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- /*! noble-curves - MIT License (c) 2022 Paul Miller (paulmillr.com) */
- import { blake2s } from '@noble/hashes/blake2s';
- import { sha512 } from '@noble/hashes/sha512';
- import { concatBytes, randomBytes, utf8ToBytes } from '@noble/hashes/utils';
- import { twistedEdwards } from './abstract/edwards.js';
- import { Field } from './abstract/modular.js';
- /**
- * jubjub Twisted Edwards curve.
- * https://neuromancer.sk/std/other/JubJub
- * jubjub does not use EdDSA, so `hash`/sha512 params are passed because interface expects them.
- */
- export const jubjub = /* @__PURE__ */ twistedEdwards({
- // Params: a, d
- a: BigInt('0x73eda753299d7d483339d80809a1d80553bda402fffe5bfeffffffff00000000'),
- d: BigInt('0x2a9318e74bfa2b48f5fd9207e6bd7fd4292d7f6d37579d2601065fd6d6343eb1'),
- // Finite field 𝔽p over which we'll do calculations
- // Same value as bls12-381 Fr (not Fp)
- Fp: Field(BigInt('0x73eda753299d7d483339d80809a1d80553bda402fffe5bfeffffffff00000001')),
- // Subgroup order: how many points curve has
- n: BigInt('0xe7db4ea6533afa906673b0101343b00a6682093ccc81082d0970e5ed6f72cb7'),
- // Cofactor
- h: BigInt(8),
- // Base point (x, y) aka generator point
- Gx: BigInt('0x11dafe5d23e1218086a365b99fbf3d3be72f6afd7d1f72623e6b071492d1122b'),
- Gy: BigInt('0x1d523cf1ddab1a1793132e78c866c0c33e26ba5cc220fed7cc3f870e59d292aa'),
- hash: sha512,
- randomBytes,
- });
- const GH_FIRST_BLOCK = utf8ToBytes('096b36a5804bfacef1691e173c366a47ff5ba84a44f26ddd7e8d9f79d5b42df0');
- // Returns point at JubJub curve which is prime order and not zero
- export function groupHash(tag, personalization) {
- const h = blake2s.create({ personalization, dkLen: 32 });
- h.update(GH_FIRST_BLOCK);
- h.update(tag);
- // NOTE: returns ExtendedPoint, in case it will be multiplied later
- let p = jubjub.ExtendedPoint.fromHex(h.digest());
- // NOTE: cannot replace with isSmallOrder, returns Point*8
- p = p.multiply(jubjub.CURVE.h);
- if (p.equals(jubjub.ExtendedPoint.ZERO))
- throw new Error('Point has small order');
- return p;
- }
- export function findGroupHash(m, personalization) {
- const tag = concatBytes(m, new Uint8Array([0]));
- for (let i = 0; i < 256; i++) {
- tag[tag.length - 1] = i;
- try {
- return groupHash(tag, personalization);
- }
- catch (e) { }
- }
- throw new Error('findGroupHash tag overflow');
- }
- //# sourceMappingURL=jubjub.js.map
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