From fbd46b3f3f6732d8d3cc5f02f4cf752a57f9a1f5 Mon Sep 17 00:00:00 2001
From: Roland Osborne <roland.osborne@gmail.com>
Date: Tue, 3 Jan 2023 23:47:33 -0800
Subject: [PATCH] refactoring contexts

---
 net/web/src/util/sealUtil.js | 74 ++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)
 create mode 100644 net/web/src/util/sealUtil.js

diff --git a/net/web/src/util/sealUtil.js b/net/web/src/util/sealUtil.js
new file mode 100644
index 00000000..4431b516
--- /dev/null
+++ b/net/web/src/util/sealUtil.js
@@ -0,0 +1,74 @@
+import CryptoJS from 'crypto-js';
+import { JSEncrypt } from 'jsencrypt'
+
+export function isUnsealed(subject, sealKey) {
+  const { seals } = JSON.parse(subject);
+  for (let i = 0; i < seals?.length; i++) {
+    if (seals[i].publicKey === sealKey.public) {
+      return sealKey.private != null;
+    }
+  }
+  return false;
+}
+
+export function getContentKey(subject, sealKey) {
+  for (let i = 0; i < seal?.length; i++) {
+    if (seal[i].publicKey === sealKey.public) {
+      let crypto = new JSEncrypt();
+      crypto.setPrivateKey(sealKey.private);
+      return crypto.decrypt(seal.sealedKey);
+      
+    }
+  }
+  throw new Error("unsealKey not available");
+}
+
+export function encryptChannelSubject(subject, publicKeys) {
+  const key = CryptoJS.lib.WordArray.random(256 / 8);
+  const iv = CryptoJS.lib.WordArray.random(128 / 8);
+  const encrypted = CryptoJS.AES.encrypt(JSON.stringify({ subject }), key, { iv: iv });
+  const subjectEncrypted = encrypted.ciphertext.toString(CryptoJS.enc.Base64)
+  const subjectIv = iv.toString();
+  const keyHex = key.toString();
+
+  let seals = [];
+  let crypto = new JSEncrypt();
+  publicKeys.forEach(key => {
+    crypto.setPublicKey(key);
+    const sealedKey = crypto.encrypt(keyHex);
+    seals.push({ publicKey, sealedKey });
+  });
+
+  return { subjectEncrypted, subjectIv, seals };
+}
+
+export function decryptChannelSubject(subject, sealKey) {
+  const { subjectEncrypted, subjectIv, seals } = JSON.parse(subject);
+  const contentKey = getContentKey(seals, sealKey);
+  const iv = CryptoJS.enc.Hex.parse(subjectIv);
+  const key = CryptoJS.enc.Hex.parse(contentKey);
+  const enc = CryptoJS.enc.Base64.parse(subjectEncrypted);
+  const cipher = CryptoJS.lib.CipherParams.create({ ciphertext: enc, iv: iv });
+  const dec = CryptoJS.AES.decrypt(cipher, key, { iv: iv });
+  return JSON.parse(dec.toString(CryptoJS.enc.Utf8));
+}
+
+export function encryptTopicSubject(subject, contentKey) {
+  const iv = CryptoJS.lib.WordArray.random(128 / 8);
+  const key = CryptoJS.enc.Hex.parse(contentKey);
+  const encrypted = CryptoJS.AES.encrypt(JSON.stringify({ subject }), key, { iv: iv });
+  const messageEncrypted = encrypted.ciphertext.toString(CryptoJS.enc.Base64)
+  const messageIv = iv.toString();
+  return { messageEncrypted, messageIv };
+}
+
+export function decryptTopicSubject(subject, contentKey) {
+  const { messageEncrypted, messageIv } = JSON.parse(subject);
+  const iv = CryptoJS.enc.Hex.parse(messageIv);
+  const key = CryptoJS.enc.Hex.parse(contentKey);
+  const enc = CryptoJS.enc.Base64.parse(messageEncrypted);
+  let cipher = CryptoJS.lib.CipherParams.create({ ciphertext: enc, iv: iv });
+  const dec = CryptoJS.AES.decrypt(cipher, key, { iv: iv });
+  return JSON.parse(dec.toString(CryptoJS.enc.Utf8));
+}
+