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

Fix associated constants of `InputWeightPrediction` 

These constants had an error that they had `script_size` set to 0 which
was incorrect because it's not length of the script but serialized size.
Rather than just bumping the value this uses the `from_slice` method
which is less error-prone.

This also deletes a useless test of the constants.

Closes #1834
This commit is contained in:
Martin Habovstiak 2023-05-04 20:19:32 +02:00
parent 7769221921
commit 6fec1789b9
1 changed files with 4 additions and 43 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

47
bitcoin/src/blockdata/transaction.rs
View File

@ -1347,24 +1347,21 @@ impl InputWeightPrediction {
/// under-paying. See [`ground_p2wpkh`](Self::ground_p2wpkh) if you do use signature grinding.
///
/// [signature grinding]: https://bitcoin.stackexchange.com/questions/111660/what-is-signature-grinding
pub const P2WPKH_MAX: Self =
InputWeightPrediction { script_size: 0, witness_size: 1 + 1 + 73 + 1 + 33 };
pub const P2WPKH_MAX: Self = InputWeightPrediction::from_slice(0, &[73, 33]);
/// Input weight prediction corresponding to spending of taproot output using the key and
/// default sighash.
///
/// If the input in your transaction uses Taproot key spend you can use this instead of
/// [`InputWeightPrediction::new`].
pub const P2TR_KEY_DEFAULT_SIGHASH: Self =
InputWeightPrediction { script_size: 0, witness_size: 1 + 1 + 64 };
pub const P2TR_KEY_DEFAULT_SIGHASH: Self = InputWeightPrediction::from_slice(0, &[64]);
/// Input weight prediction corresponding to spending of taproot output using the key and
/// **non**-default sighash.
///
/// If the input in your transaction uses Taproot key spend you can use this instead of
/// [`InputWeightPrediction::new`].
pub const P2TR_KEY_NON_DEFAULT_SIGHASH: Self =
InputWeightPrediction { script_size: 0, witness_size: 1 + 1 + 65 };
pub const P2TR_KEY_NON_DEFAULT_SIGHASH: Self = InputWeightPrediction::from_slice(0, &[65]);
/// Input weight prediction corresponding to spending of P2WPKH output using [signature
/// grinding].
@ -1383,13 +1380,7 @@ impl InputWeightPrediction {
pub const fn ground_p2wpkh(bytes_to_grind: usize) -> Self {
// Written to trigger const/debug panic for unreasonably high values.
let der_signature_size = 10 + (62 - bytes_to_grind);
let witness_size = 1 // length of element count varint
+ 1 // length of element size varint (max signature length is 73B)
+ der_signature_size
+ 1 // sighash flag
+ 1 // length of element size varint
+ 33; // length of (always-compressed) public key
InputWeightPrediction { script_size: 0, witness_size }
InputWeightPrediction::from_slice(0, &[der_signature_size, 33])
}
/// Computes the prediction for a single input.
@ -1465,36 +1456,6 @@ mod tests {
assert_eq!(raw_tx, &buf[..size]);
}
#[test]
fn predict_weight_all_witness_size() {
// 109
let p2wpkh = InputWeightPrediction::P2WPKH_MAX;
// 66
let p2tr_default = InputWeightPrediction::P2TR_KEY_DEFAULT_SIGHASH;
// 67
let p2tr_non_default = InputWeightPrediction::P2TR_KEY_NON_DEFAULT_SIGHASH;
// 109 + 66 + 67 = 242
let p = vec![p2wpkh, p2tr_default, p2tr_non_default];
let output_script_lens = vec![1];
let w = predict_weight(p, output_script_lens);
// input_weight = partial_input_weight + input_count * 4 * (32 + 4 + 4)
// input_weight = 242 + 3 * 4 * (32 + 4 + 4)
// input_weight = 722
// output_size = 8 * output_count + output_scripts_size
// output_size = 8 * 1 + 2
// output_size = 10
// weight = non_input_size * 4 + input_weight + input_count - inputs_with_witnesses + 2
// weight = 20 * 4 + 722 + 3 - 3 + 2
// weight = 804
assert_eq!(w, Weight::from_wu(804));
}
#[test]
fn test_outpoint() {
assert_eq!(OutPoint::from_str("i don't care"), Err(ParseOutPointError::Format));