chjj

On October 11th, 2022, @ajtowns publicly disclosed a zero-day consensus fault in btcd in a github issue. The issue was posted on a public repo viewable by anyone.

According to gharchive.org logs, the github issue remained up for at least 10 hours before being deleted. The original github issue resided at https://github.com/Roasbeef/btcd/issues/35

The issue and comment can be found and reconstructed from the following JSON dumps:

• https://data.gharchive.org/2022-10-11-3.json.gz
• https://data.gharchive.org/2022-10-11-13.json.gz

Reconstruction of the issue and comment by @ajtowns

chjj

C Reserved Identifiers

This translates sections [7.1.3][1] ("Reserved Identifiers") and [7.13][1] ("Future library directions") of the ISO C90 specification into English (and regexes).

This document will also cover the additions introduced by C99's section [7.26][3] ("Future library directions"), C11's section [7.31][4] ("Future library directions"), and C17's section [7.1.3][5] ("Reserved Identifiers").

chjj

. 172800 IN DNSKEY 256 3 8 AwEAAcH+axCdUOsTc9o+jmyVq5rsGTh1EcatSumPqEfsPBT+whyj0/Uh D7cWeixV9Wqzj/cnqs8iWELqhdzGX41ZtaNQUfWNfOriASnWmX2D9m/E unplHu8nMSlDnDcT7+llE9tjk5HI1Sr7d9N16ZTIrbVALf65VB2ABbBG 39dyAb7tz21PICJbSp2cd77UF7NFqEVkqohl/LkDw+7Apalmp0qAQT1M gwi2cVxZMKUiciA6EqS+KNajf0A6olO2oEhZnGGY6b1LTg34/YfHdiII ZQqAfqbieruCGHRiSscC2ZE7iNreL/76f4JyIEUNkt6bQA29JsegxorL zQkpF7NKqZc=  ; ZSK ; alg = RSASHA256 ; bits = 2048,17 ; key id = 16749
. 172800 IN DNSKEY 257 3 8 AwEAAaz/tAm8yTn4Mfeh5eyI96WSVexTBAvkMgJzkKTOiW1vkIbzxeF3 +/4RgWOq7HrxRixHlFlExOLAJr5emLvN7SWXgnLh4+B5xQlNVz8Og8kv ArMtNROxVQuCaSnIDdD5LKyWbRd2n9WGe2R8PzgCmr3EgVLrjyBxWezF 0jLHwVN8efS3rCj/EWgvIWgb9tarpVUDK/b58Da+sqqls3eNbuv7pr+e oZG+SrDK6nWeL3c6H5Apxz7LjVc1uTIdsIXxuOLYA4/ilBmSVIzuDWfd RUfhHdY6+cn8HFRm+2hM8AnXGXws9555KrUB5qihylGa8subX2Nn6UwN R1AkUTV74bU=  ; KSK ; alg = RSASHA256 ; bits = 2048,17 ; key id = 20326
. 172800 IN DNSKEY 385 3 8 AwEAAagAIKlVZrpC6Ia7gEzahOR+9W29euxhJhVVLOyQbSEW0O8gcCjF FVQUTf6v58fLjwBd0YI0EzrAcQqBGCzh/RStIoO8g0NfnfL2MTJRkxoX b

chjj

Twisted Edwards & Short Weierstrass Equivalence

Putting this here since I don't see it documented anywhere in the literature.

Note that your Short Weierstrass curve must have 2-torsion.

1. Short Weierstrass -> Twisted Edwards

s = sqrt(3 * r^2 + a)

chjj

Covert ECDH over secp256k1

If ECDH is used to establish a shared session secret for an encrypted connection, two elliptic curve points need to be transmitted (one in each direction) before encryption starts. In order to avoid being identifiable as a (specific) ECDH negotiation, ideally those two points are sent in a way that is indistinguishable from random.

This problem is easily addressed by using curves that support Elligator-style encodings: functions that encode a (subset of) elliptic curve points as sequences of bytes with no observable bias: (almost) every byte sequence corresponds to exactly one point, and the others correspond to none.

Unfortunately, no Elligator-style encoding is known for secp256k1.

chjj

"
" ~/.vimrc
"

set nocompatible
set hidden
set ruler
set visualbell
set noerrorbells
set nostartofline

chjj

#!/usr/bin/env node

/* eslint no-control-regex: "off" */

'use strict';

const assert = require('assert');
const Path = require('path');

const {

chjj

'use strict';

const path = require('path');
const fs = require('./lib/utils/fs');

async function findFiles(dir, match, ignore, files) {
  const list = await fs.readdir(dir);

  for (const name of list) {
    if (ignore.has(name))

chjj

'use strict';

// Sweep bcc from trezor multisig.

const assert = require('assert');
const util = require('util');
const trezor = require('trezor.js-node');
const HDPublicKey = require('bcoin/lib/hd/public');

const HARDENED = 0x80000000;

chjj

[
  {
    "hash": "0000000000000000018c59d807bff651ead9f8fd6eef075ee5cffcf98bf4674c",
    "height": 464208,
    "size": 998109,
    "txs": 684,
    "inputs": 6162,
    "outputs": 1362,
    "inputCost": 5578086,
    "outputCost": 271012,