/nmap_ftp.cc
C++ | 383 lines | 224 code | 28 blank | 131 comment | 88 complexity | b5df5914c9a1a37481e7278e4c6512b3 MD5 | raw file
Possible License(s): BSD-3-Clause, GPL-2.0, Apache-2.0, LGPL-2.0, LGPL-2.1, MIT
- /***************************************************************************
- * nmap_ftp.cc -- Nmap's FTP routines used for FTP bounce scan (-b)
- * *
- ***********************IMPORTANT NMAP LICENSE TERMS************************
- * *
- * The Nmap Security Scanner is (C) 1996-2015 Insecure.Com LLC. Nmap is *
- * also a registered trademark of Insecure.Com LLC. This program is free *
- * software; you may redistribute and/or modify it under the terms of the *
- * GNU General Public License as published by the Free Software *
- * Foundation; Version 2 ("GPL"), BUT ONLY WITH ALL OF THE CLARIFICATIONS *
- * AND EXCEPTIONS DESCRIBED HEREIN. This guarantees your right to use, *
- * modify, and redistribute this software under certain conditions. If *
- * you wish to embed Nmap technology into proprietary software, we sell *
- * alternative licenses (contact sales@nmap.com). Dozens of software *
- * vendors already license Nmap technology such as host discovery, port *
- * scanning, OS detection, version detection, and the Nmap Scripting *
- * Engine. *
- * *
- * Note that the GPL places important restrictions on "derivative works", *
- * yet it does not provide a detailed definition of that term. To avoid *
- * misunderstandings, we interpret that term as broadly as copyright law *
- * allows. For example, we consider an application to constitute a *
- * derivative work for the purpose of this license if it does any of the *
- * following with any software or content covered by this license *
- * ("Covered Software"): *
- * *
- * o Integrates source code from Covered Software. *
- * *
- * o Reads or includes copyrighted data files, such as Nmap's nmap-os-db *
- * or nmap-service-probes. *
- * *
- * o Is designed specifically to execute Covered Software and parse the *
- * results (as opposed to typical shell or execution-menu apps, which will *
- * execute anything you tell them to). *
- * *
- * o Includes Covered Software in a proprietary executable installer. The *
- * installers produced by InstallShield are an example of this. Including *
- * Nmap with other software in compressed or archival form does not *
- * trigger this provision, provided appropriate open source decompression *
- * or de-archiving software is widely available for no charge. For the *
- * purposes of this license, an installer is considered to include Covered *
- * Software even if it actually retrieves a copy of Covered Software from *
- * another source during runtime (such as by downloading it from the *
- * Internet). *
- * *
- * o Links (statically or dynamically) to a library which does any of the *
- * above. *
- * *
- * o Executes a helper program, module, or script to do any of the above. *
- * *
- * This list is not exclusive, but is meant to clarify our interpretation *
- * of derived works with some common examples. Other people may interpret *
- * the plain GPL differently, so we consider this a special exception to *
- * the GPL that we apply to Covered Software. Works which meet any of *
- * these conditions must conform to all of the terms of this license, *
- * particularly including the GPL Section 3 requirements of providing *
- * source code and allowing free redistribution of the work as a whole. *
- * *
- * As another special exception to the GPL terms, Insecure.Com LLC grants *
- * permission to link the code of this program with any version of the *
- * OpenSSL library which is distributed under a license identical to that *
- * listed in the included docs/licenses/OpenSSL.txt file, and distribute *
- * linked combinations including the two. *
- * *
- * Any redistribution of Covered Software, including any derived works, *
- * must obey and carry forward all of the terms of this license, including *
- * obeying all GPL rules and restrictions. For example, source code of *
- * the whole work must be provided and free redistribution must be *
- * allowed. All GPL references to "this License", are to be treated as *
- * including the terms and conditions of this license text as well. *
- * *
- * Because this license imposes special exceptions to the GPL, Covered *
- * Work may not be combined (even as part of a larger work) with plain GPL *
- * software. The terms, conditions, and exceptions of this license must *
- * be included as well. This license is incompatible with some other open *
- * source licenses as well. In some cases we can relicense portions of *
- * Nmap or grant special permissions to use it in other open source *
- * software. Please contact fyodor@nmap.org with any such requests. *
- * Similarly, we don't incorporate incompatible open source software into *
- * Covered Software without special permission from the copyright holders. *
- * *
- * If you have any questions about the licensing restrictions on using *
- * Nmap in other works, are happy to help. As mentioned above, we also *
- * offer alternative license to integrate Nmap into proprietary *
- * applications and appliances. These contracts have been sold to dozens *
- * of software vendors, and generally include a perpetual license as well *
- * as providing for priority support and updates. They also fund the *
- * continued development of Nmap. Please email sales@nmap.com for further *
- * information. *
- * *
- * If you have received a written license agreement or contract for *
- * Covered Software stating terms other than these, you may choose to use *
- * and redistribute Covered Software under those terms instead of these. *
- * *
- * Source is provided to this software because we believe users have a *
- * right to know exactly what a program is going to do before they run it. *
- * This also allows you to audit the software for security holes. *
- * *
- * Source code also allows you to port Nmap to new platforms, fix bugs, *
- * and add new features. You are highly encouraged to send your changes *
- * to the dev@nmap.org mailing list for possible incorporation into the *
- * main distribution. By sending these changes to Fyodor or one of the *
- * Insecure.Org development mailing lists, or checking them into the Nmap *
- * source code repository, it is understood (unless you specify otherwise) *
- * that you are offering the Nmap Project (Insecure.Com LLC) the *
- * unlimited, non-exclusive right to reuse, modify, and relicense the *
- * code. Nmap will always be available Open Source, but this is important *
- * because the inability to relicense code has caused devastating problems *
- * for other Free Software projects (such as KDE and NASM). We also *
- * occasionally relicense the code to third parties as discussed above. *
- * If you wish to specify special license conditions of your *
- * contributions, just say so when you send them. *
- * *
- * This program is distributed in the hope that it will be useful, but *
- * WITHOUT ANY WARRANTY; without even the implied warranty of *
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the Nmap *
- * license file for more details (it's in a COPYING file included with *
- * Nmap, and also available from https://svn.nmap.org/nmap/COPYING) *
- * *
- ***************************************************************************/
- /* $Id$ */
- #include "nmap_ftp.h"
- #include "output.h"
- #include "NmapOps.h"
- #include "nmap_error.h"
- #include "tcpip.h"
- #include "Target.h"
- extern NmapOps o;
- struct ftpinfo get_default_ftpinfo(void) {
- #if (defined(IN_ADDR_DEEPSTRUCT) || defined(SOLARIS))
- /* Note that struct in_addr in solaris is 3 levels deep just to store an
- * unsigned int! */
- struct ftpinfo ftp = { FTPUSER, FTPPASS, "", { { { 0 } } } , 21, 0};
- #else
- struct ftpinfo ftp = { FTPUSER, FTPPASS, "", { 0 }, 21, 0};
- #endif
- return ftp;
- }
- /* parse a URL stype ftp string of the form user:pass@server:portno */
- int parse_bounce_argument(struct ftpinfo *ftp, char *url) {
- char *p = url, *q, *s;
- if ((q = strrchr(url, '@'))) { /* we have user and/or pass */
- *q++ = '\0';
- if ((s = strchr(p, ':'))) { /* we have user AND pass */
- *s++ = '\0';
- strncpy(ftp->pass, s, 255);
- } else { /* we ONLY have user */
- log_write(LOG_STDOUT, "Assuming %s is a username, and using the default password: %s\n",
- p, ftp->pass);
- }
- strncpy(ftp->user, p, 63);
- } else {
- q = url;
- }
- /* q points to beginning of server name */
- if ((s = strchr(q, ':'))) { /* we have portno */
- *s++ = '\0';
- ftp->port = atoi(s);
- }
- strncpy(ftp->server_name, q, MAXHOSTNAMELEN);
- ftp->user[63] = ftp->pass[255] = ftp->server_name[MAXHOSTNAMELEN] = 0;
- return 1;
- }
- int ftp_anon_connect(struct ftpinfo *ftp) {
- int sd;
- struct sockaddr_in sock;
- int res;
- char recvbuf[2048];
- char command[512];
- if (o.verbose || o.debugging)
- log_write(LOG_STDOUT, "Attempting connection to ftp://%s:%s@%s:%i\n",
- ftp->user, ftp->pass, ftp->server_name, ftp->port);
- if ((sd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
- gh_perror("Couldn't create %s socket", __func__);
- return 0;
- }
- socket_bindtodevice(sd, o.device);
- sock.sin_family = AF_INET;
- sock.sin_addr.s_addr = ftp->server.s_addr;
- sock.sin_port = htons(ftp->port);
- res = connect(sd, (struct sockaddr *) &sock, sizeof(struct sockaddr_in));
- if (res < 0)
- fatal("Your FTP bounce proxy server won't talk to us!");
- if (o.verbose || o.debugging)
- log_write(LOG_STDOUT, "Connected:");
- while ((res = recvtime(sd, recvbuf, sizeof(recvbuf) - 1, 7, NULL)) > 0) {
- if (o.debugging || o.verbose) {
- recvbuf[res] = '\0';
- log_write(LOG_STDOUT, "%s", recvbuf);
- }
- }
- if (res < 0)
- pfatal("recv problem from FTP bounce server");
- Snprintf(command, 511, "USER %s\r\n", ftp->user);
- send(sd, command, strlen(command), 0);
- res = recvtime(sd, recvbuf, sizeof(recvbuf) - 1, 12, NULL);
- if (res <= 0)
- pfatal("recv problem from FTP bounce server");
- recvbuf[res] = '\0';
- if (o.debugging)
- log_write(LOG_STDOUT, "sent username, received: %s", recvbuf);
- if (recvbuf[0] == '5')
- fatal("Your FTP bounce server doesn't like the username \"%s\"", ftp->user);
- Snprintf(command, 511, "PASS %s\r\n", ftp->pass);
- send(sd, command, strlen(command), 0);
- res = recvtime(sd, recvbuf, sizeof(recvbuf) - 1, 12, NULL);
- if (res < 0)
- pfatal("recv problem from FTP bounce server");
- if (!res) {
- error("Timeout from bounce server ...");
- } else {
- recvbuf[res] = '\0';
- if (o.debugging)
- log_write(LOG_STDOUT, "sent password, received: %s", recvbuf);
- if (recvbuf[0] == '5')
- fatal("Your FTP bounce server refused login combo (%s/%s)", ftp->user, ftp->pass);
- }
- while ((res = recvtime(sd, recvbuf, sizeof(recvbuf) - 1, 2, NULL)) > 0) {
- if (o.debugging) {
- recvbuf[res] = '\0';
- log_write(LOG_STDOUT, "%s", recvbuf);
- }
- }
- if (res < 0)
- pfatal("recv problem from FTP bounce server");
- if (o.verbose)
- log_write(LOG_STDOUT, "Login credentials accepted by FTP server!\n");
- ftp->sd = sd;
- return sd;
- }
- /* FTP bounce attack scan. This function is rather lame and should be
- rewritten. But I don't think it is used much anyway. If I'm going to
- allow FTP bounce scan, I should really allow SOCKS proxy scan. */
- void bounce_scan(Target *target, u16 *portarray, int numports,
- struct ftpinfo *ftp) {
- o.current_scantype = BOUNCE_SCAN;
- time_t starttime;
- int res , sd = ftp->sd, i = 0;
- const char *t = (const char *)target->v4hostip();
- int retriesleft = FTP_RETRIES;
- char recvbuf[2048];
- char targetstr[20];
- char command[512];
- char hostname[1200];
- unsigned short portno, p1, p2;
- int timedout;
- if (numports == 0)
- return; /* nothing to scan for */
- Snprintf(targetstr, 20, "%d,%d,%d,%d,", UC(t[0]), UC(t[1]), UC(t[2]), UC(t[3]));
- starttime = time(NULL);
- if (o.verbose || o.debugging) {
- struct tm *tm = localtime(&starttime);
- assert(tm);
- log_write(LOG_STDOUT, "Initiating TCP FTP bounce scan against %s at %02d:%02d\n", target->NameIP(hostname, sizeof(hostname)), tm->tm_hour, tm->tm_min );
- }
- for (i = 0; i < numports; i++) {
- /* Check for timeout */
- if (target->timedOut(NULL))
- return;
- portno = htons(portarray[i]);
- p1 = ((unsigned char *) &portno)[0];
- p2 = ((unsigned char *) &portno)[1];
- Snprintf(command, 512, "PORT %s%i,%i\r\n", targetstr, p1, p2);
- if (o.debugging)
- log_write(LOG_STDOUT, "Attempting command: %s", command);
- if (send(sd, command, strlen(command), 0) < 0 ) {
- gh_perror("send in %s", __func__);
- if (retriesleft) {
- if (o.verbose || o.debugging)
- log_write(LOG_STDOUT, "Our FTP proxy server hung up on us! retrying\n");
- retriesleft--;
- close(sd);
- ftp->sd = ftp_anon_connect(ftp);
- if (ftp->sd < 0)
- return;
- sd = ftp->sd;
- i--;
- } else {
- error("Our socket descriptor is dead and we are out of retries. Giving up.");
- close(sd);
- ftp->sd = -1;
- return;
- }
- } else { /* Our send is good */
- res = recvtime(sd, recvbuf, 2048, 15, NULL);
- if (res <= 0) {
- perror("recv problem from FTP bounce server");
- } else { /* our recv is good */
- recvbuf[res] = '\0';
- if (o.debugging)
- log_write(LOG_STDOUT, "result of port query on port %i: %s",
- portarray[i], recvbuf);
- if (recvbuf[0] == '5') {
- if (portarray[i] > 1023) {
- fatal("Your FTP bounce server sucks, it won't let us feed bogus ports!");
- } else {
- error("Your FTP bounce server doesn't allow privileged ports, skipping them.");
- while (i < numports && portarray[i] < 1024) i++;
- if (!portarray[i]) {
- fatal("And you didn't want to scan any unprivileged ports. Giving up.");
- }
- }
- } else { /* Not an error message */
- if (send(sd, "LIST\r\n", 6, 0) > 0 ) {
- res = recvtime(sd, recvbuf, 2048, 12, &timedout);
- if (res < 0) {
- perror("recv problem from FTP bounce server");
- } else if (res == 0) {
- if (timedout)
- target->ports.setPortState(portarray[i], IPPROTO_TCP, PORT_FILTERED);
- else target->ports.setPortState(portarray[i], IPPROTO_TCP, PORT_CLOSED);
- } else {
- recvbuf[res] = '\0';
- if (o.debugging)
- log_write(LOG_STDOUT, "result of LIST: %s", recvbuf);
- if (!strncmp(recvbuf, "500", 3)) {
- /* oh dear, we are not aligned properly */
- if (o.verbose || o.debugging)
- error("FTP command misalignment detected ... correcting.");
- res = recvtime(sd, recvbuf, 2048, 10, NULL);
- }
- if (recvbuf[0] == '1' || recvbuf[0] == '2') {
- target->ports.setPortState(portarray[i], IPPROTO_TCP, PORT_OPEN);
- if (recvbuf[0] == '1') {
- res = recvtime(sd, recvbuf, 2048, 5, NULL);
- if (res < 0)
- perror("recv problem from FTP bounce server");
- else {
- recvbuf[res] = '\0';
- if (res > 0) {
- if (o.debugging)
- log_write(LOG_STDOUT, "nxt line: %s", recvbuf);
- if (recvbuf[0] == '4' && recvbuf[1] == '2' && recvbuf[2] == '6') {
- target->ports.forgetPort(portarray[i], IPPROTO_TCP);
- if (o.debugging || o.verbose)
- log_write(LOG_STDOUT, "Changed my mind about port %i\n", portarray[i]);
- }
- }
- }
- }
- } else {
- /* This means the port is closed ... */
- target->ports.setPortState(portarray[i], IPPROTO_TCP, PORT_CLOSED);
- }
- }
- }
- }
- }
- }
- }
- if (o.debugging || o.verbose)
- log_write(LOG_STDOUT, "Scanned %d ports in %ld seconds via the Bounce scan.\n",
- numports, (long) time(NULL) - starttime);
- return;
- }