RE: RSA with Crypto++ v3.1

[Colestock, Robert]

Chris:

Here is a simple snippet of demonstration code I wrote for both
Crypto++4.2 and 5.0 (I believe 3.2 uses the same definitions as 4.2).
Only the private key comes from a file (also provided), the data comes
from the memory array, the public key is derived from the private key
(you can save this off to use the key pair in an application).  I also
have a simple example of sign/verify using this same key.

Hope this helps.

Bob Colestock

#include "rng.h"
#include "des.h"
#include "modes.h"
#include "integer.h"
#include "dh.h"
//#define CRYPTOPP_5_0
#ifndef CRYPTOPP_5_0
#include "cbc.h"
#include "dsa.h"
#endif //CRYPTOPP_5_0
#include "sha.h"
#include "md5.h"
#include "md2.h"
#include "dh2.h"
#include "rsa.h"
#include "rc2.h"

#include "randpool.h"
using namespace CryptoPP;
#include <iostream>

void RWCTest2();
char *lpszPrivateKey="PrivateKey.bin";
RandomPool rndRandom;
unsigned char BufData[]="THIS IS A TEST!!!!!!";
unsigned char signature[2000];
//
//
void RWCTest2()
{
    unsigned char pOutCipher[2000];
    unsigned char pchDecryptedData[2000];
    unsigned int imodulus=0;

     //RWC: THIS LOGIC FAILS using Crypto++ 5.0...
     CryptoPP::ByteQueue privateKey;
     unsigned char BufRSAPrivateKey[2000];
     FILE *fp=fopen("./PrivateKey.bin", "rb");
     unsigned int iLength = fread(BufRSAPrivateKey, 1, 2000, fp);
     fclose(fp);

     privateKey.Put(BufRSAPrivateKey, iLength);
     RSAES_PKCS1v15_Decryptor rsaPriv(privateKey);

     RSAES_PKCS1v15_Encryptor rsaPub(rsaPriv);
     rsaPub.Encrypt(rndRandom, BufData, strlen((char *)BufData),
pOutCipher);

#ifndef CRYPTOPP_5_0
     imodulus = rsaPub.CipherTextLength(); /*SM_FREE_DEFAULT_KEYBITS /
8;*/
     int outLen  = rsaPriv.Decrypt(pOutCipher, pchDecryptedData); 
#else // CRYPTOPP_5_0
     imodulus =
rsaPub.FixedCiphertextLength();//RWC;CiphertextLength(0); 
                /*RWC;???BASED on key I hope!!!??? */
     DecodingResult drResult = rsaPriv.Decrypt(pOutCipher, imodulus,
pchDecryptedData); 
     int outLen = drResult.messageLength;
#endif // CRYPTOPP_5_0

     if (outLen > 0)
         std::cout << "RWCTest2: SUCCESSFUL result = |" <<
pchDecryptedData << "|\n";
     else
         std::cout << "RWCTest2: UN-SUCCESSFUL result, length = " <<
outLen << "\n";

}       // END RWCTest2

-----Original Message-----
From: Chris Losinger [mailto:[EMAIL PROTECTED]
Sent: Thursday, January 30, 2003 8:45 PM
To: [EMAIL PROTECTED]
Subject: RSA with Crypto++ v3.1



        can anyone give me a simple example of en/decrypting a chunk of
memory 
(not a file, please) using RSA, or any other PKE algorithm  ?

        -c
----
Chris Losinger
[EMAIL PROTECTED]
[EMAIL PROTECTED]          http://www.smalleranimals.com

PrivateKey.bin
Description: PrivateKey.bin