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+/*
+ * Copyright (c) 2003-2005 Tom Wu
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
+ * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * IN NO EVENT SHALL TOM WU BE LIABLE FOR ANY SPECIAL, INCIDENTAL,
+ * INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, OR ANY DAMAGES WHATSOEVER
+ * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER OR NOT ADVISED OF
+ * THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF LIABILITY, ARISING OUT
+ * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * In addition, the following condition applies:
+ *
+ * All redistributions must retain an intact copy of this copyright notice
+ * and disclaimer.
+ */
+
+// Random number generator - requires a PRNG backend, e.g. prng4.js
+
+// For best results, put code like
+// <body onClick='rng_seed_time();' onKeyPress='rng_seed_time();'>
+// in your main HTML document.
+
+var rng_state;
+var rng_pool;
+var rng_pptr;
+
+// Mix in a 32-bit integer into the pool
+function rng_seed_int(x) {
+ rng_pool[rng_pptr++] ^= x & 255;
+ rng_pool[rng_pptr++] ^= (x >> 8) & 255;
+ rng_pool[rng_pptr++] ^= (x >> 16) & 255;
+ rng_pool[rng_pptr++] ^= (x >> 24) & 255;
+ if(rng_pptr >= rng_psize) rng_pptr -= rng_psize;
+}
+
+// Mix in the current time (w/milliseconds) into the pool
+function rng_seed_time() {
+ rng_seed_int(new Date().getTime());
+}
+
+// Initialize the pool with junk if needed.
+if(rng_pool == null) {
+ rng_pool = new Array();
+ rng_pptr = 0;
+ var t;
+ if(navigator.appName == "Netscape" && navigator.appVersion < "5" && window.crypto) {
+ // Extract entropy (256 bits) from NS4 RNG if available
+ var z = window.crypto.random(32);
+ for(t = 0; t < z.length; ++t)
+ rng_pool[rng_pptr++] = z.charCodeAt(t) & 255;
+ }
+ while(rng_pptr < rng_psize) { // extract some randomness from Math.random()
+ t = Math.floor(65536 * Math.random());
+ rng_pool[rng_pptr++] = t >>> 8;
+ rng_pool[rng_pptr++] = t & 255;
+ }
+ rng_pptr = 0;
+ rng_seed_time();
+ //rng_seed_int(window.screenX);
+ //rng_seed_int(window.screenY);
+}
+
+function rng_get_byte() {
+ if(rng_state == null) {
+ rng_seed_time();
+ rng_state = prng_newstate();
+ rng_state.init(rng_pool);
+ for(rng_pptr = 0; rng_pptr < rng_pool.length; ++rng_pptr)
+ rng_pool[rng_pptr] = 0;
+ rng_pptr = 0;
+ //rng_pool = null;
+ }
+ // 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;