aboutsummaryrefslogtreecommitdiffstats
path: root/src/pubkey/blinding.cpp
blob: 47b3204620fd33918ba717f86370225f10166c49 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
n/*
* Blinding for public key operations
* (C) 1999-2010 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/

#include <botan/blinding.h>
#include <botan/numthry.h>

namespace Botan {

/*
* Blinder Constructor
*/
Blinder::Blinder(const BigInt& e, const BigInt& d, const BigInt& n)
   {
   if(e < 1 || d < 1 || n < 1)
      throw Invalid_Argument("Blinder: Arguments too small");

   reducer = Modular_Reducer(n);
   this->e = e;
   this->d = d;
   }

/*
* Blind a number
*/
BigInt Blinder::blind(const BigInt& i) const
   {
   if(!reducer.initialized())
      return i;

   e = reducer.square(e);
   d = reducer.square(d);
   return reducer.multiply(i, e);
   }

/*
* Unblind a number
*/
BigInt Blinder::unblind(const BigInt& i) const
   {
   if(!reducer.initialized())
      return i;
   return reducer.multiply(i, d);
   }

}