nr.cpp

含有多种公开密钥算法、多种块加密、多种数据流加密、多种HASH函数、多种CheckSum校验、多种MAC校验等几十种加密算法的程序

/*************************************************
* Nyberg-Rueppel Source File                     *
* (C) 1999-2002 The Botan Project                *
*************************************************/

#include <botan/nr.h>
#include <botan/numthry.h>
#include <botan/primes.h>

namespace Botan {

/*************************************************
* NR_PublicKey Constructor                       *
*************************************************/
NR_PublicKey::NR_PublicKey(const DL_Group& domain, const BigInt& key) :
   group(domain), p(group.get_p()), q(group.get_q()), g(group.get_g()),
   y(key), powermod_g_p(g, p), powermod_y_p(y, p)
   {
   if(group.type() != DL_Group::DSA_Group)
      throw Invalid_Argument("NR: Domain is not a DSA-style group");
   if(y < 0 || y >= p)
      throw Invalid_Argument("NR_PublicKey: Invalid public parameter");
   }

/*************************************************
* NR_PublicKey Copy Constructor                  *
*************************************************/
NR_PublicKey::NR_PublicKey(const NR_PublicKey& key) :
   PK_Verifying_with_MR_Key(),
   group(key.group), p(group.get_p()), q(group.get_q()), g(group.get_g()),
   y(key.get_y()), powermod_g_p(g, p), powermod_y_p(y, p)
   {
   }

/*************************************************
* Check Public Nyberg-Rueppel Parameters         *
*************************************************/
bool NR_PublicKey::check_params() const
   {
   if(y < 2 || y >= p)
      return false;
   if(!group.verify())
      return false;
   return true;
   }

/*************************************************
* Nyberg-Rueppel Verification Function           *
*************************************************/
SecureVector<byte> NR_PublicKey::verify(const byte sig[], u32bit sig_len) const
   {
   if(sig_len != 2*q.bytes())
      return false;

   BigInt c(sig, q.bytes());
   BigInt d(sig + q.bytes(), q.bytes());

   if(c.is_zero() || c >= q || d >= q)
      throw Invalid_Argument("Nyberg-Rueppel: Invalid signature");

   BigInt i = (powermod_g_p(d) * powermod_y_p(c)) % p;
   BigInt f = (c - i) % q;

   return encode(f);
   }

/*************************************************
* NR_PrivateKey Constructor                      *
*************************************************/
NR_PrivateKey::NR_PrivateKey(const DL_Group& domain) : NR_PublicKey(domain, 0)
   {
   x = random_integer(1, q - 1);
   y = powermod_g_p(x);
   powermod_y_p = FixedBase_Exp(y, p);
   }

/*************************************************
* NR_PrivateKey Constructor                      *
*************************************************/
NR_PrivateKey::NR_PrivateKey(const DL_Group& domain,
                             const BigInt& priv, const BigInt& pub) :
   NR_PublicKey(domain, pub), x(priv)
   {
   if(x <= 1 || y <= 1 || x >= p || y >= p)
      throw Invalid_Argument("NR_PrivateKey: invalid private key");
   }

/*************************************************
* Check Private Nyberg-Rueppel Parameters        *
*************************************************/
bool NR_PrivateKey::check_params() const
   {
   if(!NR_PublicKey::check_params())
      return false;
   if(y != powermod_g_p(x))
      return false;
   return true;
   }

/*************************************************
* Nyberg-Rueppel Signature Operation             *
*************************************************/
SecureVector<byte> NR_PrivateKey::sign(const byte in[], u32bit len) const
   {
   BigInt f;
   f.binary_decode(in, len);

   if(f > q)
      throw Invalid_Argument("NR_PrivateKey::sign: Input is too large");

   while(true)
      {
      BigInt k(Random, q.bits());
      while(k >= q)
         k.randomize(q.bits());

      BigInt c = (powermod_g_p(k) + f) % q;
      if(c.is_zero())
         continue;

      BigInt d = (k - x * c) % q;

      SecureVector<byte> output(2*q.bytes());
      c.binary_encode(output + (output.size() / 2 - c.bytes()));
      d.binary_encode(output + (output.size() - d.bytes()));
      return output;
      }
   }

}