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script.rs
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script.rs
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// Rust Bitcoin Library
// Written in 2014 by
// Andrew Poelstra <apoelstra@wpsoftware.net>
//
// To the extent possible under law, the author(s) have dedicated all
// copyright and related and neighboring rights to this software to
// the public domain worldwide. This software is distributed without
// any warranty.
//
// You should have received a copy of the CC0 Public Domain Dedication
// along with this software.
// If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
//
//! Script
//!
//! 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.
//!
//! This module provides the structures and functions needed to support scripts.
//!
use std::default::Default;
use std::{error, fmt, io, str};
#[cfg(feature = "serde")] use serde;
use hash_types::{PubkeyHash, WPubkeyHash, ScriptHash, WScriptHash};
use blockdata::opcodes;
use consensus::{encode, Decodable, Encodable};
use hashes::{Hash, hex};
#[cfg(feature="bitcoinconsensus")] use bitcoinconsensus;
#[cfg(feature="bitcoinconsensus")] use std::convert;
#[cfg(feature="bitcoinconsensus")] use OutPoint;
use util::ecdsa::PublicKey;
#[derive(Clone, Default, PartialOrd, Ord, PartialEq, Eq, Hash)]
/// A Bitcoin script
pub struct Script(Box<[u8]>);
impl AsRef<[u8]> for Script {
fn as_ref(&self) -> &[u8] {
&self.0
}
}
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::Display for Script {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Debug::fmt(self, f)
}
}
impl fmt::LowerHex for Script {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
for &ch in self.0.iter() {
write!(f, "{:02x}", ch)?;
}
Ok(())
}
}
impl fmt::UpperHex for Script {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
for &ch in self.0.iter() {
write!(f, "{:02X}", ch)?;
}
Ok(())
}
}
impl hex::FromHex for Script {
fn from_byte_iter<I>(iter: I) -> Result<Self, hex::Error>
where I: Iterator<Item=Result<u8, hex::Error>> +
ExactSizeIterator +
DoubleEndedIterator,
{
Vec::from_byte_iter(iter).map(|v| Script(Box::<[u8]>::from(v)))
}
}
impl str::FromStr for Script {
type Err = hex::Error;
fn from_str(s: &str) -> Result<Self, hex::Error> {
hex::FromHex::from_hex(s)
}
}
#[derive(PartialEq, Eq, Debug, Clone)]
/// An object which can be used to construct a script piece by piece
pub struct Builder(Vec<u8>, Option<opcodes::All>);
display_from_debug!(Builder);
/// 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)]
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,
#[cfg(feature="bitcoinconsensus")]
/// Error validating the script with bitcoinconsensus library
BitcoinConsensus(bitcoinconsensus::Error),
#[cfg(feature="bitcoinconsensus")]
/// Can not find the spent output
UnknownSpentOutput(OutPoint),
#[cfg(feature="bitcoinconsensus")]
/// Can not serialize the spending transaction
SerializationError
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let str = match *self {
Error::NonMinimalPush => "non-minimal datapush",
Error::EarlyEndOfScript => "unexpected end of script",
Error::NumericOverflow => "numeric overflow (number on stack larger than 4 bytes)",
#[cfg(feature="bitcoinconsensus")]
Error::BitcoinConsensus(ref _n) => "bitcoinconsensus verification failed",
#[cfg(feature="bitcoinconsensus")]
Error::UnknownSpentOutput(ref _point) => "unknown spent output Transaction::verify()",
#[cfg(feature="bitcoinconsensus")]
Error::SerializationError => "can not serialize the spending transaction in Transaction::verify()",
};
f.write_str(str)
}
}
impl error::Error for Error {}
#[cfg(feature="bitcoinconsensus")]
#[doc(hidden)]
impl convert::From<bitcoinconsensus::Error> for Error {
fn from(err: bitcoinconsensus::Error) -> Error {
match err {
_ => Error::BitcoinConsensus(err)
}
}
}
/// Helper to encode an integer in script format
fn build_scriptint(n: i64) -> Vec<u8> {
if n == 0 { return vec![] }
let neg = n < 0;
let mut abs = if neg { -n } else { n } as usize;
let mut v = vec![];
while abs > 0xFF {
v.push((abs & 0xFF) as u8);
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 {
v.push(abs as u8);
v.push(if neg { 0x80u8 } else { 0u8 });
}
// Otherwise we just set the sign bit ourselves
else {
abs |= if neg { 0x80 } else { 0 };
v.push(abs as u8);
}
v
}
/// Helper to decode an integer in script 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 == 0 { return Ok(0); }
if len > 4 { return Err(Error::NumericOverflow); }
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)
}
/// 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 {
!(v.is_empty() ||
((v[v.len() - 1] == 0 || v[v.len() - 1] == 0x80) &&
v.iter().rev().skip(1).all(|&w| w == 0)))
}
/// Read a script-encoded unsigned integer
pub fn read_uint(data: &[u8], size: usize) -> Result<usize, Error> {
if data.len() < size {
Err(Error::EarlyEndOfScript)
} else {
let mut ret = 0;
for (i, item) in data.iter().take(size).enumerate() {
ret += (*item as usize) << (i * 8);
}
Ok(ret)
}
}
impl Script {
/// Creates a new empty script
pub fn new() -> Script { Script(vec![].into_boxed_slice()) }
/// Generates P2PK-type of scriptPubkey
pub fn new_p2pk(pubkey: &PublicKey) -> Script {
Builder::new()
.push_key(pubkey)
.push_opcode(opcodes::all::OP_CHECKSIG)
.into_script()
}
/// Generates P2PKH-type of scriptPubkey
pub fn new_p2pkh(pubkey_hash: &PubkeyHash) -> Script {
Builder::new()
.push_opcode(opcodes::all::OP_DUP)
.push_opcode(opcodes::all::OP_HASH160)
.push_slice(&pubkey_hash[..])
.push_opcode(opcodes::all::OP_EQUALVERIFY)
.push_opcode(opcodes::all::OP_CHECKSIG)
.into_script()
}
/// Generates P2SH-type of scriptPubkey with a given hash of the redeem script
pub fn new_p2sh(script_hash: &ScriptHash) -> Script {
Builder::new()
.push_opcode(opcodes::all::OP_HASH160)
.push_slice(&script_hash[..])
.push_opcode(opcodes::all::OP_EQUAL)
.into_script()
}
/// Generates P2WPKH-type of scriptPubkey
pub fn new_v0_wpkh(pubkey_hash: &WPubkeyHash) -> Script {
Script::new_witness_program(::bech32::u5::try_from_u8(0).unwrap(), &pubkey_hash.to_vec())
}
/// Generates P2WSH-type of scriptPubkey with a given hash of the redeem script
pub fn new_v0_wsh(script_hash: &WScriptHash) -> Script {
Script::new_witness_program(::bech32::u5::try_from_u8(0).unwrap(), &script_hash.to_vec())
}
/// Generates P2WSH-type of scriptPubkey with a given hash of the redeem script
pub fn new_witness_program(ver: ::bech32::u5, program: &[u8]) -> Script {
let mut verop = ver.to_u8();
assert!(verop <= 16, "incorrect witness version provided: {}", verop);
if verop > 0 {
verop = 0x50 + verop;
}
Builder::new()
.push_opcode(verop.into())
.push_slice(&program)
.into_script()
}
/// Generates OP_RETURN-type of scriptPubkey for a given data
pub fn new_op_return(data: &[u8]) -> Script {
Builder::new()
.push_opcode(opcodes::all::OP_RETURN)
.push_slice(data)
.into_script()
}
/// Returns 160-bit hash of the script
pub fn script_hash(&self) -> ScriptHash {
ScriptHash::hash(&self.as_bytes())
}
/// Returns 256-bit hash of the script for P2WSH outputs
pub fn wscript_hash(&self) -> WScriptHash {
WScriptHash::hash(&self.as_bytes())
}
/// The length in bytes of the script
pub fn len(&self) -> usize { self.0.len() }
/// Whether the script is the empty script
pub fn is_empty(&self) -> bool { self.0.is_empty() }
/// Returns the script data
pub fn as_bytes(&self) -> &[u8] { &*self.0 }
/// Returns a copy of the script data
pub fn to_bytes(&self) -> Vec<u8> { self.0.clone().into_vec() }
/// Convert the script into a byte vector
pub fn into_bytes(self) -> Vec<u8> { self.0.into_vec() }
/// Compute the P2SH output corresponding to this redeem script
pub fn to_p2sh(&self) -> Script {
Script::new_p2sh(&self.script_hash())
}
/// Compute the P2WSH output corresponding to this witnessScript (aka the "witness redeem
/// script")
pub fn to_v0_p2wsh(&self) -> Script {
Script::new_v0_wsh(&self.wscript_hash())
}
/// Checks whether a script pubkey is a p2sh output
#[inline]
pub fn is_p2sh(&self) -> bool {
self.0.len() == 23 &&
self.0[0] == opcodes::all::OP_HASH160.into_u8() &&
self.0[1] == opcodes::all::OP_PUSHBYTES_20.into_u8() &&
self.0[22] == opcodes::all::OP_EQUAL.into_u8()
}
/// Checks whether a script pubkey is a p2pkh output
#[inline]
pub fn is_p2pkh(&self) -> bool {
self.0.len() == 25 &&
self.0[0] == opcodes::all::OP_DUP.into_u8() &&
self.0[1] == opcodes::all::OP_HASH160.into_u8() &&
self.0[2] == opcodes::all::OP_PUSHBYTES_20.into_u8() &&
self.0[23] == opcodes::all::OP_EQUALVERIFY.into_u8() &&
self.0[24] == opcodes::all::OP_CHECKSIG.into_u8()
}
/// Checks whether a script pubkey is a p2pk output
#[inline]
pub fn is_p2pk(&self) -> bool {
(self.0.len() == 67 &&
self.0[0] == opcodes::all::OP_PUSHBYTES_65.into_u8() &&
self.0[66] == opcodes::all::OP_CHECKSIG.into_u8())
|| (self.0.len() == 35 &&
self.0[0] == opcodes::all::OP_PUSHBYTES_33.into_u8() &&
self.0[34] == opcodes::all::OP_CHECKSIG.into_u8())
}
/// 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 min_vernum: u8 = opcodes::all::OP_PUSHNUM_1.into_u8();
let max_vernum: u8 = opcodes::all::OP_PUSHNUM_16.into_u8();
self.0.len() >= 4
&& self.0.len() <= 42
// Version 0 or PUSHNUM_1-PUSHNUM_16
&& (self.0[0] == 0 || self.0[0] >= min_vernum && self.0[0] <= max_vernum)
// Second byte push opcode 2-40 bytes
&& self.0[1] >= opcodes::all::OP_PUSHBYTES_2.into_u8()
&& self.0[1] <= opcodes::all::OP_PUSHBYTES_40.into_u8()
// Check that the rest of the script has the correct size
&& self.0.len() - 2 == self.0[1] as usize
}
/// Checks whether a script pubkey is a p2wsh output
#[inline]
pub fn is_v0_p2wsh(&self) -> bool {
self.0.len() == 34 &&
self.0[0] == opcodes::all::OP_PUSHBYTES_0.into_u8() &&
self.0[1] == opcodes::all::OP_PUSHBYTES_32.into_u8()
}
/// Checks whether a script pubkey is a p2wpkh output
#[inline]
pub fn is_v0_p2wpkh(&self) -> bool {
self.0.len() == 22 &&
self.0[0] == opcodes::all::OP_PUSHBYTES_0.into_u8() &&
self.0[1] == opcodes::all::OP_PUSHBYTES_20.into_u8()
}
/// Check if this is an OP_RETURN output
pub fn is_op_return (&self) -> bool {
!self.0.is_empty() && (opcodes::All::from(self.0[0]) == opcodes::all::OP_RETURN)
}
/// Whether a script can be proven to have no satisfying input
pub fn is_provably_unspendable(&self) -> bool {
!self.0.is_empty() && (opcodes::All::from(self.0[0]).classify() == opcodes::Class::ReturnOp ||
opcodes::All::from(self.0[0]).classify() == opcodes::Class::IllegalOp)
}
/// The minimum value an output to a witness script must have in order to be
/// broadcastable on today's bitcoin network.
pub const WITNESS_OUTPUT_DUST_THRESHOLD: u64 = 294;
/// The minimum value an output to a non-witness script must have in order to be
/// broadcastable on today's bitcoin network.
pub const LEGACY_OUTPUT_DUST_THRESHOLD: u64 = 546;
/// Gets 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) -> u64 {
if self.is_op_return() {
0
} else if self.is_witness_program() {
Self::WITNESS_OUTPUT_DUST_THRESHOLD
} else {
Self::LEGACY_OUTPUT_DUST_THRESHOLD
}
}
/// Iterate over the script in the form of `Instruction`s, which are an 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, treat
/// it as a slice using `script[..]` or convert it to a vector using `into_bytes()`.
///
/// To force minimal pushes, use [Self::instructions_minimal].
pub fn instructions(&self) -> Instructions {
Instructions {
data: &self.0[..],
enforce_minimal: false,
}
}
/// Iterate over the script in the form of `Instruction`s while enforcing
/// minimal pushes.
pub fn instructions_minimal(&self) -> Instructions {
Instructions {
data: &self.0[..],
enforce_minimal: true,
}
}
#[cfg(feature="bitcoinconsensus")]
/// verify spend of an input script
/// # Parameters
/// * index - the input index in spending which is spending this transaction
/// * amount - the amount this script guards
/// * spending - the transaction that attempts to spend the output holding this script
pub fn verify (&self, index: usize, amount: u64, spending: &[u8]) -> Result<(), Error> {
Ok(bitcoinconsensus::verify (&self.0[..], amount, spending, index)?)
}
/// Write the assembly decoding of the script bytes to the formatter.
pub fn bytes_to_asm_fmt(script: &[u8], f: &mut dyn fmt::Write) -> fmt::Result {
let mut index = 0;
while index < script.len() {
let opcode = opcodes::All::from(script[index]);
index += 1;
let data_len = if let opcodes::Class::PushBytes(n) = opcode.classify() {
n as usize
} else {
match opcode {
opcodes::all::OP_PUSHDATA1 => {
if script.len() < index + 1 {
f.write_str("<unexpected end>")?;
break;
}
match read_uint(&script[index..], 1) {
Ok(n) => { index += 1; n as usize }
Err(_) => { f.write_str("<bad length>")?; break; }
}
}
opcodes::all::OP_PUSHDATA2 => {
if script.len() < index + 2 {
f.write_str("<unexpected end>")?;
break;
}
match read_uint(&script[index..], 2) {
Ok(n) => { index += 2; n as usize }
Err(_) => { f.write_str("<bad length>")?; break; }
}
}
opcodes::all::OP_PUSHDATA4 => {
if script.len() < index + 4 {
f.write_str("<unexpected end>")?;
break;
}
match read_uint(&script[index..], 4) {
Ok(n) => { index += 4; n as usize }
Err(_) => { f.write_str("<bad length>")?; break; }
}
}
_ => 0
}
};
if index > 1 { f.write_str(" ")?; }
// Write the opcode
if opcode == opcodes::all::OP_PUSHBYTES_0 {
f.write_str("OP_0")?;
} else {
write!(f, "{:?}", opcode)?;
}
// Write any pushdata
if data_len > 0 {
f.write_str(" ")?;
if index + data_len <= script.len() {
for ch in &script[index..index + data_len] {
write!(f, "{:02x}", ch)?;
}
index += data_len;
} else {
f.write_str("<push past end>")?;
break;
}
}
}
Ok(())
}
/// Write the assembly decoding of the script to the formatter.
pub fn fmt_asm(&self, f: &mut dyn fmt::Write) -> fmt::Result {
Script::bytes_to_asm_fmt(self.as_ref(), f)
}
/// Create an assembly decoding of the script in the given byte slice.
pub fn bytes_to_asm(script: &[u8]) -> String {
let mut buf = String::new();
Script::bytes_to_asm_fmt(script, &mut buf).unwrap();
buf
}
/// Get the assembly decoding of the script.
pub fn asm(&self) -> String {
Script::bytes_to_asm(self.as_ref())
}
}
/// Creates a new script from an existing vector
impl From<Vec<u8>> for Script {
fn from(v: Vec<u8>) -> Script { Script(v.into_boxed_slice()) }
}
impl_index_newtype!(Script, u8);
/// A "parsed opcode" which allows iterating over a Script in a more sensible way
#[derive(Debug, PartialEq, Eq, Clone)]
pub enum Instruction<'a> {
/// Push a bunch of data
PushBytes(&'a [u8]),
/// Some non-push opcode
Op(opcodes::All),
}
/// Iterator over a script returning parsed opcodes
pub struct Instructions<'a> {
data: &'a [u8],
enforce_minimal: bool,
}
impl<'a> Iterator for Instructions<'a> {
type Item = Result<Instruction<'a>, Error>;
fn next(&mut self) -> Option<Result<Instruction<'a>, Error>> {
if self.data.is_empty() {
return None;
}
match opcodes::All::from(self.data[0]).classify() {
opcodes::Class::PushBytes(n) => {
let n = n as usize;
if self.data.len() < n + 1 {
self.data = &[]; // Kill iterator so that it does not return an infinite stream of errors
return Some(Err(Error::EarlyEndOfScript));
}
if self.enforce_minimal {
if n == 1 && (self.data[1] == 0x81 || (self.data[1] > 0 && self.data[1] <= 16)) {
self.data = &[];
return Some(Err(Error::NonMinimalPush));
}
}
let ret = Some(Ok(Instruction::PushBytes(&self.data[1..n+1])));
self.data = &self.data[n + 1..];
ret
}
opcodes::Class::Ordinary(opcodes::Ordinary::OP_PUSHDATA1) => {
if self.data.len() < 2 {
self.data = &[];
return Some(Err(Error::EarlyEndOfScript));
}
let n = match read_uint(&self.data[1..], 1) {
Ok(n) => n,
Err(e) => {
self.data = &[];
return Some(Err(e));
}
};
if self.data.len() < n + 2 {
self.data = &[];
return Some(Err(Error::EarlyEndOfScript));
}
if self.enforce_minimal && n < 76 {
self.data = &[];
return Some(Err(Error::NonMinimalPush));
}
let ret = Some(Ok(Instruction::PushBytes(&self.data[2..n+2])));
self.data = &self.data[n + 2..];
ret
}
opcodes::Class::Ordinary(opcodes::Ordinary::OP_PUSHDATA2) => {
if self.data.len() < 3 {
self.data = &[];
return Some(Err(Error::EarlyEndOfScript));
}
let n = match read_uint(&self.data[1..], 2) {
Ok(n) => n,
Err(e) => {
self.data = &[];
return Some(Err(e));
}
};
if self.enforce_minimal && n < 0x100 {
self.data = &[];
return Some(Err(Error::NonMinimalPush));
}
if self.data.len() < n + 3 {
self.data = &[];
return Some(Err(Error::EarlyEndOfScript));
}
let ret = Some(Ok(Instruction::PushBytes(&self.data[3..n + 3])));
self.data = &self.data[n + 3..];
ret
}
opcodes::Class::Ordinary(opcodes::Ordinary::OP_PUSHDATA4) => {
if self.data.len() < 5 {
self.data = &[];
return Some(Err(Error::EarlyEndOfScript));
}
let n = match read_uint(&self.data[1..], 4) {
Ok(n) => n,
Err(e) => {
self.data = &[];
return Some(Err(e));
}
};
if self.enforce_minimal && n < 0x10000 {
self.data = &[];
return Some(Err(Error::NonMinimalPush));
}
if self.data.len() < n + 5 {
self.data = &[];
return Some(Err(Error::EarlyEndOfScript));
}
let ret = Some(Ok(Instruction::PushBytes(&self.data[5..n + 5])));
self.data = &self.data[n + 5..];
ret
}
// Everything else we can push right through
_ => {
let ret = Some(Ok(Instruction::Op(opcodes::All::from(self.data[0]))));
self.data = &self.data[1..];
ret
}
}
}
}
impl Builder {
/// Creates a new empty script
pub fn new() -> Self {
Builder(vec![], None)
}
/// The length in bytes of the script
pub fn len(&self) -> usize { self.0.len() }
/// 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 || (data >= 1 && data <= 16) {
let opcode = opcodes::All::from(
(data - 1 + opcodes::OP_TRUE.into_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_scriptint(data) }
}
/// Adds instructions to push an integer onto the stack, using the explicit
/// encoding regardless of the availability of dedicated opcodes.
pub fn push_scriptint(self, data: i64) -> Builder {
self.push_slice(&build_scriptint(data))
}
/// Adds instructions to push some arbitrary data onto the stack
pub fn push_slice(mut self, data: &[u8]) -> Builder {
// 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.into_u8());
self.0.push(n as u8);
},
n if n < 0x10000 => {
self.0.push(opcodes::Ordinary::OP_PUSHDATA2.into_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.into_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(data.iter().cloned());
self.1 = None;
self
}
/// Pushes a public key
pub fn push_key(self, key: &PublicKey) -> Builder {
if key.compressed {
self.push_slice(&key.key.serialize()[..])
} else {
self.push_slice(&key.key.serialize_uncompressed()[..])
}
}
/// Adds a single opcode to the script
pub fn push_opcode(mut self, data: opcodes::All) -> Builder {
self.0.push(data.into_u8());
self.1 = Some(data);
self
}
/// Adds an `OP_VERIFY` to the script, unless the most-recently-added
/// opcode has an alternate `VERIFY` form, in which case that opcode
/// is replaced. e.g. `OP_CHECKSIG` will become `OP_CHECKSIGVERIFY`.
pub fn push_verify(mut self) -> Builder {
match self.1 {
Some(opcodes::all::OP_EQUAL) => {
self.0.pop();
self.push_opcode(opcodes::all::OP_EQUALVERIFY)
},
Some(opcodes::all::OP_NUMEQUAL) => {
self.0.pop();
self.push_opcode(opcodes::all::OP_NUMEQUALVERIFY)
},
Some(opcodes::all::OP_CHECKSIG) => {
self.0.pop();
self.push_opcode(opcodes::all::OP_CHECKSIGVERIFY)
},
Some(opcodes::all::OP_CHECKMULTISIG) => {
self.0.pop();
self.push_opcode(opcodes::all::OP_CHECKMULTISIGVERIFY)
},
_ => self.push_opcode(opcodes::all::OP_VERIFY),
}
}
/// Converts the `Builder` into an unmodifiable `Script`
pub fn into_script(self) -> Script {
Script(self.0.into_boxed_slice())
}
}
/// Adds an individual opcode to the script
impl Default for Builder {
fn default() -> Builder { Builder::new() }
}
/// Creates a new script from an existing vector
impl From<Vec<u8>> for Builder {
fn from(v: Vec<u8>) -> Builder {
let script = Script(v.into_boxed_slice());
let last_op = match script.instructions().last() {
Some(Ok(Instruction::Op(op))) => Some(op),
_ => None,
};
Builder(script.into_bytes(), last_op)
}
}
impl_index_newtype!(Builder, u8);
#[cfg(feature = "serde")]
impl<'de> serde::Deserialize<'de> for Script {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: serde::Deserializer<'de>,
{
use std::fmt::Formatter;
use hashes::hex::FromHex;
struct Visitor;
impl<'de> serde::de::Visitor<'de> for Visitor {
type Value = Script;
fn expecting(&self, formatter: &mut Formatter) -> fmt::Result {
formatter.write_str("a script")
}
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(Script::from(v))
}
fn visit_borrowed_str<E>(self, v: &'de str) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
self.visit_str(v)
}
fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
self.visit_str(&v)
}
}
deserializer.deserialize_str(Visitor)
}
}
#[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,
{
serializer.serialize_str(&format!("{:x}", self))
}
}
// Network serialization
impl Encodable for Script {
#[inline]
fn consensus_encode<S: io::Write>(
&self,
s: S,
) -> Result<usize, io::Error> {
self.0.consensus_encode(s)
}
}
impl Decodable for Script {
#[inline]
fn consensus_decode<D: io::Read>(d: D) -> Result<Self, encode::Error> {
Ok(Script(Decodable::consensus_decode(d)?))
}
}
#[cfg(test)]
mod test {
use std::str::FromStr;
use super::*;
use super::build_scriptint;
use hashes::hex::{FromHex, ToHex};
use consensus::encode::{deserialize, serialize};
use blockdata::opcodes;
use util::ecdsa::PublicKey;
use util::psbt::serialize::Serialize;
#[test]
fn script() {
let mut comp = vec![];
let mut script = Builder::new();
assert_eq!(&script[..], &comp[..]);
// small ints
script = script.push_int(1); comp.push(81u8); assert_eq!(&script[..], &comp[..]);
script = script.push_int(0); comp.push(0u8); assert_eq!(&script[..], &comp[..]);
script = script.push_int(4); comp.push(84u8); assert_eq!(&script[..], &comp[..]);
script = script.push_int(-1); comp.push(79u8); assert_eq!(&script[..], &comp[..]);
// forced scriptint
script = script.push_scriptint(4); comp.extend([1u8, 4].iter().cloned()); assert_eq!(&script[..], &comp[..]);
// big ints
script = script.push_int(17); comp.extend([1u8, 17].iter().cloned()); assert_eq!(&script[..], &comp[..]);
script = script.push_int(10000); comp.extend([2u8, 16, 39].iter().cloned()); assert_eq!(&script[..], &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[..], &comp[..]);
script = script.push_int(-10000000); comp.extend([4u8, 128, 150, 152, 128].iter().cloned()); assert_eq!(&script[..], &comp[..]);
// data
script = script.push_slice("NRA4VR".as_bytes()); comp.extend([6u8, 78, 82, 65, 52, 86, 82].iter().cloned()); assert_eq!(&script[..], &comp[..]);
// keys
let keystr = "21032e58afe51f9ed8ad3cc7897f634d881fdbe49a81564629ded8156bebd2ffd1af";
let key = PublicKey::from_str(&keystr[2..]).unwrap();
script = script.push_key(&key); comp.extend(Vec::from_hex(keystr).unwrap().iter().cloned()); assert_eq!(&script[..], &comp[..]);
let keystr = "41042e58afe51f9ed8ad3cc7897f634d881fdbe49a81564629ded8156bebd2ffd1af191923a2964c177f5b5923ae500fca49e99492d534aa3759d6b25a8bc971b133";
let key = PublicKey::from_str(&keystr[2..]).unwrap();
script = script.push_key(&key); comp.extend(Vec::from_hex(keystr).unwrap().iter().cloned()); assert_eq!(&script[..], &comp[..]);
// opcodes
script = script.push_opcode(opcodes::all::OP_CHECKSIG); comp.push(0xACu8); assert_eq!(&script[..], &comp[..]);
script = script.push_opcode(opcodes::all::OP_CHECKSIG); comp.push(0xACu8); assert_eq!(&script[..], &comp[..]);
}
#[test]
fn script_builder() {
// from txid 3bb5e6434c11fb93f64574af5d116736510717f2c595eb45b52c28e31622dfff which was in my mempool when I wrote the test
let script = Builder::new().push_opcode(opcodes::all::OP_DUP)
.push_opcode(opcodes::all::OP_HASH160)
.push_slice(&Vec::from_hex("16e1ae70ff0fa102905d4af297f6912bda6cce19").unwrap())
.push_opcode(opcodes::all::OP_EQUALVERIFY)
.push_opcode(opcodes::all::OP_CHECKSIG)
.into_script();
assert_eq!(&format!("{:x}", script), "76a91416e1ae70ff0fa102905d4af297f6912bda6cce1988ac");
}
#[test]
fn script_generators() {
let pubkey = PublicKey::from_str("0234e6a79c5359c613762d537e0e19d86c77c1666d8c9ab050f23acd198e97f93e").unwrap();
assert!(Script::new_p2pk(&pubkey).is_p2pk());
let pubkey_hash = PubkeyHash::hash(&pubkey.serialize());
assert!(Script::new_p2pkh(&pubkey_hash).is_p2pkh());
let wpubkey_hash = WPubkeyHash::hash(&pubkey.serialize());
assert!(Script::new_v0_wpkh(&wpubkey_hash).is_v0_p2wpkh());
let script = Builder::new().push_opcode(opcodes::all::OP_NUMEQUAL)
.push_verify()
.into_script();
let script_hash = ScriptHash::hash(&script.serialize());
let p2sh = Script::new_p2sh(&script_hash);
assert!(p2sh.is_p2sh());
assert_eq!(script.to_p2sh(), p2sh);
let wscript_hash = WScriptHash::hash(&script.serialize());
let p2wsh = Script::new_v0_wsh(&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 = Script::new_op_return(&data);
assert!(op_return.is_op_return());
assert_eq!(op_return.to_hex(), "6a24aa21a9ed20280f53f2d21663cac89e6bd2ad19edbabb048cda08e73ed19e9268d0afea2a");
}
#[test]
fn script_builder_verify() {
let simple = Builder::new()
.push_verify()
.into_script();
assert_eq!(format!("{:x}", simple), "69");
let simple2 = Builder::from(vec![])
.push_verify()
.into_script();
assert_eq!(format!("{:x}", simple2), "69");
let nonverify = Builder::new()
.push_verify()
.push_verify()
.into_script();
assert_eq!(format!("{:x}", nonverify), "6969");
let nonverify2 = Builder::from(vec![0x69])
.push_verify()
.into_script();
assert_eq!(format!("{:x}", nonverify2), "6969");
let equal = Builder::new()
.push_opcode(opcodes::all::OP_EQUAL)
.push_verify()
.into_script();
assert_eq!(format!("{:x}", equal), "88");