wip: rsa impl

src/public/js/main.js

@@ -1,3 +1,5 @@
+import { gen_RSA_keypair, RSA_enc } from "./rsa.js";
+
 window.addEventListener("load", () => main());
 
 const main = () => {
@@ -54,7 +56,12 @@ const send = (file, element) => {
         parent.appendChild(newText);
     }
 
-    // TODO: Encrypt the file before sending it
+    // Encrypt the file
+    gen_RSA_keypair(1024).then((keys) =>
+        console.log(`p=${keys[0]}, s=${keys[1]}`)
+    );
+
+    // Send it
     const data = new FormData();
     data.append("file", file);
 

src/public/js/rsa.js

@@ -0,0 +1,53 @@
+BigNumber.prototype.floor = function () {
+    return this.integerValue(BigNumber.ROUND_FLOOR);
+};
+
+export const gen_RSA_keypair = async (bits) => {
+    const getPrime = (bits) => {
+        return new Promise((ok, ko) => {
+            forge.prime.generateProbablePrime(bits, (err, data) => {
+                if (err) return ko(err);
+                ok(new BigNumber(data));
+            });
+        });
+    };
+
+    const pq_size = bits / 2;
+
+    const p = await getPrime(pq_size);
+    const q = await getPrime(pq_size);
+    console.assert(p != q);
+
+    const n = p.times(q);
+
+    const phi_n = p.minus(1).times(q.minus(1));
+
+    const e = new BigNumber(65537);
+    console.assert(e.isLessThan(phi_n) && phi_n.modulo(e) != 0);
+
+    // https://stackoverflow.com/a/51562038/15436737
+    const inverse = (a, m) => {
+        const s = [];
+        let b = m;
+        while (b) {
+            [a, b] = [b, a % b];
+            s.push({ a, b });
+        }
+        let x = 1;
+        let y = 0;
+        for (let i = s.length - 2; i >= 0; --i) {
+            [x, y] = [y, x - y * Math.floor(s[i].a / s[i].b)];
+        }
+
+        return ((y % m) + m) % m;
+    };
+
+    const d = inverse(e, phi_n);
+
+    console.log((e, n), (d, n));
+    return [(e, n), (d, n)];
+};
+
+const RSA = () => {};
+
+export const RSA_enc = (key, data) => {};

src/templates/index.html

@@ -34,6 +34,19 @@
             <p>NPNO</p>
         </footer>
 
-        <script src="../js/main.js"></script>
+        <script
+            src="https://cdnjs.cloudflare.com/ajax/libs/forge/1.3.1/forge.min.js"
+            integrity="sha512-95iy0RZIbw3H/FgfAj2wnCQJlzFQ+eaSfUeV/l8WVyGHKSRMzm3M/O+85j9ba/HFphkijrCTDjcuDX0BL2lthA=="
+            crossorigin="anonymous"
+            referrerpolicy="no-referrer"
+        ></script>
+        <script
+            src="https://cdnjs.cloudflare.com/ajax/libs/bignumber.js/9.1.0/bignumber.min.js"
+            integrity="sha512-w9skcoMiLIpBsmoP7TBpXooZl4nnj7z354N2w+T52bBy965eXP68U6cUvq5/aXGmn8YmwNAirnUtQPPPjk1prQ=="
+            crossorigin="anonymous"
+            referrerpolicy="no-referrer"
+        ></script>
+
+        <script type="module" src="../js/main.js"></script>
     </body>
 </html>