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nmap_ftp.cc
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/***************************************************************************
* 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 [email protected]). 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 [email protected] 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 [email protected] 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 [email protected] 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"
#include "nmap_tty.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;
ScanProgressMeter *SPM;
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];
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]));
SPM = new ScanProgressMeter(scantype2str(BOUNCE_SCAN));
for (i = 0; i < numports; i++) {
/* Check for timeout */
if (target->timedOut(NULL)) {
Snprintf(recvbuf, sizeof(recvbuf), "Target timed out");
SPM->endTask(NULL, recvbuf);
delete SPM;
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) {
Snprintf(recvbuf, sizeof(recvbuf), "Error connecting");
SPM->endTask(NULL, recvbuf);
delete SPM;
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;
Snprintf(recvbuf, sizeof(recvbuf), "Max retries exceeded");
SPM->endTask(NULL, recvbuf);
delete SPM;
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 (SPM->mayBePrinted(NULL)) {
SPM->printStatsIfNecessary((double) i / numports, NULL);
}
else if (keyWasPressed()) {
SPM->printStats((double) i / numports, NULL);
log_flush(LOG_STDOUT);
}
}
Snprintf(recvbuf, sizeof(recvbuf), "%d total ports", numports);
SPM->endTask(NULL, recvbuf);
delete SPM;
return;
}