Estimate the satisfaction cost
assert_eq!(desc.max_satisfaction_weight().unwrap(), 293);
Re-exports
pub use bitcoin;
pub use crate::descriptor::Descriptor;
pub use crate::interpreter::Interpreter;
pub use crate::miniscript::analyzable::AnalysisError;
pub use crate::miniscript::analyzable::ExtParams;
pub use crate::miniscript::decode::Terminal;
pub use crate::miniscript::satisfy::Preimage32;
pub use crate::miniscript::satisfy::Satisfier;
pub use crate::miniscript::hash256;
pub use crate::miniscript::Miniscript;
Modules
Macros
Structs
DescriptorPublicKey
without any wildcards.Enums
Bare
ScriptContextTraits
t
to do
the actual translation function calls.TranslatePk
trait to do the actual translations.