New probabilistic random number generation algorithms; UNTESTED

src/crypto/public_key/prime.js

@@ -0,0 +1,135 @@
+// OpenPGP.js - An OpenPGP implementation in javascript
+// Copyright (C) 2018 Proton Technologies AG
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 3.0 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+
+// Algorithms for probabilistic primality testing
+
+/**
+ * @requires bn.js
+ * @requires crypto/random
+ * @module crypto/public_key/prime
+ */
+
+import BN from 'bn.js';
+import random from '../random';
+
+function randomProbablePrime(b) {
+  let n;
+  const min = new BN(1).shln(b-1);
+  do {
+    n = random.getRandomBN(min, min.shln(1));
+    if (n.isEven()) {
+      n.iaddn(1); // force odd
+    }
+  } while (!isProbablePrime(n));
+//    this.dAddOffset(2, 0);
+//    if (this.bitLength() > b)
+//      this.subTo(BigInteger.ONE.shiftLeft(b - 1), this);
+}
+
+function isProbablePrime(n) {
+  if (!fermat(n)) {
+    return false;
+  }
+  if (!millerRabin(n)) {
+    return false;
+  }
+  return true;
+}
+
+/**
+ * Tests whether n is probably prime or not using Fermat's test with b = 2.
+ * Fails if b^(n-1) mod n === 1.
+ */
+export function fermat(n, b) {
+  b = b || new BN(2);
+  return b.toRed(BN.mont(n)).redPow(n.subn(1)).cmpn(1) === 0;
+}
+
+
+// Miller-Rabin - Miller Rabin algorithm for primality test
+// Copyright Fedor Indutny, 2014.
+//
+// This software is licensed under the MIT License.
+//
+// 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", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+// Adapted on Jan 2018 from version 4.0.1 at https://github.com/indutny/miller-rabin
+// TODO check this against jsbn's bnpMillerRabin
+// TODO implement fixed base Miller-Rabin; for instance by writing a function that
+// picks a number within the given range from a precomputed list of primes.
+
+/**
+ * Tests whether n is probably prime or not using the Miller-Rabin test.
+ * See HAC Remark 4.28.
+ */
+export function millerRabin(n, k, cb) {
+  var len = n.bitLength();
+  var red = BN.mont(n);
+  var rone = new BN(1).toRed(red);
+
+  if (!k)
+    k = Math.max(1, (len / 48) | 0);
+
+  // Find d and s, (n - 1) = (2 ^ s) * d;
+  var n1 = n.subn(1);
+  for (var s = 0; !n1.testn(s); s++) {}
+  var d = n.shrn(s);
+
+  var rn1 = n1.toRed(red);
+
+  var prime = true;
+  for (; k > 0; k--) {
+    var a = random.getRandomBN(new BN(2), n1);
+    if (cb)
+      cb(a);
+
+    var x = a.toRed(red).redPow(d);
+    if (x.cmp(rone) === 0 || x.cmp(rn1) === 0)
+      continue;
+
+    for (var i = 1; i < s; i++) {
+      x = x.redSqr();
+
+      if (x.cmp(rone) === 0)
+        return false;
+      if (x.cmp(rn1) === 0)
+        break;
+    }
+
+    if (i === s)
+      return false;
+  }
+
+  return prime;
+};

src/crypto/public_key/rsa.js

@@ -20,6 +20,7 @@
 /**
  * @requires bn.js
  * @requires asmcrypto.js
+ * @requires crypto/public_key/prime
  * @requires crypto/random
  * @requires config
  * @requires util
@@ -31,6 +32,7 @@ import BN from 'bn.js';
 import { RSA } from 'asmcrypto.js/src/rsa/exports-keygen';
 import { RSA_RAW } from 'asmcrypto.js/src/rsa/exports-raw';
 import { random as asmcrypto_random } from 'asmcrypto.js/src/random/exports';
+import prime from './prime';
 import random from '../random';
 import config from '../../config';
 import util from '../../util';

src/crypto/random.js

@@ -97,7 +97,7 @@ export default {
   },
 
   /**
-   * Create a secure random MPI in specified range
+   * Create a secure random MPI that is greater than or equal to min and less than max.
    * @param {module:type/mpi} min Lower bound, included
    * @param {module:type/mpi} max Upper bound, excluded
    * @return {module:BN} Random MPI
@@ -107,18 +107,19 @@ export default {
       throw new Error('Illegal parameter value: max <= min');
     }
 
+    let r;
     const modulus = max.sub(min);
     const length = modulus.byteLength();
-    let r = new BN(this.getRandomBytes(length));
+
     // Using a while loop is necessary to avoid bias
-    while (r.cmp(modulus) >= 0) {
+    do {
       r = new BN(this.getRandomBytes(length));
-    }
+    } while (r.cmp(modulus) >= 0);
+
     return r.iadd(min);
   },
 
   randomBuffer: new RandomBuffer()
-
 };
 
 /**

src/type/mpi.js

@@ -21,8 +21,7 @@
 // - MPI = c | d << 8 | e << ((MPI.length -2)*8) | f ((MPI.length -2)*8)
 
 /**
- * Implementation of type MPI ({@link https://tools.ietf.org/html/rfc4880#section-3.2|RFC4880 3.2})<br/>
- * <br/>
+ * Implementation of type MPI ({@link https://tools.ietf.org/html/rfc4880#section-3.2|RFC4880 3.2})
  * Multiprecision integers (also called MPIs) are unsigned integers used
  * to hold large integers such as the ones used in cryptographic
  * calculations.
@@ -67,7 +66,7 @@ MPI.prototype.read = function (bytes, endian='be') {
   }
 
   const bits = (bytes[0] << 8) | bytes[1];
-  const bytelen = Math.ceil(bits / 8);
+  const bytelen = (bits + 7) >>> 3;
   const payload = bytes.subarray(2, 2 + bytelen);
 
   if (endian === 'le') {