nfqws: --dpi-desync-hostfakesplit-mod

nfq/desync.c

@@ -2036,9 +2036,36 @@ static uint8_t dpi_desync_tcp_packet_play(bool replay, size_t reasm_offset, uint
 						DLOG("fakehost out of memory\n");
 						goto send_orig;
 					}
-					fill_random_az(fakehost,1);
+					if (*dp->hfs_mod.host)
-					fill_random_az09(fakehost+1,host_size-1);
+					{
-					if (host_size>=7) fakehost[host_size-4] = '.';
+						if (host_size<=dp->hfs_mod.host_size)
+						{
+							// "google.com" => "gle.com"
+							// "google.com" => "google.com"
+							memcpy(fakehost,dp->hfs_mod.host+dp->hfs_mod.host_size-host_size,host_size);
+						}
+						else
+						{
+							// "google.com" => "nb4auv9.google.com"
+							// "google.com" => ".google.com"
+							sz = host_size - dp->hfs_mod.host_size;
+							memcpy(fakehost+sz,dp->hfs_mod.host,dp->hfs_mod.host_size);
+							fakehost[--sz]='.';
+							if (sz)
+							{
+								fill_random_az(fakehost,1);
+								sz--;
+							}
+							fill_random_az09(fakehost+1,sz);
+						}
+					}
+					else
+					{
+						fill_random_az(fakehost,1);
+						fill_random_az09(fakehost+1,host_size-1);
+						if (host_size>=7) fakehost[host_size-4] = '.';
+					}
+					fakehost[host_size]=0;
 					DLOG("generated fake host: %s\n",fakehost);
 
 					pkt2_len = sizeof(pkt2);

nfq/nfqws.c

@@ -1098,6 +1098,49 @@ err:
 	return false;
 }
 
+static bool parse_hostfakesplit_mod(char *opt, struct hostfakesplit_mod *hfs_mod)
+{
+	char *e,*e2,*p,c,c2;
+
+	for (p=opt ; p ; )
+	{
+		for (e2=p ; *e2 && *e2!=',' && *e2!='=' ; e2++);
+
+		if ((e = strchr(e2,',')))
+		{
+			c=*e;
+			*e=0;
+		}
+
+		if (*e2=='=')
+		{
+			c2=*e2;
+			*e2=0;
+		}
+		else
+			e2=NULL;
+
+		if (!strcmp(p,"host"))
+		{
+			if (!e2 || !e2[1] || e2[1]==',') goto err;
+			strncpy(hfs_mod->host,e2+1,sizeof(hfs_mod->host)-1);
+			hfs_mod->host[sizeof(hfs_mod->host)-1-1]=0;
+			hfs_mod->host_size = strlen(hfs_mod->host); // cache value
+		}
+		else if (strcmp(p,"none"))
+			goto err;
+
+		if (e2) *e2=c2;
+		if (e) *e++=c;
+		p = e;
+	}
+	return true;
+err:
+	if (e2) *e2=c2;
+	if (e) *e++=c;
+	return false;
+}
+
 static bool parse_fooling(char *opt, unsigned int *fooling_mode)
 {
 	char *e,*p = opt;
@@ -1642,6 +1685,7 @@ static void exithelp(void)
 		" --dpi-desync-split-seqovl-pattern=<filename>|0xHEX ; pattern for the fake part of overlap\n"
 		" --dpi-desync-fakedsplit-pattern=<filename>|0xHEX ; fake pattern for fakedsplit/fakeddisorder\n"
 		" --dpi-desync-hostfakesplit-midhost=marker+N|marker-N ; additionally split real hostname at specified marker. must be within host..endhost or won't be splitted.\n"
+		" --dpi-desync-hostfakesplit-mod=mod[,mod]\t; can be none or host=<hostname>\n"
 		" --dpi-desync-ipfrag-pos-tcp=<8..%u>\t\t; ip frag position starting from the transport header. multiple of 8, default %u.\n"
 		" --dpi-desync-ipfrag-pos-udp=<8..%u>\t\t; ip frag position starting from the transport header. multiple of 8, default %u.\n"
 		" --dpi-desync-ts-increment=<int|0xHEX>\t\t; ts fooling TSval signed increment. default %d\n"
@@ -1821,6 +1865,7 @@ enum opt_indices {
 	IDX_DPI_DESYNC_SPLIT_SEQOVL_PATTERN,
 	IDX_DPI_DESYNC_FAKEDSPLIT_PATTERN,
 	IDX_DPI_DESYNC_HOSTFAKESPLIT_MIDHOST,
+	IDX_DPI_DESYNC_HOSTFAKESPLIT_MOD,
 	IDX_DPI_DESYNC_IPFRAG_POS_TCP,
 	IDX_DPI_DESYNC_IPFRAG_POS_UDP,
 	IDX_DPI_DESYNC_TS_INCREMENT,
@@ -1950,6 +1995,7 @@ static const struct option long_options[] = {
 	[IDX_DPI_DESYNC_SPLIT_SEQOVL_PATTERN] = {"dpi-desync-split-seqovl-pattern", required_argument, 0, 0},
 	[IDX_DPI_DESYNC_FAKEDSPLIT_PATTERN] = {"dpi-desync-fakedsplit-pattern", required_argument, 0, 0},
 	[IDX_DPI_DESYNC_HOSTFAKESPLIT_MIDHOST] = {"dpi-desync-hostfakesplit-midhost", required_argument, 0, 0},
+	[IDX_DPI_DESYNC_HOSTFAKESPLIT_MOD] = {"dpi-desync-hostfakesplit-mod", required_argument, 0, 0},
 	[IDX_DPI_DESYNC_IPFRAG_POS_TCP] = {"dpi-desync-ipfrag-pos-tcp", required_argument, 0, 0},
 	[IDX_DPI_DESYNC_IPFRAG_POS_UDP] = {"dpi-desync-ipfrag-pos-udp", required_argument, 0, 0},
 	[IDX_DPI_DESYNC_TS_INCREMENT] = {"dpi-desync-ts-increment", required_argument, 0, 0},
@@ -2599,6 +2645,13 @@ int main(int argc, char **argv)
 				exit_clean(1);
 			}
 			break;
+		case IDX_DPI_DESYNC_HOSTFAKESPLIT_MOD:
+			if (!parse_hostfakesplit_mod(optarg,&dp->hfs_mod))
+			{
+				DLOG_ERR("Invalid fakehostsplit mod : %s\n",optarg);
+				exit_clean(1);
+			}
+			break;
 		case IDX_DPI_DESYNC_IPFRAG_POS_TCP:
 			if (sscanf(optarg,"%u",&dp->desync_ipfrag_pos_tcp)<1 || dp->desync_ipfrag_pos_tcp<1 || dp->desync_ipfrag_pos_tcp>DPI_DESYNC_MAX_FAKE_LEN)
 			{

nfq/params.h

@@ -76,9 +76,14 @@ struct fake_tls_mod_cache
 };
 struct fake_tls_mod
 {
-	char sni[64];
+	char sni[128];
 	uint32_t mod;
 };
+struct hostfakesplit_mod
+{
+	char host[128];
+	size_t host_size;
+};
 
 typedef enum {SS_NONE=0,SS_SYN,SS_SYNACK,SS_ACKSYN} t_synack_split;
 
@@ -132,6 +137,8 @@ struct desync_profile
 	struct fake_tls_mod tls_mod_last;
 	struct blob_item *tls_fake_last;
 
+	struct hostfakesplit_mod hfs_mod;
+
 	int udplen_increment;
 
 	bool filter_ipv4,filter_ipv6;