@coolwallet/sol/src/utils/ed25519.ts

Coolwallet Solana sdk

/* eslint-disable */
import nacl from 'tweetnacl';
// @ts-ignore
let naclLowLevel = nacl.lowlevel;

function neq25519(a: any, b: any) {
  var c = new Uint8Array(32),
    d = new Uint8Array(32);
  naclLowLevel.pack25519(c, a);
  naclLowLevel.pack25519(d, b);
  return naclLowLevel.crypto_verify_32(c, 0, d, 0);
}

// Check that a pubkey is on the curve.
// This function and its dependents were sourced from:
// https://github.com/dchest/tweetnacl-js/blob/f1ec050ceae0861f34280e62498b1d3ed9c350c6/nacl.js#L792
function is_on_curve(p: any) {
  var r = [naclLowLevel.gf(), naclLowLevel.gf(), naclLowLevel.gf(), naclLowLevel.gf()];

  var t = naclLowLevel.gf(),
    chk = naclLowLevel.gf(),
    num = naclLowLevel.gf(),
    den = naclLowLevel.gf(),
    den2 = naclLowLevel.gf(),
    den4 = naclLowLevel.gf(),
    den6 = naclLowLevel.gf();

  naclLowLevel.set25519(r[2], gf1);
  naclLowLevel.unpack25519(r[1], p);
  naclLowLevel.S(num, r[1]);
  naclLowLevel.M(den, num, naclLowLevel.D);
  naclLowLevel.Z(num, num, r[2]);
  naclLowLevel.A(den, r[2], den);

  naclLowLevel.S(den2, den);
  naclLowLevel.S(den4, den2);
  naclLowLevel.M(den6, den4, den2);
  naclLowLevel.M(t, den6, num);
  naclLowLevel.M(t, t, den);

  naclLowLevel.pow2523(t, t);
  naclLowLevel.M(t, t, num);
  naclLowLevel.M(t, t, den);
  naclLowLevel.M(t, t, den);
  naclLowLevel.M(r[0], t, den);

  naclLowLevel.S(chk, r[0]);
  naclLowLevel.M(chk, chk, den);
  if (neq25519(chk, num)) naclLowLevel.M(r[0], r[0], I);

  naclLowLevel.S(chk, r[0]);
  naclLowLevel.M(chk, chk, den);
  if (neq25519(chk, num)) return 0;
  return 1;
}
let gf1 = naclLowLevel.gf([1]);
let I = naclLowLevel.gf([
  0xa0b0, 0x4a0e, 0x1b27, 0xc4ee, 0xe478, 0xad2f, 0x1806, 0x2f43, 0xd7a7, 0x3dfb, 0x0099, 0x2b4d, 0xdf0b, 0x4fc1,
  0x2480, 0x2b83,
]);

export { is_on_curve };