@waku/rln
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RLN (Rate Limiting Nullifier) implementation for Waku
113 lines (110 loc) • 4.46 kB
JavaScript
import { HashMD, SHA256_IV, Chi, Maj } from './_md.js';
import { createHasher, clean, rotr } from './utils.js';
/**
* SHA2 hash function. A.k.a. sha256, sha384, sha512, sha512_224, sha512_256.
* SHA256 is the fastest hash implementable in JS, even faster than Blake3.
* Check out [RFC 4634](https://datatracker.ietf.org/doc/html/rfc4634) and
* [FIPS 180-4](https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.180-4.pdf).
* @module
*/
/**
* Round constants:
* First 32 bits of fractional parts of the cube roots of the first 64 primes 2..311)
*/
// prettier-ignore
const SHA256_K = /* @__PURE__ */ Uint32Array.from([
0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
]);
/** Reusable temporary buffer. "W" comes straight from spec. */
const SHA256_W = /* @__PURE__ */ new Uint32Array(64);
class SHA256 extends HashMD {
constructor(outputLen = 32) {
super(64, outputLen, 8, false);
// We cannot use array here since array allows indexing by variable
// which means optimizer/compiler cannot use registers.
this.A = SHA256_IV[0] | 0;
this.B = SHA256_IV[1] | 0;
this.C = SHA256_IV[2] | 0;
this.D = SHA256_IV[3] | 0;
this.E = SHA256_IV[4] | 0;
this.F = SHA256_IV[5] | 0;
this.G = SHA256_IV[6] | 0;
this.H = SHA256_IV[7] | 0;
}
get() {
const { A, B, C, D, E, F, G, H } = this;
return [A, B, C, D, E, F, G, H];
}
// prettier-ignore
set(A, B, C, D, E, F, G, H) {
this.A = A | 0;
this.B = B | 0;
this.C = C | 0;
this.D = D | 0;
this.E = E | 0;
this.F = F | 0;
this.G = G | 0;
this.H = H | 0;
}
process(view, offset) {
// Extend the first 16 words into the remaining 48 words w[16..63] of the message schedule array
for (let i = 0; i < 16; i++, offset += 4)
SHA256_W[i] = view.getUint32(offset, false);
for (let i = 16; i < 64; i++) {
const W15 = SHA256_W[i - 15];
const W2 = SHA256_W[i - 2];
const s0 = rotr(W15, 7) ^ rotr(W15, 18) ^ (W15 >>> 3);
const s1 = rotr(W2, 17) ^ rotr(W2, 19) ^ (W2 >>> 10);
SHA256_W[i] = (s1 + SHA256_W[i - 7] + s0 + SHA256_W[i - 16]) | 0;
}
// Compression function main loop, 64 rounds
let { A, B, C, D, E, F, G, H } = this;
for (let i = 0; i < 64; i++) {
const sigma1 = rotr(E, 6) ^ rotr(E, 11) ^ rotr(E, 25);
const T1 = (H + sigma1 + Chi(E, F, G) + SHA256_K[i] + SHA256_W[i]) | 0;
const sigma0 = rotr(A, 2) ^ rotr(A, 13) ^ rotr(A, 22);
const T2 = (sigma0 + Maj(A, B, C)) | 0;
H = G;
G = F;
F = E;
E = (D + T1) | 0;
D = C;
C = B;
B = A;
A = (T1 + T2) | 0;
}
// Add the compressed chunk to the current hash value
A = (A + this.A) | 0;
B = (B + this.B) | 0;
C = (C + this.C) | 0;
D = (D + this.D) | 0;
E = (E + this.E) | 0;
F = (F + this.F) | 0;
G = (G + this.G) | 0;
H = (H + this.H) | 0;
this.set(A, B, C, D, E, F, G, H);
}
roundClean() {
clean(SHA256_W);
}
destroy() {
this.set(0, 0, 0, 0, 0, 0, 0, 0);
clean(this.buffer);
}
}
/**
* SHA2-256 hash function from RFC 4634.
*
* It is the fastest JS hash, even faster than Blake3.
* To break sha256 using birthday attack, attackers need to try 2^128 hashes.
* BTC network is doing 2^70 hashes/sec (2^95 hashes/year) as per 2025.
*/
const sha256 = /* @__PURE__ */ createHasher(() => new SHA256());
export { SHA256, sha256 };