transaction:: Return custom error from verify function

There is not need to return the general `script::Error` from the
transaction verify functions. We can better describe the error path by
returning a custom error.
This commit is contained in:
Tobin C. Harding 2023-06-23 15:13:52 +10:00
parent ca2512f471
commit ca38dbd16d
No known key found for this signature in database
GPG Key ID: 40BF9E4C269D6607
2 changed files with 83 additions and 61 deletions

View File

@ -680,66 +680,19 @@ pub enum Error {
EarlyEndOfScript,
/// Tried to read an array off the stack as a number when it was more than 4 bytes.
NumericOverflow,
/// Error validating the script with bitcoinconsensus library.
#[cfg(feature = "bitcoinconsensus")]
BitcoinConsensus(bitcoinconsensus::Error),
/// Can not find the spent output.
UnknownSpentOutput(OutPoint),
/// Can not serialize the spending transaction.
Serialization,
}
// If bitcoinonsensus-std is off but bitcoinconsensus is present we patch the error type to
// implement `std::error::Error`.
#[cfg(all(feature = "std", feature = "bitcoinconsensus", not(feature = "bitcoinconsensus-std")))]
mod bitcoinconsensus_hack {
use core::fmt;
#[repr(transparent)]
pub(crate) struct Error(bitcoinconsensus::Error);
impl fmt::Debug for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { fmt::Debug::fmt(&self.0, f) }
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { fmt::Display::fmt(&self.0, f) }
}
// bitcoinconsensus::Error has no sources at this time
impl std::error::Error for Error {}
pub(crate) fn wrap_error(error: &bitcoinconsensus::Error) -> &Error {
// Unfortunately, we cannot have the reference inside `Error` struct because of the 'static
// bound on `source` return type, so we have to use unsafe to overcome the limitation.
// SAFETY: the type is repr(transparent) and the lifetimes match
unsafe { &*(error as *const _ as *const Error) }
}
}
#[cfg(not(all(
feature = "std",
feature = "bitcoinconsensus",
not(feature = "bitcoinconsensus-std")
)))]
mod bitcoinconsensus_hack {
#[allow(unused_imports)] // conditionally used
pub(crate) use core::convert::identity as wrap_error;
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
#[cfg(feature = "bitcoinconsensus")]
use internals::write_err;
match *self {
Error::NonMinimalPush => f.write_str("non-minimal datapush"),
Error::EarlyEndOfScript => f.write_str("unexpected end of script"),
Error::NumericOverflow =>
f.write_str("numeric overflow (number on stack larger than 4 bytes)"),
#[cfg(feature = "bitcoinconsensus")]
Error::BitcoinConsensus(ref e) =>
write_err!(f, "bitcoinconsensus verification failed"; bitcoinconsensus_hack::wrap_error(e)),
Error::UnknownSpentOutput(ref point) => write!(f, "unknown spent output: {}", point),
Error::Serialization =>
f.write_str("can not serialize the spending transaction in Transaction::verify()"),
@ -758,8 +711,6 @@ impl std::error::Error for Error {
| NumericOverflow
| UnknownSpentOutput(_)
| Serialization => None,
#[cfg(feature = "bitcoinconsensus")]
BitcoinConsensus(ref e) => Some(bitcoinconsensus_hack::wrap_error(e)),
}
}
}
@ -779,8 +730,3 @@ impl From<UintError> for Error {
}
}
}
#[cfg(feature = "bitcoinconsensus")]
impl From<bitcoinconsensus::Error> for Error {
fn from(err: bitcoinconsensus::Error) -> Error { Error::BitcoinConsensus(err) }
}

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@ -21,8 +21,6 @@ use internals::write_err;
use super::Weight;
use crate::blockdata::locktime::absolute::{self, Height, Time};
use crate::blockdata::locktime::relative;
#[cfg(feature = "bitcoinconsensus")]
use crate::blockdata::script;
use crate::blockdata::script::{Script, ScriptBuf};
use crate::blockdata::witness::Witness;
use crate::consensus::{encode, Decodable, Encodable};
@ -931,7 +929,7 @@ impl Transaction {
/// Shorthand for [`Self::verify_with_flags`] with flag [`bitcoinconsensus::VERIFY_ALL`].
#[cfg(feature = "bitcoinconsensus")]
pub fn verify<S>(&self, spent: S) -> Result<(), script::Error>
pub fn verify<S>(&self, spent: S) -> Result<(), TxVerifyError>
where
S: FnMut(&OutPoint) -> Option<TxOut>,
{
@ -942,7 +940,7 @@ impl Transaction {
///
/// The `spent` closure should not return the same [`TxOut`] twice!
#[cfg(feature = "bitcoinconsensus")]
pub fn verify_with_flags<S, F>(&self, mut spent: S, flags: F) -> Result<(), script::Error>
pub fn verify_with_flags<S, F>(&self, mut spent: S, flags: F) -> Result<(), TxVerifyError>
where
S: FnMut(&OutPoint) -> Option<TxOut>,
F: Into<u32>,
@ -953,7 +951,7 @@ impl Transaction {
if let Some(output) = spent(&input.previous_output) {
output.script_pubkey.verify_with_flags(idx, output.value, tx.as_slice(), flags)?;
} else {
return Err(script::Error::UnknownSpentOutput(input.previous_output));
return Err(TxVerifyError::UnknownSpentOutput(input.previous_output));
}
}
Ok(())
@ -1416,6 +1414,85 @@ impl InputWeightPrediction {
}
}
/// An error during transaction validation.
#[cfg(feature = "bitcoinconsensus")]
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum TxVerifyError {
/// Error validating the script with bitcoinconsensus library.
ScriptVerification(bitcoinconsensus::Error),
/// Can not find the spent output.
UnknownSpentOutput(OutPoint),
}
#[cfg(feature = "bitcoinconsensus")]
impl fmt::Display for TxVerifyError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
use TxVerifyError::*;
match *self {
ScriptVerification(ref e) => {
write_err!(f, "bitcoinconsensus verification failed"; bitcoinconsensus_hack::wrap_error(e))
}
UnknownSpentOutput(ref p) => write!(f, "unknown spent output: {}", p),
}
}
}
#[cfg(all(feature = "std", feature = "bitcoinconsensus"))]
impl std::error::Error for TxVerifyError {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
use TxVerifyError::*;
match *self {
ScriptVerification(ref e) => Some(bitcoinconsensus_hack::wrap_error(e)),
UnknownSpentOutput(_) => None,
}
}
}
#[cfg(feature = "bitcoinconsensus")]
impl From<bitcoinconsensus::Error> for TxVerifyError {
fn from(e: bitcoinconsensus::Error) -> Self { TxVerifyError::ScriptVerification(e) }
}
// If bitcoinonsensus-std is off but bitcoinconsensus is present we patch the error type to
// implement `std::error::Error`.
#[cfg(all(feature = "std", feature = "bitcoinconsensus", not(feature = "bitcoinconsensus-std")))]
mod bitcoinconsensus_hack {
use core::fmt;
#[repr(transparent)]
pub(crate) struct Error(bitcoinconsensus::Error);
impl fmt::Debug for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { fmt::Debug::fmt(&self.0, f) }
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { fmt::Display::fmt(&self.0, f) }
}
// bitcoinconsensus::Error has no sources at this time
impl std::error::Error for Error {}
pub(crate) fn wrap_error(error: &bitcoinconsensus::Error) -> &Error {
// Unfortunately, we cannot have the reference inside `Error` struct because of the 'static
// bound on `source` return type, so we have to use unsafe to overcome the limitation.
// SAFETY: the type is repr(transparent) and the lifetimes match
unsafe { &*(error as *const _ as *const Error) }
}
}
#[cfg(not(all(
feature = "std",
feature = "bitcoinconsensus",
not(feature = "bitcoinconsensus-std")
)))]
mod bitcoinconsensus_hack {
#[allow(unused_imports)] // conditionally used
pub(crate) use core::convert::identity as wrap_error;
}
#[cfg(test)]
mod tests {
use core::str::FromStr;
@ -1838,7 +1915,6 @@ mod tests {
fn test_transaction_verify() {
use std::collections::HashMap;
use crate::blockdata::script;
use crate::blockdata::witness::Witness;
// a random recent segwit transaction from blockchain using both old and segwit inputs
@ -1895,7 +1971,7 @@ mod tests {
.err()
.unwrap()
{
script::Error::BitcoinConsensus(_) => {}
TxVerifyError::ScriptVerification(_) => {}
_ => panic!("Wrong error type"),
}
}