ssl_client.c
/* ssl_client.c
*
* Copyright (c) 2000 Sean Walton and Macmillan Publishers. Use may be in
* whole or in part in accordance to the General Public License (GPL).
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*****************************************************************************/
/*** ssl_client.c ***/
/*** ***/
/*** Demonstrate an SSL client. ***/
/*****************************************************************************/
#include <errno.h>
#include <netdb.h>
#include <resolv.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#include "ssl_client.h"
#include "util.h"
#define FAIL -1
/*---------------------------------------------------------------------*/
/*--- OpenConnection - create socket and connect to server. ---*/
/*---------------------------------------------------------------------*/
int OpenConnection(const char *hostname, int port)
{ int sd;
struct hostent *host;
struct sockaddr_in addr;
if ( (host = gethostbyname(hostname)) == NULL )
{
perror(hostname);
abort();
}
sd = socket(PF_INET, SOCK_STREAM, 0);
bzero(&addr, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
addr.sin_addr.s_addr = *(long*)(host->h_addr);
if ( connect(sd, (struct sockaddr*)&addr, sizeof(addr)) != 0 )
{
close(sd);
perror(hostname);
return -1;
}
return sd;
}
/*---------------------------------------------------------------------*/
/*--- InitCTX - initialize the SSL engine. ---*/
/*---------------------------------------------------------------------*/
SSL_CTX* InitCTX(void) {
OpenSSL_add_all_algorithms();
SSL_library_init();
SSL_load_error_strings();
/**
* For some reason, SSL_METHOD is const
* on Debian but not on Mac OS X
*/
#ifdef __APPLE__
SSL_METHOD* method = SSLv23_client_method();
#else
const SSL_METHOD* method = SSLv23_client_method();
#endif
SSL_CTX* ctx = SSL_CTX_new(method);
if ( ctx == NULL )
{
ERR_print_errors_fp(stderr);
abort();
}
return ctx;
}
/*---------------------------------------------------------------------*/
/*--- main - create SSL context and connect ---*/
/*---------------------------------------------------------------------*/
bool MakeSSLRequest(const char* hostname, int port,
ClientFunction client_func, void* client_data)
{
// Set up context
SSL_CTX* ctx = InitCTX();
CHECK_CALL(ctx);
// Connect to server
int server = OpenConnection(hostname, port);
if(server < 0) return false;
CHECK_CALL(server);
SSL* ssl = SSL_new(ctx);
SSL_set_fd(ssl, server);
// Do handshake
if ( SSL_connect(ssl) == FAIL ) {
ERR_print_errors_fp(stderr);
return false;
}
client_func(ssl, client_data);
fprintf(stderr, "Connected with %s encryption\n", SSL_get_cipher(ssl));
SSL_free(ssl);
close(server);
SSL_CTX_free(ctx);
ERR_free_strings();
ERR_remove_state(0);
EVP_cleanup();
return true;
}