Struct Witness

pub struct Witness { /* private fields */ }

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.

Implementations

impl Witness

pub const fn new() -> Witness

Creates a new empty Witness.

pub fn p2wpkh(signature: &Signature, pubkey: &PublicKey) -> Witness

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 p2tr_key_spend(signature: &Signature) -> Witness

Creates a witness required to do a key path spend of a P2TR output.

pub fn from_slice<T>(slice: &[T]) -> Witness

where T: AsRef<[u8]>,

Creates a Witness object from a slice of bytes slices where each slice is a witness item.

pub fn to_vec(&self) -> Vec<Vec<u8>>

Convenience method to create an array of byte-arrays from this witness.

pub fn is_empty(&self) -> bool

Returns true if the witness contains no element.

pub fn iter(&self) -> Iter<'_>

Returns a struct implementing Iterator.

pub fn len(&self) -> usize

Returns the number of elements this witness holds.

pub fn size(&self) -> usize

Returns the number of bytes this witness contributes to a transactions total size.

pub fn clear(&mut self)

Clear the witness.

pub fn push<T>(&mut self, new_element: T)

where T: AsRef<[u8]>,

Push a new element on the witness, requires an allocation.

pub fn push_ecdsa_signature(&mut self, signature: &Signature)

Pushes, as a new element on the witness, an ECDSA signature.

Pushes the DER encoded signature + sighash_type, requires an allocation.

pub fn last(&self) -> Option<&[u8]>

Returns the last element in the witness, if any.

pub fn second_to_last(&self) -> Option<&[u8]>

Returns the second-to-last element in the witness, if any.

pub fn third_to_last(&self) -> Option<&[u8]>

Returns the third-to-last element in the witness, if any.

pub fn nth(&self, index: usize) -> Option<&[u8]>

Return the nth element in the witness, if any

pub fn tapscript(&self) -> Option<&Script>

👎Deprecated: use taproot_leaf_script and check leaf version, if applicable

Get leaf script following BIP341 rules regarding accounting for an annex.

This method is broken: it’s called tapscript but it’s actually returning a leaf script. We’re not going to fix it because someone might be relying on it thinking leaf script and tapscript are the same thing (they are not). Instead, this is deprecated and will be removed in the next breaking release. You need to use taproot_leaf_script and if you intended to use it as leaf script, just access the script field of the returned type. If you intended tapscript specifically you have to check the version first and bail if it’s not LeafVersion::TapScript.

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 to check whether this is actually a Taproot witness.

pub fn taproot_leaf_script(&self) -> Option<LeafScript<&Script>>

Returns the leaf script with its version but without the merkle proof.

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 and the associated version.

pub fn taproot_control_block(&self) -> Option<&[u8]>

Get the taproot control block following BIP341 rules.

This does not guarantee that this represents a P2TR Witness. It merely gets the last or second to last element depending on the first byte of the last element being equal to 0x50.

See Script::is_p2tr to check whether this is actually a Taproot witness.

pub fn taproot_annex(&self) -> Option<&[u8]>

Get the taproot annex following BIP341 rules.

This does not guarantee that this represents a P2TR Witness.

See Script::is_p2tr to check whether this is actually a Taproot witness.

pub fn witness_script(&self) -> Option<&Script>

Get the p2wsh witness script following BIP141 rules.

This does not guarantee that this represents a P2WS Witness. See Script::is_p2wsh to check whether this is actually a P2WSH witness.

Trait Implementations

impl Clone for Witness

fn clone(&self) -> Witness

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Witness

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Decodable for Witness

fn consensus_decode<R>(r: &mut R) -> Result<Witness, Error>

where R: Read + ?Sized,

Decode an object with a well-defined format.

fn consensus_decode_from_finite_reader<R>(reader: &mut R) -> Result<Self, Error>

where R: Read + ?Sized,

Decode Self from a size-limited reader.

impl Default for Witness

fn default() -> Witness

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Witness

fn deserialize<D>( deserializer: D, ) -> Result<Witness, <D as Deserializer<'de>>::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Encodable for Witness

fn consensus_encode<W>(&self, w: &mut W) -> Result<usize, Error>

where W: Write + ?Sized,

Encodes an object with a well-defined format.

impl From<&[&[u8]]> for Witness

fn from(slice: &[&[u8]]) -> Witness

Converts to this type from the input type.

impl From<&[Vec<u8>]> for Witness

fn from(slice: &[Vec<u8>]) -> Witness

Converts to this type from the input type.

impl From<Vec<&[u8]>> for Witness

fn from(vec: Vec<&[u8]>) -> Witness

Converts to this type from the input type.

impl From<Vec<Vec<u8>>> for Witness

fn from(vec: Vec<Vec<u8>>) -> Witness

Converts to this type from the input type.

impl Hash for Witness

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Index<usize> for Witness

type Output = [u8]

The returned type after indexing.

fn index(&self, index: usize) -> &<Witness as Index<usize>>::Output

Performs the indexing (container[index]) operation.

impl<'a> IntoIterator for &'a Witness

type IntoIter = Iter<'a>

Which kind of iterator are we turning this into?

type Item = &'a [u8]

The type of the elements being iterated over.

fn into_iter(self) -> <&'a Witness as IntoIterator>::IntoIter

Creates an iterator from a value.

impl Ord for Witness

fn cmp(&self, other: &Witness) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for Witness

fn eq(&self, other: &Witness) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for Witness

fn partial_cmp(&self, other: &Witness) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Readable for Witness

fn read<R>(r: &mut R) -> Result<Witness, DecodeError>

where R: Read,

Reads a Self in from the given Read.

impl Serialize for Witness

fn serialize<S>( &self, serializer: S, ) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl Writeable for Witness

fn write<W>(&self, writer: &mut W) -> Result<(), Error>

where W: Writer,

Writes self out to the given Writer.

fn encode(&self) -> Vec<u8>

Writes self out to a Vec<u8>.

fn serialized_length(&self) -> usize

Gets the length of this object after it has been serialized. This can be overridden to optimize cases where we prepend an object with its length.

impl Eq for Witness

impl StructuralPartialEq for Witness