Experiments with RSA encryption

vendors/jsbn/rng.js

@@ -0,0 +1,65 @@
+// Random number generator - requires a PRNG backend, e.g. prng4.js
+var rng_state;
+var rng_pool;
+var rng_pptr;
+
+// Initialize the pool with junk if needed.
+if(rng_pool == null) {
+  rng_pool = new Array();
+  rng_pptr = 0;
+  var t;
+  if(window.crypto && window.crypto.getRandomValues) {
+    // Extract entropy (2048 bits) from RNG if available
+    var z = new Uint32Array(256);
+    window.crypto.getRandomValues(z);
+    for (t = 0; t < z.length; ++t)
+      rng_pool[rng_pptr++] = z[t] & 255;
+  } 
+  
+  // Use mouse events for entropy, if we do not have enough entropy by the time
+  // we need it, entropy will be generated by Math.random.
+  var onMouseMoveListener = function(ev) {
+    this.count = this.count || 0;
+    if (this.count >= 256 || rng_pptr >= rng_psize) {
+      if (window.removeEventListener)
+        window.removeEventListener("mousemove", onMouseMoveListener);
+      else if (window.detachEvent)
+        window.detachEvent("onmousemove", onMouseMoveListener);
+      return;
+    }
+    this.count += 1;
+    var mouseCoordinates = ev.x + ev.y;
+    rng_pool[rng_pptr++] = mouseCoordinates & 255;
+  };
+  if (window.addEventListener)
+    window.addEventListener("mousemove", onMouseMoveListener);
+  else if (window.attachEvent)
+    window.attachEvent("onmousemove", onMouseMoveListener);
+  
+}
+
+function rng_get_byte() {
+  if(rng_state == null) {
+    rng_state = prng_newstate();
+    // At this point, we may not have collected enough entropy.  If not, fall back to Math.random
+    while (rng_pptr < rng_psize) {
+      var random = Math.floor(65536 * Math.random());
+      rng_pool[rng_pptr++] = random & 255;
+    }
+    rng_state.init(rng_pool);
+    for(rng_pptr = 0; rng_pptr < rng_pool.length; ++rng_pptr)
+      rng_pool[rng_pptr] = 0;
+    rng_pptr = 0;
+  }
+  // TODO: allow reseeding after first request
+  return rng_state.next();
+}
+
+function rng_get_bytes(ba) {
+  var i;
+  for(i = 0; i < ba.length; ++i) ba[i] = rng_get_byte();
+}
+
+function SecureRandom() {}
+
+SecureRandom.prototype.nextBytes = rng_get_bytes;