- dns over ssl support, ssl-service-pem and ssl-service-key files

can be given and then TCP queries are serviced wrapped in SSL.


git-svn-id: file:///svn/unbound/trunk@2530 be551aaa-1e26-0410-a405-d3ace91eadb9

Makefile.in

@@ -239,7 +239,7 @@ endif
 libunbound.la:	$(LIBUNBOUND_OBJ)
 	$(INFO) Link $@
 ifeq ($(CHECKLOCK_SRC),)
-	$Q$(LINK_LIB) $(UBSYMS) -o $@ $(sort $(LIBUNBOUND_OBJ)) -rpath $(libdir) $(LIBS)
+	$Q$(LINK_LIB) $(UBSYMS) -o $@ $(sort $(LIBUNBOUND_OBJ)) -rpath $(libdir) -lssl $(LIBS)
 else
 	cp $(srcdir)/libunbound/ubsyms.def $(BUILD)clubsyms.def
 	echo lock_protect >> $(BUILD)clubsyms.def
@@ -252,7 +252,7 @@ else
 	echo checklock_init >> $(BUILD)clubsyms.def
 	echo checklock_thrcreate >> $(BUILD)clubsyms.def
 	echo checklock_thrjoin >> $(BUILD)clubsyms.def
-	$Q$(LINK_LIB) $(CLUBSYMS) -o $@ $(sort $(LIBUNBOUND_OBJ)) -rpath $(libdir) $(LIBS)
+	$Q$(LINK_LIB) $(CLUBSYMS) -o $@ $(sort $(LIBUNBOUND_OBJ)) -rpath $(libdir) -lssl $(LIBS)
 endif
 
 unbound$(EXEEXT):	$(DAEMON_OBJ) libunbound.la
@@ -289,7 +289,7 @@ anchor-update$(EXEEXT):  $(ANCHORUPD_OBJ) libunbound.la
 
 unittest$(EXEEXT):	$(UNITTEST_OBJ)
 	$(INFO) Link $@
-	$Q$(LINK) -o $@ $(sort $(UNITTEST_OBJ)) $(LIBS)
+	$Q$(LINK) -o $@ $(sort $(UNITTEST_OBJ)) -lssl $(LIBS)
 
 testbound$(EXEEXT):	$(TESTBOUND_OBJ)
 	$(INFO) Link $@
@@ -297,7 +297,7 @@ testbound$(EXEEXT):	$(TESTBOUND_OBJ)
 
 lock-verify$(EXEEXT):	$(LOCKVERIFY_OBJ)
 	$(INFO) Link $@
-	$Q$(LINK) -o $@ $(sort $(LOCKVERIFY_OBJ)) $(LIBS)
+	$Q$(LINK) -o $@ $(sort $(LOCKVERIFY_OBJ)) -lssl $(LIBS)
 
 petal$(EXEEXT):	$(PETAL_OBJ)
 	$(INFO) Link $@
@@ -305,15 +305,15 @@ petal$(EXEEXT):	$(PETAL_OBJ)
 
 pktview$(EXEEXT):	$(PKTVIEW_OBJ)
 	$(INFO) Link $@
-	$Q$(LINK) -o $@ $(sort $(PKTVIEW_OBJ)) $(LIBS)
+	$Q$(LINK) -o $@ $(sort $(PKTVIEW_OBJ)) -lssl $(LIBS)
 
 signit$(EXEEXT):	$(SIGNIT_OBJ)
 	$(INFO) Link $@
-	$Q$(LINK) -o $@ $(sort $(SIGNIT_OBJ)) $(LIBS)
+	$Q$(LINK) -o $@ $(sort $(SIGNIT_OBJ)) -lssl $(LIBS)
 
 memstats$(EXEEXT):	$(MEMSTATS_OBJ)
 	$(INFO) Link $@
-	$Q$(LINK) -o $@ $(sort $(MEMSTATS_OBJ)) $(LIBS)
+	$Q$(LINK) -o $@ $(sort $(MEMSTATS_OBJ)) -lssl $(LIBS)
 
 asynclook$(EXEEXT):	$(ASYNCLOOK_OBJ) libunbound.la
 	$(INFO) Link $@
@@ -321,15 +321,15 @@ asynclook$(EXEEXT):	$(ASYNCLOOK_OBJ) libunbound.la
 
 streamtcp$(EXEEXT):	$(STREAMTCP_OBJ)
 	$(INFO) Link $@
-	$Q$(LINK) -o $@ $(sort $(STREAMTCP_OBJ)) $(LIBS)
+	$Q$(LINK) -o $@ $(sort $(STREAMTCP_OBJ)) -lssl $(LIBS)
 
 perf$(EXEEXT):	$(PERF_OBJ)
 	$(INFO) Link $@
-	$Q$(LINK) -o $@ $(sort $(PERF_OBJ)) $(LIBS)
+	$Q$(LINK) -o $@ $(sort $(PERF_OBJ)) -lssl $(LIBS)
 
 delayer$(EXEEXT):	$(DELAYER_OBJ)
 	$(INFO) Link $@
-	$Q$(LINK) -o $@ $(sort $(DELAYER_OBJ)) $(LIBS)
+	$Q$(LINK) -o $@ $(sort $(DELAYER_OBJ)) -lssl $(LIBS)
 
 harvest$(EXEEXT):	$(HARVEST_OBJ) libunbound.la
 	$(INFO) Link $@

daemon/daemon.c

@@ -528,6 +528,8 @@ daemon_delete(struct daemon* daemon)
 	free(daemon->chroot);
 	free(daemon->pidfile);
 	free(daemon->env);
+	SSL_CTX_free((SSL_CTX*)daemon->listen_sslctx);
+	SSL_CTX_free((SSL_CTX*)daemon->connect_sslctx);
 	free(daemon);
 #ifdef LEX_HAS_YYLEX_DESTROY
 	/* lex cleanup */

daemon/daemon.h

@@ -80,6 +80,8 @@ struct daemon {
 	struct listen_port* rc_ports;
 	/** remote control connections management (for first worker) */
 	struct daemon_remote* rc;
+	/** ssl context for listening to dnstcp over ssl, and connecting ssl */
+	void* listen_sslctx, *connect_sslctx;
 	/** num threads allocated */
 	int num;
 	/** the worker entries */

daemon/remote.c

@@ -92,21 +92,6 @@
 /** if true, inhibits a lot of =0 lines from the stats output */
 static const int inhibit_zero = 1;
 
-/** log ssl crypto err */
-static void
-log_crypto_err(const char* str)
-{
-	/* error:[error code]:[library name]:[function name]:[reason string] */
-	char buf[128];
-	unsigned long e;
-	ERR_error_string_n(ERR_get_error(), buf, sizeof(buf));
-	log_err("%s crypto %s", str, buf);
-	while( (e=ERR_get_error()) ) {
-		ERR_error_string_n(e, buf, sizeof(buf));
-		log_err("and additionally crypto %s", buf);
-	}
-}
-
 /** subtract timers and the values do not overflow or become negative */
 static void
 timeval_subtract(struct timeval* d, const struct timeval* end, 

daemon/unbound.c

@@ -55,6 +55,7 @@
 #include "services/cache/infra.h"
 #include "util/data/msgreply.h"
 #include "util/module.h"
+#include "util/net_help.h"
 #include <signal.h>
 #include <fcntl.h>
 #include <openssl/crypto.h>
@@ -446,6 +447,13 @@ perform_setup(struct daemon* daemon, struct config_file* cfg, int debug_mode,
 	/* read ssl keys while superuser and outside chroot */
 	if(!(daemon->rc = daemon_remote_create(cfg)))
 		fatal_exit("could not set up remote-control");
+	if(cfg->ssl_service_key && cfg->ssl_service_key[0]) {
+		if(!(daemon->listen_sslctx = listen_sslctx_create(
+			cfg->ssl_service_key, cfg->ssl_service_pem, NULL)))
+			fatal_exit("could not set up listen SSL_CTX");
+	}
+	if(!(daemon->connect_sslctx = connect_sslctx_create(NULL, NULL, NULL)))
+		fatal_exit("could not set up connect SSL_CTX");
 
 #ifdef HAVE_KILL
 	/* check old pid file before forking */

daemon/worker.c

@@ -1092,7 +1092,7 @@ worker_init(struct worker* worker, struct config_file *cfg,
 	}
 	worker->front = listen_create(worker->base, ports,
 		cfg->msg_buffer_size, (int)cfg->incoming_num_tcp, 
-		worker_handle_request, worker);
+		worker->daemon->listen_sslctx, worker_handle_request, worker);
 	if(!worker->front) {
 		log_err("could not create listening sockets");
 		worker_delete(worker);
@@ -1105,7 +1105,7 @@ worker_init(struct worker* worker, struct config_file *cfg,
 		worker->daemon->env->infra_cache, worker->rndstate,
 		cfg->use_caps_bits_for_id, worker->ports, worker->numports,
 		cfg->unwanted_threshold, &worker_alloc_cleanup, worker,
-		cfg->do_udp);
+		cfg->do_udp, worker->daemon->connect_sslctx);
 	if(!worker->back) {
 		log_err("could not create outgoing sockets");
 		worker_delete(worker);
@@ -1255,9 +1255,9 @@ worker_send_query(uint8_t* qname, size_t qnamelen, uint16_t qtype,
 	e->qstate = q;
 	e->qsent = outnet_serviced_query(worker->back, qname,
 		qnamelen, qtype, qclass, flags, dnssec, want_dnssec,
-		q->env->cfg->tcp_upstream, addr, addrlen, zone, zonelen,
+		q->env->cfg->tcp_upstream || q->env->cfg->ssl_upstream, addr,
-		worker_handle_service_reply, e, worker->back->udp_buff,
+		addrlen, zone, zonelen, worker_handle_service_reply, e,
-		&outbound_entry_compare);
+		worker->back->udp_buff, &outbound_entry_compare);
 	if(!e->qsent) {
 		return NULL;
 	}

doc/Changelog

@@ -1,3 +1,7 @@
+31 October 2011: Wouter
+	- dns over ssl support, ssl-service-pem and ssl-service-key files
+	  can be given and then TCP queries are serviced wrapped in SSL.
+
 27 October 2011: Wouter
 	- lame-ttl and lame-size options no longer exist, it is integrated
 	  with the host info.  They are ignored (with verbose warning) if

libunbound/libworker.c

@@ -44,6 +44,7 @@
 #include "config.h"
 #include <ldns/dname.h>
 #include <ldns/wire2host.h>
+#include <openssl/ssl.h>
 #include "libunbound/libworker.h"
 #include "libunbound/context.h"
 #include "libunbound/unbound.h"
@@ -84,6 +85,7 @@ libworker_delete(struct libworker* w)
 		ub_randfree(w->env->rnd);
 		free(w->env);
 	}
+	SSL_CTX_free(w->sslctx);
 	outside_network_delete(w->back);
 	comm_base_delete(w->base);
 	free(w);
@@ -124,6 +126,13 @@ libworker_setup(struct ub_ctx* ctx, int is_bg)
 		forwards_delete(w->env->fwds);
 		w->env->fwds = NULL;
 	}
+	if(cfg->ssl_upstream) {
+		w->sslctx = connect_sslctx_create(NULL, NULL, NULL);
+		if(!w->sslctx) {
+			libworker_delete(w);
+			return NULL;
+		}
+	}
 	if(!w->is_bg || w->is_bg_thread) {
 		lock_basic_unlock(&ctx->cfglock);
 	}
@@ -171,7 +180,7 @@ libworker_setup(struct ub_ctx* ctx, int is_bg)
 		cfg->do_tcp?cfg->outgoing_num_tcp:0,
 		w->env->infra_cache, w->env->rnd, cfg->use_caps_bits_for_id,
 		ports, numports, cfg->unwanted_threshold,
-		&libworker_alloc_cleanup, w, cfg->do_udp);
+		&libworker_alloc_cleanup, w, cfg->do_udp, w->sslctx);
 	if(!w->is_bg || w->is_bg_thread) {
 		lock_basic_unlock(&ctx->cfglock);
 	}
@@ -695,9 +704,9 @@ struct outbound_entry* libworker_send_query(uint8_t* qname, size_t qnamelen,
 	e->qstate = q;
 	e->qsent = outnet_serviced_query(w->back, qname,
 		qnamelen, qtype, qclass, flags, dnssec, want_dnssec,
-		q->env->cfg->tcp_upstream, addr, addrlen, zone, zonelen,
+		q->env->cfg->tcp_upstream || q->env->cfg->ssl_upstream, addr,
-		libworker_handle_service_reply, e, w->back->udp_buff,
+		addrlen, zone, zonelen, libworker_handle_service_reply, e,
-		&outbound_entry_compare);
+		w->back->udp_buff, &outbound_entry_compare);
 	if(!e->qsent) {
 		return NULL;
 	}

libunbound/libworker.h

@@ -81,6 +81,8 @@ struct libworker {
 	struct outside_network* back;
 	/** random() table for this worker. */
 	struct ub_randstate* rndstate;
+	/** sslcontext for SSL wrapped DNS over TCP queries */
+	void* sslctx;
 };
 
 /**

services/listen_dnsport.c

@@ -723,7 +723,7 @@ listen_cp_insert(struct comm_point* c, struct listen_dnsport* front)
 
 struct listen_dnsport* 
 listen_create(struct comm_base* base, struct listen_port* ports,
-	size_t bufsize, int tcp_accept_count,
+	size_t bufsize, int tcp_accept_count, void* sslctx,
 	comm_point_callback_t* cb, void *cb_arg)
 {
 	struct listen_dnsport* front = (struct listen_dnsport*)
@@ -736,6 +736,9 @@ listen_create(struct comm_base* base, struct listen_port* ports,
 		free(front);
 		return NULL;
 	}
+	if(sslctx) {
+		verbose(VERB_ALGO, "setup for SSL-wrapped TCP service");
+	}
 
 	/* create comm points as needed */
 	while(ports) {
@@ -743,10 +746,11 @@ listen_create(struct comm_base* base, struct listen_port* ports,
 		if(ports->ftype == listen_type_udp) 
 			cp = comm_point_create_udp(base, ports->fd, 
 				front->udp_buff, cb, cb_arg);
-		else if(ports->ftype == listen_type_tcp)
+		else if(ports->ftype == listen_type_tcp) {
 			cp = comm_point_create_tcp(base, ports->fd, 
 				tcp_accept_count, bufsize, cb, cb_arg);
-		else if(ports->ftype == listen_type_udpancil) 
+			cp->ssl = sslctx;
+		} else if(ports->ftype == listen_type_udpancil) 
 			cp = comm_point_create_udp_ancil(base, ports->fd, 
 				front->udp_buff, cb, cb_arg);
 		if(!cp) {

services/listen_dnsport.h

@@ -121,6 +121,7 @@ void listening_ports_free(struct listen_port* list);
  * @param bufsize: size of datagram buffer.
  * @param tcp_accept_count: max number of simultaneous TCP connections 
  * 	from clients.
+ * @param sslctx: nonNULL if ssl context.
  * @param cb: callback function when a request arrives. It is passed
  *	  the packet and user argument. Return true to send a reply.
  * @param cb_arg: user data argument for callback function.
@@ -128,7 +129,7 @@ void listening_ports_free(struct listen_port* list);
  */
 struct listen_dnsport* listen_create(struct comm_base* base,
 	struct listen_port* ports, size_t bufsize, int tcp_accept_count,
-	comm_point_callback_t* cb, void* cb_arg);
+	void* sslctx, comm_point_callback_t* cb, void* cb_arg);
 
 /**
  * delete the listening structure

services/outside_network.c

@@ -535,7 +535,8 @@ outside_network_create(struct comm_base *base, size_t bufsize,
 	int do_ip6, size_t num_tcp, struct infra_cache* infra,
 	struct ub_randstate* rnd, int use_caps_for_id, int* availports, 
 	int numavailports, size_t unwanted_threshold,
-	void (*unwanted_action)(void*), void* unwanted_param, int do_udp)
+	void (*unwanted_action)(void*), void* unwanted_param, int do_udp,
+	void* sslctx)
 {
 	struct outside_network* outnet = (struct outside_network*)
 		calloc(1, sizeof(struct outside_network));
@@ -549,6 +550,7 @@ outside_network_create(struct comm_base *base, size_t bufsize,
 	outnet->num_tcp = num_tcp;
 	outnet->infra = infra;
 	outnet->rnd = rnd;
+	outnet->sslctx = sslctx;
 	outnet->svcd_overhead = 0;
 	outnet->want_to_quit = 0;
 	outnet->unwanted_threshold = unwanted_threshold;

services/outside_network.h

@@ -118,6 +118,8 @@ struct outside_network {
 	struct infra_cache* infra;
 	/** where to get random numbers */
 	struct ub_randstate* rnd;
+	/** ssl context to create ssl wrapped TCP with DNS connections */
+	void* sslctx;
 
 	/**
 	 * Array of tcp pending used for outgoing TCP connections.
@@ -369,6 +371,7 @@ struct serviced_query {
  * @param unwanted_action: the action to take.
  * @param unwanted_param: user parameter to action.
  * @param do_udp: if udp is done.
+ * @param sslctx: context to create outgoing connections with (if enabled).
  * @return: the new structure (with no pending answers) or NULL on error.
  */
 struct outside_network* outside_network_create(struct comm_base* base,
@@ -376,7 +379,8 @@ struct outside_network* outside_network_create(struct comm_base* base,
 	int do_ip4, int do_ip6, size_t num_tcp, struct infra_cache* infra, 
 	struct ub_randstate* rnd, int use_caps_for_id, int* availports, 
 	int numavailports, size_t unwanted_threshold,
-	void (*unwanted_action)(void*), void* unwanted_param, int do_udp);
+	void (*unwanted_action)(void*), void* unwanted_param, int do_udp,
+	void* sslctx);
 
 /**
  * Delete outside_network structure.

testcode/fake_event.c

@@ -708,7 +708,7 @@ run_scenario(struct replay_runtime* runtime)
 struct listen_dnsport* 
 listen_create(struct comm_base* base, struct listen_port* ATTR_UNUSED(ports),
 	size_t bufsize, int ATTR_UNUSED(tcp_accept_count),
-	comm_point_callback_t* cb, void* cb_arg)
+	void* ATTR_UNUSED(sslctx), comm_point_callback_t* cb, void* cb_arg)
 {
 	struct replay_runtime* runtime = (struct replay_runtime*)base;
 	struct listen_dnsport* l= calloc(1, sizeof(struct listen_dnsport));
@@ -877,7 +877,7 @@ outside_network_create(struct comm_base* base, size_t bufsize,
 	int ATTR_UNUSED(use_caps_for_id), int* ATTR_UNUSED(availports),
 	int ATTR_UNUSED(numavailports), size_t ATTR_UNUSED(unwanted_threshold),
 	void (*unwanted_action)(void*), void* ATTR_UNUSED(unwanted_param),
-	int ATTR_UNUSED(do_udp))
+	int ATTR_UNUSED(do_udp), void* ATTR_UNUSED(sslctx))
 {
 	struct replay_runtime* runtime = (struct replay_runtime*)base;
 	struct outside_network* outnet =  calloc(1, 

testcode/streamtcp.c

@@ -49,6 +49,7 @@
 #include "util/log.h"
 #include "util/net_help.h"
 #include "util/data/msgencode.h"
+#include "util/data/msgparse.h"
 #include "util/data/msgreply.h"
 #include "util/data/dname.h"
 
@@ -65,6 +66,7 @@ static void usage(char* argv[])
 	printf("-f server	what ipaddr@portnr to send the queries to\n");
 	printf("-u 		use UDP. No retries are attempted.\n");
 	printf("-n 		do not wait for an answer.\n");
+	printf("-s		use ssl\n");
 	printf("-h 		this help text\n");
 	exit(1);
 }
@@ -105,7 +107,7 @@ open_svr(const char* svr, int udp)
 
 /** write a query over the TCP fd */
 static void
-write_q(int fd, int udp, ldns_buffer* buf, int id, 
+write_q(int fd, int udp, SSL* ssl, ldns_buffer* buf, uint16_t id, 
 	const char* strname, const char* strtype, const char* strclass)
 {
 	struct query_info qinfo;
@@ -128,14 +130,31 @@ write_q(int fd, int udp, ldns_buffer* buf, int id,
 
 	/* make query */
 	qinfo_query_encode(buf, &qinfo);
-	ldns_buffer_write_u16_at(buf, 0, (uint16_t)id);
+	ldns_buffer_write_u16_at(buf, 0, id);
 	ldns_buffer_write_u16_at(buf, 2, BIT_RD);
 
+	if(1) {
+		/* add EDNS DO */
+		struct edns_data edns;
+		memset(&edns, 0, sizeof(edns));
+		edns.edns_present = 1;
+		edns.bits = EDNS_DO;
+		edns.udp_size = 4096;
+		attach_edns_record(buf, &edns);
+	}
+
 	/* send it */
 	if(!udp) {
 		len = (uint16_t)ldns_buffer_limit(buf);
 		len = htons(len);
-		if(send(fd, (void*)&len, sizeof(len), 0)<(ssize_t)sizeof(len)){
+		if(ssl) {
+			if(SSL_write(ssl, (void*)&len, (int)sizeof(len)) <= 0) {
+				log_crypto_err("cannot SSL_write");
+				exit(1);
+			}
+		} else {
+			if(send(fd, (void*)&len, sizeof(len), 0) <
+				(ssize_t)sizeof(len)){
 #ifndef USE_WINSOCK
 				perror("send() len failed");
 #else
@@ -145,7 +164,16 @@ write_q(int fd, int udp, ldns_buffer* buf, int id,
 				exit(1);
 			}
 		}
-	if(send(fd, (void*)ldns_buffer_begin(buf), ldns_buffer_limit(buf), 0) < 
+	}
+	if(ssl) {
+		if(SSL_write(ssl, (void*)ldns_buffer_begin(buf),
+			(int)ldns_buffer_limit(buf)) <= 0) {
+			log_crypto_err("cannot SSL_write");
+			exit(1);
+		}
+	} else {
+		if(send(fd, (void*)ldns_buffer_begin(buf),
+			ldns_buffer_limit(buf), 0) < 
 			(ssize_t)ldns_buffer_limit(buf)) {
 #ifndef USE_WINSOCK
 			perror("send() data failed");
@@ -154,19 +182,27 @@ write_q(int fd, int udp, ldns_buffer* buf, int id,
 #endif
 			exit(1);
 		}
+	}
 
 	free(qinfo.qname);
 }
 
 /** receive DNS datagram over TCP and print it */
 static void
-recv_one(int fd, int udp, ldns_buffer* buf)
+recv_one(int fd, int udp, SSL* ssl, ldns_buffer* buf)
 {
 	uint16_t len;
 	ldns_pkt* pkt;
 	ldns_status status;
 	if(!udp) {
-		if(recv(fd, (void*)&len, sizeof(len), 0)<(ssize_t)sizeof(len)){
+		if(ssl) {
+			if(SSL_read(ssl, (void*)&len, (int)sizeof(len)) <= 0) {
+				log_crypto_err("could not SSL_read");
+				exit(1);
+			}
+		} else {
+			if(recv(fd, (void*)&len, sizeof(len), 0) <
+				(ssize_t)sizeof(len)) {
 #ifndef USE_WINSOCK
 				perror("read() len failed");
 #else
@@ -175,9 +211,20 @@ recv_one(int fd, int udp, ldns_buffer* buf)
 #endif
 				exit(1);
 			}
+		}
 		len = ntohs(len);
 		ldns_buffer_clear(buf);
 		ldns_buffer_set_limit(buf, len);
+		if(ssl) {
+			int r = SSL_read(ssl, (void*)ldns_buffer_begin(buf),
+				(int)len);
+			if(r <= 0) {
+				log_crypto_err("could not SSL_read");
+				exit(1);
+			}
+			if(r != (int)len)
+				fatal_exit("ssl_read %d of %d", r, len);
+		} else {
 			if(recv(fd, (void*)ldns_buffer_begin(buf), len, 0) < 
 				(ssize_t)len) {
 #ifndef USE_WINSOCK
@@ -188,6 +235,7 @@ recv_one(int fd, int udp, ldns_buffer* buf)
 #endif
 				exit(1);
 			}
+		}
 	} else {
 		ssize_t l;
 		ldns_buffer_clear(buf);
@@ -220,20 +268,34 @@ recv_one(int fd, int udp, ldns_buffer* buf)
 
 /** send the TCP queries and print answers */
 static void
-send_em(const char* svr, int udp, int noanswer, int num, char** qs)
+send_em(const char* svr, int udp, int usessl, int noanswer, int num, char** qs)
 {
 	ldns_buffer* buf = ldns_buffer_new(65553);
 	int fd = open_svr(svr, udp);
 	int i;
+	SSL_CTX* ctx;
+	SSL* ssl;
 	if(!buf) fatal_exit("out of memory");
+	if(usessl) {
+		ctx = connect_sslctx_create(NULL, NULL, NULL);
+		if(!ctx) fatal_exit("cannot create ssl ctx");
+		ssl = outgoing_ssl_fd(ctx, fd);
+		if(!ssl) fatal_exit("cannot create ssl");
+	}
 	for(i=0; i<num; i+=3) {
 		printf("\nNext query is %s %s %s\n", qs[i], qs[i+1], qs[i+2]);
-		write_q(fd, udp, buf, i, qs[i], qs[i+1], qs[i+2]);
+		write_q(fd, udp, ssl, buf, ldns_get_random(), qs[i],
+			qs[i+1], qs[i+2]);
 		/* print at least one result */
 		if(!noanswer)
-			recv_one(fd, udp, buf);
+			recv_one(fd, udp, ssl, buf);
 	}
 
+	if(usessl) {
+		SSL_shutdown(ssl);
+		SSL_free(ssl);
+		SSL_CTX_free(ctx);
+	}
 #ifndef USE_WINSOCK
 	close(fd);
 #else
@@ -268,6 +330,7 @@ int main(int argc, char** argv)
 	const char* svr = "127.0.0.1";
 	int udp = 0;
 	int noanswer = 0;
+	int usessl = 0;
 
 #ifdef USE_WINSOCK
 	WSADATA wsa_data;
@@ -292,7 +355,7 @@ int main(int argc, char** argv)
 	if(argc == 1) {
 		usage(argv);
 	}
-	while( (c=getopt(argc, argv, "f:hnu")) != -1) {
+	while( (c=getopt(argc, argv, "f:hnsu")) != -1) {
 		switch(c) {
 			case 'f':
 				svr = optarg;
@@ -303,6 +366,9 @@ int main(int argc, char** argv)
 			case 'u':
 				udp = 1;
 				break;
+			case 's':
+				usessl = 1;
+				break;
 			case 'h':
 			case '?':
 			default:
@@ -316,7 +382,12 @@ int main(int argc, char** argv)
 		printf("queries must be multiples of name,type,class\n");
 		return 1;
 	}
-	send_em(svr, udp, noanswer, argc, argv);
+	if(usessl) {
+		ERR_load_SSL_strings();
+		OpenSSL_add_all_algorithms();
+		SSL_library_init();
+	}
+	send_em(svr, udp, usessl, noanswer, argc, argv);
 	checklock_stop();
 #ifdef USE_WINSOCK
 	WSACleanup();

util/config_file.c

@@ -88,6 +88,9 @@ config_create(void)
 	cfg->do_udp = 1;
 	cfg->do_tcp = 1;
 	cfg->tcp_upstream = 0;
+	cfg->ssl_service_key = NULL;
+	cfg->ssl_service_pem = NULL;
+	cfg->ssl_upstream = 0;
 	cfg->use_syslog = 1;
 	cfg->log_time_ascii = 0;
 	cfg->log_queries = 0;
@@ -326,6 +329,9 @@ int config_set_option(struct config_file* cfg, const char* opt,
 	else S_YNO("do-udp:", do_udp)
 	else S_YNO("do-tcp:", do_tcp)
 	else S_YNO("tcp-upstream:", tcp_upstream)
+	else S_YNO("ssl-upstream:", ssl_upstream)
+	else S_STR("ssl-service-key:", ssl_service_key)
+	else S_STR("ssl-service-pem:", ssl_service_pem)
 	else S_YNO("interface-automatic:", if_automatic)
 	else S_YNO("do-daemonize:", do_daemonize)
 	else S_NUMBER_NONZERO("port:", port)
@@ -574,6 +580,9 @@ config_get_option(struct config_file* cfg, const char* opt,
 	else O_YNO(opt, "do-udp", do_udp)
 	else O_YNO(opt, "do-tcp", do_tcp)
 	else O_YNO(opt, "tcp-upstream", tcp_upstream)
+	else O_YNO(opt, "ssl-upstream", ssl_upstream)
+	else O_STR(opt, "ssl-service-key", ssl_service_key)
+	else O_STR(opt, "ssl-service-pem", ssl_service_pem)
 	else O_YNO(opt, "do-daemonize", do_daemonize)
 	else O_STR(opt, "chroot", chrootdir)
 	else O_STR(opt, "username", username)
@@ -728,6 +737,8 @@ config_delete(struct config_file* cfg)
 	free(cfg->logfile);
 	free(cfg->pidfile);
 	free(cfg->target_fetch_policy);
+	free(cfg->ssl_service_key);
+	free(cfg->ssl_service_pem);
 	if(cfg->ifs) {
 		int i;
 		for(i=0; i<cfg->num_ifs; i++)

util/config_file.h

@@ -79,6 +79,13 @@ struct config_file {
 	/** tcp upstream queries (no UDP upstream queries) */
 	int tcp_upstream;
 
+	/** private key file for dnstcp-ssl service (enabled if not NULL) */
+	char* ssl_service_key;
+	/** public key file for dnstcp-ssl service */
+	char* ssl_service_pem;
+	/** if outgoing tcp connections use SSL */
+	int ssl_upstream;
+
 	/** outgoing port range number of ports (per thread) */
 	int outgoing_num_ports;
 	/** number of outgoing tcp buffers per (per thread) */

util/configlexer.lex

@@ -137,6 +137,9 @@ do-ip6{COLON}			{ YDVAR(1, VAR_DO_IP6) }
 do-udp{COLON}			{ YDVAR(1, VAR_DO_UDP) }
 do-tcp{COLON}			{ YDVAR(1, VAR_DO_TCP) }
 tcp-upstream{COLON}		{ YDVAR(1, VAR_TCP_UPSTREAM) }
+ssl-upstream{COLON}		{ YDVAR(1, VAR_SSL_UPSTREAM) }
+ssl-service-key{COLON}		{ YDVAR(1, VAR_SSL_SERVICE_KEY) }
+ssl-service-pem{COLON}		{ YDVAR(1, VAR_SSL_SERVICE_PEM) }
 do-daemonize{COLON}		{ YDVAR(1, VAR_DO_DAEMONIZE) }
 interface{COLON}		{ YDVAR(1, VAR_INTERFACE) }
 outgoing-interface{COLON}	{ YDVAR(1, VAR_OUTGOING_INTERFACE) }

util/configparser.h

@@ -156,7 +156,10 @@
      VAR_HARDEN_BELOW_NXDOMAIN = 373,
      VAR_IGNORE_CD_FLAG = 374,
      VAR_LOG_QUERIES = 375,
-     VAR_TCP_UPSTREAM = 376
+     VAR_TCP_UPSTREAM = 376,
+     VAR_SSL_UPSTREAM = 377,
+     VAR_SSL_SERVICE_KEY = 378,
+     VAR_SSL_SERVICE_PEM = 379
    };
 #endif
 /* Tokens.  */
@@ -279,6 +282,9 @@
 #define VAR_IGNORE_CD_FLAG 374
 #define VAR_LOG_QUERIES 375
 #define VAR_TCP_UPSTREAM 376
+#define VAR_SSL_UPSTREAM 377
+#define VAR_SSL_SERVICE_KEY 378
+#define VAR_SSL_SERVICE_PEM 379
 
 
 
@@ -295,7 +301,7 @@ typedef union YYSTYPE
 
 
 /* Line 1685 of yacc.c  */
-#line 299 "util/configparser.h"
+#line 305 "util/configparser.h"
 } YYSTYPE;
 # define YYSTYPE_IS_TRIVIAL 1
 # define yystype YYSTYPE /* obsolescent; will be withdrawn */

util/configparser.y

@@ -102,7 +102,8 @@ extern struct config_parser_state* cfg_parser;
 %token VAR_AUTO_TRUST_ANCHOR_FILE VAR_KEEP_MISSING VAR_ADD_HOLDDOWN 
 %token VAR_DEL_HOLDDOWN VAR_SO_RCVBUF VAR_EDNS_BUFFER_SIZE VAR_PREFETCH
 %token VAR_PREFETCH_KEY VAR_SO_SNDBUF VAR_HARDEN_BELOW_NXDOMAIN
-%token VAR_IGNORE_CD_FLAG VAR_LOG_QUERIES VAR_TCP_UPSTREAM
+%token VAR_IGNORE_CD_FLAG VAR_LOG_QUERIES VAR_TCP_UPSTREAM VAR_SSL_UPSTREAM
+%token VAR_SSL_SERVICE_KEY VAR_SSL_SERVICE_PEM
 
 %%
 toplevelvars: /* empty */ | toplevelvars toplevelvar ;
@@ -157,7 +158,8 @@ content_server: server_num_threads | server_verbosity | server_port |
 	server_del_holddown | server_keep_missing | server_so_rcvbuf |
 	server_edns_buffer_size | server_prefetch | server_prefetch_key |
 	server_so_sndbuf | server_harden_below_nxdomain | server_ignore_cd_flag |
-	server_log_queries | server_tcp_upstream
+	server_log_queries | server_tcp_upstream | server_ssl_upstream |
+	server_ssl_service_key | server_ssl_service_pem
 	;
 stubstart: VAR_STUB_ZONE
 	{
@@ -374,6 +376,29 @@ server_tcp_upstream: VAR_TCP_UPSTREAM STRING_ARG
 		free($2);
 	}
 	;
+server_ssl_upstream: VAR_SSL_UPSTREAM STRING_ARG
+	{
+		OUTYY(("P(server_ssl_upstream:%s)\n", $2));
+		if(strcmp($2, "yes") != 0 && strcmp($2, "no") != 0)
+			yyerror("expected yes or no.");
+		else cfg_parser->cfg->ssl_upstream = (strcmp($2, "yes")==0);
+		free($2);
+	}
+	;
+server_ssl_service_key: VAR_SSL_SERVICE_KEY STRING_ARG
+	{
+		OUTYY(("P(server_ssl_service_key:%s)\n", $2));
+		free(cfg_parser->cfg->ssl_service_key);
+		cfg_parser->cfg->ssl_service_key = $2;
+	}
+	;
+server_ssl_service_pem: VAR_SSL_SERVICE_PEM STRING_ARG
+	{
+		OUTYY(("P(server_ssl_service_pem:%s)\n", $2));
+		free(cfg_parser->cfg->ssl_service_pem);
+		cfg_parser->cfg->ssl_service_pem = $2;
+	}
+	;
 server_do_daemonize: VAR_DO_DAEMONIZE STRING_ARG
 	{
 		OUTYY(("P(server_do_daemonize:%s)\n", $2));

util/net_help.c

@@ -45,6 +45,8 @@
 #include "util/module.h"
 #include "util/regional.h"
 #include <fcntl.h>
+#include <openssl/ssl.h>
+#include <openssl/err.h>
 
 /** max length of an IP address (the address portion) that we allow */
 #define MAX_ADDR_STRLEN 128 /* characters */
@@ -553,3 +555,139 @@ void sock_list_merge(struct sock_list** list, struct regional* region,
 			sock_list_insert(list, &p->addr, p->len, region);
 	}
 }
+
+void
+log_crypto_err(const char* str)
+{
+	/* error:[error code]:[library name]:[function name]:[reason string] */
+	char buf[128];
+	unsigned long e;
+	ERR_error_string_n(ERR_get_error(), buf, sizeof(buf));
+	log_err("%s crypto %s", str, buf);
+	while( (e=ERR_get_error()) ) {
+		ERR_error_string_n(e, buf, sizeof(buf));
+		log_err("and additionally crypto %s", buf);
+	}
+}
+
+void* listen_sslctx_create(char* key, char* pem, char* verifypem)
+{
+	SSL_CTX* ctx = SSL_CTX_new(SSLv23_server_method());
+	if(!ctx) {
+		log_crypto_err("could not SSL_CTX_new");
+		return NULL;
+	}
+	/* no SSLv2 because has defects */
+	if(!(SSL_CTX_set_options(ctx, SSL_OP_NO_SSLv2) & SSL_OP_NO_SSLv2)){
+		log_crypto_err("could not set SSL_OP_NO_SSLv2");
+		SSL_CTX_free(ctx);
+		return NULL;
+	}
+	if(!SSL_CTX_use_certificate_file(ctx, pem, SSL_FILETYPE_PEM)) {
+		log_err("error for cert file: %s", pem);
+		log_crypto_err("error in SSL_CTX use_certificate_file");
+		SSL_CTX_free(ctx);
+		return NULL;
+	}
+	if(!SSL_CTX_use_PrivateKey_file(ctx, key, SSL_FILETYPE_PEM)) {
+		log_err("error for private key file: %s", key);
+		log_crypto_err("Error in SSL_CTX use_PrivateKey_file");
+		SSL_CTX_free(ctx);
+		return NULL;
+	}
+	if(!SSL_CTX_check_private_key(ctx)) {
+		log_err("error for key file: %s", key);
+		log_crypto_err("Error in SSL_CTX check_private_key");
+		SSL_CTX_free(ctx);
+		return NULL;
+	}
+
+	if(verifypem && verifypem[0]) {
+		if(!SSL_CTX_load_verify_locations(ctx, verifypem, NULL)) {
+			log_crypto_err("Error in SSL_CTX verify locations");
+			SSL_CTX_free(ctx);
+			return NULL;
+		}
+		SSL_CTX_set_client_CA_list(ctx, SSL_load_client_CA_file(
+			verifypem));
+		SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER, NULL);
+	}
+	return ctx;
+}
+
+void* connect_sslctx_create(char* key, char* pem, char* verifypem)
+{
+	SSL_CTX* ctx = SSL_CTX_new(SSLv23_client_method());
+	if(!ctx) {
+		log_crypto_err("could not allocate SSL_CTX pointer");
+		return NULL;
+	}
+	if(!(SSL_CTX_set_options(ctx, SSL_OP_NO_SSLv2) & SSL_OP_NO_SSLv2)) {
+		log_crypto_err("could not set SSL_OP_NO_SSLv2");
+		SSL_CTX_free(ctx);
+		return NULL;
+	}
+	if(key && key[0]) {
+		if(!SSL_CTX_use_certificate_file(ctx, pem, SSL_FILETYPE_PEM)) {
+			log_err("error in client certificate %s", pem);
+			log_crypto_err("error in certificate file");
+			SSL_CTX_free(ctx);
+			return NULL;
+		}
+		if(!SSL_CTX_use_PrivateKey_file(ctx, key, SSL_FILETYPE_PEM)) {
+			log_err("error in client private key %s", key);
+			log_crypto_err("error in key file");
+			SSL_CTX_free(ctx);
+			return NULL;
+		}
+		if(!SSL_CTX_check_private_key(ctx)) {
+			log_err("error in client key %s", key);
+			log_crypto_err("error in SSL_CTX_check_private_key");
+			SSL_CTX_free(ctx);
+			return NULL;
+		}
+	}
+	if(verifypem && verifypem[0]) {
+		if(!SSL_CTX_load_verify_locations(ctx, verifypem, NULL) != 1) {
+			log_crypto_err("error in SSL_CTX verify");
+			SSL_CTX_free(ctx);
+			return NULL;
+		}
+		SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER, NULL);
+	}
+	return ctx;
+}
+
+void* incoming_ssl_fd(void* sslctx, int fd)
+{
+	SSL* ssl = SSL_new((SSL_CTX*)sslctx);
+	if(!ssl) {
+		log_crypto_err("could not SSL_new");
+		return NULL;
+	}
+	SSL_set_accept_state(ssl);
+	(void)SSL_set_mode(ssl, SSL_MODE_AUTO_RETRY);
+	if(!SSL_set_fd(ssl, fd)) {
+		log_crypto_err("could not SSL_set_fd");
+		SSL_free(ssl);
+		return NULL;
+	}
+	return ssl;
+}
+
+void* outgoing_ssl_fd(void* sslctx, int fd)
+{
+	SSL* ssl = SSL_new((SSL_CTX*)sslctx);
+	if(!ssl) {
+		log_crypto_err("could not SSL_new");
+		return NULL;
+	}
+	SSL_set_connect_state(ssl);
+	(void)SSL_set_mode(ssl, SSL_MODE_AUTO_RETRY);
+	if(!SSL_set_fd(ssl, fd)) {
+		log_crypto_err("could not SSL_set_fd");
+		SSL_free(ssl);
+		return NULL;
+	}
+	return ssl;
+}

util/net_help.h

@@ -323,4 +323,44 @@ int sock_list_find(struct sock_list* list, struct sockaddr_storage* addr,
 void sock_list_merge(struct sock_list** list, struct regional* region,
 	struct sock_list* add);
 
+/**
+ * Log libcrypto error with descriptive string. Calls log_err().
+ * @param str: what failed.
+ */
+void log_crypto_err(const char* str);
+
+/** 
+ * create SSL listen context
+ * @param key: private key file.
+ * @param pem: public key cert.
+ * @param verifypem: if nonNULL, verifylocation file.
+ * return SSL_CTX* or NULL on failure (logged).
+ */
+void* listen_sslctx_create(char* key, char* pem, char* verifypem);
+
+/**
+ * create SSL connect context
+ * @param key: if nonNULL (also pem nonNULL), the client private key.
+ * @param pem: client public key (or NULL if key is NULL).
+ * @param verifypem: if nonNULL used for verifylocation file.
+ * @return SSL_CTX* or NULL on failure (logged).
+ */
+void* connect_sslctx_create(char* key, char* pem, char* verifypem);
+
+/**
+ * accept a new fd and wrap it in a BIO in SSL
+ * @param sslctx: the SSL_CTX to use (from listen_sslctx_create()).
+ * @param fd: from accept, nonblocking.
+ * @return SSL or NULL on alloc failure.
+ */
+void* incoming_ssl_fd(void* sslctx, int fd);
+
+/**
+ * connect a new fd and wrap it in a BIO in SSL
+ * @param sslctx: the SSL_CTX to use (from connect_sslctx_create())
+ * @param fd: from connect.
+ * @return SSL or NULL on alloc failure
+ */
+void* outgoing_ssl_fd(void* sslctx, int fd);
+
 #endif /* NET_HELP_H */

util/netevent.c

@@ -44,6 +44,8 @@
 #include "util/log.h"
 #include "util/net_help.h"
 #include "util/fptr_wlist.h"
+#include <openssl/ssl.h>
+#include <openssl/err.h>
 
 /* -------- Start of local definitions -------- */
 /** if CMSG_ALIGN is not defined on this platform, a workaround */
@@ -683,6 +685,32 @@ int comm_point_perform_accept(struct comm_point* c,
 	return new_fd;
 }
 
+#ifdef USE_WINSOCK
+static long win_bio_cb(BIO *b, int oper, const char* ATTR_UNUSED(argp),
+        int ATTR_UNUSED(argi), long argl, long retvalue)
+{
+	verbose(VERB_ALGO, "bio_cb %d, %s %s %s", oper,
+		(oper&BIO_CB_RETURN)?"return":"before",
+		(oper&BIO_CB_READ)?"read":((oper&BIO_CB_WRITE)?"write":"other"),
+		WSAGetLastError()==WSAEWOULDBLOCK?"wsawb":"");
+	/* on windows, check if previous operation caused EWOULDBLOCK */
+	if( (oper == (BIO_CB_READ|BIO_CB_RETURN) && argl == 0) ||
+		(oper == (BIO_CB_GETS|BIO_CB_RETURN) && argl == 0)) {
+		if(WSAGetLastError() == WSAEWOULDBLOCK)
+			winsock_tcp_wouldblock((struct event*)
+				BIO_get_callback_arg(b), EV_READ);
+	}
+	if( (oper == (BIO_CB_WRITE|BIO_CB_RETURN) && argl == 0) ||
+		(oper == (BIO_CB_PUTS|BIO_CB_RETURN) && argl == 0)) {
+		if(WSAGetLastError() == WSAEWOULDBLOCK)
+			winsock_tcp_wouldblock((struct event*)
+				BIO_get_callback_arg(b), EV_WRITE);
+	}
+	/* return original return value */
+	return retvalue;
+}
+#endif
+
 void 
 comm_point_tcp_accept_callback(int fd, short event, void* arg)
 {
@@ -706,6 +734,21 @@ comm_point_tcp_accept_callback(int fd, short event, void* arg)
 		&c_hdl->repinfo.addrlen);
 	if(new_fd == -1)
 		return;
+	if(c->ssl) {
+		c_hdl->ssl = incoming_ssl_fd(c->ssl, new_fd);
+		if(!c_hdl->ssl)
+			return;
+		c_hdl->ssl_shake_state = comm_ssl_shake_read;
+#ifdef USE_WINSOCK
+		/* set them both just in case, but usually they are the same BIO */
+		BIO_set_callback(SSL_get_rbio(c_hdl->ssl), &win_bio_cb);
+		BIO_set_callback_arg(SSL_get_rbio(c_hdl->ssl),
+			(char*)comm_point_internal(c_hdl));
+		BIO_set_callback(SSL_get_wbio(c_hdl->ssl), &win_bio_cb);
+		BIO_set_callback_arg(SSL_get_wbio(c_hdl->ssl),
+			(char*)comm_point_internal(c_hdl));
+#endif
+	}
 
 	/* grab the tcp handler buffers */
 	c->tcp_free = c_hdl->tcp_free;
@@ -722,6 +765,11 @@ static void
 reclaim_tcp_handler(struct comm_point* c)
 {
 	log_assert(c->type == comm_tcp);
+	if(c->ssl) {
+		SSL_shutdown(c->ssl);
+		SSL_free(c->ssl);
+		c->ssl = NULL;
+	}
 	comm_point_close(c);
 	if(c->tcp_parent) {
 		c->tcp_free = c->tcp_parent->tcp_free;
@@ -764,6 +812,231 @@ tcp_callback_reader(struct comm_point* c)
 	}
 }
 
+/** continue ssl handshake */
+static int
+ssl_handshake(struct comm_point* c)
+{
+	int r;
+	if(c->ssl_shake_state == comm_ssl_shake_hs_read) {
+		/* read condition satisfied back to writing */
+		comm_point_listen_for_rw(c, 1, 1);
+		c->ssl_shake_state = comm_ssl_shake_none;
+		return 1;
+	}
+	if(c->ssl_shake_state == comm_ssl_shake_hs_write) {
+		/* write condition satisfied, back to reading */
+		comm_point_listen_for_rw(c, 1, 0);
+		c->ssl_shake_state = comm_ssl_shake_none;
+		return 1;
+	}
+
+	ERR_clear_error();
+	r = SSL_do_handshake(c->ssl);
+	if(r != 1) {
+		int want = SSL_get_error(c->ssl, r);
+		if(want == SSL_ERROR_WANT_READ) {
+			if(c->ssl_shake_state == comm_ssl_shake_read)
+				return 1;
+			c->ssl_shake_state = comm_ssl_shake_read;
+			comm_point_listen_for_rw(c, 1, 0);
+			return 1;
+		} else if(want == SSL_ERROR_WANT_WRITE) {
+			if(c->ssl_shake_state == comm_ssl_shake_write)
+				return 1;
+			c->ssl_shake_state = comm_ssl_shake_write;
+			comm_point_listen_for_rw(c, 0, 1);
+			return 1;
+		} else if(r == 0) {
+			return 0; /* closed */
+		} else if(want == SSL_ERROR_SYSCALL) {
+			/* SYSCALL and errno==0 means closed uncleanly */
+			if(errno != 0)
+				log_err("SSL_handshake syscall: %s",
+					strerror(errno));
+			return 0;
+		} else {
+			log_crypto_err("ssl handshake failed");
+			log_addr(1, "ssl handshake failed", &c->repinfo.addr,
+				c->repinfo.addrlen);
+			return 0;
+		}
+	}
+	/* this is where peer verification could take place */
+	log_addr(VERB_ALGO, "SSL connection from", &c->repinfo.addr,
+		c->repinfo.addrlen);
+
+	/* setup listen rw correctly */
+	if(c->tcp_is_reading) {
+		if(c->ssl_shake_state != comm_ssl_shake_read)
+			comm_point_listen_for_rw(c, 1, 0);
+	} else {
+		comm_point_listen_for_rw(c, 1, 1);
+	}
+	c->ssl_shake_state = comm_ssl_shake_none;
+	return 1;
+}
+
+/** ssl read callback on TCP */
+static int
+ssl_handle_read(struct comm_point* c)
+{
+	int r;
+	if(c->ssl_shake_state != comm_ssl_shake_none) {
+		if(!ssl_handshake(c))
+			return 0;
+		if(c->ssl_shake_state != comm_ssl_shake_none)
+			return 1;
+	}
+	if(c->tcp_byte_count < sizeof(uint16_t)) {
+		/* read length bytes */
+		ERR_clear_error();
+		if((r=SSL_read(c->ssl, (void*)ldns_buffer_at(c->buffer,
+			c->tcp_byte_count), (int)(sizeof(uint16_t) -
+			c->tcp_byte_count))) <= 0) {
+			int want = SSL_get_error(c->ssl, r);
+			if(want == SSL_ERROR_ZERO_RETURN) {
+				return 0; /* shutdown, closed */
+			} else if(want == SSL_ERROR_WANT_READ) {
+				return 1; /* read more later */
+			} else if(want == SSL_ERROR_WANT_WRITE) {
+				c->ssl_shake_state = comm_ssl_shake_hs_write;
+				comm_point_listen_for_rw(c, 0, 1);
+				return 1;
+			} else if(want == SSL_ERROR_SYSCALL) {
+				if(errno != 0)
+					log_err("SSL_read syscall: %s",
+						strerror(errno));
+				return 0;
+			}
+			log_crypto_err("could not SSL_read");
+			return 0;
+		}
+		c->tcp_byte_count += r;
+		if(c->tcp_byte_count != sizeof(uint16_t))
+			return 1;
+		if(ldns_buffer_read_u16_at(c->buffer, 0) >
+			ldns_buffer_capacity(c->buffer)) {
+			verbose(VERB_QUERY, "ssl: dropped larger than buffer");
+			return 0;
+		}
+		ldns_buffer_set_limit(c->buffer,
+			ldns_buffer_read_u16_at(c->buffer, 0));
+		if(ldns_buffer_limit(c->buffer) < LDNS_HEADER_SIZE) {
+			verbose(VERB_QUERY, "ssl: dropped bogus too short.");
+			return 0;
+		}
+		verbose(VERB_ALGO, "Reading ssl tcp query of length %d",
+			(int)ldns_buffer_limit(c->buffer));
+	}
+	log_assert(ldns_buffer_remaining(c->buffer) > 0);
+	ERR_clear_error();
+	r = SSL_read(c->ssl, (void*)ldns_buffer_current(c->buffer),
+		(int)ldns_buffer_remaining(c->buffer));
+	if(r <= 0) {
+		int want = SSL_get_error(c->ssl, r);
+		if(want == SSL_ERROR_ZERO_RETURN) {
+			return 0; /* shutdown, closed */
+		} else if(want == SSL_ERROR_WANT_READ) {
+			return 1; /* read more later */
+		} else if(want == SSL_ERROR_WANT_WRITE) {
+			c->ssl_shake_state = comm_ssl_shake_hs_write;
+			comm_point_listen_for_rw(c, 0, 1);
+			return 1;
+		} else if(want == SSL_ERROR_SYSCALL) {
+			if(errno != 0)
+				log_err("SSL_read syscall: %s",
+					strerror(errno));
+			return 0;
+		}
+		log_crypto_err("could not SSL_read");
+		return 0;
+	}
+	ldns_buffer_skip(c->buffer, (ssize_t)r);
+	if(ldns_buffer_remaining(c->buffer) <= 0) {
+		tcp_callback_reader(c);
+	}
+	return 1;
+}
+
+/** ssl write callback on TCP */
+static int
+ssl_handle_write(struct comm_point* c)
+{
+	int r;
+	if(c->ssl_shake_state != comm_ssl_shake_none) {
+		if(!ssl_handshake(c))
+			return 0;
+		if(c->ssl_shake_state != comm_ssl_shake_none)
+			return 1;
+	}
+	/* ignore return, if fails we may simply block */
+	(void)SSL_set_mode(c->ssl, SSL_MODE_ENABLE_PARTIAL_WRITE);
+	if(c->tcp_byte_count < sizeof(uint16_t)) {
+		uint16_t len = htons(ldns_buffer_limit(c->buffer));
+		ERR_clear_error();
+		r = SSL_write(c->ssl,
+			(void*)(((uint8_t*)&len)+c->tcp_byte_count),
+			(int)(sizeof(uint16_t)-c->tcp_byte_count));
+		if(r <= 0) {
+			int want = SSL_get_error(c->ssl, r);
+			if(want == SSL_ERROR_ZERO_RETURN) {
+				return 0; /* closed */
+			} else if(want == SSL_ERROR_WANT_READ) {
+				c->ssl_shake_state = comm_ssl_shake_read;
+				comm_point_listen_for_rw(c, 1, 0);
+				return 1; /* wait for read condition */
+			} else if(want == SSL_ERROR_WANT_WRITE) {
+				return 1; /* write more later */
+			} else if(want == SSL_ERROR_SYSCALL) {
+				if(errno != 0)
+					log_err("SSL_write syscall: %s",
+						strerror(errno));
+				return 0;
+			}
+			log_crypto_err("could not SSL_write");
+			return 0;
+		}
+		c->tcp_byte_count += r;
+		if(c->tcp_byte_count < sizeof(uint16_t))
+			return 1;
+		ldns_buffer_set_position(c->buffer, c->tcp_byte_count -
+			sizeof(uint16_t));
+		if(ldns_buffer_remaining(c->buffer) == 0) {
+			tcp_callback_writer(c);
+			return 1;
+		}
+	}
+	log_assert(ldns_buffer_remaining(c->buffer) > 0);
+	ERR_clear_error();
+	r = SSL_write(c->ssl, (void*)ldns_buffer_current(c->buffer),
+		(int)ldns_buffer_remaining(c->buffer));
+	if(r <= 0) {
+		int want = SSL_get_error(c->ssl, r);
+		if(want == SSL_ERROR_ZERO_RETURN) {
+			return 0; /* closed */
+		} else if(want == SSL_ERROR_WANT_READ) {
+			c->ssl_shake_state = comm_ssl_shake_read;
+			comm_point_listen_for_rw(c, 1, 0);
+			return 1; /* wait for read condition */
+		} else if(want == SSL_ERROR_WANT_WRITE) {
+			return 1; /* write more later */
+		} else if(want == SSL_ERROR_SYSCALL) {
+			if(errno != 0)
+				log_err("SSL_write syscall: %s",
+					strerror(errno));
+			return 0;
+		}
+		log_crypto_err("could not SSL_write");
+		return 0;
+	}
+	ldns_buffer_skip(c->buffer, (ssize_t)r);
+
+	if(ldns_buffer_remaining(c->buffer) == 0) {
+		tcp_callback_writer(c);
+	}
+	return 1;
+}
+
 /** Handle tcp reading callback. 
  * @param fd: file descriptor of socket.
  * @param c: comm point to read from into buffer.
@@ -777,6 +1050,8 @@ comm_point_tcp_handle_read(int fd, struct comm_point* c, int short_ok)
 	log_assert(c->type == comm_tcp || c->type == comm_local);
 	if(!c->tcp_is_reading)
 		return 0;
+	if(c->ssl)
+		return ssl_handle_read(c);
 
 	log_assert(fd != -1);
 	if(c->tcp_byte_count < sizeof(uint16_t)) {
@@ -915,6 +1190,8 @@ comm_point_tcp_handle_write(int fd, struct comm_point* c)
 			return 0;
 		}
 	}
+	if(c->ssl)
+		return ssl_handle_write(c);
 
 	if(c->tcp_byte_count < sizeof(uint16_t)) {
 		uint16_t len = htons(ldns_buffer_limit(c->buffer));
@@ -1476,6 +1753,10 @@ comm_point_delete(struct comm_point* c)
 {
 	if(!c) 
 		return;
+	if(c->type == comm_tcp && c->ssl) {
+		SSL_shutdown(c->ssl);
+		SSL_free(c->ssl);
+	}
 	comm_point_close(c);
 	if(c->tcp_handlers) {
 		int i;

util/netevent.h

@@ -160,6 +160,23 @@ struct comm_point {
 	    For tcp_accept the first entry, for tcp_handlers the next one. */
 	struct comm_point* tcp_free;
 
+	/* -------- SSL TCP DNS ------- */
+	/** the SSL object with rw bio (owned) or for commaccept ctx ref */
+	void* ssl;
+	/** handshake state for init and renegotiate */
+	enum {
+		/** no handshake, it has been done */
+		comm_ssl_shake_none = 0,
+		/** ssl initial handshake wants to read */
+		comm_ssl_shake_read,
+		/** ssl initial handshake wants to write */
+		comm_ssl_shake_write,
+		/** ssl_write wants to read */
+		comm_ssl_shake_hs_read,
+		/** ssl_read wants to write */
+		comm_ssl_shake_hs_write
+	} ssl_shake_state;
+
 	/** is this a UDP, TCP-accept or TCP socket. */
 	enum comm_point_type {
 		/** UDP socket - handle datagrams. */