#54 syn-cookies now depend on seed (58736df1) · Commits · nimrod / masscan

src/main.c

+14 −13

Original line number	Diff line number	Diff line
		@@ -277,6 +277,7 @@ transmit_thread(void v) /aka. scanning_thread() */
		uint64_t seed = masscan->seed;
		uint64_t repeats = 0; /* --infinite repeats */
		uint64_t *status_syn_count;
		uint64_t entropy = masscan->seed;

		LOG(1, "xmit: starting transmit thread #%u\n", parms->nic_index);

		@@ -387,14 +388,15 @@ infinite:
		if (src_ip_mask > 1 \|\| src_port_mask > 1) {
		uint64_t ck = syn_cookie((unsigned)(i+repeats),
		(unsigned)((i+repeats)>>32),
		(unsigned)xXx, (unsigned)(xXx>>32));
		(unsigned)xXx, (unsigned)(xXx>>32),
		entropy);
		port_me = src_port + (ck & src_port_mask);
		ip_me = src_ip + ((ck>>16) & src_ip_mask);
		} else {
		ip_me = src_ip;
		port_me = src_port;
		}
		cookie = syn_cookie(ip_them, port_them, ip_me, port_me);
		cookie = syn_cookie(ip_them, port_them, ip_me, port_me, entropy);
		//printf("0x%08x 0x%08x 0x%04x 0x%08x 0x%04x \n", cookie, ip_them, port_them, ip_me, port_me);
		/*
		* SEND THE PROBE
		@@ -542,6 +544,7 @@ receive_thread(void *v)
		struct TCP_ConnectionTable *tcpcon = 0;
		uint64_t *status_synack_count;
		uint64_t *status_tcb_count;
		uint64_t entropy = masscan->seed;

		/* some status variables */
		status_synack_count = (uint64_t*)malloc(sizeof(uint64_t));
		@@ -603,7 +606,8 @@ receive_thread(void *v)
		&parms->tmplset->pkts[Proto_TCP],
		output_report_banner,
		out,
		masscan->tcb.timeout
		masscan->tcb.timeout,
		masscan->seed
		);
		tcpcon_set_banner_flags(tcpcon,
		masscan->is_capture_cert,
		@@ -716,10 +720,10 @@ receive_thread(void *v)

		switch (parsed.ip_protocol) {
		case 132: /* SCTP */
		cookie = syn_cookie(ip_them, port_them \| (Proto_SCTP<<16), ip_me, port_me) & 0xFFFFFFFF;
		cookie = syn_cookie(ip_them, port_them \| (Proto_SCTP<<16), ip_me, port_me, entropy) & 0xFFFFFFFF;
		break;
		default:
		cookie = syn_cookie(ip_them, port_them, ip_me, port_me) & 0xFFFFFFFF;
		cookie = syn_cookie(ip_them, port_them, ip_me, port_me, entropy) & 0xFFFFFFFF;
		}

		/* verify: my IP address */
		@@ -773,13 +777,13 @@ receive_thread(void *v)
		continue;
		if (parms->masscan->nmap.packet_trace)
		packet_trace(stdout, parms->pt_start, px, length, 0);
		handle_udp(out, secs, px, length, &parsed);
		handle_udp(out, secs, px, length, &parsed, entropy);
		continue;
		case FOUND_ICMP:
		handle_icmp(out, secs, px, length, &parsed);
		handle_icmp(out, secs, px, length, &parsed, entropy);
		continue;
		case FOUND_SCTP:
		handle_sctp(out, secs, px, length, cookie, &parsed);
		handle_sctp(out, secs, px, length, cookie, &parsed, entropy);
		break;
		case FOUND_TCP:
		/* fall down to below */
		@@ -1133,7 +1137,8 @@ main_scan(struct Masscan *masscan)
		parms->adapter_mac,
		parms->router_mac,
		masscan->payloads,
		rawsock_datalink(masscan->nic[index].adapter));
		rawsock_datalink(masscan->nic[index].adapter),
		masscan->seed);

		/*
		* Set the "source port" of everything we transmit.
		@@ -1423,10 +1428,6 @@ int main(int argc, char *argv[])
		snmp_init();
		x509_init();

		/* Set randomization seed for SYN-cookies */
		syn_set_entropy(masscan->seed);



		/*
		* Apply excludes. People ask us not to scan them, so we maintain a list

src/output.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -633,7 +633,7 @@ output_report_status(struct Output *out, time_t timestamp, int status,

		/* If in "--interactive" mode, then print the banner to the command
		* line screen */
		if (out->is_interactive) {
		if (out->is_interactive \|\| out->format == 0) {
		unsigned count;

		count = fprintf(stdout, "Discovered %s port %u/%s on %u.%u.%u.%u",
		@@ -749,7 +749,7 @@ output_report_banner(struct Output *out, time_t now,

		/* If in "--interactive" mode, then print the banner to the command
		* line screen */
		if (out->is_interactive) {
		if (out->is_interactive \|\| out->format == 0) {
		unsigned count;
		char banner_buffer[4096];

src/proto-dns.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -351,7 +351,10 @@ dns_set_cookie(unsigned char *px, size_t length, uint64_t cookie)
		* string for the banner.
		***************************************************************************/
		unsigned
		handle_dns(struct Output out, time_t timestamp, const unsigned char px, unsigned length, struct PreprocessedInfo *parsed)
		handle_dns(struct Output *out, time_t timestamp,
		const unsigned char *px, unsigned length,
		struct PreprocessedInfo *parsed,
		uint64_t entropy)
		{
		unsigned ip_them;
		unsigned ip_me;
		@@ -366,7 +369,7 @@ handle_dns(struct Output out, time_t timestamp, const unsigned char px, unsign
		ip_me = parsed->ip_dst[0]<<24 \| parsed->ip_dst[1]<<16
		\| parsed->ip_dst[2]<< 8 \| parsed->ip_dst[3]<<0;

		seqno = (unsigned)syn_cookie(ip_them, port_them \| Templ_UDP, ip_me, port_me);
		seqno = (unsigned)syn_cookie(ip_them, port_them \| Templ_UDP, ip_me, port_me, entropy);

		proto_dns_parse(dns, px, parsed->app_offset, parsed->app_offset + parsed->app_length);

src/proto-dns.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -5,7 +5,7 @@
		struct PreprocessedInfo;
		struct Output;

		unsigned handle_dns(struct Output out, time_t timestamp, const unsigned char px, unsigned length, struct PreprocessedInfo *parsed);
		unsigned handle_dns(struct Output out, time_t timestamp, const unsigned char px, unsigned length, struct PreprocessedInfo *parsed, uint64_t entropy);

		unsigned dns_set_cookie(unsigned char *px, size_t length, uint64_t seqno);

src/proto-icmp.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -55,7 +55,8 @@ parse_port_unreachable(const unsigned char *px, unsigned length,
		void
		handle_icmp(struct Output *out, time_t timestamp,
		const unsigned char *px, unsigned length,
		struct PreprocessedInfo *parsed)
		struct PreprocessedInfo *parsed,
		uint64_t entropy)
		{
		unsigned type = parsed->port_src;
		unsigned code = parsed->port_dst;
		@@ -76,7 +77,7 @@ handle_icmp(struct Output *out, time_t timestamp,

		switch (type) {
		case 0: /* ICMP echo reply */
		cookie = (unsigned)syn_cookie(ip_them, Templ_ICMP_echo, ip_me, 0);
		cookie = (unsigned)syn_cookie(ip_them, Templ_ICMP_echo, ip_me, 0, entropy);
		if ((cookie & 0xFFFFFFFF) != seqno_me)
		return; /* not my response */