/*************************************************************************** * 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; }