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