Struct ECVRF 

pub struct ECVRF { /* private fields */ }

Implementations

impl ECVRF

pub fn from_suite(suite: CipherSuite) -> Result<Self, Error>

Associated function to initialize a ECVRF structure with an initialized context for the given cipher suite.

Arguments:

• suite: Identifying ciphersuite

Returns:

• a ECVRF struct if successful

pub fn hash_to_try_and_increment( &mut self, public_key: &EcPoint, alpha_string: &[u8], ) -> Result<EcPoint, Error>

ECVRF_hash_to_curve implementation as specified in Section 5.4.1.1 [VRF-draft-05]

Arguments

• public_key: an Elliptical Curve point
• alpha_string: value to be hashed, an octet string

Returns:

• a finite EC point in G

pub fn arbitrary_string_to_point( &mut self, data: &[u8], ) -> Result<EcPoint, Error>

Converts an arbitrary string to a point in the curve as specified in Section 5.5 [VRF-draft-05]

Arguments

• data: a 32 octet string to be converted to a point

returns an EcPoint representing the converted point if successful

pub fn generate_nonce( &mut self, secret_key: &BigNum, data: &[u8], ) -> Result<BigNum, Error>

Generates a nonce deterministically from the algorithm specified in Section 3.2 RFC6979

Arguments

• secret key: a BigNum representing the secret key.
• data: a slice of octets representing the message

Returns:

• a BigNum representing the nonce.

pub fn hash_points(&mut self, points: &[&EcPoint]) -> Result<BigNum, Error>

Hashes a slice of EC points to a BigNum integer as specified in Section 5.4.3 [VRF-draft-05]

Arguments

• points: a slice of points that need to be hashed

Returns:

• a BigNum integer (0 < x < 2^(8n) - 1) representing the hash of points truncated to length n, if successful.

pub fn derive_public_key_point( &mut self, private_key: &BigNum, ) -> Result<EcPoint, Error>

Function to derive public key point given a private key.

Arguments

• private_key: a BigNum representing the private key

Returns:

• an EcPoint representing the public key, if successful

pub fn derive_public_key( &mut self, private_key: &[u8], ) -> Result<Vec<u8>, Error>

Function to derive public key given a private key.

Arguments

• private_key: a slice of octets representing the private key

Returns:

• an slice of octets representing the public key, if successful

pub fn decode_proof( &mut self, pi_string: &[u8], ) -> Result<(EcPoint, BigNum, BigNum), Error>

Function to decode a proof pi_string produced by EC_prove, to (gamma, c, s) as specified in Section 5.4.4 [VRF-draft-05]

Arguments

• pi_string: a slice of octets representing the generated proof

Returns

• gamma: an EcPoint
• c: integer between 0 and 2 ^ (8n) - 1
• s: integer between 0 and 2 ^ (8qlen) - 1

Trait Implementations

impl ECVRF<&[u8], &[u8]> for ECVRF

fn prove(&mut self, pkey: &[u8], alpha_string: &[u8]) -> Result<Vec<u8>, Error>

Generates proof from a private key and a message as specified in Section 5.1 [VRF-draft-05]

Arguments:

• pkey: a private key
• alpha_string: octet string message represented by a slice

Returns:

• if successful, a vector of octets representing the proof pi_string

fn proof_to_hash(&mut self, pi_string: &[u8]) -> Result<Vec<u8>, Error>

Generates ECVRF hash output from the provided proof

Arguments:

• pi_string: generated ECVRF proof

Returns

• beta_string: the ECVRF hash output

fn verify( &mut self, public_key: &[u8], alpha_string: &[u8], pi_string: &[u8], ) -> Result<Vec<u8>, Error>

Verifies the provided VRF proof and computes the VRF hash output

Arguments:

• public_key: a slice representing the public key in octets
• alpha_string: VRF hash input, an octet string
• pi_string: proof to be verified, an octet string

Returns:

• if successful, a vector of octets with the VRF hash output

type Error = Error