Server - Client RSA keypair exchange - c++

Question

I'm new to programming and i've got this little project going for my diploma and i need help on this little code. This is a Server->Client C++ code where server generates and sends RSA Keypair to client. My problem is that both server and client codes compiled without any problem but when i start it the client side doesn't get any keypair just blank.
Here is my server code:
#include <iostream>
#include <cstdlib>
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/rsa.h>
#include <openssl/pem.h>
#include <stdio.h>
#include <string.h>
#define KEY_LENGTH 1024
#define PUB_EXP 3
#define PRINT_KEYS
#define WRITE_TO_FILE
using std::exit;
#define int_error(msg) handle_error(__FILE__, __LINE__, msg)
void handle_error(const char* file, int lineno, const char* msg)
{
std::cerr << "\n** " << file << ":" << lineno << " " << msg << "\n";
ERR_print_errors_fp(stderr);
exit(-1);
}
void init_OpenSSL()
{
std::cout << "Initializng OpenSSL library ... ";
if (!SSL_library_init())
int_error("OpenSSL initialization failed");
std::cout << "done\n";
SSL_load_error_strings();
}
DH* setup_dh()
{
DH* dh = DH_new();
if (!dh)
int_error("DH_new failed");
std::cout << "Generating DH parameters ... ";
if (!DH_generate_parameters_ex(dh, 2, DH_GENERATOR_2, 0))
int_error("DH_generate_parameters_ex failed");
std::cout << "done\n";
std::cout << "Checking DH parameters ... ";
int codes = 0;
if (!DH_check(dh, &codes))
int_error("DH_check failed");
std::cout << "done\n";
std::cout << "Generating DH keys ... ";
if (!DH_generate_key(dh))
int_error("DH_generate_key failed");
std::cout << "done\n";
return dh;
}
SSL_CTX* setup_ctx()
{
SSL_CTX* ctx;
std::cout << "Creating context ... ";
ctx = SSL_CTX_new(TLSv1_server_method());
if (!ctx)
int_error("SSL_CTX_new failed");
std::cout << "done\n";
DH* dh = setup_dh();
std::cout << "Setting DH parameters ... ";
SSL_CTX_set_tmp_dh(ctx, dh);
std::cout << "done\n";
std::cout << "Setting cipher list ... ";
if (SSL_CTX_set_cipher_list(ctx, "ADH-AES256-SHA") != 1)
int_error("Error setting cipher list (no valid ciphers)");
std::cout << "done\n";
return ctx;
}
int main()
{
init_OpenSSL();
BIO *acc, *client;
SSL* ssl;
SSL_CTX* ctx;
ctx = setup_ctx();
size_t pri_len;
size_t pub_len;
char *pri_key;
char *pub_key;
std::cout << "Generating RSA (%d bits) keypair...\n", 1024;
RSA *keypair = RSA_generate_key(1024, 3, NULL, NULL);
BIO *pri = BIO_new(BIO_s_mem());
BIO *pub = BIO_new(BIO_s_mem());
PEM_write_bio_RSAPrivateKey(pri, keypair, NULL, NULL, 0, NULL, NULL);
PEM_write_bio_RSAPublicKey(pub, keypair);
pri_len = BIO_pending(pri);
pub_len = BIO_pending(pub);
pri_key = (char*)malloc(pri_len + 1);
pub_key = (char*)malloc(pub_len + 1);
BIO_read(pri, pri_key, pri_len);
BIO_read(pub, pub_key, pub_len);
pri_key[pri_len] = '\0';
pub_key[pub_len] = '\0';
std::cout << "Creating server socket ... ";
acc = BIO_new_accept("*:5055");
if (!acc)
int_error("Error creating server socket");
std::cout << "done\n";
std::cout << "Binding server socket ... ";
if (BIO_do_accept(acc) <= 0)
int_error("Error binding server socket");
std::cout << "done\n";
while (true) {
std::cout << "Accepting connections ...\n";
if (BIO_do_accept(acc) <= 0)
int_error("Error accepting connection");
client = BIO_pop(acc);
std::cout << "Creating context ... ";
if (!(ssl = SSL_new(ctx)))
int_error("Error creating SSL context");
std::cout << "done\n";
SSL_set_bio(ssl, client, client);
if (SSL_accept(ssl) <= 0)
int_error("Error accepting SSL connection");
std::cout << "SSL connection opened: " << SSL_get_cipher(ssl) << " " <<
SSL_get_cipher_version(ssl) << " (" << SSL_get_cipher_bits(ssl, 0) << " bits)\n";
char buff[256] = {0};
int r = SSL_read(ssl, buff, sizeof buff);
if (r > 0) {
std::cout << buff;
SSL_write(ssl, keypair, 1024 );
}
SSL_shutdown(ssl);
SSL_free(ssl);
std::cout << "SSL connection finished\n";
}
SSL_CTX_free(ctx);
BIO_free(acc);
std::cout << "Server closed\n";
}
Here is my client code:
#include <iostream>
#include <cstdlib>
#include <string>
#include <fstream>
#include <openssl/ssl.h>
#include <openssl/err.h>
using namespace std;
using std::exit;
#define int_error(msg) handle_error(__FILE__, __LINE__, msg)
void handle_error(const char* file, int lineno, const char* msg)
{
std::cerr << "** " << file << ":" << lineno << " " << msg << "\n";
ERR_print_errors_fp(stderr);
exit(-1);
}
void init_OpenSSL()
{
std::cout << "Initializng OpenSSL library ... ";
if (!SSL_library_init())
int_error("OpenSSL initialization failed");
std::cout << "done\n";
SSL_load_error_strings();
}
SSL_CTX* setup_ctx()
{
SSL_CTX* ctx;
std::cout << "Creating context ... ";
ctx = SSL_CTX_new(TLSv1_client_method());
if (!ctx)
int_error("SSL_CTX_new failed");
std::cout << "done\n";
std::cout << "Setting cipher list ... ";
if (SSL_CTX_set_cipher_list(ctx, "ADH-AES256-SHA") != 1)
int_error("Error setting cipher list (no valid ciphers)");
std::cout << "done\n";
return ctx;
}
int main()
{
init_OpenSSL();
BIO* conn;
SSL* ssl;
SSL_CTX* ctx;
ofstream myfile;
ctx = setup_ctx();
std::cout << "Creating connection ... ";
conn = BIO_new_connect("192.168.1.10:5055");
if (!conn)
int_error("Error creating connection");
std::cout << "done\n";
std::cout << "Connecting to server ... ";
if (BIO_do_connect(conn) <= 0)
int_error("Error connecting to server");
std::cout << "done\n";
std::cout << "Creating context ... ";
if (!(ssl = SSL_new(ctx)))
int_error("Error creating an SSL context");
std::cout << "done\n";
SSL_set_bio(ssl, conn, conn);
std::cout << "Opening connection ... ";
if (SSL_connect(ssl) <= 0)
int_error("Error connecting SSL object");
std::cout << "done\n";
SSL_write(ssl, "The client is connected", 26);
char buff[64] = {0};
int bread = SSL_read(ssl, buff, sizeof buff);
if (bread > 0)
std::cout << "The key has been recieved\n";
myfile.open ("keypair.pem");
myfile << buff;
myfile.close();
SSL_shutdown(ssl);
SSL_free(ssl);
std::cout << "SSL connection finished\n";
SSL_CTX_free(ctx);
std::cout << "Client finished\n";
}
Can someone show me what i did wrong and it would be great if someone can tell me how i can get my private key and public keys(server generated) separately. Thanks a lot guys...really appreciate it