rnetclient.c

   1 /*
   2  *  Copyright (C) 2011  Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
   3  *
   4  *  This program is free software; you can redistribute it and/or modify
   5  *  it under the terms of the GNU General Public License as published by
   6  *  the Free Software Foundation; either version 2 of the License, or
   7  *  (at your option) any later version.
   8  *
   9  *  This program is distributed in the hope that it will be useful,
  10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *  GNU General Public License for more details.
  13  *
  14  *  You should have received a copy of the GNU General Public License along
  15  *  with this program; if not, write to the Free Software Foundation, Inc.,
  16  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 #include <string.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <unistd.h>
  23 #include <sys/socket.h>
  24 #include <netinet/in.h>
  25 #include <arpa/inet.h>
  26 #include <gnutls/gnutls.h>
  27 #include <zlib.h>
  28
  29 static void * get_creds(char *certfile)
  30 {
  31         static gnutls_certificate_credentials_t cred;
  32         gnutls_certificate_allocate_credentials(&cred);
  33         gnutls_certificate_set_x509_trust_file(cred, certfile,
  34                                         GNUTLS_X509_FMT_PEM);
  35         return cred;
  36 }
  37
  38 static void session_new(gnutls_session_t *session)
  39 {
  40         static void *cred;
  41         cred = get_creds("cert.pem");
  42         gnutls_init(session, GNUTLS_CLIENT);
  43         gnutls_set_default_priority(*session);
  44         gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE, cred);
  45 }
  46
  47 static int deflateRecord(char *buffer, size_t len, char **out, size_t *olen)
  48 {
  49         z_stream zstrm;
  50         int r;
  51         zstrm.zalloc = Z_NULL;
  52         zstrm.zfree = Z_NULL;
  53         zstrm.opaque = Z_NULL;
  54         if ((r = deflateInit(&zstrm, Z_DEFAULT_COMPRESSION)) != Z_OK)
  55                 return -1;
  56         *out = malloc(len * 2 + 36);
  57         if (!out) {
  58                 deflateEnd(&zstrm);
  59                 return -1;
  60         }
  61         zstrm.next_in = buffer;
  62         zstrm.avail_in = len;
  63         zstrm.next_out = *out + 6;
  64         zstrm.avail_out = len * 2 + 30;
  65         while ((r = deflate(&zstrm, Z_FINISH)) != Z_STREAM_END &&
  66                 zstrm.avail_out > 0);
  67         if ((r = deflate(&zstrm, Z_FINISH)) != Z_STREAM_END) {
  68                 deflateEnd(&zstrm);
  69                 free(*out);
  70                 return -1;
  71         }
  72         *olen = zstrm.avail_out + 6;
  73         (*out)[0] = 0x1;
  74         (*out)[1] = (zstrm.avail_out >> 8);
  75         (*out)[2] = (zstrm.avail_out & 0xff);
  76         (*out)[3] = (len >> 8);
  77         (*out)[4] = (len & 0xff);
  78         (*out)[5] = 0x1;
  79         deflateEnd(&zstrm);
  80         return 0;
  81 }
  82
  83 int main(int argc, char **argv)
  84 {
  85         struct sockaddr_in saddr;
  86         int c;
  87         int r;
  88         char buffer[256];
  89         char *out;
  90         size_t olen;
  91         gnutls_session_t session;
  92         gnutls_global_init();
  93         session_new(&session);
  94         c = socket(PF_INET, SOCK_STREAM, 0);
  95         saddr.sin_family = AF_INET;
  96         saddr.sin_port = htons(3456);
  97         saddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
  98         connect(c, (struct sockaddr *) &saddr, sizeof(saddr));
  99         gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) c);
 100         buffer[0] = 1;
 101         write(c, buffer, 1);
 102         write(c, "00000000000000", 14);
 103         r = read(c, buffer, 1);
 104         if (r != 1 && buffer[0] != 'E')
 105                 exit(1);
 106         r = read(c, buffer, 14);
 107         if (r != 14)
 108                 exit(1);
 109         if ((r = gnutls_handshake(session)) < 0)
 110                 fprintf(stderr, "error in handshake: %s\n",
 111                                 gnutls_strerror(r));
 112         else
 113                 fprintf(stderr, "handshake ok\n");
 114         buffer[0] = 0x40;
 115         deflateRecord(buffer, 1, &out, &olen);
 116         gnutls_record_send(session, out, olen);
 117         free(out);
 118         while ((r = gnutls_record_recv(session, buffer, sizeof(buffer))) > 0)
 119                 write(1, buffer, r);
 120         close(c);
 121         gnutls_global_deinit();
 122         return 0;
 123 }