Re: NIST Curve P192 Fails Validate (Set Up As User Defined Domain Parameter)

[Jeffrey Walton]

Hi All,

I tried to punt on Initialize. Since I am worried I may be confusing
variables (NIST: r = Crypto++: n, etc).Still no joy.

I know Curve ec is correct - it is p, a, and b.
I know G is correct - it is x, y.

That leave two big numbers. When I try to inialize as below, I still
fail??? Any help or would be greatly appreciated.

Jeff

// PrivateKey.Initialize( ec, CryptoPP::ECP::Point( x, y ), n, h );
// PrivateKey.Initialize( rng, ec, CryptoPP::ECP::Point( x, y ), h );
// PrivateKey.Initialize( rng, ec, CryptoPP::ECP::Point( x, y ), n );

On 11/16/06, Jeffrey Walton <[EMAIL PROTECTED]> wrote:

Hi All,

Below is the sample which demonstrates the failure. My one question is
in reference to cofactor S - it seems very large. If I interpreted the
document correctly, this may be an issue in the Library.

I attached Curve P192 Parameters from the NiIST document, "RECOMMENDED
ELLIPTIC CURVES FOR FEDERAL GOVERNMENT USE", July 1999.

Jeff

#include <iostream>

#include "cryptlib.h"
#include "osrng.h"
#include "eccrypto.h"
#include "ecp.h"
#include "integer.h"

int main(int argc, char* argv[]) {

   try {

       CryptoPP::AutoSeededRandomPool rng;

       // User Defined Domain Parameters
       //   This is Curve P-192 from NIST
       //   (Recommended Elliptic Curves for Federal Government Use)
       CryptoPP::Integer
p("6277101735386680763835789423207666416083908700390324961279");

       CryptoPP::Integer a("-3");
       CryptoPP::Integer
b("0x64210519e59c80e70fa7e9ab72243049feb8deecc146b9b1");

       CryptoPP::Integer
n("6277101735386680763835789423176059013767194773182842284081");
       CryptoPP::Integer
h("0x3045ae6fc8422f64ed579528d38120eae12196d5");

       CryptoPP::Integer
x("0x188da80eb03090f67cbf20eb43a18800f4ff0afd82ff101207192b95");
       CryptoPP::Integer
y("0x07192b95ffc8da78631011ed6b24cdd573f977a11e794811");

       CryptoPP::ECP ec( p, a, b );

       CryptoPP::ECIES< CryptoPP::ECP >::PrivateKey    PrivateKey;
       CryptoPP::ECIES< CryptoPP::ECP >::PublicKey     PublicKey;

       // Curve Initialization and Public Key Generation
       PrivateKey.Initialize( ec, CryptoPP::ECP::Point( x, y ), n, h );
       PrivateKey.MakePublicKey( PublicKey );

       // Key Validation
       //
       //   User Defined Domain Parameters always fail, even at level 0???
       //
       //   From cryptlib.h, Validate(...):
       //
               //   0 - using this object won't cause a crash or exception (rng 
is ignored)
               //   1 - this object will probably function (encrypt, sign, 
etc.) correctly
       //       (but may not check for weak keys and such)
               //   2 - make sure this object will function correctly, and do 
reasonable
       //       security checks
               //   3 - do checks that may take a long time
       //
       if( false == PrivateKey.Validate( rng, 0 ) )
           { throw std::string( "Private Key Validation Failure" ); }
       if( false == PublicKey.Validate( rng, 0 ) )
           { throw std::string( "Public Key Validation Failure" ); }
   }

   catch( CryptoPP::Exception& e )
       { std::cerr << "Crypto++ Error: " << e.what() << std::endl; }

   catch( std::string& s )
       { std::cerr << "Error: " << s << std::endl; }

   catch (...)
       { std::cerr << "Unknown Error" << std::endl; }

   return 0;
}