class xf::security::eddsaEd25519

#include "eddsa.hpp"

Overview

Edwards-curve Digital Signature Algorithm on curve ed25519. It take RFC 8032 “Edwards-Curve Digital Signature Algorithm (EdDSA)” as reference. This class provide signing and verifying functions.

// fields

const int b
const int c
const int n
const int a
const ap_uint <256> Bx
const ap_uint <256> By
const ap_uint <256> L
const ap_uint <256> p
const ap_uint <256> d
const ap_uint <256> p_5_d8
const ap_uint <256> sqrt_n1
const ap_uint <256> rMod
ap_uint <64> head[8]

Fields

const int b

ed25519 related curve parameters.

Methods

compress

void compress (
    ap_uint <256> x,
    ap_uint <256> y,
    ap_uint <256>& res
    )

Compress a point (x, y) on curve to its compressed form.

Parameters:

x	X coordinate of point.
y	Y coordinate of point.
res	compressed point representation.

modularSqrt

bool modularSqrt (
    ap_uint <256> u,
    ap_uint <256> v,
    ap_uint <256>& sqrt_a
    )

Calculate square root of u/v.

Parameters:

u	Input u of u/v to calculate square root.
v	Input u of u/v to calculate square root.
sqrt_a	Square root of u/v.

decompress

bool decompress (
    ap_uint <256> P,
    ap_uint <256>& Px,
    ap_uint <256>& Py
    )

Decompress a point (Px, Py) from its compressed representation.

Parameters:

P	compressed point representation.
Px	X coordinate of the point.
Py	Y coordinate of the point.

pointAdd

void pointAdd (
    ap_uint <256> x1,
    ap_uint <256> y1,
    ap_uint <256> x2,
    ap_uint <256> y2,
    ap_uint <256>& x3,
    ap_uint <256>& y3
    )

perform point addition in ed25519, (x3, y3) = (x1, y1) + (x2, y2)

Parameters:

x1	X coordinate of point 1.
y1	Y coordinate of point 1.
x2	X coordinate of point 2.
y2	Y coordinate of point 2.
x3	X coordinate of point 3.
y3	Y coordinate of point 3.

pointMul

void pointMul (
    ap_uint <256> x,
    ap_uint <256> y,
    ap_uint <256> mag,
    ap_uint <256>& resX,
    ap_uint <256>& resY
    )

perform point multiply scalar in ed25519, (resX, resY) = (x, y) * mag

Parameters:

x	X coordinate of point to be multiplied.
y	Y coordinate of point to be multiplied.
mag	scalar operand of this multiplication.
resX	X coordinate of result.
resY	Y coordinate of result.

generatePublicKey

void generatePublicKey (
    ap_uint <256> privateKey,
    ap_uint <256>& publicKey,
    ap_uint <512>& privateKeyHash
    )

Generate public key and digest value of privateKey hash value from privateKey.

Parameters:

privateKey	Private Key.
publicKey	Public Key.
privateKeyHash	Digest value of private key.

sign

void sign (
    hls::stream <ap_uint <64>>& msgStrm,
    hls::stream <ap_uint <128>>& lenStrm,
    hls::stream <bool>& endLenStrm,
    ap_uint <256> publicKey,
    ap_uint <512> privateKeyHash,
    hls::stream <ap_uint <512>>& signatureStrm,
    hls::stream <bool>& endSignatureStrm
    )

signing function

Parameters:

msgStrm	Stream to input messages to be signed, each message should be input throught this stream twice.
lenStrm	Stream to input length of input messages.
endLenStrm	Stream of end flag of lenStrm.
publicKey	Public Key.
privateKeyHash	Digest value of private key.
signatureStrm	Stream to output signature.
endSignatureStrm	Stream of end flag of signatureStrm.

verify

void verify (
    hls::stream <ap_uint <64>>& msgStrm,
    hls::stream <ap_uint <128>>& lenStrm,
    hls::stream <ap_uint <512>>& signatureStrm,
    hls::stream <bool>& endSignatureStrm,
    hls::stream <ap_uint <256>>& publicKeyStrm,
    hls::stream <bool>& ifValidStrm,
    hls::stream <bool>& endIfValidStrm
    )

verifying function

Parameters:

msgStrm	Stream to input messages to be signed.
lenStrm	Stream to input length of input messages.
signatureStrm	Stream to input signatures.
endSignatureStrm	Stream of end flag of signatures.
publicKeyStrm	Stream to input public key.
ifValidStrm	Stream to output if message signature is valid.
endIfValidStrm	Stream of end flag of ifValidStrm.