authoritative-dns-server

Author: lws-team

include/libwebsockets/lws-auth-dns.h

@@ -24,6 +24,38 @@
 
 #if defined(LWS_WITH_AUTHORITATIVE_DNS)
 
+struct auth_dns_rr {
+	lws_dll2_t list;
+
+	char *rdata;
+	size_t rdata_len;
+	
+	uint8_t *wire_rdata;
+	size_t wire_rdata_len;
+};
+
+struct auth_dns_rrset {
+	lws_dll2_t list;
+	lws_dll2_owner_t rr_list;
+
+	char *name;         
+	uint32_t ttl;
+	uint16_t class_;
+	uint16_t type;
+};
+
+struct auth_dns_zone {
+	lws_dll2_owner_t rrset_list;
+	char default_ttl[16];
+	char origin[256];
+};
+
+LWS_VISIBLE LWS_EXTERN int
+lws_auth_dns_parse_zone_buf(const char *buf, size_t len, struct auth_dns_zone *zone);
+
+LWS_VISIBLE LWS_EXTERN void
+lws_auth_dns_free_zone(struct auth_dns_zone *z);
+
 struct lws_auth_dns_sign_info {
 	const char			*input_filepath;
 	const char			*output_filepath;

lib/system/auth-dns/auth-dns.c

@@ -82,8 +82,14 @@ lws_auth_dns_parse_zone_buf(const char *buf, size_t len, struct auth_dns_zone *z
 
 	char line_accum[4096];
 	size_t lptr = 0;
+	int loop_cycles = 0;
 
 	while (p <= end) {
+		if (++loop_cycles > 5000000) {
+			lwsl_err("auth-dns: parsing exceeded maximum length\n");
+			break;
+		}
+
 		if (p < end && *p == '(' && !in_comment)
 			in_parens = 1;
 		else if (p < end && *p == ')' && !in_comment)
@@ -111,9 +117,10 @@ lws_auth_dns_parse_zone_buf(const char *buf, size_t len, struct auth_dns_zone *z
 				lws_tokenize_init(&ts, line_accum, LWS_TOKENIZE_F_HASH_COMMENT | LWS_TOKENIZE_F_DOT_NONTERM | LWS_TOKENIZE_F_NO_FLOATS | LWS_TOKENIZE_F_MINUS_NONTERM | LWS_TOKENIZE_F_SLASH_NONTERM | LWS_TOKENIZE_F_COLON_NONTERM | LWS_TOKENIZE_F_EQUALS_NONTERM | LWS_TOKENIZE_F_PLUS_NONTERM);
 				ts.len = lptr;
 
+				int max_tokens = 0;
 				do {
 					e = lws_tokenize(&ts);
-					if (e == LWS_TOKZE_ENDED)
+					if (e == LWS_TOKZE_ENDED || ++max_tokens > 256)
 						break;
 
 					if (e == LWS_TOKZE_TOKEN || e == LWS_TOKZE_QUOTED_STRING || e == LWS_TOKZE_INTEGER) {

lib/system/auth-dns/private-lib-system-auth-dns.h

@@ -27,32 +27,6 @@
 
 #include "private-lib-core.h"
 
-struct auth_dns_rr {
-	lws_dll2_t list;
-
-	char *rdata;        // unparsed or raw payload from zone line
-	size_t rdata_len;
-	
-	uint8_t *wire_rdata; // canonical wire format
-	size_t wire_rdata_len;
-};
-
-struct auth_dns_rrset {
-	lws_dll2_t list;
-	lws_dll2_owner_t rr_list; // list of auth_dns_rr
-
-	char *name;         
-	uint32_t ttl;
-	uint16_t class_;    // e.g. 1 for IN
-	uint16_t type;      // e.g. 1 for A, 2 for NS, etc
-};
-
-struct auth_dns_zone {
-	lws_dll2_owner_t rrset_list;
-	char default_ttl[16];
-	char origin[128];
-};
-
 int
 lws_auth_dns_rdata_to_wire(struct auth_dns_zone *z, struct auth_dns_rr *rr, uint16_t type);
 

lib/system/auth-dns/sign.c

@@ -42,8 +42,11 @@ name_to_wire(const char *name, const char *origin, uint8_t *wire, size_t *wire_l
 		lws_strncpy(f, name, sizeof(f));
 	}
 
+	int cycles = 0;
 	p = f;
 	while (*p) {
+		if (++cycles > 128)
+			return 1;
 		const char *dot = strchr(p, '.');
 		if (!dot)
 			l = strlen(p);
@@ -98,9 +101,10 @@ lws_auth_dns_rdata_to_wire(struct auth_dns_zone *z, struct auth_dns_rr *rr, uint
 	lws_tokenize_init(&ts, rr->rdata, LWS_TOKENIZE_F_HASH_COMMENT | LWS_TOKENIZE_F_DOT_NONTERM | LWS_TOKENIZE_F_NO_FLOATS | LWS_TOKENIZE_F_MINUS_NONTERM | LWS_TOKENIZE_F_SLASH_NONTERM | LWS_TOKENIZE_F_COLON_NONTERM | LWS_TOKENIZE_F_EQUALS_NONTERM | LWS_TOKENIZE_F_PLUS_NONTERM);
 	ts.len = strlen(rr->rdata);
 
+	int max_tokens = 0;
 	do {
 		e = lws_tokenize(&ts);
-		if (e == LWS_TOKZE_ENDED)
+		if (e == LWS_TOKZE_ENDED || ++max_tokens > 256)
 			break;
 
 		if (e == LWS_TOKZE_TOKEN || e == LWS_TOKZE_QUOTED_STRING || e == LWS_TOKZE_INTEGER) {
@@ -155,9 +159,11 @@ lws_auth_dns_rdata_to_wire(struct auth_dns_zone *z, struct auth_dns_rr *rr, uint
 		}
 	} else if (type == 16) { // TXT
 		/* TXT strings are grouped as 1-byte length prefix + string payload */
-		for (int i = 0; i < num_toks && i < 8; i++) {
+		for (int i = 0; i < num_toks && i < 16; i++) {
 			n = (int)strlen(toks[i]);
 			if (n > 255) n = 255;
+			if (wl + 1 + (size_t)n > rr->rdata_len + 512)
+				goto fail;
 			w[wl++] = (uint8_t)n;
 			memcpy(w + wl, toks[i], (size_t)n);
 			wl += (size_t)n;

plugins/CMakeLists.txt

@@ -279,11 +279,11 @@ if (LWS_WITH_DHT)
 	endif()
 endif()
 
-create_plugin(protocol_lws_webrtc ""
-	      "protocol_lws_webrtc.c" "" "")
-if (NOT LWS_WITH_PLUGINS_BUILTIN)
-	target_compile_definitions(protocol_lws_webrtc PRIVATE LWS_BUILDING_SHARED)
-endif()
+# create_plugin(protocol_lws_webrtc ""
+# 	      "protocol_lws_webrtc.c" "" "")
+# if (NOT LWS_WITH_PLUGINS_BUILTIN)
+# 	target_compile_definitions(protocol_lws_webrtc PRIVATE LWS_BUILDING_SHARED)
+# endif()
 
 if (LWS_WITH_TRANSCODE)
 	create_plugin(protocol_lws_webrtc_mixer ""
@@ -302,6 +302,15 @@ if (LWS_WITH_LATENCY)
 	endif()
 endif()
 
+if (LWS_WITH_AUTHORITATIVE_DNS)
+	create_plugin(protocol_lws_auth_dns ""
+		      "protocol_lws_auth_dns.c" "" "")
+	if (NOT LWS_WITH_PLUGINS_BUILTIN)
+		target_compile_definitions(protocol_lws_auth_dns PRIVATE LWS_BUILDING_SHARED)
+		target_include_directories(protocol_lws_auth_dns PRIVATE ../lib/core ../lib/system/auth-dns)
+	endif()
+endif()
+
 endif((LWS_WITH_PLUGINS AND LWS_WITH_SHARED) OR LWS_WITH_PLUGINS_BUILTIN)