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service_scan.cc
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/***************************************************************************
* service_scan.cc -- Routines used for service fingerprinting to determine *
* what application-level protocol is listening on a given port *
* (e.g. snmp, http, ftp, smtp, etc.) *
* *
***********************IMPORTANT NMAP LICENSE TERMS************************
* *
* The Nmap Security Scanner is (C) 1996-2020 Insecure.Com LLC ("The Nmap *
* Project"). Nmap is also a registered trademark of the Nmap Project. *
* *
* This program is distributed under the terms of the Nmap Public Source *
* License (NPSL). The exact license text applying to a particular Nmap *
* release or source code control revision is contained in the LICENSE *
* file distributed with that version of Nmap or source code control *
* revision. More Nmap copyright/legal information is available from *
* https://nmap.org/book/man-legal.html, and further information on the *
* NPSL license itself can be found at https://nmap.org/npsl. This header *
* summarizes some key points from the Nmap license, but is no substitute *
* for the actual license text. *
* *
* Nmap is generally free for end users to download and use themselves, *
* including commercial use. It is available from https://nmap.org. *
* *
* The Nmap license generally prohibits companies from using and *
* redistributing Nmap in commercial products, but we sell a special Nmap *
* OEM Edition with a more permissive license and special features for *
* this purpose. See https://nmap.org/oem *
* *
* If you have received a written Nmap license agreement or contract *
* stating terms other than these (such as an Nmap OEM license), you may *
* choose to use and redistribute Nmap under those terms instead. *
* *
* The official Nmap Windows builds include the Npcap software *
* (https://npcap.org) for packet capture and transmission. It is under *
* separate license terms which forbid redistribution without special *
* permission. So the official Nmap Windows builds may not be *
* redistributed without special permission (such as an Nmap OEM *
* license). *
* *
* 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 submit your *
* changes as a Github PR or by email to the [email protected] mailing list *
* for possible incorporation into the main distribution. Unless you *
* specify otherwise, it is understood that you are offering us very *
* broad rights to use your submissions as described in the Nmap Public *
* Source License Contributor Agreement. This is important because we *
* fund the project by selling licenses with various terms, and also *
* because the inability to relicense code has caused devastating *
* problems for other Free Software projects (such as KDE and NASM). *
* *
* The free version of Nmap 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. Warranties, *
* indemnification and commercial support are all available through the *
* Npcap OEM program--see https://nmap.org/oem. *
* *
***************************************************************************/
/* $Id$ */
#include "service_scan.h"
#include "timing.h"
#include "NmapOps.h"
#include "nsock.h"
#include "Target.h"
#include "utils.h"
#include "nmap_error.h"
#include "protocols.h"
#include "scan_lists.h"
#include "nmap_tty.h"
#include <errno.h>
#if HAVE_OPENSSL
/* OpenSSL 1.0.0 needs _WINSOCKAPI_ to be defined, otherwise it loads
<windows.h> (through openssl/dtls1.h), which is incompatible with the
<winsock2.h> that we use. (It creates errors with the redefinition of struct
timeval, for example.) _WINSOCKAPI_ should be defined by our inclusion of
<winsock2.h>, but it appears to be undefined somewhere, possibly in
libpcap. */
#define _WINSOCKAPI_
#include <openssl/ssl.h>
#endif
#if TIME_WITH_SYS_TIME
# include <sys/time.h>
# include <time.h>
#else
# if HAVE_SYS_TIME_H
# include <sys/time.h>
# else
# include <time.h>
# endif
#endif
#ifndef IPPROTO_SCTP
#include "libnetutil/netutil.h"
#endif
#include <algorithm>
#include <list>
extern NmapOps o;
// Details on a particular service (open port) we are trying to match
class ServiceNFO {
public:
ServiceNFO(AllProbes *AP);
~ServiceNFO();
// If a service response to a given probeName, this function adds
// the response the the fingerprint for that service. The
// fingerprint can be printed when nothing matches the service. You
// can obtain the fingerprint (if any) via getServiceFingerprint();
void addToServiceFingerprint(const char *probeName, const u8 *resp,
int resplen);
// Get the service fingerprint. It is NULL if there is none, such
// as if there was a match before any other probes were finished (or
// if no probes gave back data). Note that this is plain
// NUL-terminated ASCII data, although the length is optionally
// available anyway. This function terminates the service fingerprint
// with a semi-colon
const char *getServiceFingerprint(int *flen);
// Note that the next 2 members are for convenience and are not destroyed w/the ServiceNFO
Target *target; // the port belongs to this target host
// if a match is found, it is placed here. Otherwise NULL
const char *probe_matched;
// If a match is found, any product/version/info/hostname/ostype/devicetype
// is placed in these 6 strings. Otherwise the string will be 0 length.
char product_matched[80];
char version_matched[80];
char extrainfo_matched[256];
char hostname_matched[80];
char ostype_matched[32];
char devicetype_matched[32];
char cpe_a_matched[80];
char cpe_h_matched[80];
char cpe_o_matched[80];
enum service_tunnel_type tunnel; /* SERVICE_TUNNEL_NONE, SERVICE_TUNNEL_SSL */
// This stores our SSL session id, which will help speed up subsequent
// SSL connections. It's overwritten each time. void* is used so we don't
// need to #ifdef HAVE_OPENSSL all over. We'll cast later as needed.
void *ssl_session;
// if a match was found (see above), this tells whether it was a "soft"
// or hard match. It is always false if no match has been found.
bool softMatchFound;
// most recent probe executed (or in progress). If there has been a match
// (probe_matched != NULL), this will be the corresponding ServiceProbe.
ServiceProbe *currentProbe();
// computes the next probe to test, and ALSO CHANGES currentProbe() to
// that! If newresp is true, the old response info will be lost and
// invalidated. Otherwise it remains as if it had been received by
// the current probe (useful after a NULL probe).
ServiceProbe *nextProbe(bool newresp);
// Resets the probes back to the first one. One case where this is useful is
// when SSL is detected -- we redo all probes through SSL. If freeFP, any
// service fingerprint is freed too.
void resetProbes(bool freefp);
// Number of milliseconds used so far to complete the present probe. Timeval
// can omitted, it is just there as an optimization in case you have it handy.
int probe_timemsused(const ServiceProbe *probe, const struct timeval *now = NULL);
// Number of milliseconds left to complete the present probe, or 0 if
// the probe is already expired. Timeval can omitted, it is just there
// as an optimization in case you have it handy.
int probe_timemsleft(const ServiceProbe *probe, const struct timeval *now = NULL);
enum serviceprobestate probe_state; // defined in portlist.h
nsock_iod niod; // The IO Descriptor being used in this probe (or NULL)
u16 portno; // in host byte order
u8 proto; // IPPROTO_TCP or IPPROTO_UDP
// The time that the current probe was executed (meaning TCP connection
// made or first UDP packet sent
struct timeval currentprobe_exec_time;
// Append newly-received data to the current response string (if any)
void appendtocurrentproberesponse(const u8 *respstr, int respstrlen);
// Get the full current response string. Note that this pointer is
// INVALIDATED if you call appendtocurrentproberesponse() or nextProbe()
u8 *getcurrentproberesponse(int *respstrlen);
AllProbes *AP;
// Is it possible this service is tcpwrapped? Not if a probe times out or
// gets a real response.
bool tcpwrap_possible;
private:
// Adds a character to servicefp. Takes care of word wrapping if
// necessary at the given (wrapat) column. Chars will only be
// written if there is enough space. Otherwise it exits.
void addServiceChar(char c, int wrapat);
// Like addServiceChar, but for a whole zero-terminated string
void addServiceString(const char *s, int wrapat);
std::vector<ServiceProbe *>::iterator current_probe;
u8 *currentresp;
int currentresplen;
char *servicefp;
int servicefplen;
int servicefpalloc;
};
// This holds the service information for a group of Targets being service scanned.
class ServiceGroup {
public:
ServiceGroup(std::vector<Target *> &Targets, AllProbes *AP);
~ServiceGroup();
std::list<ServiceNFO *> services_finished; // Services finished (discovered or not)
std::list<ServiceNFO *> services_in_progress; // Services currently being probed
std::list<ServiceNFO *> services_remaining; // Probes not started yet
unsigned int ideal_parallelism; // Max (and desired) number of probes out at once.
ScanProgressMeter *SPM;
int num_hosts_timedout; // # of hosts timed out during (or before) scan
};
#define SUBSTARGS_MAX_ARGS 5
#define SUBSTARGS_STRLEN 128
#define SUBSTARGS_ARGTYPE_NONE 0
#define SUBSTARGS_ARGTYPE_STRING 1
#define SUBSTARGS_ARGTYPE_INT 2
struct substargs {
int num_args; // Total number of arguments found
char str_args[SUBSTARGS_MAX_ARGS][SUBSTARGS_STRLEN];
// This is the length of each string arg, since they can contain zeros.
// The str_args[] are zero-terminated for convenience in the cases where
// you know they won't contain zero.
int str_args_len[SUBSTARGS_MAX_ARGS];
int int_args[SUBSTARGS_MAX_ARGS];
// The type of each argument -- see #define's above.
int arg_types[SUBSTARGS_MAX_ARGS];
};
/******************** PROTOTYPES *******************/
static void servicescan_read_handler(nsock_pool nsp, nsock_event nse, void *mydata);
static void servicescan_write_handler(nsock_pool nsp, nsock_event nse, void *mydata);
static void servicescan_connect_handler(nsock_pool nsp, nsock_event nse, void *mydata);
static void end_svcprobe(nsock_pool nsp, enum serviceprobestate probe_state, ServiceGroup *SG, ServiceNFO *svc, nsock_iod nsi);
ServiceProbeMatch::ServiceProbeMatch() {
deflineno = -1;
servicename = NULL;
matchstr = NULL;
product_template = version_template = info_template = NULL;
hostname_template = ostype_template = devicetype_template = NULL;
regex_compiled = NULL;
regex_extra = NULL;
isInitialized = false;
matchops_ignorecase = false;
matchops_dotall = false;
isSoft = false;
}
ServiceProbeMatch::~ServiceProbeMatch() {
std::vector<char *>::iterator it;
if (!isInitialized) return;
if (servicename) free(servicename);
if (matchstr) free(matchstr);
if (product_template) free(product_template);
if (version_template) free(version_template);
if (info_template) free(info_template);
if (hostname_template) free(hostname_template);
if (ostype_template) free(ostype_template);
if (devicetype_template) free(devicetype_template);
for (it = cpe_templates.begin(); it != cpe_templates.end(); it++)
free(*it);
matchstrlen = 0;
if (regex_compiled) pcre_free(regex_compiled);
if (regex_extra) pcre_free(regex_extra);
isInitialized = false;
matchops_anchor = -1;
}
/* Realloc a malloc-allocated string and put a given prefix at the front. */
static char *string_prefix(char *string, const char *prefix)
{
size_t slen, plen;
slen = strlen(string);
plen = strlen(prefix);
string = (char *) safe_realloc(string, plen + slen + 1);
memmove(string + plen, string, slen + 1);
memmove(string, prefix, plen);
return string;
}
/* Read the next tmplt from *matchtext and update *matchtext. Return true iff
a template was read. For example, after
matchtext = "p/123/ d/456/";
next_template(&matchtext, &modestr, &flags, &tmplt);
then
matchtext == " d/456/"
modestr == "p"
tmplt == "123"
flags == ""
*modestr and *tmplt must be freed if the return value is true. */
static bool next_template(const char **matchtext, char **modestr, char **tmplt,
char **flags, int lineno) {
const char *p, *q;
char delimchar;
p = *matchtext;
while(isspace((int) (unsigned char) *p))
p++;
if (*p == '\0')
return false;
q = p;
while (isalpha(*q) || *q == ':')
q++;
if (*q == '\0' || isspace(*q))
fatal("%s: parse error on line %d of nmap-service-probes", __func__, lineno);
*modestr = mkstr(p, q);
delimchar = *q;
p = q + 1;
q = strchr(p, delimchar);
if (q == NULL)
fatal("%s: parse error on line %d of nmap-service-probes", __func__, lineno);
*tmplt = mkstr(p, q);
p = q + 1;
q = p;
while (isalpha(*q))
q++;
*flags = mkstr(p, q);
/* Update pointer for caller. */
*matchtext = q;
return true;
}
// match text from the nmap-service-probes file. This must be called
// before you try and do anything with this match. This function
// should be passed the whole line starting with "match" or
// "softmatch" in nmap-service-probes. The line number that the text
// is provided so that it can be reported in error messages. This
// function will abort the program if there is a syntax problem.
void ServiceProbeMatch::InitMatch(const char *matchtext, int lineno) {
const char *p;
char *modestr, *tmptemplate, *flags;
int pcre_compile_ops = 0;
const char *pcre_errptr = NULL;
int pcre_erroffset = 0;
char **curr_tmp = NULL;
if (isInitialized) fatal("Sorry ... %s does not yet support reinitializion", __func__);
if (!matchtext || !*matchtext)
fatal("%s: no matchtext passed in (line %d of nmap-service-probes)", __func__, lineno);
isInitialized = true;
deflineno = lineno;
while(isspace((int) (unsigned char) *matchtext)) matchtext++;
// first we find whether this is a "soft" or normal match
if (strncmp(matchtext, "softmatch ", 10) == 0) {
isSoft = true;
matchtext += 10;
} else if (strncmp(matchtext, "match ", 6) == 0) {
isSoft = false;
matchtext += 6;
} else
fatal("%s: parse error on line %d of nmap-service-probes - must begin with \"match\" or \"softmatch\"", __func__, lineno);
// next comes the service name
p = strchr(matchtext, ' ');
if (!p) fatal("%s: parse error on line %d of nmap-service-probes: could not find service name", __func__, lineno);
servicename = (char *) safe_malloc(p - matchtext + 1);
memcpy(servicename, matchtext, p - matchtext);
servicename[p - matchtext] = '\0';
// The next part is a perl style regular expression specifier, like:
// m/^220 .*smtp/i Where 'm' means a normal regular expressions is
// used, the char after m can be anything (within reason, slash in
// this case) and tells us what delineates the end of the regex.
// After the delineating character are any single-character
// options. ('i' means "case insensitive", 's' means that . matches
// newlines (both are just as in perl)
matchtext = p;
if (!next_template(&matchtext, &modestr, &matchstr, &flags, lineno))
fatal("%s: parse error on line %d of nmap-service-probes", __func__, lineno);
if (strcmp(modestr, "m") != 0)
fatal("%s: parse error on line %d of nmap-service-probes: matchtext must begin with 'm'", __func__, lineno);
matchtype = SERVICEMATCH_REGEX;
// any options?
for (p = flags; *p != '\0'; p++) {
if (*p == 'i')
matchops_ignorecase = true;
else if (*p == 's')
matchops_dotall = true;
else
fatal("%s: illegal regexp option on line %d of nmap-service-probes", __func__, lineno);
}
// Next we compile and study the regular expression to match
if (matchops_ignorecase)
pcre_compile_ops |= PCRE_CASELESS;
if (matchops_dotall)
pcre_compile_ops |= PCRE_DOTALL;
regex_compiled = pcre_compile(matchstr, pcre_compile_ops, &pcre_errptr,
&pcre_erroffset, NULL);
if (regex_compiled == NULL)
fatal("%s: illegal regexp on line %d of nmap-service-probes (at regexp offset %d): %s\n", __func__, lineno, pcre_erroffset, pcre_errptr);
// Now study the regexp for greater efficiency
regex_extra = pcre_study(regex_compiled, 0
#ifdef PCRE_STUDY_EXTRA_NEEDED
| PCRE_STUDY_EXTRA_NEEDED
#endif
, &pcre_errptr);
if (pcre_errptr != NULL)
fatal("%s: failed to pcre_study regexp on line %d of nmap-service-probes: %s\n", __func__, lineno, pcre_errptr);
if (!regex_extra) {
regex_extra = (pcre_extra *) pcre_malloc(sizeof(pcre_extra));
memset(regex_extra, 0, sizeof(pcre_extra));
}
// Set some limits to avoid evil match cases.
// These are flexible; if they cause problems, increase them.
#ifdef PCRE_ERROR_MATCHLIMIT
regex_extra->match_limit = 100000; // 100K
#endif
#ifdef PCRE_ERROR_RECURSIONLIMIT
regex_extra->match_limit_recursion = 10000; // 10K
#endif
free(modestr);
free(flags);
/* OK! Now we look for any templates of the form ?/.../
* where ? is either p, v, i, h, o, or d. / is any
* delimiter character and ... is a template */
while (next_template(&matchtext, &modestr, &tmptemplate, &flags, lineno)) {
if (strcmp(modestr, "p") == 0)
curr_tmp = &product_template;
else if (strcmp(modestr, "v") == 0)
curr_tmp = &version_template;
else if (strcmp(modestr, "i") == 0)
curr_tmp = &info_template;
else if (strcmp(modestr, "h") == 0)
curr_tmp = &hostname_template;
else if (strcmp(modestr, "o") == 0)
curr_tmp = &ostype_template;
else if (strcmp(modestr, "d") == 0)
curr_tmp = &devicetype_template;
else if (strcmp(modestr, "cpe:") == 0) {
tmptemplate = string_prefix(tmptemplate, "cpe:/");
cpe_templates.push_back(NULL);
curr_tmp = &cpe_templates.back();
} else
fatal("%s: Unknown template specifier '%s' on line %d of nmap-service-probes", __func__, modestr, lineno);
/* This one already defined? */
if (*curr_tmp) {
if (o.debugging) {
error("WARNING: Template \"%s/%s/\" replaced with \"%s/%s/\" on line %d of nmap-service-probes",
modestr, *curr_tmp, modestr, tmptemplate, lineno);
}
free(*curr_tmp);
}
*curr_tmp = tmptemplate;
free(modestr);
free(flags);
}
isInitialized = 1;
}
// If the buf (of length buflen) match the regex in this
// ServiceProbeMatch, returns the details of the match (service
// name, version number if applicable, and whether this is a "soft"
// match. If the buf doesn't match, the serviceName field in the
// structure will be NULL. The MatchDetails structure returned is
// only valid until the next time this function is called. The only
// exception is that the serviceName field can be saved throughout
// program execution. If no version matched, that field will be
// NULL.
const struct MatchDetails *ServiceProbeMatch::testMatch(const u8 *buf, int buflen) {
int rc;
static char product[80];
static char version[80];
static char info[256]; /* We will truncate with ... later */
static char hostname[80];
static char ostype[32];
static char devicetype[32];
static char cpe_a[80], cpe_h[80], cpe_o[80];
char *bufc = (char *) buf;
int ovector[150]; // allows 50 substring matches (including the overall match)
assert(isInitialized);
assert (matchtype == SERVICEMATCH_REGEX);
// Clear out the output struct
memset(&MD_return, 0, sizeof(MD_return));
MD_return.isSoft = isSoft;
rc = pcre_exec(regex_compiled, regex_extra, bufc, buflen, 0, 0, ovector, sizeof(ovector) / sizeof(*ovector));
if (rc < 0) {
#ifdef PCRE_ERROR_MATCHLIMIT // earlier PCRE versions lack this
if (rc == PCRE_ERROR_MATCHLIMIT) {
if (o.debugging || o.verbose > 1)
error("Warning: Hit PCRE_ERROR_MATCHLIMIT when probing for service %s with the regex '%s'", servicename, matchstr);
} else
#endif // PCRE_ERROR_MATCHLIMIT
#ifdef PCRE_ERROR_RECURSIONLIMIT
if (rc == PCRE_ERROR_RECURSIONLIMIT) {
if (o.debugging || o.verbose > 1)
error("Warning: Hit PCRE_ERROR_RECURSIONLIMIT when probing for service %s with the regex '%s'", servicename, matchstr);
} else
#endif // PCRE_ERROR_RECURSIONLIMIT
if (rc != PCRE_ERROR_NOMATCH) {
fatal("Unexpected PCRE error (%d) when probing for service %s with the regex '%s'", rc, servicename, matchstr);
}
} else {
// Yeah! Match apparently succeeded.
// Now lets get the version number if available
getVersionStr(buf, buflen, ovector, rc, product, sizeof(product), version, sizeof(version), info, sizeof(info),
hostname, sizeof(hostname), ostype, sizeof(ostype), devicetype, sizeof(devicetype),
cpe_a, sizeof(cpe_a), cpe_h, sizeof(cpe_h), cpe_o, sizeof(cpe_o));
if (*product) MD_return.product = product;
if (*version) MD_return.version = version;
if (*info) MD_return.info = info;
if (*hostname) MD_return.hostname = hostname;
if (*ostype) MD_return.ostype = ostype;
if (*devicetype) MD_return.devicetype = devicetype;
if (*cpe_a) MD_return.cpe_a = cpe_a;
if (*cpe_h) MD_return.cpe_h = cpe_h;
if (*cpe_o) MD_return.cpe_o = cpe_o;
MD_return.serviceName = servicename;
MD_return.lineno = getLineNo();
}
return &MD_return;
}
// This simple function parses arguments out of a string. The string
// starts with the first argument. Each argument can be a string or
// an integer. Strings must be enclosed in double quotes (""). Most
// standard C-style escapes are supported. If this is successful, the
// number of args found is returned, args is filled appropriately, and
// args_end (if non-null) is set to the character after the closing
// ')'. Otherwise we return -1 and the values of args and args_end
// are undefined.
static int getsubstcommandargs(struct substargs *args, char *args_start,
char **args_end) {
char *p;
unsigned int len;
if (!args || !args_start) return -1;
memset(args, 0, sizeof(*args));
while(*args_start && *args_start != ')') {
// Find the next argument.
while(isspace((int) (unsigned char) *args_start)) args_start++;
if (*args_start == ')')
break;
else if (*args_start == '"') {
// OK - it is a string
// Do we have space for another arg?
if (args->num_args == SUBSTARGS_MAX_ARGS)
return -1;
do {
args_start++;
if (*args_start == '"' && (*(args_start - 1) != '\\' || *(args_start - 2) == '\\'))
break;
len = args->str_args_len[args->num_args];
if (len >= SUBSTARGS_STRLEN - 1)
return -1;
args->str_args[args->num_args][len] = *args_start;
args->str_args_len[args->num_args]++;
} while(*args_start);
len = args->str_args_len[args->num_args];
args->str_args[args->num_args][len] = '\0';
// Now handle escaped characters and such
if (!cstring_unescape(args->str_args[args->num_args], &len))
return -1;
args->str_args_len[args->num_args] = len;
args->arg_types[args->num_args] = SUBSTARGS_ARGTYPE_STRING;
args->num_args++;
args_start++;
args_start = strpbrk(args_start, ",)");
if (!args_start) return -1;
if (*args_start == ',') args_start++;
} else {
// Must be an integer argument
args->int_args[args->num_args] = (int) strtol(args_start, &p, 0);
if (p <= args_start) return -1;
args_start = p;
args->arg_types[args->num_args] = SUBSTARGS_ARGTYPE_INT;
args->num_args++;
args_start = strpbrk(args_start, ",)");
if (!args_start) return -1;
if (*args_start == ',') args_start++;
}
}
if (*args_start == ')') args_start++;
if (args_end) *args_end = args_start;
return args->num_args;
}
/* These three functions manage a growing string buffer, appended to at the end.
Begin with strbuf_init, follow with any number of strbuf_append, and end with
strbuf_finish. */
static void strbuf_init(char **buf, size_t *n, size_t *len) {
*buf = NULL;
*n = 0;
*len = 0;
}
static void strbuf_append(char **buf, size_t *n, size_t *len,
const char *from, size_t fromlen) {
/* Double the size of the buffer if necessary. */
if (*len == 0 || *len + fromlen > *n) {
*n = (*len + fromlen) * 2;
*buf = (char *) safe_realloc(*buf, *n + 1);
}
memcpy(*buf + *len, from, fromlen);
*len += fromlen;
}
/* Trim to length. (Also does initial allocation when *buf is empty.) */
static void strbuf_finish(char **buf, size_t *n, size_t *len) {
*buf = (char *) safe_realloc(*buf, *len + 1);
(*buf)[*len] = '\0';
}
/* Transform a string so that it is safe to insert into the middle of a CPE URL. */
static char *transform_cpe(const char *s) {
char *result;
size_t n, len, repllen;
const char *p;
strbuf_init(&result, &n, &len);
for (p = s; *p != '\0'; p++) {
const char *repl;
char buf[32];
/* Section 5.4 of the CPE specification lists these characters to be
escaped. */
if (strchr(":/?#[]@!$&'()*+,;=%<>\"", *p) != NULL) {
Snprintf(buf, sizeof(buf), "%%%02X", *p);
repl = buf;
/* Replacing spaces with underscores is also a convention. */
} else if (isspace(*p)) {
repl = "_";
/* Otherwise just make lower-case. */
} else {
buf[0] = tolower(*p);
buf[1] = '\0';
repl = buf;
}
repllen = strlen(repl);
strbuf_append(&result, &n, &len, repl, repllen);
}
strbuf_finish(&result, &n, &len);
return result;
}
// This function does the substitution of a placeholder like $2 or $P(4). It
// returns a newly allocated string, or NULL if it fails. tmplvar is a template
// variable, such as "$P(2)". We set *tmplvarend to the character after the
// variable. subject, subjectlen, ovector, and nummatches mean the same as in
// dotmplsubst().
static char *substvar(char *tmplvar, char **tmplvarend,
const u8 *subject, int subjectlen, int *ovector,
int nummatches) {
char substcommand[16];
char *p = NULL;
char *p_end;
int subnum = 0;
int offstart, offend;
int rc;
int i;
struct substargs command_args;
char *result;
size_t n, len;
// skip the '$'
if (*tmplvar != '$') return NULL;
tmplvar++;
if (!isdigit((int) (unsigned char) *tmplvar)) {
int commandlen;
/* This is a command like $P(1). */
p = strchr(tmplvar, '(');
if (!p) return NULL;
commandlen = p - tmplvar;
if (!commandlen || commandlen >= (int) sizeof(substcommand))
return NULL;
memcpy(substcommand, tmplvar, commandlen);
substcommand[commandlen] = '\0';
tmplvar = p+1;
// Now we grab the arguments.
rc = getsubstcommandargs(&command_args, tmplvar, &p_end);
if (rc <= 0) return NULL;
tmplvar = p_end;
} else {
/* This is a placeholder like $2. */
substcommand[0] = '\0';
subnum = *tmplvar - '0';
tmplvar++;
}
if (tmplvarend) *tmplvarend = tmplvar;
strbuf_init(&result, &n, &len);
if (!*substcommand) {
/* Handler for a placeholder like $2. */
if (subnum > 9 || subnum <= 0) return NULL;
if (subnum >= nummatches) return NULL;
offstart = ovector[subnum * 2];
offend = ovector[subnum * 2 + 1];
assert(offstart >= 0 && offstart <= subjectlen);
assert(offend >= 0 && offend <= subjectlen);
// A plain-jane copy
strbuf_append(&result, &n, &len, (const char *) subject + offstart, offend - offstart);
} else if (strcmp(substcommand, "P") == 0) {
if (command_args.num_args != 1 ||
command_args.arg_types[0] != SUBSTARGS_ARGTYPE_INT) {
return NULL;
}
subnum = command_args.int_args[0];
if (subnum > 9 || subnum <= 0) return NULL;
if (subnum >= nummatches) return NULL;
offstart = ovector[subnum * 2];
offend = ovector[subnum * 2 + 1];
assert(offstart >= 0 && offstart <= subjectlen);
assert(offend >= 0 && offend <= subjectlen);
// This filter only includes printable characters. It is particularly
// useful for collapsing unicode text that looks like
// "W\0O\0R\0K\0G\0R\0O\0U\0P\0"
for(i=offstart; i < offend; i++) {
if (isprint((int) subject[i]))
strbuf_append(&result, &n, &len, (const char *) subject + i, 1);
}
} else if (strcmp(substcommand, "SUBST") == 0) {
char *findstr, *replstr;
int findstrlen, replstrlen;
if (command_args.num_args != 3 ||
command_args.arg_types[0] != SUBSTARGS_ARGTYPE_INT ||
command_args.arg_types[1] != SUBSTARGS_ARGTYPE_STRING ||
command_args.arg_types[2] != SUBSTARGS_ARGTYPE_STRING) {
return NULL;
}
subnum = command_args.int_args[0];
if (subnum > 9 || subnum <= 0) return NULL;
if (subnum >= nummatches) return NULL;
offstart = ovector[subnum * 2];
offend = ovector[subnum * 2 + 1];
assert(offstart >= 0 && offstart <= subjectlen);
assert(offend >= 0 && offend <= subjectlen);
findstr = command_args.str_args[1];
findstrlen = command_args.str_args_len[1];
replstr = command_args.str_args[2];
replstrlen = command_args.str_args_len[2];
for(i=offstart; i < offend; ) {
if (memcmp(subject + i, findstr, findstrlen) != 0) {
strbuf_append(&result, &n, &len, (const char *) subject + i, 1); // no match
i++;
} else {
// The find string was found, copy it to newstring
strbuf_append(&result, &n, &len, replstr, replstrlen);
i += findstrlen;
}
}
} else if (strcmp(substcommand, "I") == 0 ){
// Parse an unsigned int
long long unsigned val = 0;
bool bigendian = true;
char buf[24]; //0xffffffffffffffff = 18446744073709551615, 20 chars
int buflen;
if (command_args.num_args != 2 ||
command_args.arg_types[0] != SUBSTARGS_ARGTYPE_INT ||
command_args.arg_types[1] != SUBSTARGS_ARGTYPE_STRING ||
command_args.str_args_len[1] != 1) {
return NULL;
}
subnum = command_args.int_args[0];
if (subnum > 9 || subnum <= 0) return NULL;
if (subnum >= nummatches) return NULL;
offstart = ovector[subnum * 2];
offend = ovector[subnum * 2 + 1];
assert(offstart >= 0 && offstart <= subjectlen);
// overflow
if (offend - offstart > 8) {
return NULL;
}
switch (command_args.str_args[1][0]) {
case '>':
bigendian = true;
break;
case '<':
bigendian = false;
break;
default:
return NULL;
break;
}
if (bigendian) {
for(i=offstart; i < offend; i++) {
val = (val<<8) + subject[i];
}
} else {
for(i=offend - 1; i > offstart - 1; i--) {
val = (val<<8) + subject[i];
}
}
buflen = Snprintf(buf, sizeof(buf), "%llu", val);
if (buflen < 0 || buflen >= (int) sizeof(buf)) {
return NULL;
}
strbuf_append(&result, &n, &len, buf, buflen);
} else return NULL; // Unknown command
strbuf_finish(&result, &n, &len);
return result;
}
// This function takes a template string (tmpl) which can have
// placeholders in it such as $1 for substring matches in a regexp
// that was run against subject, and subjectlen, with the 'nummatches'
// matches in ovector. The NUL-terminated newly composted string is
// placed into 'newstr', as long as it doesn't exceed 'newstrlen'
// bytes. Trailing whitespace and commas are removed. Returns zero for success
//
// The transform argument is a function pointer. If not NULL, the given
// function is applied to all substitutions before they are inserted
// into the result string.
static int dotmplsubst(const u8 *subject, int subjectlen,
int *ovector, int nummatches, char *tmpl, char *newstr,
int newstrlen,
char *(*transform)(const char *) = NULL) {
int newlen;
char *srcstart=tmpl, *srcend;
char *dst = newstr;
char *newstrend = newstr + newstrlen; // Right after the final char
char *subst;
if (!newstr || !tmpl) return -1;
if (newstrlen < 3) return -1; // Have a nice day!
while(*srcstart) {
// First do any literal text before '$'
srcend = strchr(srcstart, '$');
if (!srcend) {
// Only literal text remain!
while(*srcstart) {
if (dst >= newstrend - 1)
return -1;
*dst++ = *srcstart++;
}
*dst = '\0';
while (--dst >= newstr) {
if (isspace((int) (unsigned char) *dst) || *dst == ',')
*dst = '\0';
else break;
}
return 0;
} else {
// Copy the literal text up to the '$', then do the substitution
newlen = srcend - srcstart;
if (newlen > 0) {
if (newstrend - dst <= newlen - 1)
return -1;
memcpy(dst, srcstart, newlen);
dst += newlen;
}
srcstart = srcend;
subst = substvar(srcstart, &srcend, subject, subjectlen, ovector, nummatches);
if (subst == NULL)
return -1;
/* Apply transformation if requested. */
if (transform != NULL) {
char *tmp = subst;
subst = transform(subst);
free(tmp);
if (subst == NULL)
return -1;
}
newlen = strlen(subst);
if (dst + newlen >= newstrend - 1) {
free(subst);
return -1;
}
memcpy(dst, subst, newlen);
free(subst);
dst += newlen;
srcstart = srcend;
}
}
if (dst >= newstrend - 1)
return -1;
*dst = '\0';
while (--dst >= newstr) {
if (isspace((int) (unsigned char) *dst) || *dst == ',')
*dst = '\0';
else break;
}
return 0;
}
// Use the version templates and the match data included here
// to put the version info into the given strings, (as long as the sizes
// are sufficient). Returns zero for success. If no template is available
// for a string, that string will have zero length after the function
// call (assuming the corresponding length passed in is at least 1)
int ServiceProbeMatch::getVersionStr(const u8 *subject, int subjectlen,
int *ovector, int nummatches, char *product, int productlen,
char *version, int versionlen, char *info, int infolen,
char *hostname, int hostnamelen, char *ostype, int ostypelen,
char *devicetype, int devicetypelen,
char *cpe_a, int cpe_alen,
char *cpe_h, int cpe_hlen,
char *cpe_o, int cpe_olen) const {
int rc;
assert(productlen >= 0 && versionlen >= 0 && infolen >= 0 &&
hostnamelen >= 0 && ostypelen >= 0 && devicetypelen >= 0);
if (productlen > 0) *product = '\0';
if (versionlen > 0) *version = '\0';
if (infolen > 0) *info = '\0';
if (hostnamelen > 0) *hostname = '\0';
if (ostypelen > 0) *ostype = '\0';
if (devicetypelen > 0) *devicetype = '\0';
if (cpe_alen > 0) *cpe_a = '\0';
if (cpe_hlen > 0) *cpe_h = '\0';
if (cpe_olen > 0) *cpe_o = '\0';
int retval = 0;
// Now lets get this started! We begin with the product name
if (product_template) {
rc = dotmplsubst(subject, subjectlen, ovector, nummatches, product_template, product, productlen);
if (rc != 0) {
error("Warning: Servicescan failed to fill product_template (subjectlen: %d, productlen: %d). Capture exceeds length? Match string was line %d: p/%s/%s/%s", subjectlen, productlen, deflineno,
(product_template)? product_template : "",
(version_template)? version_template : "",
(info_template)? info_template : "");
if (productlen > 0) *product = '\0';
retval = -1;
}
}
if (version_template) {
rc = dotmplsubst(subject, subjectlen, ovector, nummatches, version_template, version, versionlen);
if (rc != 0) {
error("Warning: Servicescan failed to fill version_template (subjectlen: %d, versionlen: %d). Capture exceeds length? Match string was line %d: v/%s/%s/%s", subjectlen, versionlen, deflineno,
(product_template)? product_template : "",
(version_template)? version_template : "",
(info_template)? info_template : "");
if (versionlen > 0) *version = '\0';
retval = -1;
}
}
if (info_template) {
rc = dotmplsubst(subject, subjectlen, ovector, nummatches, info_template, info, infolen);
if (rc != 0) {
error("Warning: Servicescan failed to fill info_template (subjectlen: %d, infolen: %d). Capture exceeds length? Match string was line %d: i/%s/%s/%s", subjectlen, infolen, deflineno,
(product_template)? product_template : "",
(version_template)? version_template : "",
(info_template)? info_template : "");
if (infolen > 0) *info = '\0';
retval = -1;
}
}
if (hostname_template) {
rc = dotmplsubst(subject, subjectlen, ovector, nummatches, hostname_template, hostname, hostnamelen);
if (rc != 0) {
error("Warning: Servicescan failed to fill hostname_template (subjectlen: %d, hostnamelen: %d). Capture exceeds length? Match string was line %d: h/%s/", subjectlen, hostnamelen, deflineno,
(hostname_template)? hostname_template : "");