Add back in blinding to RSA, RW, ElGamal, and DH.

There are multiple unsatisfactory elements to the current solution,
as compared to how blinding was previously done:

Firstly, blinding is only used in the baseline implementations; the code
using OpenSSL and GMP is not protected by blinding at all.

Secondly, at the point we need to set up blinding, there is no access
to a PRNG. Currently I am going with a quite nasty solution, of using
a private key parameter to seed a simple PRNG constructed as:
  SHA-512(TS1 || private_key_param || public_key_param || TS2)

I really want to fix both of these elements but I'm not sure how to do
so easily.

3 files changed, 0 insertions, 85 deletions

diff --git a/src/math/numbertheory/blinding.cpp b/src/math/numbertheory/blinding.cpp
deleted file mode 100644
index c6a3fd1bd..000000000
--- a/src/math/numbertheory/blinding.cpp
+++ /dev/null
@@ -1,49 +0,0 @@
-/*
-* Blinder
-* (C) 1999-2007 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);
-   }
-
-}
diff --git a/src/math/numbertheory/blinding.h b/src/math/numbertheory/blinding.h
deleted file mode 100644
index 5f7f9e6b7..000000000
--- a/src/math/numbertheory/blinding.h
+++ /dev/null
@@ -1,34 +0,0 @@
-/*
-* Blinder
-* (C) 1999-2007 Jack Lloyd
-*
-* Distributed under the terms of the Botan license
-*/
-
-#ifndef BOTAN_BLINDER_H__
-#define BOTAN_BLINDER_H__
-
-#include <botan/bigint.h>
-#include <botan/reducer.h>
-
-namespace Botan {
-
-/*
-* Blinding Function Object
-*/
-class BOTAN_DLL Blinder
-   {
-   public:
-      BigInt blind(const BigInt&) const;
-      BigInt unblind(const BigInt&) const;
-
-      Blinder() {}
-      Blinder(const BigInt&, const BigInt&, const BigInt&);
-   private:
-      Modular_Reducer reducer;
-      mutable BigInt e, d;
-   };
-
-}
-
-#endif
diff --git a/src/math/numbertheory/info.txt b/src/math/numbertheory/info.txt
index 58851e055..18349ef78 100644
--- a/src/math/numbertheory/info.txt
+++ b/src/math/numbertheory/info.txt
@@ -3,7 +3,6 @@ load_on auto
 define BIGINT_MATH
 
 <header:public>
-blinding.h
 curve_gfp.h
 numthry.h
 point_gfp.h
@@ -16,7 +15,6 @@ def_powm.h
 </header:internal>
 
 <source>
-blinding.cpp
 dsa_gen.cpp
 jacobi.cpp
 make_prm.cpp