The Tor Browser / file revision

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 //-----------------------------------------------------------------------------

 var BUGNUMBER = 452008;

 var summary = 'Bad math with JIT';

 var actual = '';

 var expect = '';

 //-----------------------------------------------------------------------------

 test();

 //-----------------------------------------------------------------------------

 function test()

 {

   enterFunc ('test');

   printBugNumber(BUGNUMBER);

   printStatus (summary);

   jit(true);

 // regression test for Bug 452008 - TM: SRP in Clipperz crypto library fails when JIT (TraceMonkey) is enabled. 

   var x = [9385, 32112, 25383, 16317, 30138, 14565, 17812, 24500, 2719, 30174, 3546, 9096, 15352, 19120, 20648, 14334, 7426, 0, 0, 0];

   var n = [27875, 25925, 30422, 12227, 27798, 32170, 10873, 21748, 30629, 26296, 20697, 5125, 4815, 2221, 14392, 23369, 5560, 2, 0, 0];

   var np = 18229;

   var expected = [18770, 31456, 17999, 32635, 27508, 29131, 2856, 16233, 5439, 27580, 7093, 18192, 30804, 5472, 8529, 28649, 14852, 0, 0, 0];

 //globals

   bpe=0;         //bits stored per array element

   mask=0;        //AND this with an array element to chop it down to bpe bits

 //initialize the global variables

   for (bpe=0; (1<<(bpe+1)) > (1<<bpe); bpe++);  //bpe=number of bits in the mantissa on this platform

   bpe>>=1;                   //bpe=number of bits in one element of the array representing the bigInt

   mask=(1<<bpe)-1;           //AND the mask with an integer to get its bpe least significant bits

 //the following global variables are scratchpad memory to

 //reduce dynamic memory allocation in the inner loop

   sa = new Array(0); //used in mont_()

 //do x=y on bigInts x and y.  x must be an array at least as big as y (not counting the leading zeros in y).

   function copy_(x,y) {

     var i;

     var k=x.length<y.length ? x.length : y.length;

     for (i=0;i<k;i++)

       x[i]=y[i];

     for (i=k;i<x.length;i++)

       x[i]=0;

   }

 //do x=y on bigInt x and integer y.

   function copyInt_(x,n) {

     var i,c;

     for (c=n,i=0;i<x.length;i++) {

       x[i]=c & mask;

       c>>=bpe;

     }

   }

 //is x > y? (x and y both nonnegative)

   function greater(x,y) {

     var i;

     var k=(x.length<y.length) ? x.length : y.length;

     for (i=x.length;i<y.length;i++)

       if (y[i])

         return 0;  //y has more digits

     for (i=y.length;i<x.length;i++)

       if (x[i])

         return 1;  //x has more digits

     for (i=k-1;i>=0;i--)

       if (x[i]>y[i])

         return 1;

       else if (x[i]<y[i])

         return 0;

     return 0;

   }

 //do x=x*y*Ri mod n for bigInts x,y,n,

 //  where Ri = 2**(-kn*bpe) mod n, and kn is the

 //  number of elements in the n array, not

 //  counting leading zeros.

 //x must be large enough to hold the answer.

 //It's OK if x and y are the same variable.

 //must have:

 //  x,y < n

 //  n is odd

 //  np = -(n^(-1)) mod radix

   function mont_(x,y,n,np) {

     var i,j,c,ui,t;

     var kn=n.length;

     var ky=y.length;

     if (sa.length!=kn)

       sa=new Array(kn);

     for (;kn>0 && n[kn-1]==0;kn--); //ignore leading zeros of n

     for (;ky>0 && y[ky-1]==0;ky--); //ignore leading zeros of y

     copyInt_(sa,0);

     //the following loop consumes 95% of the runtime for randTruePrime_() and powMod_() for large keys

     for (i=0; i<kn; i++) {

       t=sa[0]+x[i]*y[0];

       ui=((t & mask) * np) & mask;  //the inner "& mask" is needed on Macintosh MSIE, but not windows MSIE

       c=(t+ui*n[0]) >> bpe;

       t=x[i];

       //do sa=(sa+x[i]*y+ui*n)/b   where b=2**bpe

       for (j=1;j<ky;j++) {

         c+=sa[j]+t*y[j]+ui*n[j];

         sa[j-1]=c & mask;

         c>>=bpe;

       }

       for (;j<kn;j++) {

         c+=sa[j]+ui*n[j];

         sa[j-1]=c & mask;

         c>>=bpe;

       }

       sa[j-1]=c & mask;

     }

     if (!greater(n,sa))

       sub_(sa,n);

     copy_(x,sa);

   }

   mont_(x, x, n, np);

   var passed = expected.length == x.length;

   for (var i = 0; i < expected.length; i++) {

     if (passed)

       passed = expected[i] == x[i];

   }

   print(passed);

   jit(false);

   expect = true;

   actual = passed;

   reportCompare(expect, actual, summary);

   exitFunc ('test');

 }