oprf

Documentation

Overview

Package oprf implements the Elliptic Curve Oblivious Pseudorandom Function (EC-OPRF) from https://tools.ietf.org/html/draft-irtf-cfrg-voprf.

Index

• type Client
  • func (c *Client) Blind(input []byte, blind *group.Scalar) *group.Element
  • func (c *Client) Finalize(evaluation *group.Element) []byte
• type Identifier
  • func IDFromGroup(g group.Group) Identifier
  • func (i Identifier) Available() bool
  • func (i Identifier) Client() *Client
  • func (i Identifier) DeriveKey(seed, info []byte) *group.Scalar
  • func (i Identifier) Evaluate(privateKey *group.Scalar, blindedElement *group.Element) *group.Element
  • func (i Identifier) Group() group.Group

Types

type Client

type Client struct {
	Identifier
	// contains filtered or unexported fields
}

Client implements the OPRF client and holds its state.

func (*Client) Blind

func (c *Client) Blind(input []byte, blind *group.Scalar) *group.Element

Blind masks the input.

func (*Client) Finalize

func (c *Client) Finalize(evaluation *group.Element) []byte

Finalize terminates the OPRF by unblinding the evaluation and hashing the transcript.

type Identifier

type Identifier string

Identifier of the OPRF compatible cipher suite to be used.

const (
	// Ristretto255Sha512 is the OPRF cipher suite of the Ristretto255 group and SHA-512.
	Ristretto255Sha512 Identifier = "ristretto255-SHA512"

	// P256Sha256 is the OPRF cipher suite of the NIST P-256 group and SHA-256.
	P256Sha256 Identifier = "P256-SHA256"

	// P384Sha384 is the OPRF cipher suite of the NIST P-384 group and SHA-384.
	P384Sha384 Identifier = "P384-SHA384"

	// P521Sha512 is the OPRF cipher suite of the NIST P-512 group and SHA-512.
	P521Sha512 Identifier = "P521-SHA512"
)

func IDFromGroup

func IDFromGroup(g group.Group) Identifier

IDFromGroup returns the OPRF identifier corresponding to the input group.

func (Identifier) Available

func (i Identifier) Available() bool

Available returns whether the Identifier has been registered of not.

func (Identifier) Client

func (i Identifier) Client() *Client

Client returns an OPRF client.

func (Identifier) DeriveKey

func (i Identifier) DeriveKey(seed, info []byte) *group.Scalar

DeriveKey returns a scalar mapped from the input.

func (Identifier) Evaluate

func (i Identifier) Evaluate(privateKey *group.Scalar, blindedElement *group.Element) *group.Element

Evaluate evaluates the blinded input with the given key.

func (Identifier) Group

func (i Identifier) Group() group.Group

Group returns the Group identifier for the cipher suite.