millerRabin set to 40 iterations; doc fixes

src/crypto/crypto.js

@@ -280,7 +280,7 @@ export default {
           return constructParams(types, [keyObject.oid, keyObject.Q, [keyObject.hash, keyObject.cipher], keyObject.d]);
         });
       default:
-        throw new Error('Invalid public key encryption algorithm.');
+        throw new Error('Invalid public key algorithm.');
     }
   },
 

src/crypto/public_key/prime.js

@@ -15,7 +15,7 @@
 // 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 prime generation
+// Algorithms for probabilistic random prime generation
 
 /**
  * @requires bn.js
@@ -30,7 +30,14 @@ export default {
   randomProbablePrime, isProbablePrime, fermat, millerRabin
 };
 
-function randomProbablePrime(bits, e) {
+/**
+ * Probabilistic random number generator
+ * @param {Integer} bits Bit length of the prime
+ * @param {BN}      e    Optional RSA exponent to check against the prime
+ * @param {Integer} k    Optional number of iterations of Miller-Rabin test
+ * @return BN
+ */
+function randomProbablePrime(bits, e, k) {
   const min = new BN(1).shln(bits - 1);
 
   let n = random.getRandomBN(min, min.shln(1));
@@ -38,7 +45,7 @@ function randomProbablePrime(bits, e) {
     n.iaddn(1); // force odd
   }
 
-  while (!isProbablePrime(n, e)) {
+  while (!isProbablePrime(n, e, k)) {
     n.iaddn(2);
     // If reached the maximum, go back to the minimum.
     if (n.bitLength() > bits) {
@@ -48,14 +55,21 @@ function randomProbablePrime(bits, e) {
   return n;
 }
 
-function isProbablePrime(n, e) {
+/**
+ * Probabilistic primality testing
+ * @param {BN}      n Number to test
+ * @param {BN}      e Optional RSA exponent to check against the prime
+ * @param {Integer} k Optional number of iterations of Miller-Rabin test
+ * @return {boolean}
+ */
+function isProbablePrime(n, e, k) {
   if (e && !n.subn(1).gcd(e).eqn(1)) {
     return false;
   }
   if (!fermat(n)) {
     return false;
   }
-  if (!millerRabin(n)) {
+  if (!millerRabin(n, k)) {
     return false;
   }
   return true;
@@ -64,6 +78,9 @@ function isProbablePrime(n, e) {
 /**
  * Tests whether n is probably prime or not using Fermat's test with b = 2.
  * Fails if b^(n-1) mod n === 1.
+ * @param {BN}      n Number to test
+ * @param {Integer} b Optional Fermat test base
+ * @return {boolean}
  */
 function fermat(n, b) {
   b = b || new BN(2);
@@ -103,33 +120,38 @@ function fermat(n, b) {
 /**
  * Tests whether n is probably prime or not using the Miller-Rabin test.
  * See HAC Remark 4.28.
+ * @param {BN}       n  Number to test
+ * @param {Integer}  k  Optional number of iterations of Miller-Rabin test
+ * @param {Function} cb Optional callback function to call with random witnesses
+ * @return {boolean}
  */
 function millerRabin(n, k, cb) {
-  var len = n.bitLength();
+  const len = n.bitLength();
-  var red = BN.mont(n);
+  const red = BN.mont(n);
-  var rone = new BN(1).toRed(red);
+  const 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);
+  const n1 = n.subn(1);
-  for (var s = 0; !n1.testn(s); s++) {}
+  let s = 0;
-  var d = n.shrn(s);
+  while (!n1.testn(s)) { s++; }
+  const d = n.shrn(s);
 
-  var rn1 = n1.toRed(red);
+  const rn1 = n1.toRed(red);
 
-  var prime = true;
   for (; k > 0; k--) {
-    var a = random.getRandomBN(new BN(2), n1);
+    let a = random.getRandomBN(new BN(2), n1);
     if (cb)
       cb(a);
 
-    var x = a.toRed(red).redPow(d);
+    let x = a.toRed(red).redPow(d);
     if (x.cmp(rone) === 0 || x.cmp(rn1) === 0)
       continue;
 
-    for (var i = 1; i < s; i++) {
+    let i;
+    for (i = 1; i < s; i++) {
       x = x.redSqr();
 
       if (x.cmp(rone) === 0)
@@ -142,5 +164,5 @@ function millerRabin(n, k, cb) {
       return false;
   }
 
-  return prime;
+  return true;
 };

src/crypto/public_key/rsa.js

@@ -19,7 +19,6 @@
 
 /**
  * @requires bn.js
- * @requires asmcrypto.js
  * @requires crypto/public_key/prime
  * @requires crypto/random
  * @requires config
@@ -135,7 +134,10 @@ export default {
   /**
    * Generate a new random private key B bits long with public exponent E
    * @param {Integer} B RSA bit length
-   * @param {String} E RSA public exponent in hex
+   * @param {String}  E RSA public exponent in hex string
+   * @return {{n: BN, e: BN, d: BN,
+               p: BN, q: BN, u: BN}} RSA public modulus, RSA public exponent, RSA private exponent,
+                                     RSA private prime p, RSA private prime q, u = q ** -1 mod p
    */
   generate: async function(B, E) {
     let key;
@@ -193,13 +195,13 @@ export default {
     }
 
     while (true) {
-      let p = prime.randomProbablePrime(B - (B >> 1), E);
+      // 40 iterations of the Miller-Rabin test
-      let q = prime.randomProbablePrime(B >> 1, E);
+      // See https://stackoverflow.com/a/6330138 for justification
+      let p = prime.randomProbablePrime(B - (B >> 1), E, 40);
+      let q = prime.randomProbablePrime(B >> 1, E, 40);
 
       if (p.cmp(q) < 0) {
-        const t = p;
+        [p, q] = [q, p];
-        p = q;
-        q = t;
       }
 
       const phi = p.subn(1).mul(q.subn(1));
@@ -214,5 +216,7 @@ export default {
         u: p.invm(q)
       };
     }
-  }
+  },
+
+  prime: prime
 };

test/crypto/crypto.js

@@ -1,5 +1,4 @@
 const openpgp = typeof window !== 'undefined' && window.openpgp ? window.openpgp : require('../../dist/openpgp');
-const AES_CFB = require('asmcrypto.js/asmcrypto.all.js').AES_CFB;
 
 const chai = require('chai');
 chai.use(require('chai-as-promised'));
@@ -297,11 +296,7 @@ describe('API functional testing', function() {
           const prefix = util.concatUint8Array([rndm, repeat]);
 
           const symmencData = crypto.cfb.encrypt(rndm, algo, util.str2Uint8Array(plaintext), symmKey, false);
-          const symmencData2 = AES_CFB.encrypt(util.concatUint8Array([prefix, util.str2Uint8Array(plaintext)]), symmKey);
+          const decrypted = crypto.cfb.decrypt(algo, symmKey, symmencData, false);
-
-          let decrypted = AES_CFB.decrypt(symmencData, symmKey);
-          decrypted = decrypted.subarray(crypto.cipher[algo].blockSize + 2, decrypted.length);
-          expect(util.Uint8Array2str(symmencData)).to.equal(util.Uint8Array2str(symmencData2));
 
           const text = util.Uint8Array2str(decrypted);
           expect(text).to.equal(plaintext);