client.c

   1 /*
   2  * Copyright (C) 1997-2006 Andre Noll <maan@systemlinux.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 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
  15  *     along with this program; if not, write to the Free Software
  16  *     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  17  */
  18
  19 /** \file client.c the client program used to connect to para_server */
  20
  21 #include "para.h"
  22 #include "config.h"
  23 #include "client.cmdline.h"
  24 #include "crypt.h"
  25 #include "rc4.h"
  26 #include <openssl/rc4.h>
  27 #include "net.h"
  28 #include "string.h"
  29 #include "error.h"
  30
  31 enum {CL_CONNECTED, CL_SENT_AUTH, CL_RECEIVED_CHALLENGE, CL_SENT_CH_RESPONSE,
  32         CL_RECEIVED_PROCEED, CL_SENT_COMMAND, CL_SENDING_STDIN, CL_RECV_DATA};
  33
  34 struct private_client_data {
  35         int status;
  36         int fd;
  37         struct client_args_info conf;
  38         char *config_file;
  39         char *key_file;
  40         char *user;
  41         RC4_KEY rc4_recv_key;
  42         RC4_KEY rc4_send_key;
  43
  44         char *in_buf;
  45         size_t *in_loaded;
  46         char *out_buf;
  47         size_t *out_loaded;
  48 };
  49
  50 INIT_CLIENT_ERRLISTS;
  51
  52 static struct private_client_data *pcd;
  53
  54 static void rc4_send(unsigned long len, const unsigned char *indata,
  55                 unsigned char *outdata)
  56 {
  57         RC4(&pcd->rc4_send_key, len, indata, outdata);
  58 }
  59
  60 static void rc4_recv(unsigned long len, const unsigned char *indata,
  61                 unsigned char *outdata)
  62 {
  63         RC4(&pcd->rc4_recv_key, len, indata, outdata);
  64 }
  65
  66
  67 /*
  68  * client log function
  69  */
  70 void para_log(int ll, const char* fmt,...)
  71 {
  72         va_list argp;
  73
  74         /* ignore log message if loglevel is not high enough */
  75         if (pcd && ll < pcd->conf.loglevel_arg)
  76                 return;
  77         va_start(argp, fmt);
  78         vfprintf(stderr, fmt, argp);
  79         va_end(argp);
  80 }
  81
  82 static void client_close(struct private_client_data *pcd)
  83 {
  84         if (pcd)
  85                 return;
  86         if (pcd->fd >= 0)
  87                 close(pcd->fd);
  88         free(pcd->user);
  89         free(pcd->config_file);
  90         free(pcd->key_file);
  91         free(pcd);
  92 }
  93
  94 static void append_str(char **data, const char* append)
  95 {
  96         if (*data) {
  97                 char *tmp = make_message("%s\n%s", *data, append);
  98                 free(*data);
  99                 *data = tmp;
 100         } else
 101                 *data = para_strdup(append);
 102 }
 103
 104 static int client_parse_config(int argc, char *argv[],
 105                 struct private_client_data **pcd_ptr)
 106 {
 107         char *home = para_homedir();
 108         struct stat statbuf;
 109         int ret;
 110         struct private_client_data *p =
 111                 para_calloc(sizeof(struct private_client_data));
 112
 113         p->fd = -1;
 114         cmdline_parser(argc, argv, &p->conf);
 115         ret = - E_CLIENT_SYNTAX;
 116         if (!p->conf.inputs_num)
 117                 goto out;
 118         p->user = p->conf.user_given?
 119                 para_strdup(p->conf.user_arg) : para_logname();
 120
 121         p->key_file = p->conf.key_file_given?
 122                 para_strdup(p->conf.key_file_arg) :
 123                 make_message("%s/.paraslash/key.%s", home, p->user);
 124
 125         p->config_file = p->conf.config_file_given?
 126                 para_strdup(p->conf.config_file_arg) :
 127                 make_message("%s/.paraslash/client.conf", home);
 128         ret = stat(p->config_file, &statbuf);
 129         if (ret && p->conf.config_file_given) {
 130                 ret = -E_NO_CONFIG;
 131                 goto out;
 132         }
 133         if (!ret)
 134                 cmdline_parser_configfile(p->config_file, &p->conf, 0, 0, 0);
 135         ret = 1;
 136 out:
 137         free(home);
 138         if (ret < 0)
 139                 client_close(p);
 140         else
 141                 *pcd_ptr = p;
 142         return ret;
 143 }
 144
 145 static int send_stdin(int fd)
 146 {
 147         char buf[8192];
 148         int ret;
 149
 150         PARA_NOTICE_LOG("%s", "sending stdin\n");
 151         for (;;) {
 152                 ret = read(STDIN_FILENO, buf, sizeof(buf));
 153                 if (ret <= 0)
 154                         return ret;
 155                 ret = send_bin_buffer(fd, buf, ret);
 156                 if (ret < 0)
 157                         return ret;
 158         }
 159         return 1;
 160 }
 161
 162 static int client_open(struct private_client_data *pcd)
 163 {
 164         int ret;
 165         struct hostent *he;
 166         struct sockaddr_in their_addr;
 167
 168         /* get the host info */
 169         PARA_NOTICE_LOG("getting host info of %s\n",
 170                 pcd->conf.hostname_arg);
 171         ret = get_host_info(pcd->conf.hostname_arg, &he);
 172         if (ret < 0)
 173                 goto out;
 174         /* get new socket */
 175         ret = get_socket();
 176         if (ret < 0)
 177                 goto out;
 178         pcd->fd = ret;
 179         /* init their_addr */
 180         init_sockaddr(&their_addr, pcd->conf.server_port_arg, he);
 181         /* connect */
 182         PARA_NOTICE_LOG("connecting to %s\n", pcd->conf.hostname_arg);
 183         ret = para_connect(pcd->fd, &their_addr);
 184         if (ret < 0)
 185                 goto out;
 186         ret = 1;
 187 out:
 188         return ret;
 189 }
 190
 191
 192 /*
 193  * MAIN
 194  */
 195 int main(int argc, char *argv[])
 196 {
 197
 198         int numbytes, i, received, ret;
 199         struct hostent *he;
 200         struct sockaddr_in their_addr;
 201         char *command = NULL;
 202         char buf[8192];
 203         char *auth_str;
 204         long unsigned challenge_nr;
 205         unsigned char rc4_buf[2 * RC4_KEY_LEN] = "";
 206
 207         ret = client_parse_config(argc, argv, &pcd);
 208         if (ret < 0)
 209                 goto out;
 210         if (pcd->conf.loglevel_arg <= NOTICE)
 211                 cmdline_parser_print_version();
 212         PARA_INFO_LOG(
 213                 "current loglevel: %d\n"
 214                 "using config_file: %s\n"
 215                 "using key_file: %s\n"
 216                 "connecting to %s:%d\n",
 217                 pcd->conf.loglevel_arg,
 218                 pcd->config_file,
 219                 pcd->key_file,
 220                 pcd->conf.hostname_arg,
 221                 pcd->conf.server_port_arg
 222         );
 223         ret = client_open(pcd);
 224         if (ret < 0)
 225                 goto out;
 226         /* receive welcome message */
 227         ret = recv_buffer(pcd->fd, buf, sizeof(buf));
 228         if (ret < 0)
 229                 goto out;
 230         /* send auth command */
 231         auth_str = make_message("auth %s%s", pcd->conf.plain_given?  "" : "rc4 ",
 232                 pcd->user);
 233         PARA_INFO_LOG("<-- %s--> %s\n", buf, auth_str);
 234         ret = send_buffer(pcd->fd, auth_str);
 235         if (ret < 0)
 236                 goto out;
 237         /* receive challenge number */
 238         ret = recv_buffer(pcd->fd, buf, sizeof(buf));
 239         if (ret < 0)
 240                 goto out;
 241         if (ret != 64) {
 242                 ret = -E_INVALID_CHALLENGE;
 243                 PARA_ERROR_LOG("received the following: %s\n", buf);
 244                 goto out;
 245         }
 246         PARA_INFO_LOG("%s", "<-- [challenge]\n");
 247         /* decrypt challenge number */
 248         ret = para_decrypt_challenge(pcd->key_file, &challenge_nr,
 249                 (unsigned char *) buf, 64);
 250         if (ret < 0)
 251                 goto out;
 252         /* send decrypted challenge */
 253         PARA_INFO_LOG("--> %lu\n", challenge_nr);
 254         ret = send_va_buffer(pcd->fd, "%s%lu", CHALLENGE_RESPONSE_MSG, challenge_nr);
 255         if (ret < 0)
 256                 goto out;
 257         /* wait for approval */
 258         PARA_NOTICE_LOG("%s", "waiting for approval from server\n");
 259         ret = recv_buffer(pcd->fd, buf, sizeof(buf));
 260         if (ret < 0)
 261                 goto out;
 262         numbytes = ret;
 263         PARA_INFO_LOG("++++ server info ++++\n%s\n++++ end of server "
 264                 "info ++++\n", buf);
 265         /* check if server has sent "Proceed" message */
 266         ret = -E_CLIENT_AUTH;
 267         if (!strstr(buf, PROCEED_MSG))
 268                 goto out;
 269         if (numbytes >= PROCEED_MSG_LEN + 32) {
 270                 PARA_INFO_LOG("%s", "decrypting session key\n");
 271                 ret = para_decrypt_buffer(pcd->key_file, rc4_buf,
 272                         (unsigned char *)buf + PROCEED_MSG_LEN + 1,
 273                         numbytes - PROCEED_MSG_LEN - 1);
 274                 if (ret < 0)
 275                         goto out;
 276                 RC4_set_key(&pcd->rc4_send_key, RC4_KEY_LEN, rc4_buf);
 277                 RC4_set_key(&pcd->rc4_recv_key, RC4_KEY_LEN, rc4_buf + RC4_KEY_LEN);
 278                 PARA_INFO_LOG("rc4 encryption activated: %x:%x:%x:%x\n",
 279                         rc4_buf[0], rc4_buf[1], rc4_buf[2], rc4_buf[3]);
 280                 enable_crypt(pcd->fd, rc4_recv, rc4_send);
 281         }
 282         /* concat args */
 283         for (i = 0; i < pcd->conf.inputs_num; i++)
 284                 append_str(&command, pcd->conf.inputs[i]);
 285         /* send command */
 286         PARA_INFO_LOG("--> %s\n", command);
 287         ret = send_buffer(pcd->fd, command);
 288         if (ret < 0)
 289                 goto out;
 290         free(command);
 291         command = NULL;
 292         ret = send_buffer(pcd->fd, EOC_MSG "\n");
 293         if (ret < 0)
 294                 goto out;
 295         PARA_NOTICE_LOG("%s", "command sent.\n");
 296         received = 0;
 297         for (;;) {
 298                 ret = recv_bin_buffer(pcd->fd, buf, sizeof(buf) - 1);
 299                 if (ret <= 0) {
 300                         if (!ret)
 301                                 PARA_NOTICE_LOG("%s", "connection closed by peer\n");
 302                         goto out;
 303                 }
 304                 buf[ret] = '\0';
 305                 numbytes = ret;
 306                 if (!received && strstr(buf, AWAITING_DATA_MSG)) {
 307                         ret = send_stdin(pcd->fd);
 308                         goto out;
 309                 }
 310                 received = 1;
 311                 ret = write(STDOUT_FILENO, buf, numbytes);
 312                 if (ret != numbytes) {
 313                         ret = -E_SHORT_CLIENT_WRITE;
 314                         goto out;
 315                 }
 316         }
 317         client_close(pcd);
 318 out:
 319         if (ret < 0)
 320                 PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
 321         return ret >= 0? EXIT_SUCCESS: EXIT_FAILURE;
 322 }