newsroom/node_modules/nostr-tools/lib/cjs/nip44.js

"use strict";
var __defProp = Object.defineProperty;
var __getOwnPropDesc = Object.getOwnPropertyDescriptor;
var __getOwnPropNames = Object.getOwnPropertyNames;
var __hasOwnProp = Object.prototype.hasOwnProperty;
var __export = (target, all) => {
  for (var name in all)
    __defProp(target, name, { get: all[name], enumerable: true });
};
var __copyProps = (to, from, except, desc) => {
  if (from && typeof from === "object" || typeof from === "function") {
    for (let key of __getOwnPropNames(from))
      if (!__hasOwnProp.call(to, key) && key !== except)
        __defProp(to, key, { get: () => from[key], enumerable: !(desc = __getOwnPropDesc(from, key)) || desc.enumerable });
  }
  return to;
};
var __toCommonJS = (mod) => __copyProps(__defProp({}, "__esModule", { value: true }), mod);

// nip44.ts
var nip44_exports = {};
__export(nip44_exports, {
  decrypt: () => decrypt,
  encrypt: () => encrypt,
  getConversationKey: () => getConversationKey,
  v2: () => v2
});
module.exports = __toCommonJS(nip44_exports);
var import_chacha = require("@noble/ciphers/chacha");
var import_utils2 = require("@noble/ciphers/utils");
var import_secp256k1 = require("@noble/curves/secp256k1");
var import_hkdf = require("@noble/hashes/hkdf");
var import_hmac = require("@noble/hashes/hmac");
var import_sha256 = require("@noble/hashes/sha256");
var import_utils3 = require("@noble/hashes/utils");
var import_base = require("@scure/base");

// utils.ts
var import_utils = require("@noble/hashes/utils");
var utf8Decoder = new TextDecoder("utf-8");
var utf8Encoder = new TextEncoder();

// nip44.ts
var minPlaintextSize = 1;
var maxPlaintextSize = 65535;
function getConversationKey(privkeyA, pubkeyB) {
  const sharedX = import_secp256k1.secp256k1.getSharedSecret(privkeyA, "02" + pubkeyB).subarray(1, 33);
  return (0, import_hkdf.extract)(import_sha256.sha256, sharedX, "nip44-v2");
}
function getMessageKeys(conversationKey, nonce) {
  const keys = (0, import_hkdf.expand)(import_sha256.sha256, conversationKey, nonce, 76);
  return {
    chacha_key: keys.subarray(0, 32),
    chacha_nonce: keys.subarray(32, 44),
    hmac_key: keys.subarray(44, 76)
  };
}
function calcPaddedLen(len) {
  if (!Number.isSafeInteger(len) || len < 1)
    throw new Error("expected positive integer");
  if (len <= 32)
    return 32;
  const nextPower = 1 << Math.floor(Math.log2(len - 1)) + 1;
  const chunk = nextPower <= 256 ? 32 : nextPower / 8;
  return chunk * (Math.floor((len - 1) / chunk) + 1);
}
function writeU16BE(num) {
  if (!Number.isSafeInteger(num) || num < minPlaintextSize || num > maxPlaintextSize)
    throw new Error("invalid plaintext size: must be between 1 and 65535 bytes");
  const arr = new Uint8Array(2);
  new DataView(arr.buffer).setUint16(0, num, false);
  return arr;
}
function pad(plaintext) {
  const unpadded = utf8Encoder.encode(plaintext);
  const unpaddedLen = unpadded.length;
  const prefix = writeU16BE(unpaddedLen);
  const suffix = new Uint8Array(calcPaddedLen(unpaddedLen) - unpaddedLen);
  return (0, import_utils3.concatBytes)(prefix, unpadded, suffix);
}
function unpad(padded) {
  const unpaddedLen = new DataView(padded.buffer).getUint16(0);
  const unpadded = padded.subarray(2, 2 + unpaddedLen);
  if (unpaddedLen < minPlaintextSize || unpaddedLen > maxPlaintextSize || unpadded.length !== unpaddedLen || padded.length !== 2 + calcPaddedLen(unpaddedLen))
    throw new Error("invalid padding");
  return utf8Decoder.decode(unpadded);
}
function hmacAad(key, message, aad) {
  if (aad.length !== 32)
    throw new Error("AAD associated data must be 32 bytes");
  const combined = (0, import_utils3.concatBytes)(aad, message);
  return (0, import_hmac.hmac)(import_sha256.sha256, key, combined);
}
function decodePayload(payload) {
  if (typeof payload !== "string")
    throw new Error("payload must be a valid string");
  const plen = payload.length;
  if (plen < 132 || plen > 87472)
    throw new Error("invalid payload length: " + plen);
  if (payload[0] === "#")
    throw new Error("unknown encryption version");
  let data;
  try {
    data = import_base.base64.decode(payload);
  } catch (error) {
    throw new Error("invalid base64: " + error.message);
  }
  const dlen = data.length;
  if (dlen < 99 || dlen > 65603)
    throw new Error("invalid data length: " + dlen);
  const vers = data[0];
  if (vers !== 2)
    throw new Error("unknown encryption version " + vers);
  return {
    nonce: data.subarray(1, 33),
    ciphertext: data.subarray(33, -32),
    mac: data.subarray(-32)
  };
}
function encrypt(plaintext, conversationKey, nonce = (0, import_utils3.randomBytes)(32)) {
  const { chacha_key, chacha_nonce, hmac_key } = getMessageKeys(conversationKey, nonce);
  const padded = pad(plaintext);
  const ciphertext = (0, import_chacha.chacha20)(chacha_key, chacha_nonce, padded);
  const mac = hmacAad(hmac_key, ciphertext, nonce);
  return import_base.base64.encode((0, import_utils3.concatBytes)(new Uint8Array([2]), nonce, ciphertext, mac));
}
function decrypt(payload, conversationKey) {
  const { nonce, ciphertext, mac } = decodePayload(payload);
  const { chacha_key, chacha_nonce, hmac_key } = getMessageKeys(conversationKey, nonce);
  const calculatedMac = hmacAad(hmac_key, ciphertext, nonce);
  if (!(0, import_utils2.equalBytes)(calculatedMac, mac))
    throw new Error("invalid MAC");
  const padded = (0, import_chacha.chacha20)(chacha_key, chacha_nonce, ciphertext);
  return unpad(padded);
}
var v2 = {
  utils: {
    getConversationKey,
    calcPaddedLen
  },
  encrypt,
  decrypt
};