rnetclient.c

   1 /*
   2  *  Copyright (C) 2012-2013  Thadeu Lima de Souza Cascardo <cascardo@minaslivre.org>
   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 3 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 <errno.h>
  23 #include <unistd.h>
  24 #include <sys/socket.h>
  25 #include <netinet/in.h>
  26 #include <arpa/inet.h>
  27 #include <netdb.h>
  28 #include <gnutls/gnutls.h>
  29 #include <zlib.h>
  30
  31 static void * get_creds(char *certfile)
  32 {
  33         static gnutls_certificate_credentials_t cred;
  34         gnutls_certificate_allocate_credentials(&cred);
  35         gnutls_certificate_set_x509_trust_file(cred, certfile,
  36                                         GNUTLS_X509_FMT_PEM);
  37         return cred;
  38 }
  39
  40 static void session_new(gnutls_session_t *session)
  41 {
  42         static void *cred;
  43         cred = get_creds("cert.pem");
  44         gnutls_init(session, GNUTLS_CLIENT);
  45         gnutls_set_default_priority(*session);
  46         gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE, cred);
  47 }
  48
  49 static int deflateRecord(char *buffer, size_t len, char **out, size_t *olen)
  50 {
  51         z_stream zstrm;
  52         int r;
  53         zstrm.zalloc = Z_NULL;
  54         zstrm.zfree = Z_NULL;
  55         zstrm.opaque = Z_NULL;
  56         if ((r = deflateInit(&zstrm, Z_DEFAULT_COMPRESSION)) != Z_OK)
  57                 return -1;
  58         *out = malloc(len * 2 + 36);
  59         if (!out) {
  60                 deflateEnd(&zstrm);
  61                 return -1;
  62         }
  63         zstrm.next_in = buffer;
  64         zstrm.avail_in = len;
  65         zstrm.next_out = *out + 6;
  66         zstrm.avail_out = len * 2 + 30;
  67         while ((r = deflate(&zstrm, Z_FINISH)) != Z_STREAM_END &&
  68                 zstrm.avail_out > 0);
  69         if ((r = deflate(&zstrm, Z_FINISH)) != Z_STREAM_END) {
  70                 deflateEnd(&zstrm);
  71                 free(*out);
  72                 return -1;
  73         }
  74         *olen = zstrm.avail_out + 6;
  75         (*out)[0] = 0x1;
  76         (*out)[1] = (zstrm.avail_out >> 8);
  77         (*out)[2] = (zstrm.avail_out & 0xff);
  78         (*out)[3] = (len >> 8);
  79         (*out)[4] = (len & 0xff);
  80         (*out)[5] = 0x1;
  81         deflateEnd(&zstrm);
  82         return 0;
  83 }
  84
  85 static int inflateRecord(char *buffer, size_t len, char **out, size_t *olen)
  86 {
  87         z_stream zstrm;
  88         int r;
  89         zstrm.zalloc = Z_NULL;
  90         zstrm.zfree = Z_NULL;
  91         zstrm.opaque = Z_NULL;
  92         if ((r = inflateInit(&zstrm)) != Z_OK)
  93                 return -1;
  94         *olen = (buffer[3] << 8 & buffer[4]);
  95         *out = malloc(*olen);
  96         if (!out) {
  97                 inflateEnd(&zstrm);
  98                 return -1;
  99         }
 100         zstrm.next_in = buffer + 6;
 101         zstrm.avail_in = len - 6;
 102         zstrm.next_out = *out;
 103         zstrm.avail_out = *olen;
 104         while ((r = inflate(&zstrm, Z_FINISH)) != Z_STREAM_END &&
 105                 zstrm.avail_out > 0);
 106         if ((r = inflate(&zstrm, Z_FINISH)) != Z_STREAM_END) {
 107                 inflateEnd(&zstrm);
 108                 free(*out);
 109                 return -1;
 110         }
 111         inflateEnd(&zstrm);
 112         return 0;
 113 }
 114
 115 #define RNET_ADDRESS "receitanet.receita.fazenda.gov.br"
 116
 117 static int connect_rnet(int *c)
 118 {
 119         struct addrinfo *addresses;
 120         struct addrinfo *addr;
 121         struct addrinfo hint;
 122         struct sockaddr_in saddr;
 123         int r;
 124         int fd = *c = -1;
 125         int i;
 126         memset(&hint, 0, sizeof(hint));
 127         hint.ai_family = AF_UNSPEC;
 128         hint.ai_socktype = SOCK_STREAM;
 129         hint.ai_protocol = IPPROTO_TCP;
 130         hint.ai_flags = AI_ADDRCONFIG;
 131         r = getaddrinfo(RNET_ADDRESS, "3456", &hint, &addresses);
 132         if (r) {
 133                 return r;
 134         }
 135         for (addr = addresses; addr != NULL; addr = addr->ai_next) {
 136                 fd = socket(addr->ai_family, addr->ai_socktype,
 137                                 addr->ai_protocol);
 138                 if (fd >= 0)
 139                         if (!(r = connect(fd, addr->ai_addr,
 140                                                 addr->ai_addrlen)))
 141                                 break;
 142                 close(fd);
 143                 fd = -1;
 144         }
 145         freeaddrinfo(addresses);
 146         *c = fd;
 147         if (fd == -1)
 148                 return EAI_SYSTEM;
 149         return 0;
 150 }
 151
 152 static int handshake(int c)
 153 {
 154         char buffer[16];
 155         int r;
 156         buffer[0] = 1;
 157         write(c, buffer, 1);
 158         write(c, "00000000000000", 14);
 159         r = read(c, buffer, 1);
 160         if (r != 1 && buffer[0] != 'E')
 161                 return -1;
 162         r = read(c, buffer, 14);
 163         if (r != 14)
 164                 return -1;
 165         return 0;
 166 }
 167
 168 int main(int argc, char **argv)
 169 {
 170         int c;
 171         int r;
 172         char buffer[2048];
 173         char *out;
 174         size_t olen;
 175         gnutls_session_t session;
 176         gnutls_global_init();
 177         session_new(&session);
 178         r = connect_rnet(&c);
 179         if (r) {
 180                 fprintf(stderr, "error connecting to server: %s\n",
 181                         r == EAI_SYSTEM ? strerror(errno) : gai_strerror(r));
 182                 exit(1);
 183         }
 184         gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) c);
 185         r = handshake(c);
 186         if (r < 0) {
 187                 exit(1);
 188         }
 189         if ((r = gnutls_handshake(session)) < 0)
 190                 fprintf(stderr, "error in handshake: %s\n",
 191                                 gnutls_strerror(r));
 192         else
 193                 fprintf(stderr, "handshake ok\n");
 194         r = read(0, buffer, sizeof(buffer));
 195         deflateRecord(buffer, r, &out, &olen);
 196         gnutls_record_send(session, out, olen);
 197         free(out);
 198         while ((r = gnutls_record_recv(session, buffer, sizeof(buffer))) > 0)
 199                 write(1, buffer, r);
 200         close(c);
 201         gnutls_global_deinit();
 202         return 0;
 203 }