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.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/pubkey/rw/rw.h b/src/pubkey/rw/rw.h
index 8ca8d18b0..25e7be634 100644
--- a/src/pubkey/rw/rw.h
+++ b/src/pubkey/rw/rw.h
@@ -10,6 +10,7 @@
 
 #include <botan/if_algo.h>
 #include <botan/reducer.h>
+#include <botan/blinding.h>
 
 namespace Botan {
 
@@ -73,6 +74,7 @@ class BOTAN_DLL RW_Signature_Operation : public PK_Ops::Signature
 
       Fixed_Exponent_Power_Mod powermod_d1_p, powermod_d2_q;
       Modular_Reducer mod_p;
+      Blinder blinder;
    };
 
 class BOTAN_DLL RW_Verification_Operation : public PK_Ops::Verification