Fix panic while decoding large Miniscripts from Script

CHANGELOG.md

@@ -1,3 +1,6 @@
+# 11.2.0 - July 20, 2024
+
+- Fix panics while decoding large miniscripts from script [#712](https://github.com/rust-bitcoin/rust-miniscript/pull/712)
 
 # 11.1.0 - July 9, 2024
 

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "miniscript"
-version = "11.1.0"
+version = "11.2.0"
 authors = ["Andrew Poelstra <apoelstra@wpsoftware.net>, Sanket Kanjalkar <sanket1729@gmail.com>"]
 license = "CC0-1.0"
 homepage = "https://github.com/rust-bitcoin/rust-miniscript/"

src/miniscript/decode.rs

@@ -6,7 +6,6 @@
 //!
 
 use core::fmt;
-use core::marker::PhantomData;
 #[cfg(feature = "std")]
 use std::error;
 
@@ -16,8 +15,6 @@ use sync::Arc;
 
 use crate::miniscript::lex::{Token as Tk, TokenIter};
 use crate::miniscript::limits::MAX_PUBKEYS_PER_MULTISIG;
-use crate::miniscript::types::extra_props::ExtData;
-use crate::miniscript::types::{Property, Type};
 use crate::miniscript::ScriptContext;
 use crate::prelude::*;
 #[cfg(doc)]
@@ -212,10 +209,7 @@ impl<Pk: MiniscriptKey, Ctx: ScriptContext> TerminalStack<Pk, Ctx> {
 
  ///reduce, type check and push a 0-arg node
  fn reduce0(&mut self, ms: Terminal<Pk, Ctx>) -> Result<(), Error> {
- let ty = Type::type_check(&ms)?;
- let ext = ExtData::type_check(&ms)?;
- let ms = Miniscript { node: ms, ty, ext, phantom: PhantomData };
- Ctx::check_global_validity(&ms)?;
+ let ms = Miniscript::from_ast(ms)?;
  self.0.push(ms);
  Ok(())
  }
@@ -228,10 +222,7 @@ impl<Pk: MiniscriptKey, Ctx: ScriptContext> TerminalStack<Pk, Ctx> {
  let top = self.pop().unwrap();
  let wrapped_ms = wrap(Arc::new(top));
 
- let ty = Type::type_check(&wrapped_ms)?;
- let ext = ExtData::type_check(&wrapped_ms)?;
- let ms = Miniscript { node: wrapped_ms, ty, ext, phantom: PhantomData };
- Ctx::check_global_validity(&ms)?;
+ let ms = Miniscript::from_ast(wrapped_ms)?;
  self.0.push(ms);
  Ok(())
  }
@@ -246,10 +237,7 @@ impl<Pk: MiniscriptKey, Ctx: ScriptContext> TerminalStack<Pk, Ctx> {
 
  let wrapped_ms = wrap(Arc::new(left), Arc::new(right));
 
- let ty = Type::type_check(&wrapped_ms)?;
- let ext = ExtData::type_check(&wrapped_ms)?;
- let ms = Miniscript { node: wrapped_ms, ty, ext, phantom: PhantomData };
- Ctx::check_global_validity(&ms)?;
+ let ms = Miniscript::from_ast(wrapped_ms)?;
  self.0.push(ms);
  Ok(())
  }
@@ -531,11 +519,7 @@ pub fn parse<Ctx: ScriptContext>(
  let c = term.pop().unwrap();
  let wrapped_ms = Terminal::AndOr(Arc::new(a), Arc::new(c), Arc::new(b));
 
- let ty = Type::type_check(&wrapped_ms)?;
- let ext = ExtData::type_check(&wrapped_ms)?;
-
- term.0
- .push(Miniscript { node: wrapped_ms, ty, ext, phantom: PhantomData });
+ term.0.push(Miniscript::from_ast(wrapped_ms)?);
  }
  Some(NonTerm::ThreshW { n, k }) => {
  match_token!(

src/miniscript/mod.rs

@@ -12,7 +12,6 @@
 //! components of the AST.
 //!
 
-use core::marker::PhantomData;
 use core::{fmt, hash, str};
 
 use bitcoin::hashes::hash160;
@@ -22,7 +21,7 @@ use bitcoin::taproot::{LeafVersion, TapLeafHash};
 use self::analyzable::ExtParams;
 pub use self::context::{BareCtx, Legacy, Segwitv0, Tap};
 use crate::iter::TreeLike;
-use crate::{prelude::*, MAX_RECURSION_DEPTH};
+use crate::prelude::*;
 use crate::{script_num_size, TranslateErr};
 
 pub mod analyzable;
@@ -43,62 +42,73 @@ use self::lex::{lex, TokenIter};
 use self::types::Property;
 pub use crate::miniscript::context::ScriptContext;
 use crate::miniscript::decode::Terminal;
-use crate::miniscript::types::extra_props::ExtData;
-use crate::miniscript::types::Type;
 use crate::{
  expression, plan, Error, ForEachKey, MiniscriptKey, ToPublicKey, TranslatePk, Translator,
 };
 #[cfg(test)]
 mod ms_tests;
 
-/// The top-level miniscript abstract syntax tree (AST).
-#[derive(Clone)]
-pub struct Miniscript<Pk: MiniscriptKey, Ctx: ScriptContext> {
- /// A node in the AST.
- pub node: Terminal<Pk, Ctx>,
- /// The correctness and malleability type information for the AST node.
- pub ty: types::Type,
- /// Additional information helpful for extra analysis.
- pub ext: types::extra_props::ExtData,
- /// Context PhantomData. Only accessible inside this crate
- phantom: PhantomData<Ctx>,
-}
+mod private {
+ use core::marker::PhantomData;
 
-impl<Pk: MiniscriptKey, Ctx: ScriptContext> Miniscript<Pk, Ctx> {
- /// Add type information(Type and Extdata) to Miniscript based on
- /// `AstElem` fragment. Dependent on display and clone because of Error
- /// Display code of type_check.
- pub fn from_ast(t: Terminal<Pk, Ctx>) -> Result<Miniscript<Pk, Ctx>, Error> {
- let res = Miniscript {
- ty: Type::type_check(&t)?,
- ext: ExtData::type_check(&t)?,
- node: t,
- phantom: PhantomData,
- };
- // TODO: This recursion depth is based on segwitv0.
- // We can relax this in tapscript, but this should be good for almost
- // all practical cases and we can revisit this if needed.
- // casting to u32 is safe because tree_height will never go more than u32::MAX
- if (res.ext.tree_height as u32) > MAX_RECURSION_DEPTH {
- return Err(Error::MaxRecursiveDepthExceeded);
- }
- Ctx::check_global_consensus_validity(&res)?;
- Ok(res)
+ use super::types::{ExtData, Property, Type};
+ pub use crate::miniscript::context::ScriptContext;
+ use crate::miniscript::types;
+ use crate::{Error, MiniscriptKey, Terminal, MAX_RECURSION_DEPTH};
+
+ /// The top-level miniscript abstract syntax tree (AST).
+ #[derive(Clone)]
+ pub struct Miniscript<Pk: MiniscriptKey, Ctx: ScriptContext> {
+ /// A node in the AST.
+ pub node: Terminal<Pk, Ctx>,
+ /// The correctness and malleability type information for the AST node.
+ pub ty: types::Type,
+ /// Additional information helpful for extra analysis.
+ pub ext: types::extra_props::ExtData,
+ /// Context PhantomData. Only accessible inside this crate
+ phantom: PhantomData<Ctx>,
  }
+ impl<Pk: MiniscriptKey, Ctx: ScriptContext> Miniscript<Pk, Ctx> {
+
+ /// Add type information(Type and Extdata) to Miniscript based on
+ /// `AstElem` fragment. Dependent on display and clone because of Error
+ /// Display code of type_check.
+ pub fn from_ast(t: Terminal<Pk, Ctx>) -> Result<Miniscript<Pk, Ctx>, Error> {
+ let res = Miniscript {
+ ty: Type::type_check(&t)?,
+ ext: ExtData::type_check(&t)?,
+ node: t,
+ phantom: PhantomData,
+ };
+ // TODO: This recursion depth is based on segwitv0.
+ // We can relax this in tapscript, but this should be good for almost
+ // all practical cases and we can revisit this if needed.
+ // casting to u32 is safe because tree_height will never go more than u32::MAX
+ if (res.ext.tree_height as u32) > MAX_RECURSION_DEPTH {
+ return Err(Error::MaxRecursiveDepthExceeded);
+ }
+ Ctx::check_global_consensus_validity(&res)?;
+ Ok(res)
+ }
 
- /// Create a new `Miniscript` from a `Terminal` node and a `Type` annotation
- /// This does not check the typing rules. The user is responsible for ensuring
- /// that the type provided is correct.
- ///
- /// You should almost always use `Miniscript::from_ast` instead of this function.
- pub fn from_components_unchecked(
- node: Terminal<Pk, Ctx>,
- ty: types::Type,
- ext: types::extra_props::ExtData,
- ) -> Miniscript<Pk, Ctx> {
- Miniscript { node, ty, ext, phantom: PhantomData }
+ /// Create a new `Miniscript` from a `Terminal` node and a `Type` annotation
+ /// This does not check the typing rules. The user is responsible for ensuring
+ /// that the type provided is correct.
+ ///
+ /// You should almost always use `Miniscript::from_ast` instead of this function.
+ pub fn from_components_unchecked(
+ node: Terminal<Pk, Ctx>,
+ ty: types::Type,
+ ext: types::extra_props::ExtData,
+ ) -> Miniscript<Pk, Ctx> {
+ Miniscript { node, ty, ext, phantom: PhantomData }
+ }
  }
+}
+
+pub use private::Miniscript;
 
+impl<Pk: MiniscriptKey, Ctx: ScriptContext> Miniscript<Pk, Ctx> {
  /// Extracts the `AstElem` representing the root of the miniscript
  pub fn into_inner(self) -> Terminal<Pk, Ctx> { self.node }
 
@@ -603,7 +613,6 @@ pub mod hash256 {
 #[cfg(test)]
 mod tests {
 
- use core::marker::PhantomData;
  use core::str;
  use core::str::FromStr;
 
@@ -614,7 +623,7 @@ mod tests {
  use sync::Arc;
 
  use super::{Miniscript, ScriptContext, Segwitv0, Tap};
- use crate::miniscript::types::{self, ExtData, Property, Type};
+ use crate::miniscript::types;
  use crate::miniscript::Terminal;
  use crate::policy::Liftable;
  use crate::{prelude::*, Error};
@@ -800,21 +809,15 @@ mod tests {
  .unwrap();
  let hash = hash160::Hash::from_byte_array([17; 20]);
 
- let pk_node = Terminal::Check(Arc::new(Miniscript {
- node: Terminal::PkK(String::from("")),
- ty: Type::from_pk_k::<Segwitv0>(),
- ext: types::extra_props::ExtData::from_pk_k::<Segwitv0>(),
- phantom: PhantomData,
- }));
+ let pk_node = Terminal::Check(Arc::new(
+ Miniscript::from_ast(Terminal::PkK(String::from(""))).unwrap(),
+ ));
  let pkk_ms: Miniscript<String, Segwitv0> = Miniscript::from_ast(pk_node).unwrap();
  dummy_string_rtt(pkk_ms, "[B/onduesm]c:[K/onduesm]pk_k(\"\")", "pk()");
 
- let pkh_node = Terminal::Check(Arc::new(Miniscript {
- node: Terminal::PkH(String::from("")),
- ty: Type::from_pk_h::<Segwitv0>(),
- ext: types::extra_props::ExtData::from_pk_h::<Segwitv0>(),
- phantom: PhantomData,
- }));
+ let pkh_node = Terminal::Check(Arc::new(
+ Miniscript::from_ast(Terminal::PkH(String::from(""))).unwrap(),
+ ));
  let pkh_ms: Miniscript<String, Segwitv0> = Miniscript::from_ast(pkh_node).unwrap();
 
  let expected_debug = "[B/nduesm]c:[K/nduesm]pk_h(\"\")";
@@ -830,12 +833,7 @@ mod tests {
  assert_eq!(display, expected);
  }
 
- let pkk_node = Terminal::Check(Arc::new(Miniscript {
- node: Terminal::PkK(pk),
- ty: Type::from_pk_k::<Segwitv0>(),
- ext: types::extra_props::ExtData::from_pk_k::<Segwitv0>(),
- phantom: PhantomData,
- }));
+ let pkk_node = Terminal::Check(Arc::new(Miniscript::from_ast(Terminal::PkK(pk)).unwrap()));
  let pkk_ms: Segwitv0Script = Miniscript::from_ast(pkk_node).unwrap();
 
  script_rtt(
@@ -844,17 +842,10 @@ mod tests {
  202020202ac",
  );
 
- let pkh_ms: Segwitv0Script = Miniscript {
- node: Terminal::Check(Arc::new(Miniscript {
- node: Terminal::RawPkH(hash),
- ty: Type::from_pk_h::<Segwitv0>(),
- ext: types::extra_props::ExtData::from_pk_h::<Segwitv0>(),
- phantom: PhantomData,
- })),
- ty: Type::cast_check(Type::from_pk_h::<Segwitv0>()).unwrap(),
- ext: ExtData::cast_check(ExtData::from_pk_h::<Segwitv0>()).unwrap(),
- phantom: PhantomData,
- };
+ let pkh_ms: Segwitv0Script = Miniscript::from_ast(Terminal::Check(Arc::new(
+ Miniscript::from_ast(Terminal::RawPkH(hash)).unwrap(),
+ )))
+ .unwrap();
 
  script_rtt(pkh_ms, "76a914111111111111111111111111111111111111111188ac");
  }
@@ -1366,4 +1357,13 @@ mod tests {
  Err(Error::MaxRecursiveDepthExceeded)
  );
  }
+
+ #[test]
+ fn test_script_parse_dos() {
+ let mut script = bitcoin::script::Builder::new().push_opcode(bitcoin::opcodes::OP_TRUE);
+ for _ in 0..10000 {
+ script = script.push_opcode(bitcoin::opcodes::all::OP_0NOTEQUAL);
+ }
+ Tapscript::parse_insane(&script.into_script()).unwrap_err();
+ }
 }