Struct sp_application_crypto::bandersnatch::vrf::VrfSignData

pub struct VrfSignData {
    pub transcript: Transcript,
    pub inputs: BoundedVec<VrfInput, ConstU32<sp_core::::bandersnatch::vrf::VrfIosVec::{constant#0}>>,
}

Data to be signed via one of the two provided vrf flavors.

The object contains a transcript and a sequence of VrfInputs ready to be signed.

The transcript summarizes a set of messages which are defining a particular protocol by automating the Fiat-Shamir transform for challenge generation. A good explanation of the topic can be found in Merlin docs

The inputs is a sequence of VrfInputs which, during the signing procedure, are first transformed to VrfPreOutputs. Both inputs and pre-outputs are then appended to the transcript before signing the Fiat-Shamir transform result (the challenge).

In practice, as a user, all these technical details can be easily ignored. What is important to remember is:

• Transcript is an object defining the protocol and used to produce the signature. This object doesn’t influence the VrfPreOutputs values.
• Vrf inputs is some additional data which is used to produce vrf pre-outputs. This data will contribute to the signature as well.

Fields

transcript: Transcript

Associated protocol transcript.

inputs: BoundedVec<VrfInput, ConstU32<sp_core::::bandersnatch::vrf::VrfIosVec::{constant#0}>>

VRF inputs to be signed.

Implementations

impl VrfSignData

pub fn new( transcript_label: &'static [u8], transcript_data: impl IntoIterator<Item = impl AsRef<[u8]>>, inputs: impl IntoIterator<Item = VrfInput>, ) -> Result<VrfSignData, ()>

Construct a new data to be signed.

Fails if the inputs iterator yields more elements than MAX_VRF_IOS

Refer to VrfSignData for details about transcript and inputs.

pub fn new_unchecked( transcript_label: &'static [u8], transcript_data: impl IntoIterator<Item = impl AsRef<[u8]>>, inputs: impl IntoIterator<Item = VrfInput>, ) -> VrfSignData

Construct a new data to be signed.

At most the first MAX_VRF_IOS elements of inputs are used.

Refer to VrfSignData for details about transcript and inputs.

pub fn push_transcript_data(&mut self, data: &[u8])

Append a message to the transcript.

pub fn push_vrf_input(&mut self, input: VrfInput) -> Result<(), VrfInput>

Tries to append a VrfInput to the vrf inputs list.

On failure, returns back the VrfInput parameter.

pub fn challenge<const N: usize>(&self) -> [u8; N]

Get the challenge associated to the transcript contained within the signing data.

Ignores the vrf inputs and outputs.

Trait Implementations

impl Clone for VrfSignData

fn clone(&self) -> VrfSignData

Returns a copy of the value.

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

Performs copy-assignment from source.