// SPDX-License-Identifier: CC0-1.0
//! Witness
//!
//! This module contains the [`Witness`] struct and related methods to operate on it
//!
use core::fmt;
use core::ops::Index;
use crate::consensus::encode::{Error, MAX_VEC_SIZE};
use crate::consensus::{Decodable, Encodable, WriteExt};
use crate::crypto::ecdsa;
use crate::io::{self, Read, Write};
use crate::prelude::*;
use crate::taproot::TAPROOT_ANNEX_PREFIX;
use crate::{Script, VarInt};
/// The Witness is the data used to unlock bitcoin since the [segwit upgrade].
///
/// Can be logically seen as an array of bytestrings, i.e. `Vec<Vec<u8>>`, and it is serialized on the wire
/// in that format. You can convert between this type and `Vec<Vec<u8>>` by using [`Witness::from_slice`]
/// and [`Witness::to_vec`].
///
/// For serialization and deserialization performance it is stored internally as a single `Vec`,
/// saving some allocations.
///
/// [segwit upgrade]: <https://github.com/bitcoin/bips/blob/master/bip-0143.mediawiki>
#[derive(Clone, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct Witness {
/// Contains the witness `Vec<Vec<u8>>` serialization without the initial varint indicating the
/// number of elements (which is stored in `witness_elements`).
content: Vec<u8>,
/// The number of elements in the witness.
///
/// Stored separately (instead of as a VarInt in the initial part of content) so that methods
/// like [`Witness::push`] don't have to shift the entire array.
witness_elements: usize,
/// This is the valid index pointing to the beginning of the index area. This area is 4 *
/// stack_size bytes at the end of the content vector which stores the indices of each item.
indices_start: usize,
}
impl fmt::Debug for Witness {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
if f.alternate() {
fmt_debug_pretty(self, f)
} else {
fmt_debug(self, f)
}
}
}
fn fmt_debug(w: &Witness, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
#[rustfmt::skip]
let comma_or_close = |current_index, last_index| {
if current_index == last_index { "]" } else { ", " }
};
f.write_str("Witness: { ")?;
write!(f, "indices: {}, ", w.witness_elements)?;
write!(f, "indices_start: {}, ", w.indices_start)?;
f.write_str("witnesses: [")?;
let instructions = w.iter();
match instructions.len().checked_sub(1) {
Some(last_instruction) => {
for (i, instruction) in instructions.enumerate() {
let bytes = instruction.iter();
match bytes.len().checked_sub(1) {
Some(last_byte) => {
f.write_str("[")?;
for (j, byte) in bytes.enumerate() {
write!(f, "{:#04x}", byte)?;
f.write_str(comma_or_close(j, last_byte))?;
}
}
None => {
// This is possible because the varint is not part of the instruction (see Iter).
write!(f, "[]")?;
}
}
f.write_str(comma_or_close(i, last_instruction))?;
}
}
None => {
// Witnesses can be empty because the 0x00 var int is not stored in content.
write!(f, "]")?;
}
}
f.write_str(" }")
}
fn fmt_debug_pretty(w: &Witness, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
f.write_str("Witness: {\n")?;
writeln!(f, " indices: {},", w.witness_elements)?;
writeln!(f, " indices_start: {},", w.indices_start)?;
f.write_str(" witnesses: [\n")?;
for instruction in w.iter() {
f.write_str(" [")?;
for (j, byte) in instruction.iter().enumerate() {
if j > 0 {
f.write_str(", ")?;
}
write!(f, "{:#04x}", byte)?;
}
f.write_str("],\n")?;
}
writeln!(f, " ],")?;
writeln!(f, "}}")
}
/// An iterator returning individual witness elements.
pub struct Iter<'a> {
inner: &'a [u8],
indices_start: usize,
current_index: usize,
}
impl Decodable for Witness {
fn consensus_decode<R: Read + ?Sized>(r: &mut R) -> Result<Self, Error> {
let witness_elements = VarInt::consensus_decode(r)?.0 as usize;
// Minimum size of witness element is 1 byte, so if the count is
// greater than MAX_VEC_SIZE we must return an error.
if witness_elements > MAX_VEC_SIZE {
return Err(self::Error::OversizedVectorAllocation {
requested: witness_elements,
max: MAX_VEC_SIZE,
});
}
if witness_elements == 0 {
Ok(Witness::default())
} else {
// Leave space at the head for element positions.
// We will rotate them to the end of the Vec later.
let witness_index_space = witness_elements * 4;
let mut cursor = witness_index_space;
// this number should be determined as high enough to cover most witness, and low enough
// to avoid wasting space without reallocating
let mut content = vec![0u8; cursor + 128];
for i in 0..witness_elements {
let element_size_varint = VarInt::consensus_decode(r)?;
let element_size_varint_len = element_size_varint.size();
let element_size = element_size_varint.0 as usize;
let required_len = cursor
.checked_add(element_size)
.ok_or(self::Error::OversizedVectorAllocation {
requested: usize::MAX,
max: MAX_VEC_SIZE,
})?
.checked_add(element_size_varint_len)
.ok_or(self::Error::OversizedVectorAllocation {
requested: usize::MAX,
max: MAX_VEC_SIZE,
})?;
if required_len > MAX_VEC_SIZE + witness_index_space {
return Err(self::Error::OversizedVectorAllocation {
requested: required_len,
max: MAX_VEC_SIZE,
});
}
// We will do content.rotate_left(witness_index_space) later.
// Encode the position's value AFTER we rotate left.
encode_cursor(&mut content, 0, i, cursor - witness_index_space);
resize_if_needed(&mut content, required_len);
element_size_varint.consensus_encode(
&mut &mut content[cursor..cursor + element_size_varint_len],
)?;
cursor += element_size_varint_len;
r.read_exact(&mut content[cursor..cursor + element_size])?;
cursor += element_size;
}
content.truncate(cursor);
// Index space is now at the end of the Vec
content.rotate_left(witness_index_space);
Ok(Witness { content, witness_elements, indices_start: cursor - witness_index_space })
}
}
}
/// Correctness Requirements: value must always fit within u32
#[inline]
fn encode_cursor(bytes: &mut [u8], start_of_indices: usize, index: usize, value: usize) {
let start = start_of_indices + index * 4;
let end = start + 4;
bytes[start..end]
.copy_from_slice(&u32::to_ne_bytes(value.try_into().expect("Larger than u32")));
}
#[inline]
fn decode_cursor(bytes: &[u8], start_of_indices: usize, index: usize) -> Option<usize> {
let start = start_of_indices + index * 4;
let end = start + 4;
if end > bytes.len() {
None
} else {
Some(u32::from_ne_bytes(bytes[start..end].try_into().expect("is u32 size")) as usize)
}
}
fn resize_if_needed(vec: &mut Vec<u8>, required_len: usize) {
if required_len >= vec.len() {
let mut new_len = vec.len().max(1);
while new_len <= required_len {
new_len *= 2;
}
vec.resize(new_len, 0);
}
}
impl Encodable for Witness {
fn consensus_encode<W: Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
let len = VarInt::from(self.witness_elements);
len.consensus_encode(w)?;
let content_with_indices_len = self.content.len();
let indices_size = self.witness_elements * 4;
let content_len = content_with_indices_len - indices_size;
w.emit_slice(&self.content[..content_len])?;
Ok(content_len + len.size())
}
}
impl Witness {
/// Creates a new empty [`Witness`].
pub fn new() -> Self { Witness::default() }
/// Creates a witness required to spend a P2WPKH output.
///
/// The witness will be made up of the DER encoded signature + sighash_type followed by the
/// serialized public key. Also useful for spending a P2SH-P2WPKH output.
///
/// It is expected that `pubkey` is related to the secret key used to create `signature`.
pub fn p2wpkh(signature: &ecdsa::Signature, pubkey: &secp256k1::PublicKey) -> Witness {
let mut witness = Witness::new();
witness.push_slice(&signature.serialize());
witness.push_slice(&pubkey.serialize());
witness
}
/// Creates a [`Witness`] object from a slice of bytes slices where each slice is a witness item.
pub fn from_slice<T: AsRef<[u8]>>(slice: &[T]) -> Self {
let witness_elements = slice.len();
let index_size = witness_elements * 4;
let content_size = slice
.iter()
.map(|elem| elem.as_ref().len() + VarInt::from(elem.as_ref().len()).size())
.sum();
let mut content = vec![0u8; content_size + index_size];
let mut cursor = 0usize;
for (i, elem) in slice.iter().enumerate() {
encode_cursor(&mut content, content_size, i, cursor);
let elem_len_varint = VarInt::from(elem.as_ref().len());
elem_len_varint
.consensus_encode(&mut &mut content[cursor..cursor + elem_len_varint.size()])
.expect("writers on vec don't errors, space granted by content_size");
cursor += elem_len_varint.size();
content[cursor..cursor + elem.as_ref().len()].copy_from_slice(elem.as_ref());
cursor += elem.as_ref().len();
}
Witness { witness_elements, content, indices_start: content_size }
}
/// Convenience method to create an array of byte-arrays from this witness.
pub fn to_vec(&self) -> Vec<Vec<u8>> { self.iter().map(|s| s.to_vec()).collect() }
/// Returns `true` if the witness contains no element.
pub fn is_empty(&self) -> bool { self.witness_elements == 0 }
/// Returns a struct implementing [`Iterator`].
pub fn iter(&self) -> Iter {
Iter { inner: self.content.as_slice(), indices_start: self.indices_start, current_index: 0 }
}
/// Returns the number of elements this witness holds.
pub fn len(&self) -> usize { self.witness_elements }
/// Returns the number of bytes this witness contributes to a transactions total size.
pub fn size(&self) -> usize {
let mut size: usize = 0;
size += VarInt::from(self.witness_elements).size();
size += self
.iter()
.map(|witness_element| {
VarInt::from(witness_element.len()).size() + witness_element.len()
})
.sum::<usize>();
size
}
/// Clear the witness.
pub fn clear(&mut self) {
self.content.clear();
self.witness_elements = 0;
self.indices_start = 0;
}
/// Push a new element on the witness, requires an allocation.
pub fn push<T: AsRef<[u8]>>(&mut self, new_element: T) {
self.push_slice(new_element.as_ref());
}
/// Push a new element slice onto the witness stack.
fn push_slice(&mut self, new_element: &[u8]) {
self.witness_elements += 1;
let previous_content_end = self.indices_start;
let element_len_varint = VarInt::from(new_element.len());
let current_content_len = self.content.len();
let new_item_total_len = element_len_varint.size() + new_element.len();
self.content.resize(current_content_len + new_item_total_len + 4, 0);
self.content[previous_content_end..].rotate_right(new_item_total_len);
self.indices_start += new_item_total_len;
encode_cursor(
&mut self.content,
self.indices_start,
self.witness_elements - 1,
previous_content_end,
);
let end_varint = previous_content_end + element_len_varint.size();
element_len_varint
.consensus_encode(&mut &mut self.content[previous_content_end..end_varint])
.expect("writers on vec don't error, space granted through previous resize");
self.content[end_varint..end_varint + new_element.len()].copy_from_slice(new_element);
}
/// Pushes, as a new element on the witness, an ECDSA signature.
///
/// Pushes the DER encoded signature + sighash_type, requires an allocation.
pub fn push_ecdsa_signature(&mut self, signature: &ecdsa::Signature) {
self.push_slice(&signature.serialize())
}
fn element_at(&self, index: usize) -> Option<&[u8]> {
let varint = VarInt::consensus_decode(&mut &self.content[index..]).ok()?;
let start = index + varint.size();
Some(&self.content[start..start + varint.0 as usize])
}
/// Returns the last element in the witness, if any.
pub fn last(&self) -> Option<&[u8]> {
if self.witness_elements == 0 {
None
} else {
self.nth(self.witness_elements - 1)
}
}
/// Returns the second-to-last element in the witness, if any.
pub fn second_to_last(&self) -> Option<&[u8]> {
if self.witness_elements <= 1 {
None
} else {
self.nth(self.witness_elements - 2)
}
}
/// Return the nth element in the witness, if any
pub fn nth(&self, index: usize) -> Option<&[u8]> {
let pos = decode_cursor(&self.content, self.indices_start, index)?;
self.element_at(pos)
}
/// Get Tapscript following BIP341 rules regarding accounting for an annex.
///
/// This does not guarantee that this represents a P2TR [`Witness`]. It
/// merely gets the second to last or third to last element depending on
/// the first byte of the last element being equal to 0x50. See
/// [Script::is_p2tr](crate::blockdata::script::Script::is_p2tr) to
/// check whether this is actually a Taproot witness.
pub fn tapscript(&self) -> Option<&Script> {
let len = self.len();
self.last()
.map(|last_elem| {
// From BIP341:
// If there are at least two witness elements, and the first byte of
// the last element is 0x50, this last element is called annex a
// and is removed from the witness stack.
if len >= 2 && last_elem.first() == Some(&TAPROOT_ANNEX_PREFIX) {
// account for the extra item removed from the end
3
} else {
// otherwise script is 2nd from last
2
}
})
.filter(|&script_pos_from_last| len >= script_pos_from_last)
.and_then(|script_pos_from_last| self.nth(len - script_pos_from_last))
.map(Script::from_bytes)
}
}
impl Index<usize> for Witness {
type Output = [u8];
fn index(&self, index: usize) -> &Self::Output { self.nth(index).expect("Out of Bounds") }
}
impl<'a> Iterator for Iter<'a> {
type Item = &'a [u8];
fn next(&mut self) -> Option<Self::Item> {
let index = decode_cursor(self.inner, self.indices_start, self.current_index)?;
let varint = VarInt::consensus_decode(&mut &self.inner[index..]).ok()?;
let start = index + varint.size();
let end = start + varint.0 as usize;
let slice = &self.inner[start..end];
self.current_index += 1;
Some(slice)
}
fn size_hint(&self) -> (usize, Option<usize>) {
let total_count = (self.inner.len() - self.indices_start) / 4;
let remaining = total_count - self.current_index;
(remaining, Some(remaining))
}
}
impl<'a> ExactSizeIterator for Iter<'a> {}
impl<'a> IntoIterator for &'a Witness {
type IntoIter = Iter<'a>;
type Item = &'a [u8];
fn into_iter(self) -> Self::IntoIter { self.iter() }
}
// Serde keep backward compatibility with old Vec<Vec<u8>> format
#[cfg(feature = "serde")]
impl serde::Serialize for Witness {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: serde::Serializer,
{
use serde::ser::SerializeSeq;
let human_readable = serializer.is_human_readable();
let mut seq = serializer.serialize_seq(Some(self.witness_elements))?;
for elem in self.iter() {
if human_readable {
seq.serialize_element(&crate::serde_utils::SerializeBytesAsHex(elem))?;
} else {
seq.serialize_element(&elem)?;
}
}
seq.end()
}
}
#[cfg(feature = "serde")]
impl<'de> serde::Deserialize<'de> for Witness {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: serde::Deserializer<'de>,
{
struct Visitor; // Human-readable visitor.
impl<'de> serde::de::Visitor<'de> for Visitor {
type Value = Witness;
fn expecting(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
write!(f, "a sequence of hex arrays")
}
fn visit_seq<A: serde::de::SeqAccess<'de>>(
self,
mut a: A,
) -> Result<Self::Value, A::Error> {
use hex::FromHex;
use hex::HexToBytesError::*;
use serde::de::{self, Unexpected};
let mut ret = match a.size_hint() {
Some(len) => Vec::with_capacity(len),
None => Vec::new(),
};
while let Some(elem) = a.next_element::<String>()? {
let vec = Vec::<u8>::from_hex(&elem).map_err(|e| match e {
InvalidChar(b) => match core::char::from_u32(b.into()) {
Some(c) => de::Error::invalid_value(
Unexpected::Char(c),
&"a valid hex character",
),
None => de::Error::invalid_value(
Unexpected::Unsigned(b.into()),
&"a valid hex character",
),
},
OddLengthString(len) =>
de::Error::invalid_length(len, &"an even length string"),
})?;
ret.push(vec);
}
Ok(Witness::from_slice(&ret))
}
}
if deserializer.is_human_readable() {
deserializer.deserialize_seq(Visitor)
} else {
let vec: Vec<Vec<u8>> = serde::Deserialize::deserialize(deserializer)?;
Ok(Witness::from_slice(&vec))
}
}
}
impl From<Vec<Vec<u8>>> for Witness {
fn from(vec: Vec<Vec<u8>>) -> Self { Witness::from_slice(&vec) }
}
impl From<&[&[u8]]> for Witness {
fn from(slice: &[&[u8]]) -> Self { Witness::from_slice(slice) }
}
impl From<&[Vec<u8>]> for Witness {
fn from(slice: &[Vec<u8>]) -> Self { Witness::from_slice(slice) }
}
impl From<Vec<&[u8]>> for Witness {
fn from(vec: Vec<&[u8]>) -> Self { Witness::from_slice(&vec) }
}
#[cfg(test)]
mod test {
use hex::test_hex_unwrap as hex;
use super::*;
use crate::consensus::{deserialize, serialize};
use crate::sighash::EcdsaSighashType;
use crate::Transaction;
fn append_u32_vec(mut v: Vec<u8>, n: &[u32]) -> Vec<u8> {
for &num in n {
v.extend_from_slice(&num.to_ne_bytes());
}
v
}
#[test]
fn witness_debug_can_display_empty_instruction() {
let witness = Witness {
witness_elements: 1,
content: append_u32_vec(vec![], &[0]),
indices_start: 2,
};
println!("{:?}", witness);
}
#[test]
fn test_push() {
let mut witness = Witness::default();
assert_eq!(witness.last(), None);
assert_eq!(witness.second_to_last(), None);
assert_eq!(witness.nth(0), None);
assert_eq!(witness.nth(1), None);
assert_eq!(witness.nth(2), None);
assert_eq!(witness.nth(3), None);
witness.push(&vec![0u8]);
let expected = Witness {
witness_elements: 1,
content: append_u32_vec(vec![1u8, 0], &[0]),
indices_start: 2,
};
assert_eq!(witness, expected);
assert_eq!(witness.last(), Some(&[0u8][..]));
assert_eq!(witness.second_to_last(), None);
assert_eq!(witness.nth(0), Some(&[0u8][..]));
assert_eq!(witness.nth(1), None);
assert_eq!(witness.nth(2), None);
assert_eq!(witness.nth(3), None);
assert_eq!(&witness[0], &[0u8][..]);
witness.push(&vec![2u8, 3u8]);
let expected = Witness {
witness_elements: 2,
content: append_u32_vec(vec![1u8, 0, 2, 2, 3], &[0, 2]),
indices_start: 5,
};
assert_eq!(witness, expected);
assert_eq!(witness.last(), Some(&[2u8, 3u8][..]));
assert_eq!(witness.second_to_last(), Some(&[0u8][..]));
assert_eq!(witness.nth(0), Some(&[0u8][..]));
assert_eq!(witness.nth(1), Some(&[2u8, 3u8][..]));
assert_eq!(witness.nth(2), None);
assert_eq!(witness.nth(3), None);
assert_eq!(&witness[0], &[0u8][..]);
assert_eq!(&witness[1], &[2u8, 3u8][..]);
witness.push(&vec![4u8, 5u8]);
let expected = Witness {
witness_elements: 3,
content: append_u32_vec(vec![1u8, 0, 2, 2, 3, 2, 4, 5], &[0, 2, 5]),
indices_start: 8,
};
assert_eq!(witness, expected);
assert_eq!(witness.last(), Some(&[4u8, 5u8][..]));
assert_eq!(witness.second_to_last(), Some(&[2u8, 3u8][..]));
assert_eq!(witness.nth(0), Some(&[0u8][..]));
assert_eq!(witness.nth(1), Some(&[2u8, 3u8][..]));
assert_eq!(witness.nth(2), Some(&[4u8, 5u8][..]));
assert_eq!(witness.nth(3), None);
assert_eq!(&witness[0], &[0u8][..]);
assert_eq!(&witness[1], &[2u8, 3u8][..]);
assert_eq!(&witness[2], &[4u8, 5u8][..]);
}
#[test]
fn test_iter_len() {
let mut witness = Witness::default();
for i in 0..5 {
assert_eq!(witness.iter().len(), i);
witness.push(&vec![0u8]);
}
let mut iter = witness.iter();
for i in (0..=5).rev() {
assert_eq!(iter.len(), i);
iter.next();
}
}
#[test]
fn test_push_ecdsa_sig() {
// The very first signature in block 734,958
let sig_bytes =
hex!("304402207c800d698f4b0298c5aac830b822f011bb02df41eb114ade9a6702f364d5e39c0220366900d2a60cab903e77ef7dd415d46509b1f78ac78906e3296f495aa1b1b541");
let sig = secp256k1::ecdsa::Signature::from_der(&sig_bytes).unwrap();
let mut witness = Witness::default();
let signature = crate::ecdsa::Signature { sig, hash_ty: EcdsaSighashType::All };
witness.push_ecdsa_signature(&signature);
let expected_witness = vec![hex!(
"304402207c800d698f4b0298c5aac830b822f011bb02df41eb114ade9a6702f364d5e39c0220366900d2a60cab903e77ef7dd415d46509b1f78ac78906e3296f495aa1b1b54101")
];
assert_eq!(witness.to_vec(), expected_witness);
}
#[test]
fn test_witness() {
let w0 = hex!("03d2e15674941bad4a996372cb87e1856d3652606d98562fe39c5e9e7e413f2105");
let w1 = hex!("000000");
let witness_vec = vec![w0.clone(), w1.clone()];
let witness_serialized: Vec<u8> = serialize(&witness_vec);
let witness = Witness {
content: append_u32_vec(witness_serialized[1..].to_vec(), &[0, 34]),
witness_elements: 2,
indices_start: 38,
};
for (i, el) in witness.iter().enumerate() {
assert_eq!(witness_vec[i], el);
}
assert_eq!(witness.last(), Some(&w1[..]));
assert_eq!(witness.second_to_last(), Some(&w0[..]));
assert_eq!(witness.nth(0), Some(&w0[..]));
assert_eq!(witness.nth(1), Some(&w1[..]));
assert_eq!(witness.nth(2), None);
assert_eq!(&witness[0], &w0[..]);
assert_eq!(&witness[1], &w1[..]);
let w_into = Witness::from_slice(&witness_vec);
assert_eq!(w_into, witness);
assert_eq!(witness_serialized, serialize(&witness));
}
#[test]
fn test_get_tapscript() {
let tapscript = hex!("deadbeef");
let control_block = hex!("02");
// annex starting with 0x50 causes the branching logic.
let annex = hex!("50");
let witness_vec = vec![tapscript.clone(), control_block.clone()];
let witness_vec_annex = vec![tapscript.clone(), control_block, annex];
let witness_serialized: Vec<u8> = serialize(&witness_vec);
let witness_serialized_annex: Vec<u8> = serialize(&witness_vec_annex);
let witness = Witness {
content: append_u32_vec(witness_serialized[1..].to_vec(), &[0, 5]),
witness_elements: 2,
indices_start: 7,
};
let witness_annex = Witness {
content: append_u32_vec(witness_serialized_annex[1..].to_vec(), &[0, 5, 7]),
witness_elements: 3,
indices_start: 9,
};
// With or without annex, the tapscript should be returned.
assert_eq!(witness.tapscript(), Some(Script::from_bytes(&tapscript[..])));
assert_eq!(witness_annex.tapscript(), Some(Script::from_bytes(&tapscript[..])));
}
#[test]
fn test_tx() {
const S: &str = "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";
let tx_bytes = hex!(S);
let tx: Transaction = deserialize(&tx_bytes).unwrap();
let expected_wit = ["304502210084622878c94f4c356ce49c8e33a063ec90f6ee9c0208540888cfab056cd1fca9022014e8dbfdfa46d318c6887afd92dcfa54510e057565e091d64d2ee3a66488f82c01", "026e181ffb98ebfe5a64c983073398ea4bcd1548e7b971b4c175346a25a1c12e95"];
for (i, wit_el) in tx.input[0].witness.iter().enumerate() {
assert_eq!(expected_wit[i], wit_el.to_lower_hex_string());
}
assert_eq!(expected_wit[1], tx.input[0].witness.last().unwrap().to_lower_hex_string());
assert_eq!(
expected_wit[0],
tx.input[0].witness.second_to_last().unwrap().to_lower_hex_string()
);
assert_eq!(expected_wit[0], tx.input[0].witness.nth(0).unwrap().to_lower_hex_string());
assert_eq!(expected_wit[1], tx.input[0].witness.nth(1).unwrap().to_lower_hex_string());
assert_eq!(None, tx.input[0].witness.nth(2));
assert_eq!(expected_wit[0], tx.input[0].witness[0].to_lower_hex_string());
assert_eq!(expected_wit[1], tx.input[0].witness[1].to_lower_hex_string());
let tx_bytes_back = serialize(&tx);
assert_eq!(tx_bytes_back, tx_bytes);
}
#[test]
fn fuzz_cases() {
let bytes = hex!("26ff0000000000c94ce592cf7a4cbb68eb00ce374300000057cd0000000000000026");
assert!(deserialize::<Witness>(&bytes).is_err()); // OversizedVectorAllocation
let bytes = hex!("24000000ffffffffffffffffffffffff");
assert!(deserialize::<Witness>(&bytes).is_err()); // OversizedVectorAllocation
}
#[cfg(feature = "serde")]
#[test]
fn test_serde_bincode() {
use bincode;
let old_witness_format = vec![vec![0u8], vec![2]];
let new_witness_format = Witness::from_slice(&old_witness_format);
let old = bincode::serialize(&old_witness_format).unwrap();
let new = bincode::serialize(&new_witness_format).unwrap();
assert_eq!(old, new);
let back: Witness = bincode::deserialize(&new).unwrap();
assert_eq!(new_witness_format, back);
}
#[cfg(feature = "serde")]
#[test]
fn test_serde_human() {
use serde_json;
let witness = Witness::from_slice(&[vec![0u8, 123, 75], vec![2u8, 6, 3, 7, 8]]);
let json = serde_json::to_string(&witness).unwrap();
assert_eq!(json, r#"["007b4b","0206030708"]"#);
let back: Witness = serde_json::from_str(&json).unwrap();
assert_eq!(witness, back);
}
}
#[cfg(bench)]
mod benches {
use test::{black_box, Bencher};
use super::Witness;
#[bench]
pub fn bench_big_witness_to_vec(bh: &mut Bencher) {
let raw_witness = [[1u8]; 5];
let witness = Witness::from_slice(&raw_witness);
bh.iter(|| {
black_box(witness.to_vec());
});
}
#[bench]
pub fn bench_witness_to_vec(bh: &mut Bencher) {
let raw_witness = vec![vec![1u8]; 3];
let witness = Witness::from_slice(&raw_witness);
bh.iter(|| {
black_box(witness.to_vec());
});
}
}