milksad
/
rust-bitcoin-unsafe-fast
14
0
Fork 0
Code Issues Pull Requests Activity
rust-bitcoin-unsafe-fast/bitcoin/src/crypto/sighash.rs

2158 lines
86 KiB
Rust
Raw Blame History

// SPDX-License-Identifier: CC0-1.0
//! Signature hash implementation (used in transaction signing).
//!
//! Efficient implementation of the algorithm to compute the message to be signed according to
//! [Bip341](https://github.com/bitcoin/bips/blob/150ab6f5c3aca9da05fccc5b435e9667853407f4/bip-0341.mediawiki),
//! [Bip143](https://github.com/bitcoin/bips/blob/99701f68a88ce33b2d0838eb84e115cef505b4c2/bip-0143.mediawiki)
//! and legacy (before Bip143).
//!
//! Computing signature hashes is required to sign a transaction and this module is designed to
//! handle its complexity efficiently. Computing these hashes is as simple as creating
//! [`SighashCache`] and calling its methods.
use core::{fmt, str};
use hashes::{hash_newtype, sha256, sha256d, sha256t_hash_newtype, Hash};
use internals::write_err;
use io::Write;
use crate::blockdata::witness::Witness;
use crate::consensus::{encode, Encodable};
use crate::taproot::{LeafVersion, TapLeafHash, TAPROOT_ANNEX_PREFIX};
use crate::prelude::*;
use crate::{transaction, Amount, Script, ScriptBuf, Sequence, Transaction, TxIn, TxOut};
/// Used for signature hash for invalid use of SIGHASH_SINGLE.
#[rustfmt::skip]
pub(crate) const UINT256_ONE: [u8; 32] = [
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0
];
macro_rules! impl_thirty_two_byte_hash {
($ty:ident) => {
impl secp256k1::ThirtyTwoByteHash for $ty {
fn into_32(self) -> [u8; 32] { self.to_byte_array() }
}
};
}
hash_newtype! {
/// Hash of a transaction according to the legacy signature algorithm.
#[hash_newtype(forward)]
pub struct LegacySighash(sha256d::Hash);
/// Hash of a transaction according to the segwit version 0 signature algorithm.
#[hash_newtype(forward)]
pub struct SegwitV0Sighash(sha256d::Hash);
}
impl_thirty_two_byte_hash!(LegacySighash);
impl_thirty_two_byte_hash!(SegwitV0Sighash);
sha256t_hash_newtype! {
pub struct TapSighashTag = hash_str("TapSighash");
/// Taproot-tagged hash with tag \"TapSighash\".
///
/// This hash type is used for computing taproot signature hash."
#[hash_newtype(forward)]
pub struct TapSighash(_);
}
impl_thirty_two_byte_hash!(TapSighash);
/// Efficiently calculates signature hash message for legacy, segwit and taproot inputs.
#[derive(Debug)]
pub struct SighashCache<T: Borrow<Transaction>> {
/// Access to transaction required for transaction introspection. Moreover, type
/// `T: Borrow<Transaction>` allows us to use borrowed and mutable borrowed types,
/// the latter in particular is necessary for [`SighashCache::witness_mut`].
tx: T,
/// Common cache for taproot and segwit inputs, `None` for legacy inputs.
common_cache: Option<CommonCache>,
/// Cache for segwit v0 inputs (the result of another round of sha256 on `common_cache`).
segwit_cache: Option<SegwitCache>,
/// Cache for taproot v1 inputs.
taproot_cache: Option<TaprootCache>,
}
/// Common values cached between segwit and taproot inputs.
#[derive(Debug)]
struct CommonCache {
prevouts: sha256::Hash,
sequences: sha256::Hash,
/// In theory `outputs` could be an `Option` since `SIGHASH_NONE` and `SIGHASH_SINGLE` do not
/// need it, but since `SIGHASH_ALL` is by far the most used variant we don't bother.
outputs: sha256::Hash,
}
/// Values cached for segwit inputs, equivalent to [`CommonCache`] plus another round of `sha256`.
#[derive(Debug)]
struct SegwitCache {
prevouts: sha256d::Hash,
sequences: sha256d::Hash,
outputs: sha256d::Hash,
}
/// Values cached for taproot inputs.
#[derive(Debug)]
struct TaprootCache {
amounts: sha256::Hash,
script_pubkeys: sha256::Hash,
}
/// Contains outputs of previous transactions. In the case [`TapSighashType`] variant is
/// `SIGHASH_ANYONECANPAY`, [`Prevouts::One`] may be used.
#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
pub enum Prevouts<'u, T>
where
T: 'u + Borrow<TxOut>,
{
/// `One` variant allows provision of the single prevout needed. It's useful, for example, when
/// modifier `SIGHASH_ANYONECANPAY` is provided, only prevout of the current input is needed.
/// The first `usize` argument is the input index this [`TxOut`] is referring to.
One(usize, T),
/// When `SIGHASH_ANYONECANPAY` is not provided, or when the caller is giving all prevouts so
/// the same variable can be used for multiple inputs.
All(&'u [T]),
}
const KEY_VERSION_0: u8 = 0u8;
/// Information related to the script path spending.
///
/// This can be hashed into a [`TapLeafHash`].
#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
pub struct ScriptPath<'s> {
script: &'s Script,
leaf_version: LeafVersion,
}
/// Hashtype of an input's signature, encoded in the last byte of the signature.
/// Fixed values so they can be cast as integer types for encoding.
#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
pub enum TapSighashType {
/// 0x0: Used when not explicitly specified, defaults to [`TapSighashType::All`]
Default = 0x00,
/// 0x1: Sign all outputs.
All = 0x01,
/// 0x2: Sign no outputs --- anyone can choose the destination.
None = 0x02,
/// 0x3: Sign the output whose index matches this input's index. If none exists,
/// sign the hash `0000000000000000000000000000000000000000000000000000000000000001`.
/// (This rule is probably an unintentional C++ism, but it's consensus so we have
/// to follow it.)
Single = 0x03,
/// 0x81: Sign all outputs but only this input.
AllPlusAnyoneCanPay = 0x81,
/// 0x82: Sign no outputs and only this input.
NonePlusAnyoneCanPay = 0x82,
/// 0x83: Sign one output and only this input (see `Single` for what "one output" means).
SinglePlusAnyoneCanPay = 0x83,
}
#[cfg(feature = "serde")]
crate::serde_utils::serde_string_impl!(TapSighashType, "a TapSighashType data");
impl fmt::Display for TapSighashType {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
use TapSighashType::*;
let s = match self {
Default => "SIGHASH_DEFAULT",
All => "SIGHASH_ALL",
None => "SIGHASH_NONE",
Single => "SIGHASH_SINGLE",
AllPlusAnyoneCanPay => "SIGHASH_ALL|SIGHASH_ANYONECANPAY",
NonePlusAnyoneCanPay => "SIGHASH_NONE|SIGHASH_ANYONECANPAY",
SinglePlusAnyoneCanPay => "SIGHASH_SINGLE|SIGHASH_ANYONECANPAY",
};
f.write_str(s)
}
}
impl str::FromStr for TapSighashType {
type Err = SighashTypeParseError;
fn from_str(s: &str) -> Result<Self, Self::Err> {
use TapSighashType::*;
match s {
"SIGHASH_DEFAULT" => Ok(Default),
"SIGHASH_ALL" => Ok(All),
"SIGHASH_NONE" => Ok(None),
"SIGHASH_SINGLE" => Ok(Single),
"SIGHASH_ALL|SIGHASH_ANYONECANPAY" => Ok(AllPlusAnyoneCanPay),
"SIGHASH_NONE|SIGHASH_ANYONECANPAY" => Ok(NonePlusAnyoneCanPay),
"SIGHASH_SINGLE|SIGHASH_ANYONECANPAY" => Ok(SinglePlusAnyoneCanPay),
_ => Err(SighashTypeParseError { unrecognized: s.to_owned() }),
}
}
}
impl<'u, T> Prevouts<'u, T>
where
T: Borrow<TxOut>,
{
fn check_all(&self, tx: &Transaction) -> Result<(), PrevoutsSizeError> {
if let Prevouts::All(prevouts) = self {
if prevouts.len() != tx.input.len() {
return Err(PrevoutsSizeError);
}
}
Ok(())
}
fn get_all(&self) -> Result<&[T], PrevoutsKindError> {
match self {
Prevouts::All(prevouts) => Ok(*prevouts),
_ => Err(PrevoutsKindError),
}
}
fn get(&self, input_index: usize) -> Result<&TxOut, PrevoutsIndexError> {
match self {
Prevouts::One(index, prevout) =>
if input_index == *index {
Ok(prevout.borrow())
} else {
Err(PrevoutsIndexError::InvalidOneIndex)
},
Prevouts::All(prevouts) => prevouts
.get(input_index)
.map(|x| x.borrow())
.ok_or(PrevoutsIndexError::InvalidAllIndex),
}
}
}
/// The number of supplied prevouts differs from the number of inputs in the transaction.
#[derive(Debug, Clone, PartialEq, Eq)]
#[non_exhaustive]
pub struct PrevoutsSizeError;
impl fmt::Display for PrevoutsSizeError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "number of supplied prevouts differs from the number of inputs in transaction")
}
}
#[cfg(feature = "std")]
impl std::error::Error for PrevoutsSizeError {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> { None }
}
/// A single prevout was been provided but all prevouts are needed without `ANYONECANPAY`.
#[derive(Debug, Clone, PartialEq, Eq)]
#[non_exhaustive]
pub struct PrevoutsKindError;
impl fmt::Display for PrevoutsKindError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "single prevout provided but all prevouts are needed without `ANYONECANPAY`")
}
}
#[cfg(feature = "std")]
impl std::error::Error for PrevoutsKindError {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> { None }
}
/// [`Prevouts`] index related errors.
#[derive(Debug, Clone, PartialEq, Eq)]
#[non_exhaustive]
pub enum PrevoutsIndexError {
/// Invalid index when accessing a [`Prevouts::One`] kind.
InvalidOneIndex,
/// Invalid index when accessing a [`Prevouts::All`] kind.
InvalidAllIndex,
}
internals::impl_from_infallible!(PrevoutsIndexError);
impl fmt::Display for PrevoutsIndexError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
use PrevoutsIndexError::*;
match *self {
InvalidOneIndex => write!(f, "invalid index when accessing a Prevouts::One kind"),
InvalidAllIndex => write!(f, "invalid index when accessing a Prevouts::All kind"),
}
}
}
#[cfg(feature = "std")]
impl std::error::Error for PrevoutsIndexError {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
use PrevoutsIndexError::*;
match *self {
InvalidOneIndex | InvalidAllIndex => None,
}
}
}
impl<'s> ScriptPath<'s> {
/// Creates a new `ScriptPath` structure.
pub fn new(script: &'s Script, leaf_version: LeafVersion) -> Self {
ScriptPath { script, leaf_version }
}
/// Creates a new `ScriptPath` structure using default leaf version value.
pub fn with_defaults(script: &'s Script) -> Self { Self::new(script, LeafVersion::TapScript) }
/// Computes the leaf hash for this `ScriptPath`.
pub fn leaf_hash(&self) -> TapLeafHash {
let mut enc = TapLeafHash::engine();
self.leaf_version
.to_consensus()
.consensus_encode(&mut enc)
.expect("writing to hash enging should never fail");
self.script.consensus_encode(&mut enc).expect("writing to hash enging should never fail");
TapLeafHash::from_engine(enc)
}
}
impl<'s> From<ScriptPath<'s>> for TapLeafHash {
fn from(script_path: ScriptPath<'s>) -> TapLeafHash { script_path.leaf_hash() }
}
/// Hashtype of an input's signature, encoded in the last byte of the signature.
///
/// Fixed values so they can be cast as integer types for encoding (see also
/// [`TapSighashType`]).
#[derive(PartialEq, Eq, Debug, Copy, Clone, Hash)]
pub enum EcdsaSighashType {
/// 0x1: Sign all outputs.
All = 0x01,
/// 0x2: Sign no outputs --- anyone can choose the destination.
None = 0x02,
/// 0x3: Sign the output whose index matches this input's index. If none exists,
/// sign the hash `0000000000000000000000000000000000000000000000000000000000000001`.
/// (This rule is probably an unintentional C++ism, but it's consensus so we have
/// to follow it.)
Single = 0x03,
/// 0x81: Sign all outputs but only this input.
AllPlusAnyoneCanPay = 0x81,
/// 0x82: Sign no outputs and only this input.
NonePlusAnyoneCanPay = 0x82,
/// 0x83: Sign one output and only this input (see `Single` for what "one output" means).
SinglePlusAnyoneCanPay = 0x83,
}
#[cfg(feature = "serde")]
crate::serde_utils::serde_string_impl!(EcdsaSighashType, "a EcdsaSighashType data");
impl fmt::Display for EcdsaSighashType {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
use EcdsaSighashType::*;
let s = match self {
All => "SIGHASH_ALL",
None => "SIGHASH_NONE",
Single => "SIGHASH_SINGLE",
AllPlusAnyoneCanPay => "SIGHASH_ALL|SIGHASH_ANYONECANPAY",
NonePlusAnyoneCanPay => "SIGHASH_NONE|SIGHASH_ANYONECANPAY",
SinglePlusAnyoneCanPay => "SIGHASH_SINGLE|SIGHASH_ANYONECANPAY",
};
f.write_str(s)
}
}
impl str::FromStr for EcdsaSighashType {
type Err = SighashTypeParseError;
fn from_str(s: &str) -> Result<Self, Self::Err> {
use EcdsaSighashType::*;
match s {
"SIGHASH_ALL" => Ok(All),
"SIGHASH_NONE" => Ok(None),
"SIGHASH_SINGLE" => Ok(Single),
"SIGHASH_ALL|SIGHASH_ANYONECANPAY" => Ok(AllPlusAnyoneCanPay),
"SIGHASH_NONE|SIGHASH_ANYONECANPAY" => Ok(NonePlusAnyoneCanPay),
"SIGHASH_SINGLE|SIGHASH_ANYONECANPAY" => Ok(SinglePlusAnyoneCanPay),
_ => Err(SighashTypeParseError { unrecognized: s.to_owned() }),
}
}
}
impl EcdsaSighashType {
/// Splits the sighash flag into the "real" sighash flag and the ANYONECANPAY boolean.
pub(crate) fn split_anyonecanpay_flag(self) -> (EcdsaSighashType, bool) {
use EcdsaSighashType::*;
match self {
All => (All, false),
None => (None, false),
Single => (Single, false),
AllPlusAnyoneCanPay => (All, true),
NonePlusAnyoneCanPay => (None, true),
SinglePlusAnyoneCanPay => (Single, true),
}
}
/// Creates a [`EcdsaSighashType`] from a raw `u32`.
///
/// **Note**: this replicates consensus behaviour, for current standardness rules correctness
/// you probably want [`Self::from_standard`].
///
/// This might cause unexpected behavior because it does not roundtrip. That is,
/// `EcdsaSighashType::from_consensus(n) as u32 != n` for non-standard values of `n`. While
/// verifying signatures, the user should retain the `n` and use it compute the signature hash
/// message.
pub fn from_consensus(n: u32) -> EcdsaSighashType {
use EcdsaSighashType::*;
// In Bitcoin Core, the SignatureHash function will mask the (int32) value with
// 0x1f to (apparently) deactivate ACP when checking for SINGLE and NONE bits.
// We however want to be matching also against on ACP-masked ALL, SINGLE, and NONE.
// So here we re-activate ACP.
let mask = 0x1f | 0x80;
match n & mask {
// "real" sighashes
0x01 => All,
0x02 => None,
0x03 => Single,
0x81 => AllPlusAnyoneCanPay,
0x82 => NonePlusAnyoneCanPay,
0x83 => SinglePlusAnyoneCanPay,
// catchalls
x if x & 0x80 == 0x80 => AllPlusAnyoneCanPay,
_ => All,
}
}
/// Creates a [`EcdsaSighashType`] from a raw `u32`.
///
/// # Errors
///
/// If `n` is a non-standard sighash value.
pub fn from_standard(n: u32) -> Result<EcdsaSighashType, NonStandardSighashTypeError> {
use EcdsaSighashType::*;
match n {
// Standard sighashes, see https://github.com/bitcoin/bitcoin/blob/b805dbb0b9c90dadef0424e5b3bf86ac308e103e/src/script/interpreter.cpp#L189-L198
0x01 => Ok(All),
0x02 => Ok(None),
0x03 => Ok(Single),
0x81 => Ok(AllPlusAnyoneCanPay),
0x82 => Ok(NonePlusAnyoneCanPay),
0x83 => Ok(SinglePlusAnyoneCanPay),
non_standard => Err(NonStandardSighashTypeError(non_standard)),
}
}
/// Converts [`EcdsaSighashType`] to a `u32` sighash flag.
///
/// The returned value is guaranteed to be a valid according to standardness rules.
pub fn to_u32(self) -> u32 { self as u32 }
}
impl From<EcdsaSighashType> for TapSighashType {
fn from(s: EcdsaSighashType) -> Self {
use TapSighashType::*;
match s {
EcdsaSighashType::All => All,
EcdsaSighashType::None => None,
EcdsaSighashType::Single => Single,
EcdsaSighashType::AllPlusAnyoneCanPay => AllPlusAnyoneCanPay,
EcdsaSighashType::NonePlusAnyoneCanPay => NonePlusAnyoneCanPay,
EcdsaSighashType::SinglePlusAnyoneCanPay => SinglePlusAnyoneCanPay,
}
}
}
impl TapSighashType {
/// Breaks the sighash flag into the "real" sighash flag and the `SIGHASH_ANYONECANPAY` boolean.
pub(crate) fn split_anyonecanpay_flag(self) -> (TapSighashType, bool) {
use TapSighashType::*;
match self {
Default => (Default, false),
All => (All, false),
None => (None, false),
Single => (Single, false),
AllPlusAnyoneCanPay => (All, true),
NonePlusAnyoneCanPay => (None, true),
SinglePlusAnyoneCanPay => (Single, true),
}
}
/// Constructs a [`TapSighashType`] from a raw `u8`.
pub fn from_consensus_u8(sighash_type: u8) -> Result<Self, InvalidSighashTypeError> {
use TapSighashType::*;
Ok(match sighash_type {
0x00 => Default,
0x01 => All,
0x02 => None,
0x03 => Single,
0x81 => AllPlusAnyoneCanPay,
0x82 => NonePlusAnyoneCanPay,
0x83 => SinglePlusAnyoneCanPay,
x => return Err(InvalidSighashTypeError(x.into())),
})
}
}
/// Integer is not a consensus valid sighash type.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct InvalidSighashTypeError(pub u32);
impl fmt::Display for InvalidSighashTypeError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "invalid sighash type {}", self.0)
}
}
#[cfg(feature = "std")]
impl std::error::Error for InvalidSighashTypeError {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> { None }
}
/// This type is consensus valid but an input including it would prevent the transaction from
/// being relayed on today's Bitcoin network.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct NonStandardSighashTypeError(pub u32);
impl fmt::Display for NonStandardSighashTypeError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "non-standard sighash type {}", self.0)
}
}
#[cfg(feature = "std")]
impl std::error::Error for NonStandardSighashTypeError {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> { None }
}
/// Error returned for failure during parsing one of the sighash types.
///
/// This is currently returned for unrecognized sighash strings.
#[derive(Debug, Clone, PartialEq, Eq)]
#[non_exhaustive]
pub struct SighashTypeParseError {
/// The unrecognized string we attempted to parse.
pub unrecognized: String,
}
impl fmt::Display for SighashTypeParseError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "unrecognized SIGHASH string '{}'", self.unrecognized)
}
}
#[cfg(feature = "std")]
impl std::error::Error for SighashTypeParseError {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> { None }
}
impl<R: Borrow<Transaction>> SighashCache<R> {
/// Constructs a new `SighashCache` from an unsigned transaction.
///
/// The sighash components are computed in a lazy manner when required. For the generated
/// sighashes to be valid, no fields in the transaction may change except for script_sig and
/// witness.
pub fn new(tx: R) -> Self {
SighashCache { tx, common_cache: None, taproot_cache: None, segwit_cache: None }
}
/// Returns the reference to the cached transaction.
pub fn transaction(&self) -> &Transaction { self.tx.borrow() }
/// Destroys the cache and recovers the stored transaction.
pub fn into_transaction(self) -> R { self.tx }
/// Encodes the BIP341 signing data for any flag type into a given object implementing the
/// [`io::Write`] trait.
pub fn taproot_encode_signing_data_to<W: Write + ?Sized, T: Borrow<TxOut>>(
&mut self,
writer: &mut W,
input_index: usize,
prevouts: &Prevouts<T>,
annex: Option<Annex>,
leaf_hash_code_separator: Option<(TapLeafHash, u32)>,
sighash_type: TapSighashType,
) -> Result<(), SigningDataError<TaprootError>> {
prevouts.check_all(self.tx.borrow()).map_err(SigningDataError::sighash)?;
let (sighash, anyone_can_pay) = sighash_type.split_anyonecanpay_flag();
// epoch
0u8.consensus_encode(writer)?;
// * Control:
// hash_type (1).
(sighash_type as u8).consensus_encode(writer)?;
// * Transaction Data:
// nVersion (4): the nVersion of the transaction.
self.tx.borrow().version.consensus_encode(writer)?;
// nLockTime (4): the nLockTime of the transaction.
self.tx.borrow().lock_time.consensus_encode(writer)?;
// If the hash_type & 0x80 does not equal SIGHASH_ANYONECANPAY:
// sha_prevouts (32): the SHA256 of the serialization of all input outpoints.
// sha_amounts (32): the SHA256 of the serialization of all spent output amounts.
// sha_scriptpubkeys (32): the SHA256 of the serialization of all spent output scriptPubKeys.
// sha_sequences (32): the SHA256 of the serialization of all input nSequence.
if !anyone_can_pay {
self.common_cache().prevouts.consensus_encode(writer)?;
self.taproot_cache(prevouts.get_all().map_err(SigningDataError::sighash)?).amounts.consensus_encode(writer)?;
self.taproot_cache(prevouts.get_all().map_err(SigningDataError::sighash)?).script_pubkeys.consensus_encode(writer)?;
self.common_cache().sequences.consensus_encode(writer)?;
}
// If hash_type & 3 does not equal SIGHASH_NONE or SIGHASH_SINGLE:
// sha_outputs (32): the SHA256 of the serialization of all outputs in CTxOut format.
if sighash != TapSighashType::None && sighash != TapSighashType::Single {
self.common_cache().outputs.consensus_encode(writer)?;
}
// * Data about this input:
// spend_type (1): equal to (ext_flag * 2) + annex_present, where annex_present is 0
// if no annex is present, or 1 otherwise
let mut spend_type = 0u8;
if annex.is_some() {
spend_type |= 1u8;
}
if leaf_hash_code_separator.is_some() {
spend_type |= 2u8;
}
spend_type.consensus_encode(writer)?;
// If hash_type & 0x80 equals SIGHASH_ANYONECANPAY:
// outpoint (36): the COutPoint of this input (32-byte hash + 4-byte little-endian).
// amount (8): value of the previous output spent by this input.
// scriptPubKey (35): scriptPubKey of the previous output spent by this input, serialized as script inside CTxOut. Its size is always 35 bytes.
// nSequence (4): nSequence of this input.
if anyone_can_pay {
let txin = &self.tx.borrow().tx_in(input_index).map_err(SigningDataError::sighash)?;
let previous_output = prevouts.get(input_index).map_err(SigningDataError::sighash)?;
txin.previous_output.consensus_encode(writer)?;
previous_output.value.consensus_encode(writer)?;
previous_output.script_pubkey.consensus_encode(writer)?;
txin.sequence.consensus_encode(writer)?;
} else {
(input_index as u32).consensus_encode(writer)?;
}
// If an annex is present (the lowest bit of spend_type is set):
// sha_annex (32): the SHA256 of (compact_size(size of annex) || annex), where annex
// includes the mandatory 0x50 prefix.
if let Some(annex) = annex {
let mut enc = sha256::Hash::engine();
annex.consensus_encode(&mut enc)?;
let hash = sha256::Hash::from_engine(enc);
hash.consensus_encode(writer)?;
}
// * Data about this output:
// If hash_type & 3 equals SIGHASH_SINGLE:
// sha_single_output (32): the SHA256 of the corresponding output in CTxOut format.
if sighash == TapSighashType::Single {
let mut enc = sha256::Hash::engine();
self.tx
.borrow()
.output
.get(input_index)
.ok_or(TaprootError::SingleMissingOutput(SingleMissingOutputError {
input_index,
outputs_length: self.tx.borrow().output.len(),
})).map_err(SigningDataError::Sighash)?
.consensus_encode(&mut enc)?;
let hash = sha256::Hash::from_engine(enc);
hash.consensus_encode(writer)?;
}
// if (scriptpath):
// ss += TaggedHash("TapLeaf", bytes([leaf_ver]) + ser_string(script))
// ss += bytes([0])
// ss += struct.pack("<i", codeseparator_pos)
if let Some((hash, code_separator_pos)) = leaf_hash_code_separator {
hash.as_byte_array().consensus_encode(writer)?;
KEY_VERSION_0.consensus_encode(writer)?;
code_separator_pos.consensus_encode(writer)?;
}
Ok(())
}
/// Computes the BIP341 sighash for any flag type.
pub fn taproot_signature_hash<T: Borrow<TxOut>>(
&mut self,
input_index: usize,
prevouts: &Prevouts<T>,
annex: Option<Annex>,
leaf_hash_code_separator: Option<(TapLeafHash, u32)>,
sighash_type: TapSighashType,
) -> Result<TapSighash, TaprootError> {
let mut enc = TapSighash::engine();
self.taproot_encode_signing_data_to(
&mut enc,
input_index,
prevouts,
annex,
leaf_hash_code_separator,
sighash_type,
).map_err(SigningDataError::unwrap_sighash)?;
Ok(TapSighash::from_engine(enc))
}
/// Computes the BIP341 sighash for a key spend.
pub fn taproot_key_spend_signature_hash<T: Borrow<TxOut>>(
&mut self,
input_index: usize,
prevouts: &Prevouts<T>,
sighash_type: TapSighashType,
) -> Result<TapSighash, TaprootError> {
let mut enc = TapSighash::engine();
self.taproot_encode_signing_data_to(
&mut enc,
input_index,
prevouts,
None,
None,
sighash_type,
).map_err(SigningDataError::unwrap_sighash)?;
Ok(TapSighash::from_engine(enc))
}
/// Computes the BIP341 sighash for a script spend.
///
/// Assumes the default `OP_CODESEPARATOR` position of `0xFFFFFFFF`. Custom values can be
/// provided through the more fine-grained API of [`SighashCache::taproot_encode_signing_data_to`].
pub fn taproot_script_spend_signature_hash<S: Into<TapLeafHash>, T: Borrow<TxOut>>(
&mut self,
input_index: usize,
prevouts: &Prevouts<T>,
leaf_hash: S,
sighash_type: TapSighashType,
) -> Result<TapSighash, TaprootError> {
let mut enc = TapSighash::engine();
self.taproot_encode_signing_data_to(
&mut enc,
input_index,
prevouts,
None,
Some((leaf_hash.into(), 0xFFFFFFFF)),
sighash_type,
).map_err(SigningDataError::unwrap_sighash)?;
Ok(TapSighash::from_engine(enc))
}
/// Encodes the BIP143 signing data for any flag type into a given object implementing the
/// [`std::io::Write`] trait.
///
/// `script_code` is dependent on the type of the spend transaction. For p2wpkh use
/// [`Script::p2wpkh_script_code`], for p2wsh just pass in the witness script. (Also see
/// [`Self::p2wpkh_signature_hash`] and [`SighashCache::p2wsh_signature_hash`].)
pub fn segwit_v0_encode_signing_data_to<W: Write + ?Sized>(
&mut self,
writer: &mut W,
input_index: usize,
script_code: &Script,
value: Amount,
sighash_type: EcdsaSighashType,
) -> Result<(), SigningDataError<transaction::InputsIndexError>> {
let zero_hash = sha256d::Hash::all_zeros();
let (sighash, anyone_can_pay) = sighash_type.split_anyonecanpay_flag();
self.tx.borrow().version.consensus_encode(writer)?;
if !anyone_can_pay {
self.segwit_cache().prevouts.consensus_encode(writer)?;
} else {
zero_hash.consensus_encode(writer)?;
}
if !anyone_can_pay
&& sighash != EcdsaSighashType::Single
&& sighash != EcdsaSighashType::None
{
self.segwit_cache().sequences.consensus_encode(writer)?;
} else {
zero_hash.consensus_encode(writer)?;
}
{
let txin = &self.tx.borrow().tx_in(input_index).map_err(SigningDataError::sighash)?;
txin.previous_output.consensus_encode(writer)?;
script_code.consensus_encode(writer)?;
value.consensus_encode(writer)?;
txin.sequence.consensus_encode(writer)?;
}
if sighash != EcdsaSighashType::Single && sighash != EcdsaSighashType::None {
self.segwit_cache().outputs.consensus_encode(writer)?;
} else if sighash == EcdsaSighashType::Single && input_index < self.tx.borrow().output.len()
{
let mut single_enc = LegacySighash::engine();
self.tx.borrow().output[input_index].consensus_encode(&mut single_enc)?;
let hash = LegacySighash::from_engine(single_enc);
writer.write_all(&hash[..])?;
} else {
writer.write_all(&zero_hash[..])?;
}
self.tx.borrow().lock_time.consensus_encode(writer)?;
sighash_type.to_u32().consensus_encode(writer)?;
Ok(())
}
/// Computes the BIP143 sighash to spend a p2wpkh transaction for any flag type.
///
/// `script_pubkey` is the `scriptPubkey` (native segwit) of the spend transaction
/// ([`TxOut::script_pubkey`]) or the `redeemScript` (wrapped segwit).
pub fn p2wpkh_signature_hash(
&mut self,
input_index: usize,
script_pubkey: &Script,
value: Amount,
sighash_type: EcdsaSighashType,
) -> Result<SegwitV0Sighash, P2wpkhError> {
let script_code = script_pubkey.p2wpkh_script_code().ok_or(P2wpkhError::NotP2wpkhScript)?;
let mut enc = SegwitV0Sighash::engine();
self.segwit_v0_encode_signing_data_to(
&mut enc,
input_index,
&script_code,
value,
sighash_type,
).map_err(SigningDataError::unwrap_sighash)?;
Ok(SegwitV0Sighash::from_engine(enc))
}
/// Computes the BIP143 sighash to spend a p2wsh transaction for any flag type.
pub fn p2wsh_signature_hash(
&mut self,
input_index: usize,
witness_script: &Script,
value: Amount,
sighash_type: EcdsaSighashType,
) -> Result<SegwitV0Sighash, transaction::InputsIndexError> {
let mut enc = SegwitV0Sighash::engine();
self.segwit_v0_encode_signing_data_to(
&mut enc,
input_index,
witness_script,
value,
sighash_type,
).map_err(SigningDataError::unwrap_sighash)?;
Ok(SegwitV0Sighash::from_engine(enc))
}
/// Encodes the legacy signing data from which a signature hash for a given input index with a
/// given sighash flag can be computed.
///
/// To actually produce a scriptSig, this hash needs to be run through an ECDSA signer, the
/// [`EcdsaSighashType`] appended to the resulting sig, and a script written around this, but
/// this is the general (and hard) part.
///
/// The `sighash_type` supports an arbitrary `u32` value, instead of just [`EcdsaSighashType`],
/// because internally 4 bytes are being hashed, even though only the lowest byte is appended to
/// signature in a transaction.
///
/// # Warning
///
/// - Does NOT attempt to support OP_CODESEPARATOR. In general this would require evaluating
/// `script_pubkey` to determine which separators get evaluated and which don't, which we don't
/// have the information to determine.
/// - Does NOT handle the sighash single bug (see "Return type" section)
///
/// # Returns
///
/// This function can't handle the SIGHASH_SINGLE bug internally, so it returns [`EncodeSigningDataResult`]
/// that must be handled by the caller (see [`EncodeSigningDataResult::is_sighash_single_bug`]).
pub fn legacy_encode_signing_data_to<W: Write + ?Sized, U: Into<u32>>(
&self,
writer: &mut W,
input_index: usize,
script_pubkey: &Script,
sighash_type: U,
) -> EncodeSigningDataResult<SigningDataError<transaction::InputsIndexError>> {
// Validate input_index.
if let Err(e) = self.tx.borrow().tx_in(input_index) {
return EncodeSigningDataResult::WriteResult(Err(SigningDataError::Sighash(e)));
}
let sighash_type: u32 = sighash_type.into();
if is_invalid_use_of_sighash_single(
sighash_type,
input_index,
self.tx.borrow().output.len(),
) {
// We cannot correctly handle the SIGHASH_SINGLE bug here because usage of this function
// will result in the data written to the writer being hashed, however the correct
// handling of the SIGHASH_SINGLE bug is to return the 'one array' - either implement
// this behaviour manually or use `signature_hash()`.
return EncodeSigningDataResult::SighashSingleBug;
}
fn encode_signing_data_to_inner<W: Write + ?Sized>(
self_: &Transaction,
writer: &mut W,
input_index: usize,
script_pubkey: &Script,
sighash_type: u32,
) -> Result<(), io::Error> {
let (sighash, anyone_can_pay) =
EcdsaSighashType::from_consensus(sighash_type).split_anyonecanpay_flag();
// Build tx to sign
let mut tx = Transaction {
version: self_.version,
lock_time: self_.lock_time,
input: vec![],
output: vec![],
};
// Add all inputs necessary..
if anyone_can_pay {
tx.input = vec![TxIn {
previous_output: self_.input[input_index].previous_output,
script_sig: script_pubkey.to_owned(),
sequence: self_.input[input_index].sequence,
witness: Witness::default(),
}];
} else {
tx.input = Vec::with_capacity(self_.input.len());
for (n, input) in self_.input.iter().enumerate() {
tx.input.push(TxIn {
previous_output: input.previous_output,
script_sig: if n == input_index {
script_pubkey.to_owned()
} else {
ScriptBuf::new()
},
sequence: if n != input_index
&& (sighash == EcdsaSighashType::Single
|| sighash == EcdsaSighashType::None)
{
Sequence::ZERO
} else {
input.sequence
},
witness: Witness::default(),
});
}
}
// ..then all outputs
tx.output = match sighash {
EcdsaSighashType::All => self_.output.clone(),
EcdsaSighashType::Single => {
let output_iter = self_
.output
.iter()
.take(input_index + 1) // sign all outputs up to and including this one, but erase
.enumerate() // all of them except for this one
.map(|(n, out)| if n == input_index { out.clone() } else { TxOut::NULL });
output_iter.collect()
}
EcdsaSighashType::None => vec![],
_ => unreachable!(),
};
// hash the result
tx.consensus_encode(writer)?;
sighash_type.to_le_bytes().consensus_encode(writer)?;
Ok(())
}
EncodeSigningDataResult::WriteResult(
encode_signing_data_to_inner(
self.tx.borrow(),
writer,
input_index,
script_pubkey,
sighash_type,
)
.map_err(Into::into),
)
}
/// Computes a legacy signature hash for a given input index with a given sighash flag.
///
/// To actually produce a scriptSig, this hash needs to be run through an ECDSA signer, the
/// [`EcdsaSighashType`] appended to the resulting sig, and a script written around this, but
/// this is the general (and hard) part.
///
/// The `sighash_type` supports an arbitrary `u32` value, instead of just [`EcdsaSighashType`],
/// because internally 4 bytes are being hashed, even though only the lowest byte is appended to
/// signature in a transaction.
///
/// This function correctly handles the sighash single bug by returning the 'one array'. The
/// sighash single bug becomes exploitable when one tries to sign a transaction with
/// `SIGHASH_SINGLE` and there is not a corresponding output with the same index as the input.
///
/// # Warning
///
/// Does NOT attempt to support OP_CODESEPARATOR. In general this would require evaluating
/// `script_pubkey` to determine which separators get evaluated and which don't, which we don't
/// have the information to determine.
pub fn legacy_signature_hash(
&self,
input_index: usize,
script_pubkey: &Script,
sighash_type: u32,
) -> Result<LegacySighash, transaction::InputsIndexError> {
let mut engine = LegacySighash::engine();
match self
.legacy_encode_signing_data_to(&mut engine, input_index, script_pubkey, sighash_type)
.is_sighash_single_bug()
{
Ok(true) => Ok(LegacySighash::from_byte_array(UINT256_ONE)),
Ok(false) => Ok(LegacySighash::from_engine(engine)),
Err(e) => Err(e.unwrap_sighash()),
}
}
#[inline]
fn common_cache(&mut self) -> &CommonCache {
Self::common_cache_minimal_borrow(&mut self.common_cache, self.tx.borrow())
}
fn common_cache_minimal_borrow<'a>(
common_cache: &'a mut Option<CommonCache>,
tx: &Transaction,
) -> &'a CommonCache {
common_cache.get_or_insert_with(|| {
let mut enc_prevouts = sha256::Hash::engine();
let mut enc_sequences = sha256::Hash::engine();
for txin in tx.input.iter() {
txin.previous_output.consensus_encode(&mut enc_prevouts).unwrap();
txin.sequence.consensus_encode(&mut enc_sequences).unwrap();
}
CommonCache {
prevouts: sha256::Hash::from_engine(enc_prevouts),
sequences: sha256::Hash::from_engine(enc_sequences),
outputs: {
let mut enc = sha256::Hash::engine();
for txout in tx.output.iter() {
txout.consensus_encode(&mut enc).unwrap();
}
sha256::Hash::from_engine(enc)
},
}
})
}
fn segwit_cache(&mut self) -> &SegwitCache {
let common_cache = &mut self.common_cache;
let tx = self.tx.borrow();
self.segwit_cache.get_or_insert_with(|| {
let common_cache = Self::common_cache_minimal_borrow(common_cache, tx);
SegwitCache {
prevouts: common_cache.prevouts.hash_again(),
sequences: common_cache.sequences.hash_again(),
outputs: common_cache.outputs.hash_again(),
}
})
}
fn taproot_cache<T: Borrow<TxOut>>(&mut self, prevouts: &[T]) -> &TaprootCache {
self.taproot_cache.get_or_insert_with(|| {
let mut enc_amounts = sha256::Hash::engine();
let mut enc_script_pubkeys = sha256::Hash::engine();
for prevout in prevouts {
prevout.borrow().value.consensus_encode(&mut enc_amounts).unwrap();
prevout.borrow().script_pubkey.consensus_encode(&mut enc_script_pubkeys).unwrap();
}
TaprootCache {
amounts: sha256::Hash::from_engine(enc_amounts),
script_pubkeys: sha256::Hash::from_engine(enc_script_pubkeys),
}
})
}
}
impl<R: BorrowMut<Transaction>> SighashCache<R> {
/// Allows modification of witnesses.
///
/// As a lint against accidental changes to the transaction that would invalidate the cache and
/// signatures, `SighashCache` borrows the Transaction so that modifying it is not possible
/// without hacks with `UnsafeCell` (which is hopefully a strong indication that something is
/// wrong). However modifying witnesses never invalidates the cache and is actually useful - one
/// usually wants to put the signature generated for an input into the witness of that input.
///
/// This method allows doing exactly that if the transaction is owned by the `SighashCache` or
/// borrowed mutably.
///
/// # Examples
///
/// ```compile_fail
/// let mut sighasher = SighashCache::new(&mut tx_to_sign);
/// let sighash = sighasher.p2wpkh_signature_hash(input_index, &utxo.script_pubkey, amount, sighash_type)?;
///
/// let signature = {
/// // Sign the sighash using secp256k1
/// };
///
/// *sighasher.witness_mut(input_index).unwrap() = Witness::p2wpkh(&signature, &pk);
/// ```
///
/// For full signing code see the [`segwit v0`] and [`taproot`] signing examples.
///
/// [`segwit v0`]: <https://github.com/rust-bitcoin/rust-bitcoin/blob/master/bitcoin/examples/sign-tx-segwit-v0.rs>
/// [`taproot`]: <https://github.com/rust-bitcoin/rust-bitcoin/blob/master/bitcoin/examples/sign-tx-taproot.rs>
pub fn witness_mut(&mut self, input_index: usize) -> Option<&mut Witness> {
self.tx.borrow_mut().input.get_mut(input_index).map(|i| &mut i.witness)
}
}
/// The `Annex` struct is a slice wrapper enforcing first byte is `0x50`.
#[derive(Clone, PartialEq, Eq, Hash, Debug)]
pub struct Annex<'a>(&'a [u8]);
impl<'a> Annex<'a> {
/// Creates a new `Annex` struct checking the first byte is `0x50`.
pub fn new(annex_bytes: &'a [u8]) -> Result<Self, AnnexError> {
use AnnexError::*;
match annex_bytes.first() {
Some(&TAPROOT_ANNEX_PREFIX) => Ok(Annex(annex_bytes)),
Some(other) => Err(IncorrectPrefix(*other)),
None => Err(Empty),
}
}
/// Returns the Annex bytes data (including first byte `0x50`).
pub fn as_bytes(&self) -> &[u8] { self.0 }
}
impl<'a> Encodable for Annex<'a> {
fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
encode::consensus_encode_with_size(self.0, w)
}
}
/// Error computing a taproot sighash.
#[derive(Debug, Clone, PartialEq, Eq)]
#[non_exhaustive]
pub enum TaprootError {
/// Index out of bounds when accessing transaction input vector.
InputsIndex(transaction::InputsIndexError),
/// Using `SIGHASH_SINGLE` requires an output at the same index is the input.
SingleMissingOutput(SingleMissingOutputError),
/// Prevouts size error.
PrevoutsSize(PrevoutsSizeError),
/// Prevouts index error.
PrevoutsIndex(PrevoutsIndexError),
/// Prevouts kind error.
PrevoutsKind(PrevoutsKindError),
/// Invalid Sighash type.
InvalidSighashType(u32),
}
internals::impl_from_infallible!(TaprootError);
impl fmt::Display for TaprootError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
use TaprootError::*;
match *self {
InputsIndex(ref e) => write_err!(f, "inputs index"; e),
SingleMissingOutput(ref e) => write_err!(f, "sighash single"; e),
PrevoutsSize(ref e) => write_err!(f, "prevouts size"; e),
PrevoutsIndex(ref e) => write_err!(f, "prevouts index"; e),
PrevoutsKind(ref e) => write_err!(f, "prevouts kind"; e),
InvalidSighashType(hash_ty) => write!(f, "invalid taproot sighash type : {} ", hash_ty),
}
}
}
#[cfg(feature = "std")]
impl std::error::Error for TaprootError {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
use TaprootError::*;
match *self {
InputsIndex(ref e) => Some(e),
SingleMissingOutput(ref e) => Some(e),
PrevoutsSize(ref e) => Some(e),
PrevoutsIndex(ref e) => Some(e),
PrevoutsKind(ref e) => Some(e),
InvalidSighashType(_) => None,
}
}
}
impl From<transaction::InputsIndexError> for TaprootError {
fn from(e: transaction::InputsIndexError) -> Self { Self::InputsIndex(e) }
}
impl From<PrevoutsSizeError> for TaprootError {
fn from(e: PrevoutsSizeError) -> Self { Self::PrevoutsSize(e) }
}
impl From<PrevoutsKindError> for TaprootError {
fn from(e: PrevoutsKindError) -> Self { Self::PrevoutsKind(e) }
}
impl From<PrevoutsIndexError> for TaprootError {
fn from(e: PrevoutsIndexError) -> Self { Self::PrevoutsIndex(e) }
}
/// Error computing a P2WPKH sighash.
#[derive(Debug, Clone, PartialEq, Eq)]
#[non_exhaustive]
pub enum P2wpkhError {
/// Error computing the sighash.
Sighash(transaction::InputsIndexError),
/// Script is not a witness program for a p2wpkh output.
NotP2wpkhScript,
}
internals::impl_from_infallible!(P2wpkhError);
impl From<transaction::InputsIndexError> for P2wpkhError {
fn from(value: transaction::InputsIndexError) -> Self {
P2wpkhError::Sighash(value)
}
}
impl fmt::Display for P2wpkhError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
use P2wpkhError::*;
match *self {
Sighash(ref e) => write_err!(f, "error encoding segwit v0 signing data"; e),
NotP2wpkhScript => write!(f, "script is not a script pubkey for a p2wpkh output"),
}
}
}
#[cfg(feature = "std")]
impl std::error::Error for P2wpkhError {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
use P2wpkhError::*;
match *self {
Sighash(ref e) => Some(e),
NotP2wpkhScript => None,
}
}
}
/// Using `SIGHASH_SINGLE` requires an output at the same index as the input.
#[derive(Debug, Clone, PartialEq, Eq)]
#[non_exhaustive]
pub struct SingleMissingOutputError {
/// Input index.
pub input_index: usize,
/// Length of the output vector.
pub outputs_length: usize,
}
impl fmt::Display for SingleMissingOutputError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(
f,
"sighash single requires an output at the same index as the input \
(input index: {}, outputs length: {})",
self.input_index, self.outputs_length
)
}
}
#[cfg(feature = "std")]
impl std::error::Error for SingleMissingOutputError {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> { None }
}
/// Annex must be at least one byte long and the first bytes must be `0x50`.
#[derive(Debug, Clone, PartialEq, Eq)]
#[non_exhaustive]
pub enum AnnexError {
/// The annex is empty.
Empty,
/// Incorrect prefix byte in the annex.
IncorrectPrefix(u8),
}
internals::impl_from_infallible!(AnnexError);
impl fmt::Display for AnnexError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
use AnnexError::*;
match *self {
Empty => write!(f, "the annex is empty"),
IncorrectPrefix(byte) =>
write!(f, "incorrect prefix byte in the annex {:02x}, expecting 0x50", byte),
}
}
}
#[cfg(feature = "std")]
impl std::error::Error for AnnexError {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
use AnnexError::*;
match *self {
Empty | IncorrectPrefix(_) => None,
}
}
}
fn is_invalid_use_of_sighash_single(sighash: u32, input_index: usize, outputs_len: usize) -> bool {
let ty = EcdsaSighashType::from_consensus(sighash);
ty == EcdsaSighashType::Single && input_index >= outputs_len
}
/// Result of [`SighashCache::legacy_encode_signing_data_to`].
///
/// This type forces the caller to handle SIGHASH_SINGLE bug case.
///
/// This corner case can't be expressed using standard `Result`,
/// in a way that is both convenient and not-prone to accidental
/// mistakes (like calling `.expect("writer never fails")`).
#[must_use]
pub enum EncodeSigningDataResult<E> {
/// Input data is an instance of `SIGHASH_SINGLE` bug
SighashSingleBug,
/// Operation performed normally.
WriteResult(Result<(), E>),
}
impl<E> EncodeSigningDataResult<E> {
/// Checks for SIGHASH_SINGLE bug returning error if the writer failed.
///
/// This method is provided for easy and correct handling of the result because
/// SIGHASH_SINGLE bug is a special case that must not be ignored nor cause panicking.
/// Since the data is usually written directly into a hasher which never fails,
/// the recommended pattern to handle this is:
///
/// ```rust
/// # use bitcoin::consensus::deserialize;
/// # use bitcoin::hashes::{Hash, hex::FromHex};
/// # use bitcoin::sighash::{LegacySighash, SighashCache};
/// # use bitcoin::Transaction;
/// # let mut writer = LegacySighash::engine();
/// # let input_index = 0;
/// # let script_pubkey = bitcoin::ScriptBuf::new();
/// # let sighash_u32 = 0u32;
/// # const SOME_TX: &'static str = "0100000001a15d57094aa7a21a28cb20b59aab8fc7d1149a3bdbcddba9c622e4f5f6a99ece010000006c493046022100f93bb0e7d8db7bd46e40132d1f8242026e045f03a0efe71bbb8e3f475e970d790221009337cd7f1f929f00cc6ff01f03729b069a7c21b59b1736ddfee5db5946c5da8c0121033b9b137ee87d5a812d6f506efdd37f0affa7ffc310711c06c7f3e097c9447c52ffffffff0100e1f505000000001976a9140389035a9225b3839e2bbf32d826a1e222031fd888ac00000000";
/// # let raw_tx = Vec::from_hex(SOME_TX).unwrap();
/// # let tx: Transaction = deserialize(&raw_tx).unwrap();
/// let cache = SighashCache::new(&tx);
/// if cache.legacy_encode_signing_data_to(&mut writer, input_index, &script_pubkey, sighash_u32)
/// .is_sighash_single_bug()
/// .expect("writer can't fail") {
/// // use a hash value of "1", instead of computing the actual hash due to SIGHASH_SINGLE bug
/// }
/// ```
pub fn is_sighash_single_bug(self) -> Result<bool, E> {
match self {
EncodeSigningDataResult::SighashSingleBug => Ok(true),
EncodeSigningDataResult::WriteResult(Ok(())) => Ok(false),
EncodeSigningDataResult::WriteResult(Err(e)) => Err(e),
}
}
/// Maps a `Result<T, E>` to `Result<T, F>` by applying a function to a
/// contained [`Err`] value, leaving an [`Ok`] value untouched.
///
/// Like [`Result::map_err`].
pub fn map_err<E2, F>(self, f: F) -> EncodeSigningDataResult<E2>
where
F: FnOnce(E) -> E2,
{
match self {
EncodeSigningDataResult::SighashSingleBug => EncodeSigningDataResult::SighashSingleBug,
EncodeSigningDataResult::WriteResult(Err(e)) =>
EncodeSigningDataResult::WriteResult(Err(f(e))),
EncodeSigningDataResult::WriteResult(Ok(o)) =>
EncodeSigningDataResult::WriteResult(Ok(o)),
}
}
}
/// Error returned when writing signing data fails.
#[derive(Debug)]
pub enum SigningDataError<E> {
/// Can happen only when using `*_encode_signing_*` methods with custom writers, engines
/// like those used in `*_signature_hash` methods do not error.
Io(io::Error),
/// An argument to the called sighash function was invalid.
Sighash(E),
}
internals::impl_from_infallible!(SigningDataError<E>);
impl<E> SigningDataError<E> {
/// Returns the sighash variant, panicking if it's IO.
///
/// This is used when encoding to hash engine when we know that IO doesn't fail.
fn unwrap_sighash(self) -> E {
match self {
Self::Sighash(error) => error,
Self::Io(error) => panic!("hash engine error {}", error),
}
}
fn sighash<E2: Into<E>>(error: E2) -> Self {
Self::Sighash(error.into())
}
}
// We cannot simultaneously impl `From<E>`. it was determined that this alternative requires less
// manual `map_err` calls.
impl<E> From<io::Error> for SigningDataError<E> {
fn from(value: io::Error) -> Self {
Self::Io(value)
}
}
impl<E: fmt::Display> fmt::Display for SigningDataError<E> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
Self::Io(error) => write_err!(f, "failed to write sighash data"; error),
Self::Sighash(error) => write_err!(f, "failed to compute sighash data"; error),
}
}
}
#[cfg(feature = "std")]
impl<E: std::error::Error + 'static> std::error::Error for SigningDataError<E> {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
match self {
SigningDataError::Io(error) => Some(error),
SigningDataError::Sighash(error) => Some(error),
}
}
}
#[cfg(test)]
mod tests {
use std::str::FromStr;
use hashes::HashEngine;
use hex::{test_hex_unwrap as hex, FromHex};
use super::*;
use crate::blockdata::locktime::absolute;
use crate::consensus::deserialize;
extern crate serde_json;
#[test]
fn sighash_single_bug() {
const SIGHASH_SINGLE: u32 = 3;
// We need a tx with more inputs than outputs.
let tx = Transaction {
version: transaction::Version::ONE,
lock_time: absolute::LockTime::ZERO,
input: vec![TxIn::default(), TxIn::default()],
output: vec![TxOut::NULL],
};
let script = ScriptBuf::new();
let cache = SighashCache::new(&tx);
let got = cache.legacy_signature_hash(1, &script, SIGHASH_SINGLE).expect("sighash");
let want = LegacySighash::from_slice(&UINT256_ONE).unwrap();
assert_eq!(got, want)
}
#[test]
#[cfg(feature = "serde")]
fn legacy_sighash() {
use serde_json::Value;
use crate::sighash::SighashCache;
fn run_test_sighash(
tx: &str,
script: &str,
input_index: usize,
hash_type: i64,
expected_result: &str,
) {
let tx: Transaction = deserialize(&Vec::from_hex(tx).unwrap()[..]).unwrap();
let script = ScriptBuf::from(Vec::from_hex(script).unwrap());
let mut raw_expected = Vec::from_hex(expected_result).unwrap();
raw_expected.reverse();
let want = LegacySighash::from_slice(&raw_expected[..]).unwrap();
let cache = SighashCache::new(&tx);
let got = cache.legacy_signature_hash(input_index, &script, hash_type as u32).unwrap();
assert_eq!(got, want);
}
// These test vectors were stolen from libbtc, which is Copyright 2014 Jonas Schnelli MIT
// They were transformed by replacing {...} with run_test_sighash(...), then the ones containing
// OP_CODESEPARATOR in their pubkeys were removed
let data = include_str!("../../tests/data/legacy_sighash.json");
let testdata = serde_json::from_str::<Value>(data).unwrap().as_array().unwrap().clone();
for t in testdata.iter().skip(1) {
let tx = t.get(0).unwrap().as_str().unwrap();
let script = t.get(1).unwrap().as_str().unwrap_or("");
let input_index = t.get(2).unwrap().as_u64().unwrap();
let hash_type = t.get(3).unwrap().as_i64().unwrap();
let expected_sighash = t.get(4).unwrap().as_str().unwrap();
run_test_sighash(tx, script, input_index as usize, hash_type, expected_sighash);
}
}
#[test]
fn test_tap_sighash_hash() {
let bytes = hex!("00011b96877db45ffa23b307e9f0ac87b80ef9a80b4c5f0db3fbe734422453e83cc5576f3d542c5d4898fb2b696c15d43332534a7c1d1255fda38993545882df92c3e353ff6d36fbfadc4d168452afd8467f02fe53d71714fcea5dfe2ea759bd00185c4cb02bc76d42620393ca358a1a713f4997f9fc222911890afb3fe56c6a19b202df7bffdcfad08003821294279043746631b00e2dc5e52a111e213bbfe6ef09a19428d418dab0d50000000000");
let expected = hex!("04e808aad07a40b3767a1442fead79af6ef7e7c9316d82dec409bb31e77699b0");
let mut enc = TapSighash::engine();
enc.input(&bytes);
let hash = TapSighash::from_engine(enc);
assert_eq!(expected, hash.to_byte_array());
}
#[test]
fn test_sighashes_keyspending() {
// following test case has been taken from Bitcoin Core test framework
test_taproot_sighash(
"020000000164eb050a5e3da0c2a65e4786f26d753b7bc69691fabccafb11f7acef36641f1846010000003101b2b404392a22000000000017a9147f2bde86fe78bf68a0544a4f290e12f0b7e0a08c87580200000000000017a91425d11723074ecfb96a0a83c3956bfaf362ae0c908758020000000000001600147e20f938993641de67bb0cdd71682aa34c4d29ad5802000000000000160014c64984dc8761acfa99418bd6bedc79b9287d652d72000000",
"01365724000000000023542156b39dab4f8f3508e0432cfb41fab110170acaa2d4c42539cb90a4dc7c093bc500",
0,
"33ca0ebfb4a945eeee9569fc0f5040221275f88690b7f8592ada88ce3bdf6703",
TapSighashType::Default, None, None, None
);
test_taproot_sighash(
"0200000002fff49be59befe7566050737910f6ccdc5e749c7f8860ddc140386463d88c5ad0f3000000002cf68eb4a3d67f9d4c079249f7e4f27b8854815cb1ed13842d4fbf395f9e217fd605ee24090100000065235d9203f458520000000000160014b6d48333bb13b4c644e57c43a9a26df3a44b785e58020000000000001976a914eea9461a9e1e3f765d3af3e726162e0229fe3eb688ac58020000000000001976a9143a8869c9f2b5ea1d4ff3aeeb6a8fb2fffb1ad5fe88ac0ad7125c",
"02591f220000000000225120f25ad35583ea31998d968871d7de1abd2a52f6fe4178b54ea158274806ff4ece48fb310000000000225120f25ad35583ea31998d968871d7de1abd2a52f6fe4178b54ea158274806ff4ece",
1,
"626ab955d58c9a8a600a0c580549d06dc7da4e802eb2a531f62a588e430967a8",
TapSighashType::All, None, None, None
);
test_taproot_sighash(
"0200000001350005f65aa830ced2079df348e2d8c2bdb4f10e2dde6a161d8a07b40d1ad87dae000000001611d0d603d9dc0e000000000017a914459b6d7d6bbb4d8837b4bf7e9a4556f952da2f5c8758020000000000001976a9141dd70e1299ffc2d5b51f6f87de9dfe9398c33cbb88ac58020000000000001976a9141dd70e1299ffc2d5b51f6f87de9dfe9398c33cbb88aca71c1f4f",
"01c4811000000000002251201bf9297d0a2968ae6693aadd0fa514717afefd218087a239afb7418e2d22e65c",
0,
"dfa9437f9c9a1d1f9af271f79f2f5482f287cdb0d2e03fa92c8a9b216cc6061c",
TapSighashType::AllPlusAnyoneCanPay, None, None, None
);
test_taproot_sighash(
"020000000185bed1a6da2bffbd60ec681a1bfb71c5111d6395b99b3f8b2bf90167111bcb18f5010000007c83ace802ded24a00000000001600142c4698f9f7a773866879755aa78c516fb332af8e5802000000000000160014d38639dfbac4259323b98a472405db0c461b31fa61073747",
"0144c84d0000000000225120e3f2107989c88e67296ab2faca930efa2e3a5bd3ff0904835a11c9e807458621",
0,
"3129de36a5d05fff97ffca31eb75fcccbbbc27b3147a7a36a9e4b45d8b625067",
TapSighashType::None, None, None, None
);
test_taproot_sighash(
"eb93dbb901028c8515589dac980b6e7f8e4088b77ed866ca0d6d210a7218b6fd0f6b22dd6d7300000000eb4740a9047efc0e0000000000160014913da2128d8fcf292b3691db0e187414aa1783825802000000000000160014913da2128d8fcf292b3691db0e187414aa178382580200000000000017a9143dd27f01c6f7ef9bb9159937b17f17065ed01a0c875802000000000000160014d7630e19df70ada9905ede1722b800c0005f246641000000",
"013fed110000000000225120eb536ae8c33580290630fc495046e998086a64f8f33b93b07967d9029b265c55",
0,
"2441e8b0e063a2083ee790f14f2045022f07258ddde5ee01de543c9e789d80ae",
TapSighashType::NonePlusAnyoneCanPay, None, None, None
);
test_taproot_sighash(
"02000000017836b409a5fed32211407e44b971591f2032053f14701fb5b3a30c0ff382f2cc9c0100000061ac55f60288fb5600000000001976a9144ea02f6f182b082fb6ce47e36bbde390b6a41b5088ac58020000000000001976a9144ea02f6f182b082fb6ce47e36bbde390b6a41b5088ace4000000",
"01efa558000000000022512007071ea3dc7e331b0687d0193d1e6d6ed10e645ef36f10ef8831d5e522ac9e80",
0,
"30239345177cadd0e3ea413d49803580abb6cb27971b481b7788a78d35117a88",
TapSighashType::Single, None, None, None
);
test_taproot_sighash(
"0100000001aa6deae89d5e0aaca58714fc76ef6f3c8284224888089232d4e663843ed3ab3eae010000008b6657a60450cb4c0000000000160014a3d42b5413ef0c0701c4702f3cd7d4df222c147058020000000000001976a91430b4ed8723a4ee8992aa2c8814cfe5c3ad0ab9d988ac5802000000000000160014365b1166a6ed0a5e8e9dff17a6d00bbb43454bc758020000000000001976a914bc98c51a84fe7fad5dc380eb8b39586eff47241688ac4f313247",
"0107af4e00000000002251202c36d243dfc06cb56a248e62df27ecba7417307511a81ae61aa41c597a929c69",
0,
"bf9c83f26c6dd16449e4921f813f551c4218e86f2ec906ca8611175b41b566df",
TapSighashType::SinglePlusAnyoneCanPay, None, None, None
);
}
#[test]
fn test_sighashes_with_annex() {
test_taproot_sighash(
"0200000001df8123752e8f37d132c4e9f1ff7e4f9b986ade9211267e9ebd5fd22a5e718dec6d01000000ce4023b903cb7b23000000000017a914a18b36ea7a094db2f4940fc09edf154e86de7bd787580200000000000017a914afd0d512a2c5c2b40e25669e9cc460303c325b8b87580200000000000017a914a18b36ea7a094db2f4940fc09edf154e86de7bd787f6020000",
"01ea49260000000000225120ab5e9800806bf18cb246edcf5fe63441208fe955a4b5a35bbff65f5db622a010",
0,
"3b003000add359a364a156e73e02846782a59d0d95ca8c4638aaad99f2ef915c",
TapSighashType::SinglePlusAnyoneCanPay,
Some("507b979802e62d397acb29f56743a791894b99372872fc5af06a4f6e8d242d0615cda53062bb20e6ec79756fe39183f0c128adfe85559a8fa042b042c018aa8010143799e44f0893c40e1e"),
None,
None,
);
}
#[test]
fn test_sighashes_with_script_path() {
test_taproot_sighash(
"020000000189fc651483f9296b906455dd939813bf086b1bbe7c77635e157c8e14ae29062195010000004445b5c7044561320000000000160014331414dbdada7fb578f700f38fb69995fc9b5ab958020000000000001976a914268db0a8104cc6d8afd91233cc8b3d1ace8ac3ef88ac580200000000000017a914ec00dcb368d6a693e11986d265f659d2f59e8be2875802000000000000160014c715799a49a0bae3956df9c17cb4440a673ac0df6f010000",
"011bec34000000000022512028055142ea437db73382e991861446040b61dd2185c4891d7daf6893d79f7182",
0,
"d66de5274a60400c7b08c86ba6b7f198f40660079edf53aca89d2a9501317f2e",
TapSighashType::All,
None,
Some("20cc4e1107aea1d170c5ff5b6817e1303010049724fb3caa7941792ea9d29b3e2bacab"),
None,
);
}
#[test]
fn test_sighashes_with_script_path_raw_hash() {
test_taproot_sighash(
"020000000189fc651483f9296b906455dd939813bf086b1bbe7c77635e157c8e14ae29062195010000004445b5c7044561320000000000160014331414dbdada7fb578f700f38fb69995fc9b5ab958020000000000001976a914268db0a8104cc6d8afd91233cc8b3d1ace8ac3ef88ac580200000000000017a914ec00dcb368d6a693e11986d265f659d2f59e8be2875802000000000000160014c715799a49a0bae3956df9c17cb4440a673ac0df6f010000",
"011bec34000000000022512028055142ea437db73382e991861446040b61dd2185c4891d7daf6893d79f7182",
0,
"d66de5274a60400c7b08c86ba6b7f198f40660079edf53aca89d2a9501317f2e",
TapSighashType::All,
None,
None,
Some("15a2530514e399f8b5cf0b3d3112cf5b289eaa3e308ba2071b58392fdc6da68a"),
);
}
#[test]
fn test_sighashes_with_annex_and_script() {
test_taproot_sighash(
"020000000132fb72cb8fba496755f027a9743e2d698c831fdb8304e4d1a346ac92cbf51acba50100000026bdc7df044aad34000000000017a9144fa2554ed6174586854fa3bc01de58dcf33567d0875802000000000000160014950367e1e62cdf240b35b883fc2f5e39f0eb9ab95802000000000000160014950367e1e62cdf240b35b883fc2f5e39f0eb9ab958020000000000001600141b31217d48ccc8760dcc0710fade5866d628e733a02d5122",
"011458360000000000225120a7baec3fb9f84614e3899fcc010c638f80f13539344120e1f4d8b68a9a011a13",
0,
"a0042aa434f9a75904b64043f2a283f8b4c143c7f4f7f49a6cbe5b9f745f4c15",
TapSighashType::All,
Some("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"),
Some("7520ab9160dd8299dc1367659be3e8f66781fe440d52940c7f8d314a89b9f2698d406ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6ead6eadac"),
None,
);
}
#[test]
#[rustfmt::skip] // Allow long function call `taproot_signature_hash`.
fn test_sighash_errors() {
use crate::transaction::{IndexOutOfBoundsError, InputsIndexError};
let dumb_tx = Transaction {
version: transaction::Version::TWO,
lock_time: absolute::LockTime::ZERO,
input: vec![TxIn::default()],
output: vec![],
};
let mut c = SighashCache::new(&dumb_tx);
// 1.29 fixes
let empty_vec = vec![];
let empty_prevouts : Prevouts<TxOut> = Prevouts::All(&empty_vec);
assert_eq!(
c.taproot_signature_hash(0, &empty_prevouts, None, None, TapSighashType::All),
Err(TaprootError::PrevoutsSize(PrevoutsSizeError))
);
let two = vec![TxOut::NULL, TxOut::NULL];
let too_many_prevouts = Prevouts::All(&two);
assert_eq!(
c.taproot_signature_hash(0, &too_many_prevouts, None, None, TapSighashType::All),
Err(TaprootError::PrevoutsSize(PrevoutsSizeError))
);
let tx_out = TxOut::NULL;
let prevout = Prevouts::One(1, &tx_out);
assert_eq!(
c.taproot_signature_hash(0, &prevout, None, None, TapSighashType::All),
Err(TaprootError::PrevoutsKind(PrevoutsKindError))
);
assert_eq!(
c.taproot_signature_hash(0, &prevout, None, None, TapSighashType::AllPlusAnyoneCanPay),
Err(TaprootError::PrevoutsIndex(PrevoutsIndexError::InvalidOneIndex))
);
assert_eq!(
c.taproot_signature_hash(10, &prevout, None, None, TapSighashType::AllPlusAnyoneCanPay),
Err(InputsIndexError(IndexOutOfBoundsError {
index: 10,
length: 1
}).into())
);
let prevout = Prevouts::One(0, &tx_out);
assert_eq!(
c.taproot_signature_hash(0, &prevout, None, None, TapSighashType::SinglePlusAnyoneCanPay),
Err(TaprootError::SingleMissingOutput(SingleMissingOutputError {
input_index: 0,
outputs_length: 0
}))
);
assert_eq!(
c.legacy_signature_hash(10, Script::new(), 0u32),
Err(InputsIndexError(IndexOutOfBoundsError {
index: 10,
length: 1
}))
);
}
#[test]
fn test_annex_errors() {
assert_eq!(Annex::new(&[]), Err(AnnexError::Empty));
assert_eq!(Annex::new(&[0x51]), Err(AnnexError::IncorrectPrefix(0x51)));
assert_eq!(Annex::new(&[0x51, 0x50]), Err(AnnexError::IncorrectPrefix(0x51)));
}
#[allow(clippy::too_many_arguments)]
fn test_taproot_sighash(
tx_hex: &str,
prevout_hex: &str,
input_index: usize,
expected_hash: &str,
sighash_type: TapSighashType,
annex_hex: Option<&str>,
script_hex: Option<&str>,
script_leaf_hash: Option<&str>,
) {
let tx_bytes = Vec::from_hex(tx_hex).unwrap();
let tx: Transaction = deserialize(&tx_bytes).unwrap();
let prevout_bytes = Vec::from_hex(prevout_hex).unwrap();
let prevouts: Vec<TxOut> = deserialize(&prevout_bytes).unwrap();
let annex_inner;
let annex = match annex_hex {
Some(annex_hex) => {
annex_inner = Vec::from_hex(annex_hex).unwrap();
Some(Annex::new(&annex_inner).unwrap())
}
None => None,
};
let leaf_hash = match (script_hex, script_leaf_hash) {
(Some(script_hex), _) => {
let script_inner = ScriptBuf::from_hex(script_hex).unwrap();
Some(ScriptPath::with_defaults(&script_inner).leaf_hash())
}
(_, Some(script_leaf_hash)) => Some(script_leaf_hash.parse::<TapLeafHash>().unwrap()),
_ => None,
};
// All our tests use the default `0xFFFFFFFF` codeseparator value
let leaf_hash = leaf_hash.map(|lh| (lh, 0xFFFFFFFF));
let prevouts = if sighash_type.split_anyonecanpay_flag().1 && tx_bytes[0] % 2 == 0 {
// for anyonecanpay the `Prevouts::All` variant is good anyway, but sometimes we want to
// test other codepaths
Prevouts::One(input_index, prevouts[input_index].clone())
} else {
Prevouts::All(&prevouts)
};
let mut sighash_cache = SighashCache::new(&tx);
let hash = sighash_cache
.taproot_signature_hash(input_index, &prevouts, annex, leaf_hash, sighash_type)
.unwrap();
let expected = Vec::from_hex(expected_hash).unwrap();
assert_eq!(expected, hash.to_byte_array());
}
#[cfg(feature = "serde")]
#[test]
fn bip_341_sighash_tests() {
use hex::DisplayHex;
fn sighash_deser_numeric<'de, D>(deserializer: D) -> Result<TapSighashType, D::Error>
where
D: actual_serde::Deserializer<'de>,
{
use actual_serde::de::{Deserialize, Error, Unexpected};
let raw = u8::deserialize(deserializer)?;
TapSighashType::from_consensus_u8(raw).map_err(|_| {
D::Error::invalid_value(
Unexpected::Unsigned(raw.into()),
&"number in range 0-3 or 0x81-0x83",
)
})
}
use secp256k1::{SecretKey, XOnlyPublicKey};
use crate::consensus::serde as con_serde;
use crate::taproot::{TapNodeHash, TapTweakHash};
#[derive(serde::Deserialize)]
#[serde(crate = "actual_serde")]
struct UtxoSpent {
#[serde(rename = "scriptPubKey")]
script_pubkey: ScriptBuf,
#[serde(rename = "amountSats")]
value: Amount,
}
#[derive(serde::Deserialize)]
#[serde(rename_all = "camelCase")]
#[serde(crate = "actual_serde")]
struct KpsGiven {
#[serde(with = "con_serde::With::<con_serde::Hex>")]
raw_unsigned_tx: Transaction,
utxos_spent: Vec<UtxoSpent>,
}
#[derive(serde::Deserialize)]
#[serde(rename_all = "camelCase")]
#[serde(crate = "actual_serde")]
struct KpsIntermediary {
hash_prevouts: sha256::Hash,
hash_outputs: sha256::Hash,
hash_sequences: sha256::Hash,
hash_amounts: sha256::Hash,
hash_script_pubkeys: sha256::Hash,
}
#[derive(serde::Deserialize)]
#[serde(rename_all = "camelCase")]
#[serde(crate = "actual_serde")]
struct KpsInputSpendingGiven {
txin_index: usize,
internal_privkey: SecretKey,
merkle_root: Option<TapNodeHash>,
#[serde(deserialize_with = "sighash_deser_numeric")]
hash_type: TapSighashType,
}
#[derive(serde::Deserialize)]
#[serde(rename_all = "camelCase")]
#[serde(crate = "actual_serde")]
struct KpsInputSpendingIntermediary {
internal_pubkey: XOnlyPublicKey,
tweak: TapTweakHash,
tweaked_privkey: SecretKey,
sig_msg: String,
//precomputed_used: Vec<String>, // unused
sig_hash: TapSighash,
}
#[derive(serde::Deserialize)]
#[serde(rename_all = "camelCase")]
#[serde(crate = "actual_serde")]
struct KpsInputSpendingExpected {
witness: Vec<String>,
}
#[derive(serde::Deserialize)]
#[serde(rename_all = "camelCase")]
#[serde(crate = "actual_serde")]
struct KpsInputSpending {
given: KpsInputSpendingGiven,
intermediary: KpsInputSpendingIntermediary,
expected: KpsInputSpendingExpected,
// auxiliary: KpsAuxiliary, //unused
}
#[derive(serde::Deserialize)]
#[serde(rename_all = "camelCase")]
#[serde(crate = "actual_serde")]
struct KeyPathSpending {
given: KpsGiven,
intermediary: KpsIntermediary,
input_spending: Vec<KpsInputSpending>,
}
#[derive(serde::Deserialize)]
#[serde(rename_all = "camelCase")]
#[serde(crate = "actual_serde")]
struct TestData {
version: u64,
key_path_spending: Vec<KeyPathSpending>,
//script_pubkey: Vec<ScriptPubKey>, // unused
}
let json_str = include_str!("../../tests/data/bip341_tests.json");
let mut data =
serde_json::from_str::<TestData>(json_str).expect("JSON was not well-formatted");
assert_eq!(data.version, 1u64);
let secp = &secp256k1::Secp256k1::new();
let key_path = data.key_path_spending.remove(0);
let raw_unsigned_tx = key_path.given.raw_unsigned_tx;
let utxos = key_path
.given
.utxos_spent
.into_iter()
.map(|txo| TxOut { value: txo.value, script_pubkey: txo.script_pubkey })
.collect::<Vec<_>>();
// Test intermediary
let mut cache = SighashCache::new(&raw_unsigned_tx);
let expected = key_path.intermediary;
// Compute all caches
assert_eq!(expected.hash_amounts, cache.taproot_cache(&utxos).amounts);
assert_eq!(expected.hash_outputs, cache.common_cache().outputs);
assert_eq!(expected.hash_prevouts, cache.common_cache().prevouts);
assert_eq!(expected.hash_script_pubkeys, cache.taproot_cache(&utxos).script_pubkeys);
assert_eq!(expected.hash_sequences, cache.common_cache().sequences);
for mut inp in key_path.input_spending {
let tx_ind = inp.given.txin_index;
let internal_priv_key = inp.given.internal_privkey;
let merkle_root = inp.given.merkle_root;
let hash_ty = inp.given.hash_type;
let expected = inp.intermediary;
let sig_str = inp.expected.witness.remove(0);
let (expected_key_spend_sig, expected_hash_ty) = if sig_str.len() == 128 {
(
secp256k1::schnorr::Signature::from_str(&sig_str).unwrap(),
TapSighashType::Default,
)
} else {
let hash_ty = u8::from_str_radix(&sig_str[128..130], 16).unwrap();
let hash_ty = TapSighashType::from_consensus_u8(hash_ty).unwrap();
(secp256k1::schnorr::Signature::from_str(&sig_str[..128]).unwrap(), hash_ty)
};
// tests
let keypair = secp256k1::Keypair::from_secret_key(secp, &internal_priv_key);
let (internal_key, _parity) = XOnlyPublicKey::from_keypair(&keypair);
let tweak = TapTweakHash::from_key_and_tweak(internal_key, merkle_root);
let tweaked_keypair = keypair.add_xonly_tweak(secp, &tweak.to_scalar()).unwrap();
let mut sig_msg = Vec::new();
cache
.taproot_encode_signing_data_to(
&mut sig_msg,
tx_ind,
&Prevouts::All(&utxos),
None,
None,
hash_ty,
)
.unwrap();
let sighash = cache
.taproot_signature_hash(tx_ind, &Prevouts::All(&utxos), None, None, hash_ty)
.unwrap();
let msg = secp256k1::Message::from_digest(sighash.to_byte_array());
let key_spend_sig = secp.sign_schnorr_with_aux_rand(&msg, &tweaked_keypair, &[0u8; 32]);
assert_eq!(expected.internal_pubkey, internal_key);
assert_eq!(expected.tweak, tweak);
assert_eq!(expected.sig_msg, sig_msg.to_lower_hex_string());
assert_eq!(expected.sig_hash, sighash);
assert_eq!(expected_hash_ty, hash_ty);
assert_eq!(expected_key_spend_sig, key_spend_sig);
let tweaked_priv_key = SecretKey::from_keypair(&tweaked_keypair);
assert_eq!(expected.tweaked_privkey, tweaked_priv_key);
}
}
#[test]
fn sighashtype_fromstr_display() {
let sighashtypes = vec![
("SIGHASH_DEFAULT", TapSighashType::Default),
("SIGHASH_ALL", TapSighashType::All),
("SIGHASH_NONE", TapSighashType::None),
("SIGHASH_SINGLE", TapSighashType::Single),
("SIGHASH_ALL|SIGHASH_ANYONECANPAY", TapSighashType::AllPlusAnyoneCanPay),
("SIGHASH_NONE|SIGHASH_ANYONECANPAY", TapSighashType::NonePlusAnyoneCanPay),
("SIGHASH_SINGLE|SIGHASH_ANYONECANPAY", TapSighashType::SinglePlusAnyoneCanPay),
];
for (s, sht) in sighashtypes {
assert_eq!(sht.to_string(), s);
assert_eq!(TapSighashType::from_str(s).unwrap(), sht);
}
let sht_mistakes = vec![
"SIGHASH_ALL | SIGHASH_ANYONECANPAY",
"SIGHASH_NONE |SIGHASH_ANYONECANPAY",
"SIGHASH_SINGLE| SIGHASH_ANYONECANPAY",
"SIGHASH_ALL SIGHASH_ANYONECANPAY",
"SIGHASH_NONE |",
"SIGHASH_SIGNLE",
"DEFAULT",
"ALL",
"sighash_none",
"Sighash_none",
"SigHash_None",
"SigHash_NONE",
];
for s in sht_mistakes {
assert_eq!(
TapSighashType::from_str(s).unwrap_err().to_string(),
format!("unrecognized SIGHASH string '{}'", s)
);
}
}
#[test]
fn bip143_p2wpkh() {
let tx = deserialize::<Transaction>(
&hex!(
"0100000002fff7f7881a8099afa6940d42d1e7f6362bec38171ea3edf433541db4e4ad969f000000\
0000eeffffffef51e1b804cc89d182d279655c3aa89e815b1b309fe287d9b2b55d57b90ec68a01000000\
00ffffffff02202cb206000000001976a9148280b37df378db99f66f85c95a783a76ac7a6d5988ac9093\
510d000000001976a9143bde42dbee7e4dbe6a21b2d50ce2f0167faa815988ac11000000"
),
).unwrap();
let spk = ScriptBuf::from_hex("00141d0f172a0ecb48aee1be1f2687d2963ae33f71a1").unwrap();
let value = Amount::from_sat(600_000_000);
let mut cache = SighashCache::new(&tx);
assert_eq!(
cache.p2wpkh_signature_hash(1, &spk, value, EcdsaSighashType::All).unwrap(),
"c37af31116d1b27caf68aae9e3ac82f1477929014d5b917657d0eb49478cb670"
.parse::<SegwitV0Sighash>()
.unwrap(),
);
let cache = cache.segwit_cache();
// Parse hex into Vec because BIP143 test vector displays forwards but our sha256d::Hash displays backwards.
assert_eq!(
cache.prevouts.as_byte_array(),
&Vec::from_hex("96b827c8483d4e9b96712b6713a7b68d6e8003a781feba36c31143470b4efd37")
.unwrap()[..],
);
assert_eq!(
cache.sequences.as_byte_array(),
&Vec::from_hex("52b0a642eea2fb7ae638c36f6252b6750293dbe574a806984b8e4d8548339a3b")
.unwrap()[..],
);
assert_eq!(
cache.outputs.as_byte_array(),
&Vec::from_hex("863ef3e1a92afbfdb97f31ad0fc7683ee943e9abcf2501590ff8f6551f47e5e5")
.unwrap()[..],
);
}
#[test]
fn bip143_p2wpkh_nested_in_p2sh() {
let tx = deserialize::<Transaction>(
&hex!(
"0100000001db6b1b20aa0fd7b23880be2ecbd4a98130974cf4748fb66092ac4d3ceb1a5477010000\
0000feffffff02b8b4eb0b000000001976a914a457b684d7f0d539a46a45bbc043f35b59d0d96388ac00\
08af2f000000001976a914fd270b1ee6abcaea97fea7ad0402e8bd8ad6d77c88ac92040000"
),
).unwrap();
let redeem_script =
ScriptBuf::from_hex("001479091972186c449eb1ded22b78e40d009bdf0089").unwrap();
let value = Amount::from_sat(1_000_000_000);
let mut cache = SighashCache::new(&tx);
assert_eq!(
cache.p2wpkh_signature_hash(0, &redeem_script, value, EcdsaSighashType::All).unwrap(),
"64f3b0f4dd2bb3aa1ce8566d220cc74dda9df97d8490cc81d89d735c92e59fb6"
.parse::<SegwitV0Sighash>()
.unwrap(),
);
let cache = cache.segwit_cache();
// Parse hex into Vec because BIP143 test vector displays forwards but our sha256d::Hash displays backwards.
assert_eq!(
cache.prevouts.as_byte_array(),
&Vec::from_hex("b0287b4a252ac05af83d2dcef00ba313af78a3e9c329afa216eb3aa2a7b4613a")
.unwrap()[..],
);
assert_eq!(
cache.sequences.as_byte_array(),
&Vec::from_hex("18606b350cd8bf565266bc352f0caddcf01e8fa789dd8a15386327cf8cabe198")
.unwrap()[..],
);
assert_eq!(
cache.outputs.as_byte_array(),
&Vec::from_hex("de984f44532e2173ca0d64314fcefe6d30da6f8cf27bafa706da61df8a226c83")
.unwrap()[..],
);
}
// Note, if you are looking at the test vectors in BIP-143 and wondering why there is a `cf`
// prepended to all the script_code hex it is the length byte, it gets added when we consensus
// encode a script.
fn bip143_p2wsh_nested_in_p2sh_data() -> (Transaction, ScriptBuf, Amount) {
let tx = deserialize::<Transaction>(&hex!(
"010000000136641869ca081e70f394c6948e8af409e18b619df2ed74aa106c1ca29787b96e0100000000\
ffffffff0200e9a435000000001976a914389ffce9cd9ae88dcc0631e88a821ffdbe9bfe2688acc0832f\
05000000001976a9147480a33f950689af511e6e84c138dbbd3c3ee41588ac00000000"
))
.unwrap();
let witness_script = ScriptBuf::from_hex(
"56210307b8ae49ac90a048e9b53357a2354b3334e9c8bee813ecb98e99a7e07e8c3ba32103b28f0c28\
bfab54554ae8c658ac5c3e0ce6e79ad336331f78c428dd43eea8449b21034b8113d703413d57761b8b\
9781957b8c0ac1dfe69f492580ca4195f50376ba4a21033400f6afecb833092a9a21cfdf1ed1376e58\
c5d1f47de74683123987e967a8f42103a6d48b1131e94ba04d9737d61acdaa1322008af9602b3b1486\
2c07a1789aac162102d8b661b0b3302ee2f162b09e07a55ad5dfbe673a9f01d9f0c19617681024306b\
56ae",
)
.unwrap();
let value = Amount::from_sat(987_654_321);
(tx, witness_script, value)
}
#[test]
fn bip143_p2wsh_nested_in_p2sh_sighash_type_all() {
let (tx, witness_script, value) = bip143_p2wsh_nested_in_p2sh_data();
let mut cache = SighashCache::new(&tx);
assert_eq!(
cache.p2wsh_signature_hash(0, &witness_script, value, EcdsaSighashType::All).unwrap(),
"185c0be5263dce5b4bb50a047973c1b6272bfbd0103a89444597dc40b248ee7c"
.parse::<SegwitV0Sighash>()
.unwrap(),
);
// We only test the cache intermediate values for `EcdsaSighashType::All` because they are
// not the same as the BIP test vectors for all the rest of the sighash types. These fields
// are private so it does not effect sighash cache usage, we do test against the produced
// sighash for all sighash types.
let cache = cache.segwit_cache();
// Parse hex into Vec because BIP143 test vector displays forwards but our sha256d::Hash displays backwards.
assert_eq!(
cache.prevouts.as_byte_array(),
&Vec::from_hex("74afdc312af5183c4198a40ca3c1a275b485496dd3929bca388c4b5e31f7aaa0")
.unwrap()[..],
);
assert_eq!(
cache.sequences.as_byte_array(),
&Vec::from_hex("3bb13029ce7b1f559ef5e747fcac439f1455a2ec7c5f09b72290795e70665044")
.unwrap()[..],
);
assert_eq!(
cache.outputs.as_byte_array(),
&Vec::from_hex("bc4d309071414bed932f98832b27b4d76dad7e6c1346f487a8fdbb8eb90307cc")
.unwrap()[..],
);
}
macro_rules! check_bip143_p2wsh_nested_in_p2sh {
($($test_name:ident, $sighash_type:ident, $sighash:literal);* $(;)?) => {
$(
#[test]
fn $test_name() {
use EcdsaSighashType::*;
let (tx, witness_script, value) = bip143_p2wsh_nested_in_p2sh_data();
let mut cache = SighashCache::new(&tx);
assert_eq!(
cache
.p2wsh_signature_hash(0, &witness_script, value, $sighash_type)
.unwrap(),
$sighash
.parse::<SegwitV0Sighash>()
.unwrap(),
);
}
)*
}
}
check_bip143_p2wsh_nested_in_p2sh! {
// EcdsaSighashType::All tested above.
bip143_p2wsh_nested_in_p2sh_sighash_none, None, "e9733bc60ea13c95c6527066bb975a2ff29a925e80aa14c213f686cbae5d2f36";
bip143_p2wsh_nested_in_p2sh_sighash_single, Single, "1e1f1c303dc025bd664acb72e583e933fae4cff9148bf78c157d1e8f78530aea";
bip143_p2wsh_nested_in_p2sh_sighash_all_plus_anyonecanpay, AllPlusAnyoneCanPay, "2a67f03e63a6a422125878b40b82da593be8d4efaafe88ee528af6e5a9955c6e";
bip143_p2wsh_nested_in_p2sh_sighash_none_plus_anyonecanpay, NonePlusAnyoneCanPay, "781ba15f3779d5542ce8ecb5c18716733a5ee42a6f51488ec96154934e2c890a";
bip143_p2wsh_nested_in_p2sh_sighash_single_plus_anyonecanpay, SinglePlusAnyoneCanPay, "511e8e52ed574121fc1b654970395502128263f62662e076dc6baf05c2e6a99b";
}
}
Reference in New Issue View Git Blame Copy Permalink