milksad
/
rust-bitcoin-unsafe-fast
14
0
Fork 0
Code Issues Pull Requests Activity

Merge rust-bitcoin/rust-bitcoin#1600: Refactor script module 

a9108d3939 Refactor script module (Tobin C. Harding)

Pull request description:

  The `script` module is large and unwieldy.

  Refactor the `script` module, splitting it up into a tree of modules. Here are a few of the changes and their stated benefits

  - Split the two script types out into separate files: Readers of the methods can then tell immediately from the file name which type they are reading.
  - Put all the impls for the two script types together: Makes parsing the API easier because one can more quickly see which traits are implemented on what i.e., all the `AsRef` imlps are grouped together.
  - Put the impls for the two script types in order, first `Script` then `ScriptBuf`: Makes it easier for us to see if we missed something.
  - Put the `Builder` and `Instruction` (and associated) types in their own modules: Some devs find long files hard to navigate, so far there hasn't been too much push back against short files.
  - Put tests in a separate file: This idea was recently discussed.

  This is only moving code and fixing import statements etc. No other changes to the code.

  ## Note to reviewers

  This PR is impossible to review from the diff because it moves so much code. Perhaps better to look at the resulting `src/blockdata/script/` directory and see if you like it.

  #### Motivation

  While adding script tagging I was having difficulty navigating the script module.

ACKs for top commit:
  apoelstra:
    ACK a9108d3939
  Kixunil:
    ACK a9108d3939

Tree-SHA512: 19123c8cfbdce6c42b322fa75a74073a0114b0ed21bd06ca5727981b3573b74cf05075723b774b92ae2b497e20644fca6e2fac14e30cc44f2802dde5aa567f66
This commit is contained in:
Andrew Poelstra 2023-02-09 23:18:39 +00:00
parent cc3b5a080b a9108d3939
commit 2290e90b71
No known key found for this signature in database
GPG Key ID: C588D63CE41B97C1
8 changed files with 2777 additions and 2707 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2707
bitcoin/src/blockdata/script.rs
View File

File diff suppressed because it is too large Load Diff

149
bitcoin/src/blockdata/script/builder.rs Normal file
View File

@ -0,0 +1,149 @@
// Written in 2014 by Andrew Poelstra <apoelstra@wpsoftware.net>
// SPDX-License-Identifier: CC0-1.0
#[cfg(feature="bitcoinconsensus")] use core::convert::From;
use core::default::Default;
use core::fmt;
use secp256k1::XOnlyPublicKey;
use crate::blockdata::opcodes::{self, all::*};
use crate::blockdata::script::{write_scriptint, opcode_to_verify, Script, ScriptBuf};
use crate::key::PublicKey;
use crate::prelude::*;
/// An Object which can be used to construct a script piece by piece.
#[derive(PartialEq, Eq, Clone)]
pub struct Builder(ScriptBuf, Option<opcodes::All>);
impl Builder {
/// Creates a new empty script.
pub fn new() -> Self {
Builder(ScriptBuf::new(), None)
}
/// Returns the length in bytes of the script.
pub fn len(&self) -> usize { self.0.len() }
/// Checks whether the script is the empty script.
pub fn is_empty(&self) -> bool { self.0.is_empty() }
/// Adds instructions to push an integer onto the stack.
///
/// Integers are encoded as little-endian signed-magnitude numbers, but there are dedicated
/// opcodes to push some small integers.
pub fn push_int(self, data: i64) -> Builder {
// We can special-case -1, 1-16
if data == -1 || (1..=16).contains(&data) {
let opcode = opcodes::All::from(
(data - 1 + opcodes::OP_TRUE.to_u8() as i64) as u8
);
self.push_opcode(opcode)
}
// We can also special-case zero
else if data == 0 {
self.push_opcode(opcodes::OP_FALSE)
}
// Otherwise encode it as data
else { self.push_int_non_minimal(data) }
}
/// Adds instructions to push an integer onto the stack without optimization.
///
/// This uses the explicit encoding regardless of the availability of dedicated opcodes.
pub(in crate::blockdata) fn push_int_non_minimal(self, data: i64) -> Builder {
let mut buf = [0u8; 8];
let len = write_scriptint(&mut buf, data);
self.push_slice(&buf[..len])
}
/// Adds instructions to push some arbitrary data onto the stack.
pub fn push_slice(mut self, data: &[u8]) -> Builder {
self.0.push_slice(data);
self.1 = None;
self
}
/// Adds instructions to push a public key onto the stack.
pub fn push_key(self, key: &PublicKey) -> Builder {
if key.compressed {
self.push_slice(&key.inner.serialize()[..])
} else {
self.push_slice(&key.inner.serialize_uncompressed()[..])
}
}
/// Adds instructions to push an XOnly public key onto the stack.
pub fn push_x_only_key(self, x_only_key: &XOnlyPublicKey) -> Builder {
self.push_slice(&x_only_key.serialize())
}
/// Adds a single opcode to the script.
pub fn push_opcode(mut self, data: opcodes::All) -> Builder {
self.0.push_opcode(data);
self.1 = Some(data);
self
}
/// Adds an `OP_VERIFY` to the script or replaces the last opcode with VERIFY form.
///
/// Some opcodes such as `OP_CHECKSIG` have a verify variant that works as if `VERIFY` was
/// in the script right after. To save space this function appends `VERIFY` only if
/// the most-recently-added opcode *does not* have an alternate `VERIFY` form. If it does
/// the last opcode is replaced. E.g., `OP_CHECKSIG` will become `OP_CHECKSIGVERIFY`.
///
/// Note that existing `OP_*VERIFY` opcodes do not lead to the instruction being ignored
/// because `OP_VERIFY` consumes an item from the stack so ignoring them would change the
/// semantics.
pub fn push_verify(mut self) -> Builder {
// "duplicated code" because we need to update `1` field
match opcode_to_verify(self.1) {
Some(opcode) => {
(self.0).0.pop();
self.push_opcode(opcode)
},
None => self.push_opcode(OP_VERIFY),
}
}
/// Converts the `Builder` into `ScriptBuf`.
pub fn into_script(self) -> ScriptBuf {
self.0
}
/// Converts the `Builder` into script bytes
pub fn into_bytes(self) -> Vec<u8> {
self.0.into()
}
/// Returns the internal script
pub fn as_script(&self) -> &Script {
&self.0
}
/// Returns script bytes
pub fn as_bytes(&self) -> &[u8] {
self.0.as_bytes()
}
}
impl Default for Builder {
fn default() -> Builder { Builder::new() }
}
/// Creates a new builder from an existing vector.
impl From<Vec<u8>> for Builder {
fn from(v: Vec<u8>) -> Builder {
let script = ScriptBuf::from(v);
let last_op = script.last_opcode();
Builder(script, last_op)
}
}
impl fmt::Display for Builder {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
self.0.fmt_asm(f)
}
}
bitcoin_internals::debug_from_display!(Builder);

228
bitcoin/src/blockdata/script/instruction.rs Normal file
View File

@ -0,0 +1,228 @@
// Written in 2014 by Andrew Poelstra <apoelstra@wpsoftware.net>
// SPDX-License-Identifier: CC0-1.0
use crate::blockdata::opcodes;
use crate::blockdata::script::{read_uint_iter, Error, Script, ScriptBuf, UintError};
/// A "parsed opcode" which allows iterating over a [`Script`] in a more sensible way.
#[derive(Debug, PartialEq, Eq, Copy, Clone)]
pub enum Instruction<'a> {
/// Push a bunch of data.
PushBytes(&'a [u8]),
/// Some non-push opcode.
Op(opcodes::All),
}
impl<'a> Instruction<'a> {
/// Returns the opcode if the instruction is not a data push.
pub fn opcode(&self) -> Option<opcodes::All> {
match self {
Instruction::Op(op) => Some(*op),
Instruction::PushBytes(_) => None,
}
}
/// Returns the opcode if the instruction is not a data push.
pub fn push_bytes(&self) -> Option<&[u8]> {
match self {
Instruction::Op(_) => None,
Instruction::PushBytes(bytes) => Some(bytes),
}
}
/// Returns the number of bytes required to encode the instruction in script.
pub(super) fn script_serialized_len(&self) -> usize {
match self {
Instruction::Op(_) => 1,
Instruction::PushBytes(bytes) => ScriptBuf::reserved_len_for_slice(bytes.len()),
}
}
}
/// Iterator over a script returning parsed opcodes.
#[derive(Debug, Clone)]
pub struct Instructions<'a> {
pub(crate) data: core::slice::Iter<'a, u8>,
pub(crate) enforce_minimal: bool,
}
impl<'a> Instructions<'a> {
/// Views the remaining script as a slice.
///
/// This is analogous to what [`core::str::Chars::as_str`] does.
pub fn as_script(&self) -> &'a Script {
Script::from_bytes(self.data.as_slice())
}
/// Sets the iterator to end so that it won't iterate any longer.
pub(super) fn kill(&mut self) {
let len = self.data.len();
self.data.nth(len.max(1) - 1);
}
/// Takes a `len` bytes long slice from iterator and returns it, advancing the iterator.
///
/// If the iterator is not long enough [`Error::EarlyEndOfScript`] is returned and the iterator
/// is killed to avoid returning an infinite stream of errors.
pub(super) fn take_slice_or_kill(&mut self, len: usize) -> Result<&'a [u8], Error> {
if self.data.len() >= len {
let slice = &self.data.as_slice()[..len];
if len > 0 {
self.data.nth(len - 1);
}
Ok(slice)
} else {
self.kill();
Err(Error::EarlyEndOfScript)
}
}
pub(super) fn next_push_data_len(&mut self, len: usize, min_push_len: usize) -> Option<Result<Instruction<'a>, Error>> {
let n = match read_uint_iter(&mut self.data, len) {
Ok(n) => n,
// We do exhaustive matching to not forget to handle new variants if we extend
// `UintError` type.
// Overflow actually means early end of script (script is definitely shorter
// than `usize::max_value()`)
Err(UintError::EarlyEndOfScript) | Err(UintError::NumericOverflow) => {
self.kill();
return Some(Err(Error::EarlyEndOfScript));
},
};
if self.enforce_minimal && n < min_push_len {
self.kill();
return Some(Err(Error::NonMinimalPush));
}
Some(self.take_slice_or_kill(n).map(Instruction::PushBytes))
}
}
impl<'a> Iterator for Instructions<'a> {
type Item = Result<Instruction<'a>, Error>;
fn next(&mut self) -> Option<Result<Instruction<'a>, Error>> {
let &byte = self.data.next()?;
// classify parameter does not really matter here since we are only using
// it for pushes and nums
match opcodes::All::from(byte).classify(opcodes::ClassifyContext::Legacy) {
opcodes::Class::PushBytes(n) => {
// make sure safety argument holds across refactorings
let n: u32 = n;
// casting is safe because we don't support 16-bit architectures
let n = n as usize;
let op_byte = self.data.as_slice().first();
match (self.enforce_minimal, op_byte, n) {
(true, Some(&op_byte), 1) if op_byte == 0x81 || (op_byte > 0 && op_byte <= 16) => {
self.kill();
Some(Err(Error::NonMinimalPush))
},
(_, None, 0) => {
// the iterator is already empty, may as well use this information to avoid
// whole take_slice_or_kill function
Some(Ok(Instruction::PushBytes(&[])))
},
_ => {
Some(self.take_slice_or_kill(n).map(Instruction::PushBytes))
}
}
}
opcodes::Class::Ordinary(opcodes::Ordinary::OP_PUSHDATA1) => {
self.next_push_data_len(1, 76)
}
opcodes::Class::Ordinary(opcodes::Ordinary::OP_PUSHDATA2) => {
self.next_push_data_len(2, 0x100)
}
opcodes::Class::Ordinary(opcodes::Ordinary::OP_PUSHDATA4) => {
self.next_push_data_len(4, 0x10000)
}
// Everything else we can push right through
_ => {
Some(Ok(Instruction::Op(opcodes::All::from(byte))))
}
}
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
if self.data.len() == 0 {
(0, Some(0))
} else {
// There will not be more instructions than bytes
(1, Some(self.data.len()))
}
}
}
impl<'a> core::iter::FusedIterator for Instructions<'a> {}
/// Iterator over script instructions with their positions.
///
/// The returned indices can be used for slicing [`Script`] [safely](Script#slicing-safety).
///
/// This is analogous to [`core::str::CharIndices`].
#[derive(Debug, Clone)]
pub struct InstructionIndices<'a> {
instructions: Instructions<'a>,
pos: usize,
}
impl<'a> InstructionIndices<'a> {
/// Views the remaining script as a slice.
///
/// This is analogous to what [`core::str::Chars::as_str`] does.
#[inline]
pub fn as_script(&self) -> &'a Script {
self.instructions.as_script()
}
/// Creates `Self` setting `pos` to 0.
pub(super) fn from_instructions(instructions: Instructions<'a>) -> Self {
InstructionIndices {
instructions,
pos: 0,
}
}
pub(super) fn remaining_bytes(&self) -> usize {
self.instructions.as_script().len()
}
/// Modifies the iterator using `next_fn` returning the next item.
///
/// This generically computes the new position and maps the value to be returned from iterator
/// method.
pub(super) fn next_with<F: FnOnce(&mut Self) -> Option<Result<Instruction<'a>, Error>>>(&mut self, next_fn: F) -> Option<<Self as Iterator>::Item> {
let prev_remaining = self.remaining_bytes();
let prev_pos = self.pos;
let instruction = next_fn(self)?;
// No underflow: there must be less remaining bytes now than previously
let consumed = prev_remaining - self.remaining_bytes();
// No overflow: sum will never exceed slice length which itself can't exceed `usize`
self.pos += consumed;
Some(instruction.map(move |instruction| (prev_pos, instruction)))
}
}
impl<'a> Iterator for InstructionIndices<'a> {
/// The `usize` in the tuple represents index at which the returned `Instruction` is located.
type Item = Result<(usize, Instruction<'a>), Error>;
fn next(&mut self) -> Option<Self::Item> {
self.next_with(|this| this.instructions.next())
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.instructions.size_hint()
}
// the override avoids computing pos multiple times
fn nth(&mut self, n: usize) -> Option<Self::Item> {
self.next_with(|this| this.instructions.nth(n))
}
}
impl core::iter::FusedIterator for InstructionIndices<'_> {}

328
bitcoin/src/blockdata/script/mod.rs Normal file
View File

@ -0,0 +1,328 @@
// Written in 2014 by Andrew Poelstra <apoelstra@wpsoftware.net>
// SPDX-License-Identifier: CC0-1.0
//! Bitcoin scripts.
//!
//! *[See also the `Script` type](Script).*
//!
//! This module provides the structures and functions needed to support scripts.
//!
//! <details>
//! <summary>What is Bitcoin script</summary>
//!
//! Scripts define Bitcoin's digital signature scheme: a signature is formed
//! from a script (the second half of which is defined by a coin to be spent,
//! and the first half provided by the spending transaction), and is valid iff
//! the script leaves `TRUE` on the stack after being evaluated. Bitcoin's
//! script is a stack-based assembly language similar in spirit to [Forth].
//!
//! Script is represented as a sequence of bytes on the wire, each byte representing an operation,
//! or data to be pushed on the stack.
//!
//! See [Bitcoin Wiki: Script][wiki-script] for more information.
//!
//! [Forth]: https://en.wikipedia.org/wiki/Forth_(programming_language)
//!
//! [wiki-script]: https://en.bitcoin.it/wiki/Script
//! </details>
//!
//! In this library we chose to keep the byte representation in memory and decode opcodes only when
//! processing the script. This is similar to Rust choosing to represent strings as UTF-8-encoded
//! bytes rather than slice of `char`s. In both cases the individual items can have different sizes
//! and forcing them to be larger would waste memory and, in case of Bitcoin script, even some
//! performance (forcing allocations).
//!
//! ## `Script` vs `ScriptBuf` vs `Builder`
//!
//! These are the most important types in this module and they are quite similar, so it may seem
//! confusing what the differences are. `Script` is an unsized type much like `str` or `Path` are
//! and `ScriptBuf` is an owned counterpart to `Script` just like `String` is an owned counterpart
//! to `str`.
//!
//! However it is common to construct an owned script and then pass it around. For this case a
//! builder API is more convenient. To support this we provide `Builder` type which is very similar
//! to `ScriptBuf` but its methods take `self` instead of `&mut self` and return `Self`. It also
//! contains a cache that may make some modifications faster. This cache is usually not needed
//! outside of creating the script.
//!
//! At the time of writing there's only one operation using the cache - `push_verify`, so the cache
//! is minimal but we may extend it in the future if needed.
use core::fmt;
use crate::blockdata::opcodes::{self, all::*};
use crate::OutPoint;
mod builder;
mod instruction;
mod types;
#[cfg(test)]
mod tests;
pub use self::builder::*;
pub use self::instruction::*;
pub use self::types::*;
/// Encodes an integer in script(minimal CScriptNum) format.
///
/// Writes bytes into the buffer and returns the number of bytes written.
pub fn write_scriptint(out: &mut [u8; 8], n: i64) -> usize {
let mut len = 0;
if n == 0 { return len; }
let neg = n < 0;
let mut abs = if neg { -n } else { n } as usize;
while abs > 0xFF {
out[len] = (abs & 0xFF) as u8;
len += 1;
abs >>= 8;
}
// If the number's value causes the sign bit to be set, we need an extra
// byte to get the correct value and correct sign bit
if abs & 0x80 != 0 {
out[len] = abs as u8;
len += 1;
out[len] = if neg { 0x80u8 } else { 0u8 };
len += 1;
}
// Otherwise we just set the sign bit ourselves
else {
abs |= if neg { 0x80 } else { 0 };
out[len] = abs as u8;
len += 1;
}
len
}
/// Decodes an integer in script(minimal CScriptNum) format.
///
/// Notice that this fails on overflow: the result is the same as in
/// bitcoind, that only 4-byte signed-magnitude values may be read as
/// numbers. They can be added or subtracted (and a long time ago,
/// multiplied and divided), and this may result in numbers which
/// can't be written out in 4 bytes or less. This is ok! The number
/// just can't be read as a number again.
/// This is a bit crazy and subtle, but it makes sense: you can load
/// 32-bit numbers and do anything with them, which back when mult/div
/// was allowed, could result in up to a 64-bit number. We don't want
/// overflow since that's surprising --- and we don't want numbers that
/// don't fit in 64 bits (for efficiency on modern processors) so we
/// simply say, anything in excess of 32 bits is no longer a number.
/// This is basically a ranged type implementation.
pub fn read_scriptint(v: &[u8]) -> Result<i64, Error> {
let len = v.len();
if len > 4 { return Err(Error::NumericOverflow); }
let last = match v.last() {
Some(last) => last,
None => return Ok(0),
};
// Comment and code copied from Bitcoin Core:
// https://github.com/bitcoin/bitcoin/blob/447f50e4aed9a8b1d80e1891cda85801aeb80b4e/src/script/script.h#L247-L262
// If the most-significant-byte - excluding the sign bit - is zero
// then we're not minimal. Note how this test also rejects the
// negative-zero encoding, 0x80.
if (last & 0x7f) == 0 {
// One exception: if there's more than one byte and the most
// significant bit of the second-most-significant-byte is set
// it would conflict with the sign bit. An example of this case
// is +-255, which encode to 0xff00 and 0xff80 respectively.
// (big-endian).
if v.len() <= 1 || (v[v.len() - 2] & 0x80) == 0 {
return Err(Error::NonMinimalPush);
}
}
let (mut ret, sh) = v.iter()
.fold((0, 0), |(acc, sh), n| (acc + ((*n as i64) << sh), sh + 8));
if v[len - 1] & 0x80 != 0 {
ret &= (1 << (sh - 1)) - 1;
ret = -ret;
}
Ok(ret)
}
/// Decodes a boolean.
///
/// This is like "`read_scriptint` then map 0 to false and everything
/// else as true", except that the overflow rules don't apply.
#[inline]
pub fn read_scriptbool(v: &[u8]) -> bool {
match v.split_last() {
Some((last, rest)) => !((last & !0x80 == 0x00) && rest.iter().all(|&b| b == 0)),
None => false,
}
}
/// Decodes a script-encoded unsigned integer.
///
/// ## Errors
///
/// This function returns an error in these cases:
///
/// * `data` is shorter than `size` => `EarlyEndOfScript`
/// * `size` is greater than `u16::max_value / 8` (8191) => `NumericOverflow`
/// * The number being read overflows `usize` => `NumericOverflow`
///
/// Note that this does **not** return an error for `size` between `core::size_of::<usize>()`
/// and `u16::max_value / 8` if there's no overflow.
#[inline]
pub fn read_uint(data: &[u8], size: usize) -> Result<usize, Error> {
read_uint_iter(&mut data.iter(), size).map_err(Into::into)
}
// We internally use implementation based on iterator so that it automatically advances as needed
// Errors are same as above, just different type.
fn read_uint_iter(data: &mut core::slice::Iter<'_, u8>, size: usize) -> Result<usize, UintError> {
if data.len() < size {
Err(UintError::EarlyEndOfScript)
} else if size > usize::from(u16::max_value() / 8) {
// Casting to u32 would overflow
Err(UintError::NumericOverflow)
} else {
let mut ret = 0;
for (i, item) in data.take(size).enumerate() {
ret = usize::from(*item)
// Casting is safe because we checked above to not repeat the same check in a loop
.checked_shl((i * 8) as u32)
.ok_or(UintError::NumericOverflow)?
.checked_add(ret)
.ok_or(UintError::NumericOverflow)?;
}
Ok(ret)
}
}
fn opcode_to_verify(opcode: Option<opcodes::All>) -> Option<opcodes::All> {
opcode.and_then(|opcode| {
match opcode {
OP_EQUAL => Some(OP_EQUALVERIFY),
OP_NUMEQUAL => Some(OP_NUMEQUALVERIFY),
OP_CHECKSIG => Some(OP_CHECKSIGVERIFY),
OP_CHECKMULTISIG => Some(OP_CHECKMULTISIGVERIFY),
_ => None,
}
})
}
/// Ways that a script might fail. Not everything is split up as
/// much as it could be; patches welcome if more detailed errors
/// would help you.
#[derive(PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Clone, Copy)]
#[non_exhaustive]
pub enum Error {
/// Something did a non-minimal push; for more information see
/// `https://github.com/bitcoin/bips/blob/master/bip-0062.mediawiki#Push_operators`
NonMinimalPush,
/// Some opcode expected a parameter but it was missing or truncated.
EarlyEndOfScript,
/// Tried to read an array off the stack as a number when it was more than 4 bytes.
NumericOverflow,
/// Error validating the script with bitcoinconsensus library.
#[cfg(feature = "bitcoinconsensus")]
#[cfg_attr(docsrs, doc(cfg(feature = "bitcoinconsensus")))]
BitcoinConsensus(bitcoinconsensus::Error),
/// Can not find the spent output.
UnknownSpentOutput(OutPoint),
/// Can not serialize the spending transaction.
Serialization
}
// If bitcoinonsensus-std is off but bitcoinconsensus is present we patch the error type to
// implement `std::error::Error`.
#[cfg(all(feature = "std", feature = "bitcoinconsensus", not(feature = "bitcoinconsensus-std")))]
mod bitcoinconsensus_hack {
use core::fmt;
#[repr(transparent)]
pub(crate) struct Error(bitcoinconsensus::Error);
impl fmt::Debug for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Debug::fmt(&self.0, f)
}
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Display::fmt(&self.0, f)
}
}
// bitcoinconsensus::Error has no sources at this time
impl std::error::Error for Error {}
pub(crate) fn wrap_error(error: &bitcoinconsensus::Error) -> &Error {
// Unfortunately, we cannot have the reference inside `Error` struct because of the 'static
// bound on `source` return type, so we have to use unsafe to overcome the limitation.
// SAFETY: the type is repr(transparent) and the lifetimes match
unsafe {
&*(error as *const _ as *const Error)
}
}
}
#[cfg(not(all(feature = "std", feature = "bitcoinconsensus", not(feature = "bitcoinconsensus-std"))))]
mod bitcoinconsensus_hack {
#[allow(unused_imports)] // conditionally used
pub(crate) use core::convert::identity as wrap_error;
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
#[cfg(feature = "bitcoinconsensus")]
use bitcoin_internals::write_err;
match *self {
Error::NonMinimalPush => f.write_str("non-minimal datapush"),
Error::EarlyEndOfScript => f.write_str("unexpected end of script"),
Error::NumericOverflow => f.write_str("numeric overflow (number on stack larger than 4 bytes)"),
#[cfg(feature = "bitcoinconsensus")]
Error::BitcoinConsensus(ref e) => write_err!(f, "bitcoinconsensus verification failed"; bitcoinconsensus_hack::wrap_error(e)),
Error::UnknownSpentOutput(ref point) => write!(f, "unknown spent output: {}", point),
Error::Serialization => f.write_str("can not serialize the spending transaction in Transaction::verify()"),
}
}
}
#[cfg(feature = "std")]
#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
impl std::error::Error for Error {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
use self::Error::*;
match *self {
NonMinimalPush
| EarlyEndOfScript
| NumericOverflow
| UnknownSpentOutput(_)
| Serialization => None,
#[cfg(feature = "bitcoinconsensus")]
BitcoinConsensus(ref e) => Some(bitcoinconsensus_hack::wrap_error(e)),
}
}
}
// Our internal error proves that we only return these two cases from `read_uint_iter`.
// Since it's private we don't bother with trait impls besides From.
enum UintError {
EarlyEndOfScript,
NumericOverflow,
}
impl From<UintError> for Error {
fn from(error: UintError) -> Self {
match error {
UintError::EarlyEndOfScript => Error::EarlyEndOfScript,
UintError::NumericOverflow => Error::NumericOverflow,
}
}
}
#[cfg(feature = "bitcoinconsensus")]
#[doc(hidden)]
impl From<bitcoinconsensus::Error> for Error {
fn from(err: bitcoinconsensus::Error) -> Error {
Error::BitcoinConsensus(err)
}
}

660
bitcoin/src/blockdata/script/tests.rs Normal file
View File

@ -0,0 +1,660 @@
use core::str::FromStr;
use super::*;
use crate::hashes::Hash;
use crate::hashes::hex::FromHex;
use crate::hash_types::{PubkeyHash, WPubkeyHash, ScriptHash, WScriptHash};
use crate::consensus::encode::{deserialize, serialize};
use crate::blockdata::opcodes;
use crate::crypto::key::{PublicKey, XOnlyPublicKey};
use crate::psbt::serialize::Serialize;
use crate::internal_macros::hex;
#[test]
fn script() {
let mut comp = vec![];
let mut script = Builder::new();
assert_eq!(script.as_bytes(), &comp[..]);
// small ints
script = script.push_int(1); comp.push(81u8); assert_eq!(script.as_bytes(), &comp[..]);
script = script.push_int(0); comp.push(0u8); assert_eq!(script.as_bytes(), &comp[..]);
script = script.push_int(4); comp.push(84u8); assert_eq!(script.as_bytes(), &comp[..]);
script = script.push_int(-1); comp.push(79u8); assert_eq!(script.as_bytes(), &comp[..]);
// forced scriptint
script = script.push_int_non_minimal(4); comp.extend([1u8, 4].iter().cloned()); assert_eq!(script.as_bytes(), &comp[..]);
// big ints
script = script.push_int(17); comp.extend([1u8, 17].iter().cloned()); assert_eq!(script.as_bytes(), &comp[..]);
script = script.push_int(10000); comp.extend([2u8, 16, 39].iter().cloned()); assert_eq!(script.as_bytes(), &comp[..]);
// notice the sign bit set here, hence the extra zero/128 at the end
script = script.push_int(10000000); comp.extend([4u8, 128, 150, 152, 0].iter().cloned()); assert_eq!(script.as_bytes(), &comp[..]);
script = script.push_int(-10000000); comp.extend([4u8, 128, 150, 152, 128].iter().cloned()); assert_eq!(script.as_bytes(), &comp[..]);
// data
script = script.push_slice("NRA4VR".as_bytes()); comp.extend([6u8, 78, 82, 65, 52, 86, 82].iter().cloned()); assert_eq!(script.as_bytes(), &comp[..]);
// keys
const KEYSTR1: &str = "21032e58afe51f9ed8ad3cc7897f634d881fdbe49a81564629ded8156bebd2ffd1af";
let key = PublicKey::from_str(&KEYSTR1[2..]).unwrap();
script = script.push_key(&key); comp.extend_from_slice(&hex!(KEYSTR1)); assert_eq!(script.as_bytes(), &comp[..]);
const KEYSTR2: &str = "41042e58afe51f9ed8ad3cc7897f634d881fdbe49a81564629ded8156bebd2ffd1af191923a2964c177f5b5923ae500fca49e99492d534aa3759d6b25a8bc971b133";
let key = PublicKey::from_str(&KEYSTR2[2..]).unwrap();
script = script.push_key(&key); comp.extend_from_slice(&hex!(KEYSTR2)); assert_eq!(script.as_bytes(), &comp[..]);
// opcodes
script = script.push_opcode(OP_CHECKSIG); comp.push(0xACu8); assert_eq!(script.as_bytes(), &comp[..]);
script = script.push_opcode(OP_CHECKSIG); comp.push(0xACu8); assert_eq!(script.as_bytes(), &comp[..]);
}
#[test]
fn p2pk_pubkey_bytes_valid_key_and_valid_script_returns_expected_key() {
let key_str = "0411db93e1dcdb8a016b49840f8c53bc1eb68a382e97b1482ecad7b148a6909a5cb2e0eaddfb84ccf9744464f82e160bfa9b8b64f9d4c03f999b8643f656b412a3";
let key = PublicKey::from_str(key_str).unwrap();
let p2pk = Script::builder().push_key(&key).push_opcode(OP_CHECKSIG).into_script();
let actual = p2pk.p2pk_pubkey_bytes().unwrap();
assert_eq!(actual.to_vec(), key.to_bytes());
}
#[test]
fn p2pk_pubkey_bytes_no_checksig_returns_none() {
let key_str = "0411db93e1dcdb8a016b49840f8c53bc1eb68a382e97b1482ecad7b148a6909a5cb2e0eaddfb84ccf9744464f82e160bfa9b8b64f9d4c03f999b8643f656b412a3";
let key = PublicKey::from_str(key_str).unwrap();
let no_checksig = Script::builder().push_key(&key).into_script();
assert_eq!(no_checksig.p2pk_pubkey_bytes(), None);
}
#[test]
fn p2pk_pubkey_bytes_emptry_script_returns_none() {
let empty_script = Script::builder().into_script();
assert!(empty_script.p2pk_pubkey_bytes().is_none());
}
#[test]
fn p2pk_pubkey_bytes_no_key_returns_none() {
// scripts with no key should return None
let no_push_bytes = Script::builder().push_opcode(OP_CHECKSIG).into_script();
assert!(no_push_bytes.p2pk_pubkey_bytes().is_none());
}
#[test]
fn p2pk_pubkey_bytes_different_op_code_returns_none() {
let key_str = "0411db93e1dcdb8a016b49840f8c53bc1eb68a382e97b1482ecad7b148a6909a5cb2e0eaddfb84ccf9744464f82e160bfa9b8b64f9d4c03f999b8643f656b412a3";
let key = PublicKey::from_str(key_str).unwrap();
let different_op_code = Script::builder().push_key(&key).push_opcode(OP_NOP).into_script();
assert!(different_op_code.p2pk_pubkey_bytes().is_none());
}
#[test]
fn p2pk_pubkey_bytes_incorrect_key_size_returns_none() {
// 63 byte key
let malformed_key = "21032e58afe51f9ed8ad3cc7897f634d881fdbe49816429ded8156bebd2ffd1";
let invalid_p2pk_script = Script::builder()
.push_slice(malformed_key.as_bytes())
.push_opcode(OP_CHECKSIG)
.into_script();
assert!(invalid_p2pk_script.p2pk_pubkey_bytes().is_none());
}
#[test]
fn p2pk_pubkey_bytes_invalid_key_returns_some() {
let malformed_key = "21032e58afe51f9ed8ad3cc7897f634d881fdbe49816429ded8156bebd2ffd1ux";
let invalid_key_script = Script::builder()
.push_slice(malformed_key.as_bytes())
.push_opcode(OP_CHECKSIG)
.into_script();
assert!(invalid_key_script.p2pk_pubkey_bytes().is_some());
}
#[test]
fn p2pk_pubkey_bytes_compressed_key_returns_expected_key() {
let compressed_key_str = "0311db93e1dcdb8a016b49840f8c53bc1eb68a382e97b1482ecad7b148a6909a5c";
let key = PublicKey::from_str(compressed_key_str).unwrap();
let p2pk = Script::builder().push_key(&key).push_opcode(OP_CHECKSIG).into_script();
let actual = p2pk.p2pk_pubkey_bytes().unwrap();
assert_eq!(actual.to_vec(), key.to_bytes());
}
#[test]
fn p2pk_public_key_valid_key_and_valid_script_returns_expected_key() {
let key_str = "0411db93e1dcdb8a016b49840f8c53bc1eb68a382e97b1482ecad7b148a6909a5cb2e0eaddfb84ccf9744464f82e160bfa9b8b64f9d4c03f999b8643f656b412a3";
let key = PublicKey::from_str(key_str).unwrap();
let p2pk = Script::builder().push_key(&key).push_opcode(OP_CHECKSIG).into_script();
let actual = p2pk.p2pk_public_key().unwrap();
assert_eq!(actual, key);
}
#[test]
fn p2pk_public_key_no_checksig_returns_none() {
let key_str = "0411db93e1dcdb8a016b49840f8c53bc1eb68a382e97b1482ecad7b148a6909a5cb2e0eaddfb84ccf9744464f82e160bfa9b8b64f9d4c03f999b8643f656b412a3";
let key = PublicKey::from_str(key_str).unwrap();
let no_checksig = Script::builder().push_key(&key).into_script();
assert_eq!(no_checksig.p2pk_public_key(), None);
}
#[test]
fn p2pk_public_key_empty_script_returns_none() {
let empty_script = Script::builder().into_script();
assert!(empty_script.p2pk_public_key().is_none());
}
#[test]
fn p2pk_public_key_no_key_returns_none() {
let no_push_bytes = Script::builder().push_opcode(OP_CHECKSIG).into_script();
assert!(no_push_bytes.p2pk_public_key().is_none());
}
#[test]
fn p2pk_public_key_different_op_code_returns_none() {
let key_str = "0411db93e1dcdb8a016b49840f8c53bc1eb68a382e97b1482ecad7b148a6909a5cb2e0eaddfb84ccf9744464f82e160bfa9b8b64f9d4c03f999b8643f656b412a3";
let key = PublicKey::from_str(key_str).unwrap();
let different_op_code = Script::builder().push_key(&key).push_opcode(OP_NOP).into_script();
assert!(different_op_code.p2pk_public_key().is_none());
}
#[test]
fn p2pk_public_key_incorrect_size_returns_none() {
let malformed_key = "21032e58afe51f9ed8ad3cc7897f634d881fdbe49816429ded8156bebd2ffd1";
let malformed_key_script = Script::builder()
.push_slice(malformed_key.as_bytes())
.push_opcode(OP_CHECKSIG)
.into_script();
assert!(malformed_key_script.p2pk_public_key().is_none());
}
#[test]
fn p2pk_public_key_invalid_key_returns_none() {
let malformed_key = "21032e58afe51f9ed8ad3cc7897f634d881fdbe49816429ded8156bebd2ffd1ux";
let invalid_key_script = Script::builder()
.push_slice(malformed_key.as_bytes())
.push_opcode(OP_CHECKSIG)
.into_script();
assert!(invalid_key_script.p2pk_public_key().is_none());
}
#[test]
fn p2pk_public_key_compressed_key_returns_some() {
let compressed_key_str = "0311db93e1dcdb8a016b49840f8c53bc1eb68a382e97b1482ecad7b148a6909a5c";
let key = PublicKey::from_str(compressed_key_str).unwrap();
let p2pk = Script::builder().push_key(&key).push_opcode(OP_CHECKSIG).into_script();
let actual = p2pk.p2pk_public_key().unwrap();
assert_eq!(actual, key);
}
#[test]
fn script_x_only_key() {
// Notice the "20" which prepends the keystr. That 20 is hexidecimal for "32". The Builder automatically adds the 32 opcode
// to our script in order to give a heads up to the script compiler that it should add the next 32 bytes to the stack.
// From: https://github.com/bitcoin-core/btcdeb/blob/e8c2750c4a4702768c52d15640ed03bf744d2601/doc/tapscript-example.md?plain=1#L43
const KEYSTR: &str = "209997a497d964fc1a62885b05a51166a65a90df00492c8d7cf61d6accf54803be";
let x_only_key = XOnlyPublicKey::from_str(&KEYSTR[2..]).unwrap();
let script = Builder::new().push_x_only_key(&x_only_key);
assert_eq!(script.into_bytes(), hex!(KEYSTR));
}
#[test]
fn script_builder() {
// from txid 3bb5e6434c11fb93f64574af5d116736510717f2c595eb45b52c28e31622dfff which was in my mempool when I wrote the test
let script = Builder::new().push_opcode(OP_DUP)
.push_opcode(OP_HASH160)
.push_slice(&hex!("16e1ae70ff0fa102905d4af297f6912bda6cce19"))
.push_opcode(OP_EQUALVERIFY)
.push_opcode(OP_CHECKSIG)
.into_script();
assert_eq!(script.to_hex_string(), "76a91416e1ae70ff0fa102905d4af297f6912bda6cce1988ac");
}
#[test]
fn script_generators() {
let pubkey = PublicKey::from_str("0234e6a79c5359c613762d537e0e19d86c77c1666d8c9ab050f23acd198e97f93e").unwrap();
assert!(ScriptBuf::new_p2pk(&pubkey).is_p2pk());
let pubkey_hash = PubkeyHash::hash(&pubkey.inner.serialize());
assert!(ScriptBuf::new_p2pkh(&pubkey_hash).is_p2pkh());
let wpubkey_hash = WPubkeyHash::hash(&pubkey.inner.serialize());
assert!(ScriptBuf::new_v0_p2wpkh(&wpubkey_hash).is_v0_p2wpkh());
let script = Builder::new().push_opcode(OP_NUMEQUAL)
.push_verify()
.into_script();
let script_hash = ScriptHash::hash(&script.serialize());
let p2sh = ScriptBuf::new_p2sh(&script_hash);
assert!(p2sh.is_p2sh());
assert_eq!(script.to_p2sh(), p2sh);
let wscript_hash = WScriptHash::hash(&script.serialize());
let p2wsh = ScriptBuf::new_v0_p2wsh(&wscript_hash);
assert!(p2wsh.is_v0_p2wsh());
assert_eq!(script.to_v0_p2wsh(), p2wsh);
// Test data are taken from the second output of
// 2ccb3a1f745eb4eefcf29391460250adda5fab78aaddb902d25d3cd97d9d8e61 transaction
let data = Vec::<u8>::from_hex("aa21a9ed20280f53f2d21663cac89e6bd2ad19edbabb048cda08e73ed19e9268d0afea2a").unwrap();
let op_return = ScriptBuf::new_op_return(&data);
assert!(op_return.is_op_return());
assert_eq!(op_return.to_hex_string(), "6a24aa21a9ed20280f53f2d21663cac89e6bd2ad19edbabb048cda08e73ed19e9268d0afea2a");
}
#[test]
fn script_builder_verify() {
let simple = Builder::new()
.push_verify()
.into_script();
assert_eq!(simple.to_hex_string(), "69");
let simple2 = Builder::from(vec![])
.push_verify()
.into_script();
assert_eq!(simple2.to_hex_string(), "69");
let nonverify = Builder::new()
.push_verify()
.push_verify()
.into_script();
assert_eq!(nonverify.to_hex_string(), "6969");
let nonverify2 = Builder::from(vec![0x69])
.push_verify()
.into_script();
assert_eq!(nonverify2.to_hex_string(), "6969");
let equal = Builder::new()
.push_opcode(OP_EQUAL)
.push_verify()
.into_script();
assert_eq!(equal.to_hex_string(), "88");
let equal2 = Builder::from(vec![0x87])
.push_verify()
.into_script();
assert_eq!(equal2.to_hex_string(), "88");
let numequal = Builder::new()
.push_opcode(OP_NUMEQUAL)
.push_verify()
.into_script();
assert_eq!(numequal.to_hex_string(), "9d");
let numequal2 = Builder::from(vec![0x9c])
.push_verify()
.into_script();
assert_eq!(numequal2.to_hex_string(), "9d");
let checksig = Builder::new()
.push_opcode(OP_CHECKSIG)
.push_verify()
.into_script();
assert_eq!(checksig.to_hex_string(), "ad");
let checksig2 = Builder::from(vec![0xac])
.push_verify()
.into_script();
assert_eq!(checksig2.to_hex_string(), "ad");
let checkmultisig = Builder::new()
.push_opcode(OP_CHECKMULTISIG)
.push_verify()
.into_script();
assert_eq!(checkmultisig.to_hex_string(), "af");
let checkmultisig2 = Builder::from(vec![0xae])
.push_verify()
.into_script();
assert_eq!(checkmultisig2.to_hex_string(), "af");
let trick_slice = Builder::new()
.push_slice(&[0xae]) // OP_CHECKMULTISIG
.push_verify()
.into_script();
assert_eq!(trick_slice.to_hex_string(), "01ae69");
let trick_slice2 = Builder::from(vec![0x01, 0xae])
.push_verify()
.into_script();
assert_eq!(trick_slice2.to_hex_string(), "01ae69");
}
#[test]
fn script_serialize() {
let hex_script = hex!("6c493046022100f93bb0e7d8db7bd46e40132d1f8242026e045f03a0efe71bbb8e3f475e970d790221009337cd7f1f929f00cc6ff01f03729b069a7c21b59b1736ddfee5db5946c5da8c0121033b9b137ee87d5a812d6f506efdd37f0affa7ffc310711c06c7f3e097c9447c52");
let script: Result<ScriptBuf, _> = deserialize(&hex_script);
assert!(script.is_ok());
assert_eq!(serialize(&script.unwrap()), hex_script);
}
#[test]
fn scriptint_round_trip() {
fn build_scriptint(n: i64) -> Vec<u8> {
let mut buf = [0u8; 8];
let len = write_scriptint(&mut buf, n);
assert!(len <= 8);
buf[..len].to_vec()
}
assert_eq!(build_scriptint(-1), vec![0x81]);
assert_eq!(build_scriptint(255), vec![255, 0]);
assert_eq!(build_scriptint(256), vec![0, 1]);
assert_eq!(build_scriptint(257), vec![1, 1]);
assert_eq!(build_scriptint(511), vec![255, 1]);
let test_vectors = [
10, 100, 255, 256, 1000, 10000, 25000, 200000, 5000000, 1000000000,
(1 << 31) - 1, -((1 << 31) - 1),
];
for &i in test_vectors.iter() {
assert_eq!(Ok(i), read_scriptint(&build_scriptint(i)));
assert_eq!(Ok(-i), read_scriptint(&build_scriptint(-i)));
}
assert!(read_scriptint(&build_scriptint(1 << 31)).is_err());
assert!(read_scriptint(&build_scriptint(-(1 << 31))).is_err());
}
#[test]
fn non_minimal_scriptints() {
assert_eq!(read_scriptint(&[0x80, 0x00]), Ok(0x80));
assert_eq!(read_scriptint(&[0xff, 0x00]), Ok(0xff));
assert_eq!(read_scriptint(&[0x8f, 0x00, 0x00]), Err(Error::NonMinimalPush));
assert_eq!(read_scriptint(&[0x7f, 0x00]), Err(Error::NonMinimalPush));
}
#[test]
fn script_hashes() {
let script = ScriptBuf::from_hex("410446ef0102d1ec5240f0d061a4246c1bdef63fc3dbab7733052fbbf0ecd8f41fc26bf049ebb4f9527f374280259e7cfa99c48b0e3f39c51347a19a5819651503a5ac").unwrap();
assert_eq!(script.script_hash().to_string(), "8292bcfbef1884f73c813dfe9c82fd7e814291ea");
assert_eq!(script.wscript_hash().to_string(), "3e1525eb183ad4f9b3c5fa3175bdca2a52e947b135bbb90383bf9f6408e2c324");
assert_eq!(
ScriptBuf::from_hex("20d85a959b0290bf19bb89ed43c916be835475d013da4b362117393e25a48229b8ac").unwrap().tapscript_leaf_hash().to_string(),
"5b75adecf53548f3ec6ad7d78383bf84cc57b55a3127c72b9a2481752dd88b21"
);
}
#[test]
fn provably_unspendable_test() {
// p2pk
assert!(!ScriptBuf::from_hex("410446ef0102d1ec5240f0d061a4246c1bdef63fc3dbab7733052fbbf0ecd8f41fc26bf049ebb4f9527f374280259e7cfa99c48b0e3f39c51347a19a5819651503a5ac").unwrap().is_provably_unspendable());
assert!(!ScriptBuf::from_hex("4104ea1feff861b51fe3f5f8a3b12d0f4712db80e919548a80839fc47c6a21e66d957e9c5d8cd108c7a2d2324bad71f9904ac0ae7336507d785b17a2c115e427a32fac").unwrap().is_provably_unspendable());
// p2pkhash
assert!(!ScriptBuf::from_hex("76a914ee61d57ab51b9d212335b1dba62794ac20d2bcf988ac").unwrap().is_provably_unspendable());
assert!(ScriptBuf::from_hex("6aa9149eb21980dc9d413d8eac27314938b9da920ee53e87").unwrap().is_provably_unspendable());
}
#[test]
fn op_return_test() {
assert!(ScriptBuf::from_hex("6aa9149eb21980dc9d413d8eac27314938b9da920ee53e87").unwrap().is_op_return());
assert!(!ScriptBuf::from_hex("76a914ee61d57ab51b9d212335b1dba62794ac20d2bcf988ac").unwrap().is_op_return());
assert!(!ScriptBuf::from_hex("").unwrap().is_op_return());
}
#[test]
#[cfg(feature = "serde")]
fn script_json_serialize() {
use serde_json;
let original = ScriptBuf::from_hex("827651a0698faaa9a8a7a687").unwrap();
let json = serde_json::to_value(&original).unwrap();
assert_eq!(json, serde_json::Value::String("827651a0698faaa9a8a7a687".to_owned()));
let des = serde_json::from_value::<ScriptBuf>(json).unwrap();
assert_eq!(original, des);
}
#[test]
fn script_asm() {
assert_eq!(ScriptBuf::from_hex("6363636363686868686800").unwrap().to_asm_string(),
"OP_IF OP_IF OP_IF OP_IF OP_IF OP_ENDIF OP_ENDIF OP_ENDIF OP_ENDIF OP_ENDIF OP_0");
assert_eq!(ScriptBuf::from_hex("6363636363686868686800").unwrap().to_asm_string(),
"OP_IF OP_IF OP_IF OP_IF OP_IF OP_ENDIF OP_ENDIF OP_ENDIF OP_ENDIF OP_ENDIF OP_0");
assert_eq!(ScriptBuf::from_hex("2102715e91d37d239dea832f1460e91e368115d8ca6cc23a7da966795abad9e3b699ac").unwrap().to_asm_string(),
"OP_PUSHBYTES_33 02715e91d37d239dea832f1460e91e368115d8ca6cc23a7da966795abad9e3b699 OP_CHECKSIG");
// Elements Alpha peg-out transaction with some signatures removed for brevity. Mainly to test PUSHDATA1
assert_eq!(ScriptBuf::from_hex("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").unwrap().to_asm_string(),
"OP_0 OP_PUSHBYTES_71 304402202457e78cc1b7f50d0543863c27de75d07982bde8359b9e3316adec0aec165f2f02200203fd331c4e4a4a02f48cf1c291e2c0d6b2f7078a784b5b3649fca41f8794d401 OP_0 OP_PUSHDATA1 552103244e602b46755f24327142a0517288cebd159eccb6ccf41ea6edf1f601e9af952103bbbacc302d19d29dbfa62d23f37944ae19853cf260c745c2bea739c95328fcb721039227e83246bd51140fe93538b2301c9048be82ef2fb3c7fc5d78426ed6f609ad210229bf310c379b90033e2ecb07f77ecf9b8d59acb623ab7be25a0caed539e2e6472103703e2ed676936f10b3ce9149fa2d4a32060fb86fa9a70a4efe3f21d7ab90611921031e9b7c6022400a6bb0424bbcde14cff6c016b91ee3803926f3440abf5c146d05210334667f975f55a8455d515a2ef1c94fdfa3315f12319a14515d2a13d82831f62f57ae");
// Various weird scripts found in transaction 6d7ed9914625c73c0288694a6819196a27ef6c08f98e1270d975a8e65a3dc09a
// which triggerred overflow bugs on 32-bit machines in script formatting in the past.
assert_eq!(ScriptBuf::from_hex("01").unwrap().to_asm_string(),
"OP_PUSHBYTES_1 <push past end>");
assert_eq!(ScriptBuf::from_hex("0201").unwrap().to_asm_string(),
"OP_PUSHBYTES_2 <push past end>");
assert_eq!(ScriptBuf::from_hex("4c").unwrap().to_asm_string(),
"<unexpected end>");
assert_eq!(ScriptBuf::from_hex("4c0201").unwrap().to_asm_string(),
"OP_PUSHDATA1 <push past end>");
assert_eq!(ScriptBuf::from_hex("4d").unwrap().to_asm_string(),
"<unexpected end>");
assert_eq!(ScriptBuf::from_hex("4dffff01").unwrap().to_asm_string(),
"OP_PUSHDATA2 <push past end>");
assert_eq!(ScriptBuf::from_hex("4effffffff01").unwrap().to_asm_string(),
"OP_PUSHDATA4 <push past end>");
}
#[test]
fn script_buf_collect() {
assert_eq!(&core::iter::empty::<Instruction<'_>>().collect::<ScriptBuf>(), Script::empty());
let script = ScriptBuf::from_hex("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").unwrap();
assert_eq!(script.instructions().collect::<Result<ScriptBuf, _>>().unwrap(), script);
}
#[test]
fn script_p2sh_p2p2k_template() {
// random outputs I picked out of the mempool
assert!(ScriptBuf::from_hex("76a91402306a7c23f3e8010de41e9e591348bb83f11daa88ac").unwrap().is_p2pkh());
assert!(!ScriptBuf::from_hex("76a91402306a7c23f3e8010de41e9e591348bb83f11daa88ac").unwrap().is_p2sh());
assert!(!ScriptBuf::from_hex("76a91402306a7c23f3e8010de41e9e591348bb83f11daa88ad").unwrap().is_p2pkh());
assert!(!ScriptBuf::from_hex("").unwrap().is_p2pkh());
assert!(ScriptBuf::from_hex("a914acc91e6fef5c7f24e5c8b3f11a664aa8f1352ffd87").unwrap().is_p2sh());
assert!(!ScriptBuf::from_hex("a914acc91e6fef5c7f24e5c8b3f11a664aa8f1352ffd87").unwrap().is_p2pkh());
assert!(!ScriptBuf::from_hex("a314acc91e6fef5c7f24e5c8b3f11a664aa8f1352ffd87").unwrap().is_p2sh());
}
#[test]
fn script_p2pk() {
assert!(ScriptBuf::from_hex("21021aeaf2f8638a129a3156fbe7e5ef635226b0bafd495ff03afe2c843d7e3a4b51ac").unwrap().is_p2pk());
assert!(ScriptBuf::from_hex("410496b538e853519c726a2c91e61ec11600ae1390813a627c66fb8be7947be63c52da7589379515d4e0a604f8141781e62294721166bf621e73a82cbf2342c858eeac").unwrap().is_p2pk());
}
#[test]
fn p2sh_p2wsh_conversion() {
// Test vectors taken from Core tests/data/script_tests.json
// bare p2wsh
let redeem_script = ScriptBuf::from_hex("410479be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8ac").unwrap();
let expected_witout = ScriptBuf::from_hex("0020b95237b48faaa69eb078e1170be3b5cbb3fddf16d0a991e14ad274f7b33a4f64").unwrap();
assert!(redeem_script.to_v0_p2wsh().is_v0_p2wsh());
assert_eq!(redeem_script.to_v0_p2wsh(), expected_witout);
// p2sh
let redeem_script = ScriptBuf::from_hex("0479be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8").unwrap();
let expected_p2shout = ScriptBuf::from_hex("a91491b24bf9f5288532960ac687abb035127b1d28a587").unwrap();
assert!(redeem_script.to_p2sh().is_p2sh());
assert_eq!(redeem_script.to_p2sh(), expected_p2shout);
// p2sh-p2wsh
let redeem_script = ScriptBuf::from_hex("410479be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8ac").unwrap();
let expected_witout = ScriptBuf::from_hex("0020b95237b48faaa69eb078e1170be3b5cbb3fddf16d0a991e14ad274f7b33a4f64").unwrap();
let expected_out = ScriptBuf::from_hex("a914f386c2ba255cc56d20cfa6ea8b062f8b5994551887").unwrap();
assert!(redeem_script.to_p2sh().is_p2sh());
assert!(redeem_script.to_p2sh().to_v0_p2wsh().is_v0_p2wsh());
assert_eq!(redeem_script.to_v0_p2wsh(), expected_witout);
assert_eq!(redeem_script.to_v0_p2wsh().to_p2sh(), expected_out);
}
macro_rules! unwrap_all {
($($var:ident),*) => {
$(
let $var = $var.unwrap();
)*
}
}
#[test]
fn test_iterator() {
let zero = ScriptBuf::from_hex("00").unwrap();
let zeropush = ScriptBuf::from_hex("0100").unwrap();
let nonminimal = ScriptBuf::from_hex("4c0169b2").unwrap(); // PUSHDATA1 for no reason
let minimal = ScriptBuf::from_hex("0169b2").unwrap(); // minimal
let nonminimal_alt = ScriptBuf::from_hex("026900b2").unwrap(); // non-minimal number but minimal push (should be OK)
let v_zero: Result<Vec<_>, Error> = zero.instruction_indices_minimal().collect();
let v_zeropush: Result<Vec<_>, Error> = zeropush.instruction_indices_minimal().collect();
let v_min: Result<Vec<_>, Error> = minimal.instruction_indices_minimal().collect();
let v_nonmin: Result<Vec<_>, Error> = nonminimal.instruction_indices_minimal().collect();
let v_nonmin_alt: Result<Vec<_>, Error> = nonminimal_alt.instruction_indices_minimal().collect();
let slop_v_min: Result<Vec<_>, Error> = minimal.instruction_indices().collect();
let slop_v_nonmin: Result<Vec<_>, Error> = nonminimal.instruction_indices().collect();
let slop_v_nonmin_alt: Result<Vec<_>, Error> = nonminimal_alt.instruction_indices().collect();
unwrap_all!(v_zero, v_zeropush, v_min, v_nonmin_alt, slop_v_min, slop_v_nonmin, slop_v_nonmin_alt);
assert_eq!(v_zero, vec![(0, Instruction::PushBytes(&[]))]);
assert_eq!(v_zeropush, vec![(0, Instruction::PushBytes(&[0]))]);
assert_eq!(
v_min,
vec![(0, Instruction::PushBytes(&[105])), (2, Instruction::Op(opcodes::OP_NOP3))]
);
assert_eq!(v_nonmin.unwrap_err(), Error::NonMinimalPush);
assert_eq!(
v_nonmin_alt,
vec![(0, Instruction::PushBytes(&[105, 0])), (3, Instruction::Op(opcodes::OP_NOP3))]
);
assert_eq!(v_min, slop_v_min);
// indices must differ
assert_ne!(v_min, slop_v_nonmin);
// but the instructions must be equal
for ((_, v_min_instr), (_, slop_v_nomin_instr)) in v_min.iter().zip(&slop_v_nonmin) {
assert_eq!(v_min_instr, slop_v_nomin_instr);
}
assert_eq!(v_nonmin_alt, slop_v_nonmin_alt);
}
#[test]
fn script_ord() {
let script_1 = Builder::new().push_slice(&[1, 2, 3, 4]).into_script();
let script_2 = Builder::new().push_int(10).into_script();
let script_3 = Builder::new().push_int(15).into_script();
let script_4 = Builder::new().push_opcode(OP_RETURN).into_script();
assert!(script_1 < script_2);
assert!(script_2 < script_3);
assert!(script_3 < script_4);
assert!(script_1 <= script_1);
assert!(script_1 >= script_1);
assert!(script_4 > script_3);
assert!(script_3 > script_2);
assert!(script_2 > script_1);
}
#[test]
#[cfg(feature = "bitcoinconsensus")]
fn test_bitcoinconsensus () {
// a random segwit transaction from the blockchain using native segwit
let spent = Builder::from(hex!("0020701a8d401c84fb13e6baf169d59684e17abd9fa216c8cc5b9fc63d622ff8c58d")).into_script();
let spending = hex!("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");
spent.verify(0, crate::Amount::from_sat(18393430), spending.as_slice()).unwrap();
}
#[test]
fn defult_dust_value_tests() {
// Check that our dust_value() calculator correctly calculates the dust limit on common
// well-known scriptPubKey types.
let script_p2wpkh = Builder::new().push_int(0).push_slice(&[42; 20]).into_script();
assert!(script_p2wpkh.is_v0_p2wpkh());
assert_eq!(script_p2wpkh.dust_value(), crate::Amount::from_sat(294));
let script_p2pkh = Builder::new()
.push_opcode(OP_DUP)
.push_opcode(OP_HASH160)
.push_slice(&[42; 20])
.push_opcode(OP_EQUALVERIFY)
.push_opcode(OP_CHECKSIG)
.into_script();
assert!(script_p2pkh.is_p2pkh());
assert_eq!(script_p2pkh.dust_value(), crate::Amount::from_sat(546));
}
#[test]
#[cfg(feature = "serde")]
fn test_script_serde_human_and_not() {
let script = ScriptBuf::from(vec![0u8, 1u8, 2u8]);
// Serialize
let json = serde_json::to_string(&script).unwrap();
assert_eq!(json, "\"000102\"");
let bincode = bincode::serialize(&script).unwrap();
assert_eq!(bincode, [3, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2]); // bincode adds u64 for length, serde_cbor use varint
// Deserialize
assert_eq!(script, serde_json::from_str::<ScriptBuf>(&json).unwrap());
assert_eq!(script, bincode::deserialize::<ScriptBuf>(&bincode).unwrap());
}
#[test]
fn test_instructions_are_fused() {
let script = ScriptBuf::new();
let mut instructions = script.instructions();
assert!(instructions.next().is_none());
assert!(instructions.next().is_none());
assert!(instructions.next().is_none());
assert!(instructions.next().is_none());
}
#[test]
fn script_extend() {
fn cmp_scripts(new_script: &Script, orig_script: &[Instruction<'_>]) {
let mut new_instr = new_script.instructions();
let mut orig_instr = orig_script.iter().cloned();
for (new, orig) in new_instr.by_ref().zip(orig_instr.by_ref()) {
assert_eq!(new.unwrap(), orig);
}
assert!(new_instr.next().is_none() && orig_instr.next().is_none())
}
let script_5_items = [
Instruction::Op(OP_DUP),
Instruction::Op(OP_HASH160),
Instruction::PushBytes(&[42; 20]),
Instruction::Op(OP_EQUALVERIFY),
Instruction::Op(OP_CHECKSIG),
];
let new_script = script_5_items.iter().cloned().collect::<ScriptBuf>();
cmp_scripts(&new_script, &script_5_items);
let script_6_items = [
Instruction::Op(OP_DUP),
Instruction::Op(OP_HASH160),
Instruction::PushBytes(&[42; 20]),
Instruction::Op(OP_EQUALVERIFY),
Instruction::Op(OP_CHECKSIG),
Instruction::Op(OP_NOP),
];
let new_script = script_6_items.iter().cloned().collect::<ScriptBuf>();
cmp_scripts(&new_script, &script_6_items);
let script_7_items = [
Instruction::Op(OP_DUP),
Instruction::Op(OP_HASH160),
Instruction::PushBytes(&[42; 20]),
Instruction::Op(OP_EQUALVERIFY),
Instruction::Op(OP_CHECKSIG),
Instruction::Op(OP_NOP),
];
let new_script = script_7_items.iter().cloned().collect::<ScriptBuf>();
cmp_scripts(&new_script, &script_7_items);
}
#[test]
fn read_scriptbool_zero_is_false() {
let v: Vec<u8> = vec![0x00, 0x00, 0x00, 0x00];
assert!(!read_scriptbool(&v));
let v: Vec<u8> = vec![0x00, 0x00, 0x00, 0x80]; // With sign bit set.
assert!(!read_scriptbool(&v));
}
#[test]
fn read_scriptbool_non_zero_is_true() {
let v: Vec<u8> = vec![0x01, 0x00, 0x00, 0x00];
assert!(read_scriptbool(&v));
let v: Vec<u8> = vec![0x01, 0x00, 0x00, 0x80]; // With sign bit set.
assert!(read_scriptbool(&v));
}

512
bitcoin/src/blockdata/script/types/borrowed.rs Normal file
View File

@ -0,0 +1,512 @@
// Written in 2014 by Andrew Poelstra <apoelstra@wpsoftware.net>
// SPDX-License-Identifier: CC0-1.0
use core::convert::TryFrom;
use core::fmt;
#[cfg(rust_v_1_53)]
use core::ops::Bound;
use core::ops::{Index, Range, RangeFull, RangeFrom, RangeTo, RangeInclusive, RangeToInclusive};
use secp256k1::{Secp256k1, Verification};
use crate::address::WitnessVersion;
use crate::blockdata::opcodes::{self, all::*};
use crate::blockdata::script::{bytes_to_asm_fmt, Builder, Instruction, Instructions, InstructionIndices, ScriptBuf};
#[cfg(feature = "bitcoinconsensus")]
use crate::blockdata::script::Error;
use crate::consensus::Encodable;
use crate::hash_types::{ScriptHash, WScriptHash};
use crate::hashes::Hash;
use crate::key::PublicKey;
use crate::policy::DUST_RELAY_TX_FEE;
use crate::prelude::*;
use crate::schnorr::UntweakedPublicKey;
use crate::taproot::{LeafVersion, TapNodeHash, TapLeafHash};
/// Bitcoin script slice.
///
/// *[See also the `bitcoin::blockdata::script` module](crate::blockdata::script).*
///
/// `Script` is a script slice, the most primitive script type. It's usually seen in its borrowed
/// form `&Script`. It is always encoded as a series of bytes representing the opcodes and data
/// pushes.
///
/// ## Validity
///
/// `Script` does not have any validity invariants - it's essentially just a marked slice of
/// bytes. This is similar to [`Path`](std::path::Path) vs [`OsStr`](std::ffi::OsStr) where they
/// are trivially cast-able to each-other and `Path` doesn't guarantee being a usable FS path but
/// having a newtype still has value because of added methods, readability and basic type checking.
///
/// Although at least data pushes could be checked not to overflow the script, bad scripts are
/// allowed to be in a transaction (outputs just become unspendable) and there even are such
/// transactions in the chain. Thus we must allow such scripts to be placed in the transaction.
///
/// ## Slicing safety
///
/// Slicing is similar to how `str` works: some ranges may be incorrect and indexing by
/// `usize` is not supported. However, as opposed to `std`, we have no way of checking
/// correctness without causing linear complexity so there are **no panics on invalid
/// ranges!** If you supply an invalid range, you'll get a garbled script.
///
/// The range is considered valid if it's at a boundary of instruction. Care must be taken
/// especially with push operations because you could get a reference to arbitrary
/// attacker-supplied bytes that look like a valid script.
///
/// It is recommended to use `.instructions()` method to get an iterator over script
/// instructions and work with that instead.
///
/// ## Memory safety
///
/// The type is `#[repr(transparent)]` for internal purposes only!
/// No consumer crate may rely on the represenation of the struct!
///
/// ## References
///
///
/// ### Bitcoin Core References
///
/// * [CScript definition](https://github.com/bitcoin/bitcoin/blob/d492dc1cdaabdc52b0766bf4cba4bd73178325d0/src/script/script.h#L410)
///
#[derive(PartialOrd, Ord, PartialEq, Eq, Hash)]
#[repr(transparent)]
pub struct Script(pub (in crate::blockdata::script) [u8]);
impl ToOwned for Script {
type Owned = ScriptBuf;
fn to_owned(&self) -> Self::Owned {
ScriptBuf(self.0.to_owned())
}
}
impl Script {
/// Treat byte slice as `Script`
#[inline]
pub fn from_bytes(bytes: &[u8]) -> &Script {
// SAFETY: copied from `std`
// The pointer was just created from a reference which is still alive.
// Casting slice pointer to a transparent struct wrapping that slice is sound (same
// layout).
unsafe {
&*(bytes as *const [u8] as *const Script)
}
}
/// Treat mutable byte slice as `Script`
#[inline]
pub fn from_bytes_mut(bytes: &mut [u8]) -> &mut Script {
// SAFETY: copied from `std`
// The pointer was just created from a reference which is still alive.
// Casting slice pointer to a transparent struct wrapping that slice is sound (same
// layout).
// Function signature prevents callers from accessing `bytes` while the returned reference
// is alive.
unsafe {
&mut *(bytes as *mut [u8] as *mut Script)
}
}
/// Returns the script data as a byte slice.
#[inline]
pub fn as_bytes(&self) -> &[u8] {
&self.0
}
/// Returns the script data as a mutable byte slice.
#[inline]
pub fn as_mut_bytes(&mut self) -> &mut [u8] {
&mut self.0
}
/// Creates a new empty script.
#[inline]
pub fn empty() -> &'static Script { Script::from_bytes(&[]) }
/// Creates a new script builder
pub fn builder() -> Builder {
Builder::new()
}
/// Returns 160-bit hash of the script.
#[inline]
pub fn script_hash(&self) -> ScriptHash {
ScriptHash::hash(self.as_bytes())
}
/// Returns 256-bit hash of the script for P2WSH outputs.
#[inline]
pub fn wscript_hash(&self) -> WScriptHash {
WScriptHash::hash(self.as_bytes())
}
/// Computes leaf hash of tapscript.
#[inline]
pub fn tapscript_leaf_hash(&self) -> TapLeafHash {
TapLeafHash::from_script(self, LeafVersion::TapScript)
}
/// Returns the length in bytes of the script.
#[inline]
pub fn len(&self) -> usize { self.0.len() }
/// Returns whether the script is the empty script.
#[inline]
pub fn is_empty(&self) -> bool { self.0.is_empty() }
/// Returns a copy of the script data.
#[inline]
pub fn to_bytes(&self) -> Vec<u8> { self.0.to_owned() }
/// Returns an iterator over script bytes.
#[inline]
pub fn bytes(&self) -> Bytes<'_> {
Bytes(self.as_bytes().iter().copied())
}
/// Computes the P2WSH output corresponding to this witnessScript (aka the "witness redeem
/// script").
#[inline]
pub fn to_v0_p2wsh(&self) -> ScriptBuf {
ScriptBuf::new_v0_p2wsh(&self.wscript_hash())
}
/// Computes P2TR output with a given internal key and a single script spending path equal to
/// the current script, assuming that the script is a Tapscript.
#[inline]
pub fn to_v1_p2tr<C: Verification>(&self, secp: &Secp256k1<C>, internal_key: UntweakedPublicKey) -> ScriptBuf {
let leaf_hash = self.tapscript_leaf_hash();
let merkle_root = TapNodeHash::from(leaf_hash);
ScriptBuf::new_v1_p2tr(secp, internal_key, Some(merkle_root))
}
/// Returns witness version of the script, if any, assuming the script is a `scriptPubkey`.
#[inline]
pub fn witness_version(&self) -> Option<WitnessVersion> {
self.0.first().and_then(|opcode| WitnessVersion::try_from(opcodes::All::from(*opcode)).ok())
}
/// Checks whether a script pubkey is a P2SH output.
#[inline]
pub fn is_p2sh(&self) -> bool {
self.0.len() == 23
&& self.0[0] == OP_HASH160.to_u8()
&& self.0[1] == OP_PUSHBYTES_20.to_u8()
&& self.0[22] == OP_EQUAL.to_u8()
}
/// Checks whether a script pubkey is a P2PKH output.
#[inline]
pub fn is_p2pkh(&self) -> bool {
self.0.len() == 25
&& self.0[0] == OP_DUP.to_u8()
&& self.0[1] == OP_HASH160.to_u8()
&& self.0[2] == OP_PUSHBYTES_20.to_u8()
&& self.0[23] == OP_EQUALVERIFY.to_u8()
&& self.0[24] == OP_CHECKSIG.to_u8()
}
/// Checks whether a script pubkey is a P2PK output.
///
/// You can obtain the public key, if its valid,
/// by calling [`p2pk_public_key()`](Self::p2pk_public_key)
#[inline]
pub fn is_p2pk(&self) -> bool {
self.p2pk_pubkey_bytes().is_some()
}
/// Returns the public key if this script is P2PK with a **valid** public key.
///
/// This may return `None` even when [`is_p2pk()`](Self::is_p2pk) returns true.
/// This happens when the public key is invalid (e.g. the point not being on the curve).
/// It also implies the script is unspendable.
#[inline]
pub fn p2pk_public_key(&self) -> Option<PublicKey> {
PublicKey::from_slice(self.p2pk_pubkey_bytes()?).ok()
}
/// Returns the bytes of the (possibly invalid) public key if this script is P2PK.
#[inline]
pub(in crate::blockdata::script) fn p2pk_pubkey_bytes(&self) -> Option<&[u8]> {
match self.len() {
67 if self.0[0] == OP_PUSHBYTES_65.to_u8()
&& self.0[66] == OP_CHECKSIG.to_u8() => {
Some(&self.0[1..66])
}
35 if self.0[0] == OP_PUSHBYTES_33.to_u8()
&& self.0[34] == OP_CHECKSIG.to_u8() => {
Some(&self.0[1..34])
}
_ => None
}
}
/// Checks whether a script pubkey is a Segregated Witness (segwit) program.
#[inline]
pub fn is_witness_program(&self) -> bool {
// A scriptPubKey (or redeemScript as defined in BIP16/P2SH) that consists of a 1-byte
// push opcode (for 0 to 16) followed by a data push between 2 and 40 bytes gets a new
// special meaning. The value of the first push is called the "version byte". The following
// byte vector pushed is called the "witness program".
let script_len = self.0.len();
if !(4..=42).contains(&script_len) {
return false
}
let ver_opcode = opcodes::All::from(self.0[0]); // Version 0 or PUSHNUM_1-PUSHNUM_16
let push_opbyte = self.0[1]; // Second byte push opcode 2-40 bytes
WitnessVersion::try_from(ver_opcode).is_ok()
&& push_opbyte >= OP_PUSHBYTES_2.to_u8()
&& push_opbyte <= OP_PUSHBYTES_40.to_u8()
// Check that the rest of the script has the correct size
&& script_len - 2 == push_opbyte as usize
}
/// Checks whether a script pubkey is a P2WSH output.
#[inline]
pub fn is_v0_p2wsh(&self) -> bool {
self.0.len() == 34
&& self.witness_version() == Some(WitnessVersion::V0)
&& self.0[1] == OP_PUSHBYTES_32.to_u8()
}
/// Checks whether a script pubkey is a P2WPKH output.
#[inline]
pub fn is_v0_p2wpkh(&self) -> bool {
self.0.len() == 22
&& self.witness_version() == Some(WitnessVersion::V0)
&& self.0[1] == OP_PUSHBYTES_20.to_u8()
}
/// Checks whether a script pubkey is a P2TR output.
#[inline]
pub fn is_v1_p2tr(&self) -> bool {
self.0.len() == 34
&& self.witness_version() == Some(WitnessVersion::V1)
&& self.0[1] == OP_PUSHBYTES_32.to_u8()
}
/// Check if this is an OP_RETURN output.
#[inline]
pub fn is_op_return (&self) -> bool {
match self.0.first() {
Some(b) => *b == OP_RETURN.to_u8(),
None => false
}
}
/// Checks whether a script can be proven to have no satisfying input.
#[inline]
pub fn is_provably_unspendable(&self) -> bool {
use crate::blockdata::opcodes::Class::{ReturnOp, IllegalOp};
match self.0.first() {
Some(b) => {
let first = opcodes::All::from(*b);
let class = first.classify(opcodes::ClassifyContext::Legacy);
class == ReturnOp || class == IllegalOp
},
None => false,
}
}
/// Returns the minimum value an output with this script should have in order to be
/// broadcastable on today's Bitcoin network.
pub fn dust_value(&self) -> crate::Amount {
// This must never be lower than Bitcoin Core's GetDustThreshold() (as of v0.21) as it may
// otherwise allow users to create transactions which likely can never be broadcast/confirmed.
let sats = DUST_RELAY_TX_FEE as u64 / 1000 * // The default dust relay fee is 3000 satoshi/kB (i.e. 3 sat/vByte)
if self.is_op_return() {
0
} else if self.is_witness_program() {
32 + 4 + 1 + (107 / 4) + 4 + // The spend cost copied from Core
8 + // The serialized size of the TxOut's amount field
self.consensus_encode(&mut sink()).expect("sinks don't error") as u64 // The serialized size of this script_pubkey
} else {
32 + 4 + 1 + 107 + 4 + // The spend cost copied from Core
8 + // The serialized size of the TxOut's amount field
self.consensus_encode(&mut sink()).expect("sinks don't error") as u64 // The serialized size of this script_pubkey
};
crate::Amount::from_sat(sats)
}
/// Iterates over the script instructions.
///
/// Each returned item is a nested enum covering opcodes, datapushes and errors.
/// At most one error will be returned and then the iterator will end. To instead iterate over
/// the script as sequence of bytes call the [`bytes`](Self::bytes) method.
///
/// To force minimal pushes, use [`instructions_minimal`](Self::instructions_minimal).
#[inline]
pub fn instructions(&self) -> Instructions {
Instructions {
data: self.0.iter(),
enforce_minimal: false,
}
}
/// Iterates over the script instructions while enforcing minimal pushes.
///
/// This is similar to [`instructions`](Self::instructions) but an error is returned if a push
/// is not minimal.
#[inline]
pub fn instructions_minimal(&self) -> Instructions {
Instructions {
data: self.0.iter(),
enforce_minimal: true,
}
}
/// Iterates over the script instructions and their indices.
///
/// Unless the script contains an error, the returned item consists of an index pointing to the
/// position in the script where the instruction begins and the decoded instruction - either an
/// opcode or data push.
///
/// To force minimal pushes, use [`Self::instruction_indices_minimal`].
#[inline]
pub fn instruction_indices(&self) -> InstructionIndices {
InstructionIndices::from_instructions(self.instructions())
}
/// Iterates over the script instructions and their indices while enforcing minimal pushes.
///
/// This is similar to [`instruction_indices`](Self::instruction_indices) but an error is
/// returned if a push is not minimal.
#[inline]
pub fn instruction_indices_minimal(&self) -> InstructionIndices {
InstructionIndices::from_instructions(self.instructions_minimal())
}
/// Shorthand for [`Self::verify_with_flags`] with flag [bitcoinconsensus::VERIFY_ALL].
///
/// # Parameters
/// * `index` - The input index in spending which is spending this transaction.
/// * `amount` - The amount this script guards.
/// * `spending_tx` - The transaction that attempts to spend the output holding this script.
#[cfg(feature="bitcoinconsensus")]
#[cfg_attr(docsrs, doc(cfg(feature = "bitcoinconsensus")))]
pub fn verify (&self, index: usize, amount: crate::Amount, spending_tx: &[u8]) -> Result<(), Error> {
self.verify_with_flags(index, amount, spending_tx, bitcoinconsensus::VERIFY_ALL)
}
/// Verifies spend of an input script.
///
/// # Parameters
/// * `index` - The input index in spending which is spending this transaction.
/// * `amount` - The amount this script guards.
/// * `spending_tx` - The transaction that attempts to spend the output holding this script.
/// * `flags` - Verification flags, see [`bitcoinconsensus::VERIFY_ALL`] and similar.
#[cfg(feature="bitcoinconsensus")]
#[cfg_attr(docsrs, doc(cfg(feature = "bitcoinconsensus")))]
pub fn verify_with_flags<F: Into<u32>>(&self, index: usize, amount: crate::Amount, spending_tx: &[u8], flags: F) -> Result<(), Error> {
Ok(bitcoinconsensus::verify_with_flags (&self.0[..], amount.to_sat(), spending_tx, index, flags.into())?)
}
/// Writes the assembly decoding of the script to the formatter.
pub fn fmt_asm(&self, f: &mut dyn fmt::Write) -> fmt::Result {
bytes_to_asm_fmt(self.as_ref(), f)
}
/// Returns the assembly decoding of the script.
pub fn to_asm_string(&self) -> String {
let mut buf = String::new();
self.fmt_asm(&mut buf).unwrap();
buf
}
/// Formats the script as lower-case hex.
///
/// This is a more convenient and performant way to write `format!("{:x}", script)`.
/// For better performance you should generally prefer displaying the script but if `String` is
/// required (this is common in tests) this method is can be used.
pub fn to_hex_string(&self) -> String {
self.as_bytes().to_lower_hex_string()
}
/// Returns the first opcode of the script (if there is any).
pub fn first_opcode(&self) -> Option<opcodes::All> {
self.as_bytes().first().copied().map(From::from)
}
/// Iterates the script to find the last opcode.
///
/// Returns `None` is the instruction is data push or if the script is empty.
pub(in crate::blockdata::script) fn last_opcode(&self) -> Option<opcodes::All> {
match self.instructions().last() {
Some(Ok(Instruction::Op(op))) => Some(op),
_ => None,
}
}
/// Converts a [`Box<Script>`](Box) into a [`ScriptBuf`] without copying or allocating.
#[must_use = "`self` will be dropped if the result is not used"]
pub fn into_script_buf(self: Box<Self>) -> ScriptBuf {
let rw = Box::into_raw(self) as *mut [u8];
// SAFETY: copied from `std`
// The pointer was just created from a box without deallocating
// Casting a transparent struct wrapping a slice to the slice pointer is sound (same
// layout).
let inner = unsafe { Box::from_raw(rw) };
ScriptBuf(Vec::from(inner))
}
}
/// Iterator over bytes of a script
pub struct Bytes<'a>(core::iter::Copied<core::slice::Iter<'a, u8>>);
impl Iterator for Bytes<'_> {
type Item = u8;
#[inline]
fn next(&mut self) -> Option<Self::Item> {
self.0.next()
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.0.size_hint()
}
#[inline]
fn nth(&mut self, n: usize) -> Option<Self::Item> {
self.0.nth(n)
}
}
impl DoubleEndedIterator for Bytes<'_> {
#[inline]
fn next_back(&mut self) -> Option<Self::Item> {
self.0.next_back()
}
#[inline]
fn nth_back(&mut self, n: usize) -> Option<Self::Item> {
self.0.nth_back(n)
}
}
impl ExactSizeIterator for Bytes<'_> {}
impl core::iter::FusedIterator for Bytes<'_> {}
macro_rules! delegate_index {
($($type:ty),* $(,)?) => {
$(
/// Script subslicing operation - read [slicing safety](#slicing-safety)!
impl Index<$type> for Script {
type Output = Self;
#[inline]
fn index(&self, index: $type) -> &Self::Output {
Self::from_bytes(&self.0[index])
}
}
)*
}
}
delegate_index!(Range<usize>, RangeFrom<usize>, RangeTo<usize>, RangeFull, RangeInclusive<usize>, RangeToInclusive<usize>);
#[cfg(rust_v_1_53)]
#[cfg_attr(docsrs, doc(cfg(rust_v_1_53)))]
delegate_index!((Bound<usize>, Bound<usize>));

527
bitcoin/src/blockdata/script/types/mod.rs Normal file
View File

@ -0,0 +1,527 @@
// Written in 2014 by Andrew Poelstra <apoelstra@wpsoftware.net>
// SPDX-License-Identifier: CC0-1.0
//! Provides the two script types, one with owned inner data [`ScriptBuf`] and
//! one with borrowed inner data [`Script`].
use alloc::rc::Rc;
use alloc::sync::Arc;
use core::cmp::Ordering;
use core::borrow::{Borrow, BorrowMut};
use core::fmt;
use core::ops::{Deref, DerefMut};
#[cfg(feature = "serde")]
use serde;
use crate::blockdata::opcodes::{self, all::*};
use crate::blockdata::script::{read_uint_iter, UintError};
use crate::consensus::{encode, Decodable, Encodable};
use crate::hash_types::{ScriptHash, WScriptHash};
use crate::hashes::{hex};
use crate::io;
use crate::prelude::*;
mod borrowed;
mod owned;
pub use borrowed::*;
pub use owned::*;
impl From<ScriptBuf> for Box<Script> {
fn from(v: ScriptBuf) -> Self {
v.into_boxed_script()
}
}
impl From<ScriptBuf> for Cow<'_, Script> {
fn from(value: ScriptBuf) -> Self {
Cow::Owned(value)
}
}
impl<'a> From<Cow<'a, Script>> for ScriptBuf {
fn from(value: Cow<'a, Script>) -> Self {
match value {
Cow::Owned(owned) => owned,
Cow::Borrowed(borrwed) => borrwed.into(),
}
}
}
impl<'a> From<Cow<'a, Script>> for Box<Script> {
fn from(value: Cow<'a, Script>) -> Self {
match value {
Cow::Owned(owned) => owned.into(),
Cow::Borrowed(borrwed) => borrwed.into(),
}
}
}
impl<'a> From<&'a Script> for Box<Script> {
fn from(value: &'a Script) -> Self {
value.to_owned().into()
}
}
impl<'a> From<&'a Script> for ScriptBuf {
fn from(value: &'a Script) -> Self {
value.to_owned()
}
}
impl<'a> From<&'a Script> for Cow<'a, Script> {
fn from(value: &'a Script) -> Self {
Cow::Borrowed(value)
}
}
impl<'a> From<&'a Script> for Arc<Script> {
fn from(value: &'a Script) -> Self {
let rw: *const [u8] = Arc::into_raw(Arc::from(&value.0));
// SAFETY: copied from `std`
// The pointer was just created from an Arc without deallocating
// Casting a slice to a transparent struct wrapping that slice is sound (same
// layout).
unsafe { Arc::from_raw(rw as *const Script) }
}
}
impl<'a> From<&'a Script> for Rc<Script> {
fn from(value: &'a Script) -> Self {
let rw: *const [u8] = Rc::into_raw(Rc::from(&value.0));
// SAFETY: copied from `std`
// The pointer was just created from an Rc without deallocating
// Casting a slice to a transparent struct wrapping that slice is sound (same
// layout).
unsafe { Rc::from_raw(rw as *const Script) }
}
}
impl From<Vec<u8>> for ScriptBuf {
fn from(v: Vec<u8>) -> Self { ScriptBuf(v) }
}
impl From<ScriptBuf> for Vec<u8> {
fn from(v: ScriptBuf) -> Self { v.0 }
}
impl From<ScriptBuf> for ScriptHash {
fn from(script: ScriptBuf) -> ScriptHash {
script.script_hash()
}
}
impl From<&ScriptBuf> for ScriptHash {
fn from(script: &ScriptBuf) -> ScriptHash {
script.script_hash()
}
}
impl From<&Script> for ScriptHash {
fn from(script: &Script) -> ScriptHash {
script.script_hash()
}
}
impl From<ScriptBuf> for WScriptHash {
fn from(script: ScriptBuf) -> WScriptHash {
script.wscript_hash()
}
}
impl From<&ScriptBuf> for WScriptHash {
fn from(script: &ScriptBuf) -> WScriptHash {
script.wscript_hash()
}
}
impl From<&Script> for WScriptHash {
fn from(script: &Script) -> WScriptHash {
script.wscript_hash()
}
}
impl core::str::FromStr for ScriptBuf {
type Err = hex::Error;
#[inline]
fn from_str(s: &str) -> Result<Self, hex::Error> {
ScriptBuf::from_hex(s)
}
}
impl AsRef<Script> for Script {
#[inline]
fn as_ref(&self) -> &Script {
self
}
}
impl AsRef<Script> for ScriptBuf {
fn as_ref(&self) -> &Script {
self
}
}
impl AsRef<[u8]> for Script {
#[inline]
fn as_ref(&self) -> &[u8] {
self.as_bytes()
}
}
impl AsRef<[u8]> for ScriptBuf {
fn as_ref(&self) -> &[u8] {
self.as_bytes()
}
}
impl AsMut<Script> for Script {
fn as_mut(&mut self) -> &mut Script {
self
}
}
impl AsMut<Script> for ScriptBuf {
fn as_mut(&mut self) -> &mut Script {
self
}
}
impl AsMut<[u8]> for Script {
#[inline]
fn as_mut(&mut self) -> &mut [u8] {
self.as_mut_bytes()
}
}
impl AsMut<[u8]> for ScriptBuf {
fn as_mut(&mut self) -> &mut [u8] {
self.as_mut_bytes()
}
}
impl fmt::Debug for Script {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.write_str("Script(")?;
self.fmt_asm(f)?;
f.write_str(")")
}
}
impl fmt::Debug for ScriptBuf {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Debug::fmt(self.as_script(), f)
}
}
impl fmt::Display for Script {
#[inline]
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
self.fmt_asm(f)
}
}
impl fmt::Display for ScriptBuf {
#[inline]
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Display::fmt(self.as_script(), f)
}
}
impl fmt::LowerHex for Script {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::LowerHex::fmt(&self.as_bytes().as_hex(), f)
}
}
impl fmt::LowerHex for ScriptBuf {
#[inline]
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::LowerHex::fmt(self.as_script(), f)
}
}
impl fmt::UpperHex for Script {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::UpperHex::fmt(&self.as_bytes().as_hex(), f)
}
}
impl fmt::UpperHex for ScriptBuf {
#[inline]
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::UpperHex::fmt(self.as_script(), f)
}
}
impl Deref for ScriptBuf {
type Target = Script;
fn deref(&self) -> &Self::Target {
Script::from_bytes(&self.0)
}
}
impl DerefMut for ScriptBuf {
fn deref_mut(&mut self) -> &mut Self::Target {
Script::from_bytes_mut(&mut self.0)
}
}
impl Borrow<Script> for ScriptBuf {
fn borrow(&self) -> &Script {
self
}
}
impl BorrowMut<Script> for ScriptBuf {
fn borrow_mut(&mut self) -> &mut Script {
self
}
}
impl PartialEq<ScriptBuf> for Script {
fn eq(&self, other: &ScriptBuf) -> bool {
self.eq(other.as_script())
}
}
impl PartialEq<Script> for ScriptBuf {
fn eq(&self, other: &Script) -> bool {
self.as_script().eq(other)
}
}
impl PartialOrd<Script> for ScriptBuf {
fn partial_cmp(&self, other: &Script) -> Option<Ordering> {
self.as_script().partial_cmp(other)
}
}
impl PartialOrd<ScriptBuf> for Script {
fn partial_cmp(&self, other: &ScriptBuf) -> Option<Ordering> {
self.partial_cmp(other.as_script())
}
}
#[cfg(feature = "serde")]
#[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
impl serde::Serialize for Script {
/// User-facing serialization for `Script`.
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: serde::Serializer,
{
if serializer.is_human_readable() {
serializer.collect_str(&format_args!("{:x}", self))
} else {
serializer.serialize_bytes(self.as_bytes())
}
}
}
/// Can only deserialize borrowed bytes.
#[cfg(feature = "serde")]
#[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
impl<'de> serde::Deserialize<'de> for &'de Script {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: serde::Deserializer<'de>,
{
if deserializer.is_human_readable() {
use crate::serde::de::Error;
return Err(D::Error::custom("deserialization of `&Script` from human-readable formats is not possible"));
}
struct Visitor;
impl<'de> serde::de::Visitor<'de> for Visitor {
type Value = &'de Script;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("borrowed bytes")
}
fn visit_borrowed_bytes<E>(self, v: &'de [u8]) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
Ok(Script::from_bytes(v))
}
}
deserializer.deserialize_bytes(Visitor)
}
}
#[cfg(feature = "serde")]
#[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
impl serde::Serialize for ScriptBuf {
/// User-facing serialization for `Script`.
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: serde::Serializer,
{
(**self).serialize(serializer)
}
}
#[cfg(feature = "serde")]
#[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
impl<'de> serde::Deserialize<'de> for ScriptBuf {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: serde::Deserializer<'de>,
{
use core::fmt::Formatter;
use crate::hashes::hex::FromHex;
if deserializer.is_human_readable() {
struct Visitor;
impl<'de> serde::de::Visitor<'de> for Visitor {
type Value = ScriptBuf;
fn expecting(&self, formatter: &mut Formatter) -> fmt::Result {
formatter.write_str("a script hex")
}
fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
let v = Vec::from_hex(v).map_err(E::custom)?;
Ok(ScriptBuf::from(v))
}
}
deserializer.deserialize_str(Visitor)
} else {
struct BytesVisitor;
impl<'de> serde::de::Visitor<'de> for BytesVisitor {
type Value = ScriptBuf;
fn expecting(&self, formatter: &mut Formatter) -> fmt::Result {
formatter.write_str("a script Vec<u8>")
}
fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
Ok(ScriptBuf::from(v.to_vec()))
}
fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
Ok(ScriptBuf::from(v))
}
}
deserializer.deserialize_byte_buf(BytesVisitor)
}
}
}
impl Encodable for Script {
#[inline]
fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
crate::consensus::encode::consensus_encode_with_size(&self.0, w)
}
}
impl Encodable for ScriptBuf {
#[inline]
fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
self.0.consensus_encode(w)
}
}
impl Decodable for ScriptBuf {
#[inline]
fn consensus_decode_from_finite_reader<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
Ok(ScriptBuf(Decodable::consensus_decode_from_finite_reader(r)?))
}
}
/// Writes the assembly decoding of the script bytes to the formatter.
pub(super) fn bytes_to_asm_fmt(script: &[u8], f: &mut dyn fmt::Write) -> fmt::Result {
// This has to be a macro because it needs to break the loop
macro_rules! read_push_data_len {
($iter:expr, $len:literal, $formatter:expr) => {
match read_uint_iter($iter, $len) {
Ok(n) => {
n
},
Err(UintError::EarlyEndOfScript) => {
$formatter.write_str("<unexpected end>")?;
break;
}
// We got the data in a slice which implies it being shorter than `usize::max_value()`
// So if we got overflow, we can confidently say the number is higher than length of
// the slice even though we don't know the exact number. This implies attempt to push
// past end.
Err(UintError::NumericOverflow) => {
$formatter.write_str("<push past end>")?;
break;
}
}
}
}
let mut iter = script.iter();
// Was at least one opcode emitted?
let mut at_least_one = false;
// `iter` needs to be borrowed in `read_push_data_len`, so we have to use `while let` instead
// of `for`.
while let Some(byte) = iter.next() {
let opcode = opcodes::All::from(*byte);
let data_len = if let opcodes::Class::PushBytes(n) = opcode.classify(opcodes::ClassifyContext::Legacy) {
n as usize
} else {
match opcode {
OP_PUSHDATA1 => {
// side effects: may write and break from the loop
read_push_data_len!(&mut iter, 1, f)
}
OP_PUSHDATA2 => {
// side effects: may write and break from the loop
read_push_data_len!(&mut iter, 2, f)
}
OP_PUSHDATA4 => {
// side effects: may write and break from the loop
read_push_data_len!(&mut iter, 4, f)
}
_ => 0
}
};
if at_least_one {
f.write_str(" ")?;
} else {
at_least_one = true;
}
// Write the opcode
if opcode == OP_PUSHBYTES_0 {
f.write_str("OP_0")?;
} else {
write!(f, "{:?}", opcode)?;
}
// Write any pushdata
if data_len > 0 {
f.write_str(" ")?;
if data_len <= iter.len() {
for ch in iter.by_ref().take(data_len) {
write!(f, "{:02x}", ch)?;
}
} else {
f.write_str("<push past end>")?;
break;
}
}
}
Ok(())
}

373
bitcoin/src/blockdata/script/types/owned.rs Normal file
View File

@ -0,0 +1,373 @@
// Written in 2014 by Andrew Poelstra <apoelstra@wpsoftware.net>
// SPDX-License-Identifier: CC0-1.0
#[cfg(doc)]
use core::ops::Deref;
use secp256k1::{Secp256k1, Verification};
use crate::address::{WitnessVersion, WitnessProgram};
use crate::blockdata::opcodes::{self, all::*};
use crate::blockdata::script::{opcode_to_verify, Builder, Instruction, Script};
use crate::hashes::hex;
use crate::hash_types::{PubkeyHash, WPubkeyHash, ScriptHash, WScriptHash};
use crate::key::PublicKey;
use crate::prelude::*;
use crate::schnorr::{TapTweak, TweakedPublicKey, UntweakedPublicKey};
use crate::taproot::TapNodeHash;
/// An owned, growable script.
///
/// `ScriptBuf` is the most common script type that has the ownership over the contents of the
/// script. It has a close relationship with its borrowed counterpart, [`Script`].
///
/// Just as other similar types, this implements [`Deref`], so [deref coercions] apply. Also note
/// that all the safety/validity restrictions that apply to [`Script`] apply to `ScriptBuf` as well.
///
/// [deref coercions]: https://doc.rust-lang.org/std/ops/trait.Deref.html#more-on-deref-coercion
#[derive(Default, Clone, PartialOrd, Ord, PartialEq, Eq, Hash)]
pub struct ScriptBuf(pub(in crate::blockdata::script) Vec<u8>);
impl ScriptBuf {
/// Creates a new empty script.
pub fn new() -> Self {
ScriptBuf(Vec::new())
}
/// Creates a new empty script with pre-allocated capacity.
pub fn with_capacity(capacity: usize) -> Self {
ScriptBuf(Vec::with_capacity(capacity))
}
/// Pre-allocates at least `additional_len` bytes if needed.
///
/// Reserves capacity for at least `additional_len` more bytes to be inserted in the given
/// script. The script may reserve more space to speculatively avoid frequent reallocations.
/// After calling `reserve`, capacity will be greater than or equal to
/// `self.len() + additional_len`. Does nothing if capacity is already sufficient.
///
/// # Panics
///
/// Panics if the new capacity exceeds `isize::MAX bytes`.
pub fn reserve(&mut self, additional_len: usize) {
self.0.reserve(additional_len);
}
/// Pre-allocates exactly `additional_len` bytes if needed.
///
/// Unlike `reserve`, this will not deliberately over-allocate to speculatively avoid frequent
/// allocations. After calling `reserve_exact`, capacity will be greater than or equal to
/// `self.len() + additional`. Does nothing if the capacity is already sufficient.
///
/// Note that the allocator may give the collection more space than it requests. Therefore,
/// capacity can not be relied upon to be precisely minimal. Prefer [`reserve`](Self::reserve)
/// if future insertions are expected.
///
/// # Panics
///
/// Panics if the new capacity exceeds `isize::MAX bytes`.
pub fn reserve_exact(&mut self, additional_len: usize) {
self.0.reserve_exact(additional_len);
}
/// Returns a reference to unsized script.
pub fn as_script(&self) -> &Script {
Script::from_bytes(&self.0)
}
/// Returns a mutable reference to unsized script.
pub fn as_mut_script(&mut self) -> &mut Script {
Script::from_bytes_mut(&mut self.0)
}
/// Creates a new script builder
pub fn builder() -> Builder {
Builder::new()
}
/// Generates P2PK-type of scriptPubkey.
pub fn new_p2pk(pubkey: &PublicKey) -> Self {
Builder::new()
.push_key(pubkey)
.push_opcode(OP_CHECKSIG)
.into_script()
}
/// Generates P2PKH-type of scriptPubkey.
pub fn new_p2pkh(pubkey_hash: &PubkeyHash) -> Self {
Builder::new()
.push_opcode(OP_DUP)
.push_opcode(OP_HASH160)
.push_slice(&pubkey_hash[..])
.push_opcode(OP_EQUALVERIFY)
.push_opcode(OP_CHECKSIG)
.into_script()
}
/// Generates P2SH-type of scriptPubkey with a given hash of the redeem script.
pub fn new_p2sh(script_hash: &ScriptHash) -> Self {
Builder::new()
.push_opcode(OP_HASH160)
.push_slice(&script_hash[..])
.push_opcode(OP_EQUAL)
.into_script()
}
/// Generates P2WPKH-type of scriptPubkey.
pub fn new_v0_p2wpkh(pubkey_hash: &WPubkeyHash) -> Self {
// pubkey hash is 20 bytes long, so it's safe to use `new_witness_program_unchecked` (Segwitv0)
ScriptBuf::new_witness_program_unchecked(WitnessVersion::V0, &pubkey_hash[..])
}
/// Generates P2WSH-type of scriptPubkey with a given hash of the redeem script.
pub fn new_v0_p2wsh(script_hash: &WScriptHash) -> Self {
// script hash is 32 bytes long, so it's safe to use `new_witness_program_unchecked` (Segwitv0)
ScriptBuf::new_witness_program_unchecked(WitnessVersion::V0, &script_hash[..])
}
/// Generates P2TR for script spending path using an internal public key and some optional
/// script tree merkle root.
pub fn new_v1_p2tr<C: Verification>(secp: &Secp256k1<C>, internal_key: UntweakedPublicKey, merkle_root: Option<TapNodeHash>) -> Self {
let (output_key, _) = internal_key.tap_tweak(secp, merkle_root);
// output key is 32 bytes long, so it's safe to use `new_witness_program_unchecked` (Segwitv1)
ScriptBuf::new_witness_program_unchecked(WitnessVersion::V1, &output_key.serialize())
}
/// Generates P2TR for key spending path for a known [`TweakedPublicKey`].
pub fn new_v1_p2tr_tweaked(output_key: TweakedPublicKey) -> Self {
// output key is 32 bytes long, so it's safe to use `new_witness_program_unchecked` (Segwitv1)
ScriptBuf::new_witness_program_unchecked(WitnessVersion::V1, &output_key.serialize())
}
/// Generates P2WSH-type of scriptPubkey with a given [`WitnessProgram`].
pub fn new_witness_program(witness_program: &WitnessProgram) -> Self {
Builder::new()
.push_opcode(witness_program.version().into())
.push_slice(witness_program.program())
.into_script()
}
/// Generates P2WSH-type of scriptPubkey with a given [`WitnessVersion`] and the program bytes.
/// Does not do any checks on version or program length.
///
/// Convenience method used by `new_v0_p2wpkh`, `new_v0_p2wsh`, `new_v1_p2tr`, and
/// `new_v1_p2tr_tweaked`.
fn new_witness_program_unchecked(version: WitnessVersion, program: &[u8]) -> Self {
debug_assert!(program.len() >= 2 && program.len() <= 40);
// In segwit v0, the program must be 20 or 32 bytes long.
debug_assert!(version != WitnessVersion::V0 || program.len() == 20 || program.len() == 32);
Builder::new()
.push_opcode(version.into())
.push_slice(program)
.into_script()
}
/// Generates OP_RETURN-type of scriptPubkey for the given data.
pub fn new_op_return(data: &[u8]) -> Self {
Builder::new()
.push_opcode(OP_RETURN)
.push_slice(data)
.into_script()
}
/// Creates a [`ScriptBuf`] from a hex string.
pub fn from_hex(s: &str) -> Result<Self, hex::Error> {
use crate::hashes::hex::FromHex;
let v = Vec::from_hex(s)?;
Ok(ScriptBuf::from_bytes(v))
}
/// Converts byte vector into script.
///
/// This method doesn't (re)allocate.
pub fn from_bytes(bytes: Vec<u8>) -> Self {
ScriptBuf(bytes)
}
/// Converts the script into a byte vector.
///
/// This method doesn't (re)allocate.
pub fn into_bytes(self) -> Vec<u8> { self.0 }
/// Computes the P2SH output corresponding to this redeem script.
pub fn to_p2sh(&self) -> ScriptBuf {
ScriptBuf::new_p2sh(&self.script_hash())
}
/// Returns the script code used for spending a P2WPKH output if this script is a script pubkey
/// for a P2WPKH output. The `scriptCode` is described in [BIP143].
///
/// [BIP143]: <https://github.com/bitcoin/bips/blob/99701f68a88ce33b2d0838eb84e115cef505b4c2/bip-0143.mediawiki>
pub fn p2wpkh_script_code(&self) -> Option<ScriptBuf> {
if !self.is_v0_p2wpkh() {
return None
}
let script = Builder::new()
.push_opcode(OP_DUP)
.push_opcode(OP_HASH160)
.push_slice(&self.as_bytes()[2..]) // The `self` script is 0x00, 0x14, <pubkey_hash>
.push_opcode(OP_EQUALVERIFY)
.push_opcode(OP_CHECKSIG)
.into_script();
Some(script)
}
/// Adds a single opcode to the script.
pub fn push_opcode(&mut self, data: opcodes::All) {
self.0.push(data.to_u8());
}
/// Adds instructions to push some arbitrary data onto the stack.
///
/// ## Panics
///
/// The method panics if `data` length is greater or equal to 0x100000000.
pub fn push_slice(&mut self, data: &[u8]) {
self.reserve(Self::reserved_len_for_slice(data.len()));
self.push_slice_no_opt(data);
}
/// Pushes the slice without reserving
fn push_slice_no_opt(&mut self, data: &[u8]) {
// Start with a PUSH opcode
match data.len() as u64 {
n if n < opcodes::Ordinary::OP_PUSHDATA1 as u64 => { self.0.push(n as u8); },
n if n < 0x100 => {
self.0.push(opcodes::Ordinary::OP_PUSHDATA1.to_u8());
self.0.push(n as u8);
},
n if n < 0x10000 => {
self.0.push(opcodes::Ordinary::OP_PUSHDATA2.to_u8());
self.0.push((n % 0x100) as u8);
self.0.push((n / 0x100) as u8);
},
n if n < 0x100000000 => {
self.0.push(opcodes::Ordinary::OP_PUSHDATA4.to_u8());
self.0.push((n % 0x100) as u8);
self.0.push(((n / 0x100) % 0x100) as u8);
self.0.push(((n / 0x10000) % 0x100) as u8);
self.0.push((n / 0x1000000) as u8);
}
_ => panic!("tried to put a 4bn+ sized object into a script!")
}
// Then push the raw bytes
self.0.extend_from_slice(data);
}
/// Computes the sum of `len` and the lenght of an appropriate push opcode.
pub(in crate::blockdata::script) fn reserved_len_for_slice(len: usize) -> usize {
len + match len {
0..=0x4b => 1,
0x4c..=0xff => 2,
0x100..=0xffff => 3,
// we don't care about oversized, the other fn will panic anyway
_ => 5,
}
}
/// Add a single instruction to the script.
///
/// ## Panics
///
/// The method panics if the instruction is a data push with length greater or equal to
/// 0x100000000.
pub fn push_instruction(&mut self, instruction: Instruction<'_>) {
match instruction {
Instruction::Op(opcode) => self.push_opcode(opcode),
Instruction::PushBytes(bytes) => self.push_slice(bytes),
}
}
/// Like push_instruction, but avoids calling `reserve` to not re-check the length.
pub fn push_instruction_no_opt(&mut self, instruction: Instruction<'_>) {
match instruction {
Instruction::Op(opcode) => self.push_opcode(opcode),
Instruction::PushBytes(bytes) => self.push_slice_no_opt(bytes),
}
}
/// Adds an `OP_VERIFY` to the script or replaces the last opcode with VERIFY form.
///
/// Some opcodes such as `OP_CHECKSIG` have a verify variant that works as if `VERIFY` was
/// in the script right after. To save space this function appends `VERIFY` only if
/// the most-recently-added opcode *does not* have an alternate `VERIFY` form. If it does
/// the last opcode is replaced. E.g., `OP_CHECKSIG` will become `OP_CHECKSIGVERIFY`.
///
/// Note that existing `OP_*VERIFY` opcodes do not lead to the instruction being ignored
/// because `OP_VERIFY` consumes an item from the stack so ignoring them would change the
/// semantics.
///
/// This function needs to iterate over the script to find the last instruction. Prefer
/// `Builder` if you're creating the script from scratch or if you want to push `OP_VERIFY`
/// multiple times.
pub fn scan_and_push_verify(&mut self) {
self.push_verify(self.last_opcode());
}
/// Adds an `OP_VERIFY` to the script or changes the most-recently-added opcode to `VERIFY`
/// alternative.
///
/// See the public fn [`Self::scan_and_push_verify`] to learn more.
pub(in crate::blockdata::script) fn push_verify(&mut self, last_opcode: Option<opcodes::All>) {
match opcode_to_verify(last_opcode) {
Some(opcode) => {
self.0.pop();
self.push_opcode(opcode);
},
None => self.push_opcode(OP_VERIFY),
}
}
/// Converts this `ScriptBuf` into a [boxed](Box) [`Script`].
///
/// This method reallocates if the capacity is greater than lenght of the script but should not
/// when they are equal. If you know beforehand that you need to create a script of exact size
/// use [`reserve_exact`](Self::reserve_exact) before adding data to the script so that the
/// reallocation can be avoided.
#[must_use = "`self` will be dropped if the result is not used"]
#[inline]
pub fn into_boxed_script(self) -> Box<Script> {
// Copied from PathBuf::into_boxed_path
let rw = Box::into_raw(self.0.into_boxed_slice()) as *mut Script;
unsafe { Box::from_raw(rw) }
}
}
impl<'a> core::iter::FromIterator<Instruction<'a>> for ScriptBuf {
fn from_iter<T>(iter: T) -> Self where T: IntoIterator<Item = Instruction<'a>> {
let mut script = ScriptBuf::new();
script.extend(iter);
script
}
}
impl<'a> Extend<Instruction<'a>> for ScriptBuf {
fn extend<T>(&mut self, iter: T) where T: IntoIterator<Item = Instruction<'a>> {
let iter = iter.into_iter();
// Most of Bitcoin scripts have only a few opcodes, so we can avoid reallocations in many
// cases.
if iter.size_hint().1.map(|max| max < 6).unwrap_or(false) {
let mut iter = iter.fuse();
// `MaybeUninit` might be faster but we don't want to introduce more `unsafe` than
// required.
let mut head = [None; 5];
let mut total_size = 0;
for (head, instr) in head.iter_mut().zip(&mut iter) {
total_size += instr.script_serialized_len();
*head = Some(instr);
}
// Incorrect impl of `size_hint` breaks `Iterator` contract so we're free to panic.
assert!(iter.next().is_none(), "Buggy implementation of `Iterator` on {} returns invalid upper bound", core::any::type_name::<T::IntoIter>());
self.reserve(total_size);
for instr in head.iter().cloned().flatten() {
self.push_instruction_no_opt(instr);
}
} else {
for instr in iter {
self.push_instruction(instr);
}
}
}
}