Test that all supported TLS ciphers actually work. Establish

connections between client and server implemented with LibreSSL or
OpenSSL with a fixed cipher on each side.  Check the used cipher
in the session print out.

8 files changed, 308 insertions, 26 deletions

diff --git a/regress/lib/libssl/interop/LICENSE b/regress/lib/libssl/interop/LICENSE
index 86956204956..838e7f45ccd 100644
--- a/regress/lib/libssl/interop/LICENSE
+++ b/regress/lib/libssl/interop/LICENSE
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018 Alexander Bluhm <bluhm@openbsd.org>
+ * Copyright (c) 2018-2019 Alexander Bluhm <bluhm@openbsd.org>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
diff --git a/regress/lib/libssl/interop/Makefile b/regress/lib/libssl/interop/Makefile
index dcde044d977..36b233c189d 100644
--- a/regress/lib/libssl/interop/Makefile
+++ b/regress/lib/libssl/interop/Makefile
@@ -1,9 +1,10 @@
-# $OpenBSD: Makefile,v 1.5 2018/11/11 00:15:04 bluhm Exp $
+# $OpenBSD: Makefile,v 1.6 2019/02/21 23:06:33 bluhm Exp $
 
 SUBDIR =	libressl openssl openssl11
 # the above binaries must have been built before we can continue
 SUBDIR +=	netcat
 SUBDIR +=	session
+SUBDIR +=	cipher
 SUBDIR +=	cert
 
 .include <bsd.subdir.mk>
diff --git a/regress/lib/libssl/interop/Makefile.inc b/regress/lib/libssl/interop/Makefile.inc
index 7dadc3607b1..dfe14249499 100644
--- a/regress/lib/libssl/interop/Makefile.inc
+++ b/regress/lib/libssl/interop/Makefile.inc
@@ -1,4 +1,4 @@
-# $OpenBSD: Makefile.inc,v 1.5 2018/11/11 00:15:04 bluhm Exp $
+# $OpenBSD: Makefile.inc,v 1.6 2019/02/21 23:06:33 bluhm Exp $
 
 .PATH:			${.CURDIR}/..
 
@@ -37,7 +37,9 @@ run-self-client-server: client server 127.0.0.1.crt
 
 CLEANFILES +=		127.0.0.1.{crt,key} \
 			ca.{crt,key,srl} fake-ca.{crt,key} \
-			{client,server}.{req,crt,key}
+			{client,server}.{req,crt,key} \
+			{dsa,ec,gost,rsa}.{key,req,crt} \
+			dh.param
 
 127.0.0.1.crt:
 	openssl req -batch -new \
@@ -57,3 +59,33 @@ client.req server.req:
 client.crt server.crt: ca.crt ${@:R}.req
 	openssl x509 -CAcreateserial -CAkey ca.key -CA ca.crt \
 	    -req -in ${@:R}.req -out $@
+
+dh.param:
+	openssl dhparam -out $@ 1024
+
+dsa.key:
+	openssl dsaparam -genkey -out $@ 2048
+
+ec.key:
+	openssl ecparam -genkey -name secp256r1 -out $@
+
+gost.key:
+	openssl genpkey -algorithm gost2001 \
+	    -pkeyopt paramset:A -pkeyopt dgst:md_gost94 -out $@
+
+rsa.key:
+	openssl genrsa -out $@ 2048
+
+dsa.req ec.req rsa.req: ${@:R}.key
+	openssl req -batch -new \
+	    -subj /L=OpenBSD/O=tls-regress/OU=${@:R}/CN=localhost/ \
+	    -nodes -key ${@:R}.key -out $@
+
+gost.req: ${@:R}.key
+	openssl req -batch -new -md_gost94 \
+	    -subj /L=OpenBSD/O=tls-regress/OU=${@:R}/CN=localhost/ \
+	    -nodes -key ${@:R}.key -out $@
+
+dsa.crt ec.crt gost.crt rsa.crt: ca.crt ${@:R}.req
+	openssl x509 -CAcreateserial -CAkey ca.key -CA ca.crt \
+	    -req -in ${@:R}.req -out $@
diff --git a/regress/lib/libssl/interop/README b/regress/lib/libssl/interop/README
index 42d87acfdbd..54910e554de 100644
--- a/regress/lib/libssl/interop/README
+++ b/regress/lib/libssl/interop/README
@@ -17,4 +17,6 @@ libtls.  Test TLS session reuse multiple times with different library
 combinations.  The cert subdir is testing all combinations of
 certificate validation.  Having the three libraries, client and
 server certificates, missing or invalid CA or certificates, and
-enforcing peer certificate results in 1944 test cases.
+enforcing peer certificate results in 1944 test cases.  The cipher
+test establishes connections between implementations for each
+supported cipher.
diff --git a/regress/lib/libssl/interop/cert/Makefile b/regress/lib/libssl/interop/cert/Makefile
index 3e7a07cdfe2..11bc4aa2abb 100644
--- a/regress/lib/libssl/interop/cert/Makefile
+++ b/regress/lib/libssl/interop/cert/Makefile
@@ -1,4 +1,10 @@
-# $OpenBSD: Makefile,v 1.3 2018/11/11 07:39:34 bluhm Exp $
+# $OpenBSD: Makefile,v 1.4 2019/02/21 23:06:33 bluhm Exp $
+
+# Connect a client to a server.  Both can be current libressl, or
+# openssl 1.0.2, or openssl 1.1.  Create client and server certificates
+# that are signed by a CA and not signed by a fake CA.  Try all
+# combinations with, without, and with wrong CA for client and server
+# and check the result of certificate verification.
 
 LIBRARIES =		libressl
 .if exists(/usr/local/bin/eopenssl)
diff --git a/regress/lib/libssl/interop/cipher/Makefile b/regress/lib/libssl/interop/cipher/Makefile
new file mode 100644
index 00000000000..5593ab233fa
--- /dev/null
+++ b/regress/lib/libssl/interop/cipher/Makefile
@@ -0,0 +1,180 @@
+# $OpenBSD: Makefile,v 1.1 2019/02/21 23:06:33 bluhm Exp $
+
+# Connect a client to a server.  Both can be current libressl, or
+# openssl 1.0.2, or openssl 1.1.  Create lists of supported ciphers
+# and pin client and server to one of the ciphers.  Use server
+# certificate with compatible type.  Check that client and server
+# have used correct cipher by grepping in their session print out.
+
+check-cipher-GOST2001-GOST89-GOST89-client-libressl-server-libressl:
+	# cipher GOST2012256-GOST89-GOST89 is used in out file
+	# TODO: figure out why it is not GOST2001
+	@echo DISABLED
+
+check-cipher-ADH-AES128-GCM-SHA256-client-openssl11-server-openssl11 \
+check-cipher-ADH-AES128-SHA-client-openssl11-server-openssl11 \
+check-cipher-ADH-AES128-SHA256-client-openssl11-server-openssl11 \
+check-cipher-ADH-AES256-GCM-SHA384-client-openssl11-server-openssl11 \
+check-cipher-ADH-AES256-SHA-client-openssl11-server-openssl11 \
+check-cipher-ADH-AES256-SHA256-client-openssl11-server-openssl11 \
+check-cipher-ADH-CAMELLIA128-SHA-client-openssl11-server-openssl11 \
+check-cipher-ADH-CAMELLIA128-SHA256-client-openssl11-server-openssl11 \
+check-cipher-ADH-CAMELLIA256-SHA-client-openssl11-server-openssl11 \
+check-cipher-ADH-CAMELLIA256-SHA256-client-openssl11-server-openssl11 \
+check-cipher-AECDH-AES128-SHA-client-openssl11-server-openssl11 \
+check-cipher-AECDH-AES256-SHA-client-openssl11-server-openssl11 \
+check-cipher-AES128-GCM-SHA256-client-openssl11-server-openssl11 \
+check-cipher-AES128-SHA-client-openssl11-server-openssl11 \
+check-cipher-AES128-SHA256-client-openssl11-server-openssl11 \
+check-cipher-AES256-GCM-SHA384-client-openssl11-server-openssl11 \
+check-cipher-AES256-SHA-client-openssl11-server-openssl11 \
+check-cipher-AES256-SHA256-client-openssl11-server-openssl11 \
+check-cipher-CAMELLIA128-SHA-client-openssl11-server-openssl11 \
+check-cipher-CAMELLIA128-SHA256-client-openssl11-server-openssl11 \
+check-cipher-CAMELLIA256-SHA-client-openssl11-server-openssl11 \
+check-cipher-CAMELLIA256-SHA256-client-openssl11-server-openssl11 \
+check-cipher-DHE-RSA-AES128-GCM-SHA256-client-openssl11-server-openssl11 \
+check-cipher-DHE-RSA-AES128-SHA-client-openssl11-server-openssl11 \
+check-cipher-DHE-RSA-AES128-SHA256-client-openssl11-server-openssl11 \
+check-cipher-DHE-RSA-AES256-GCM-SHA384-client-openssl11-server-openssl11 \
+check-cipher-DHE-RSA-AES256-SHA-client-openssl11-server-openssl11 \
+check-cipher-DHE-RSA-AES256-SHA256-client-openssl11-server-openssl11 \
+check-cipher-DHE-RSA-CAMELLIA128-SHA-client-openssl11-server-openssl11 \
+check-cipher-DHE-RSA-CAMELLIA128-SHA256-client-openssl11-server-openssl11 \
+check-cipher-DHE-RSA-CAMELLIA256-SHA-client-openssl11-server-openssl11 \
+check-cipher-DHE-RSA-CAMELLIA256-SHA256-client-openssl11-server-openssl11 \
+check-cipher-DHE-RSA-CHACHA20-POLY1305-client-openssl11-server-openssl11 \
+check-cipher-ECDHE-ECDSA-AES128-GCM-SHA256-client-openssl11-server-openssl11 \
+check-cipher-ECDHE-ECDSA-AES128-SHA-client-openssl11-server-openssl11 \
+check-cipher-ECDHE-ECDSA-AES128-SHA256-client-openssl11-server-openssl11 \
+check-cipher-ECDHE-ECDSA-AES256-GCM-SHA384-client-openssl11-server-openssl11 \
+check-cipher-ECDHE-ECDSA-AES256-SHA-client-openssl11-server-openssl11 \
+check-cipher-ECDHE-ECDSA-AES256-SHA384-client-openssl11-server-openssl11 \
+check-cipher-ECDHE-ECDSA-CHACHA20-POLY1305-client-openssl11-server-openssl11 \
+check-cipher-ECDHE-RSA-AES128-GCM-SHA256-client-openssl11-server-openssl11 \
+check-cipher-ECDHE-RSA-AES128-SHA-client-openssl11-server-openssl11 \
+check-cipher-ECDHE-RSA-AES128-SHA256-client-openssl11-server-openssl11 \
+check-cipher-ECDHE-RSA-AES256-GCM-SHA384-client-openssl11-server-openssl11 \
+check-cipher-ECDHE-RSA-AES256-SHA-client-openssl11-server-openssl11 \
+check-cipher-ECDHE-RSA-AES256-SHA384-client-openssl11-server-openssl11 \
+check-cipher-ECDHE-RSA-CHACHA20-POLY1305-client-openssl11-server-openssl11:
+	# openssl11 always prints TLS_AES_256_GCM_SHA384 as cipher in out file
+	@echo DISABLED
+
+LIBRARIES =		libressl
+.if exists(/usr/local/bin/eopenssl)
+LIBRARIES +=		openssl
+.endif
+.if exists(/usr/local/bin/eopenssl11)
+LIBRARIES +=		openssl11
+.endif
+
+CLEANFILES =	*.tmp *.ciphers ciphers.mk
+
+.for clib in ${LIBRARIES}
+client-${clib}.ciphers:
+	LD_LIBRARY_PATH=/usr/local/lib/e${clib} \
+	    ../${clib}/client -l ALL -L >$@.tmp
+	sed -n 's/^cipher //p' <$@.tmp | sort -u >$@
+	rm $@.tmp
+.endfor
+.for slib in ${LIBRARIES}
+server-${slib}.ciphers: 127.0.0.1.crt dsa.crt ec.crt rsa.crt
+	LD_LIBRARY_PATH=/usr/local/lib/e${slib} \
+	    ../${slib}/server -l ALL -L >$@.tmp
+	sed -n 's/^cipher //p' <$@.tmp | sort -u >$@
+	rm $@.tmp
+.endfor
+
+.for clib in ${LIBRARIES}
+.for slib in ${LIBRARIES}
+ciphers.mk: client-${clib}-server-${slib}.ciphers
+client-${clib}-server-${slib}.ciphers: \
+    client-${clib}.ciphers server-${slib}.ciphers client-libressl.ciphers
+	# get ciphers shared between client and server
+	sort client-${clib}.ciphers server-${slib}.ciphers >$@.tmp
+	uniq -d <$@.tmp >$@
+	# we are only interested in cipers supported by libressl
+	sort $@ client-libressl.ciphers >$@.tmp
+	uniq -d <$@.tmp >$@
+	rm $@.tmp
+.endfor
+.endfor
+
+ciphers.mk:
+	rm -f $@ $@.tmp
+.for clib in ${LIBRARIES}
+.for slib in ${LIBRARIES}
+	echo 'CIPHERS_${clib}_${slib} =' >>$@.tmp \
+	    `cat client-${clib}-server-${slib}.ciphers`
+.endfor
+.endfor
+	mv $@.tmp $@
+
+# hack to convert generated lists into usable make variables
+.if exists(ciphers.mk)
+.include "ciphers.mk"
+.else
+regress: ciphers.mk
+	${MAKE} -C ${.CURDIR} regress
+.endif
+
+LEVEL_libressl =
+LEVEL_openssl =
+LEVEL_openssl11 = ,@SECLEVEL=0
+
+.for clib in ${LIBRARIES}
+.for slib in ${LIBRARIES}
+.for cipher in ${CIPHERS_${clib}_${slib}}
+
+.if "${cipher:M*-DSS-*}" != ""
+TYPE_${cipher} =	dsa
+.elif "${cipher:M*-ECDSA-*}" != ""
+TYPE_${cipher} =	ec
+.elif "${cipher:M*-GOST89-*}" != ""
+TYPE_${cipher} =	gost
+.elif "${cipher:M*-RSA-*}" != ""
+TYPE_${cipher} =	rsa
+.else
+TYPE_${cipher} =	127.0.0.1
+.endif
+
+.if "${slib}" == "openssl" && \
+    "${cipher:MADH-*}${cipher:MEDH-*}${cipher:MDHE-*}" != ""
+DHPARAM_${cipher}_${slib} =	-p dh.param
+.else
+DHPARAM_${cipher}_${slib} =
+.endif
+
+REGRESS_TARGETS +=	run-cipher-${cipher}-client-${clib}-server-${slib}
+run-cipher-${cipher}-client-${clib}-server-${slib} \
+client-cipher-${cipher}-client-${clib}-server-${slib}.out \
+server-cipher-${cipher}-client-${clib}-server-${slib}.out: dh.param \
+    127.0.0.1.crt ${TYPE_${cipher}}.crt ../${clib}/client ../${slib}/server
+	@echo '\n======== $@ ========'
+	LD_LIBRARY_PATH=/usr/local/lib/e${slib} \
+	    ../${slib}/server >${@:S/^run/server/}.out \
+	    -c ${TYPE_${cipher}}.crt -k ${TYPE_${cipher}}.key \
+	    -l ${cipher}${LEVEL_${slib}} ${DHPARAM_${cipher}_${slib}} \
+	    127.0.0.1 0
+	LD_LIBRARY_PATH=/usr/local/lib/e${clib} \
+	    ../${clib}/client >${@:S/^run/client/}.out \
+	    -l ${cipher}${LEVEL_${clib}} \
+	    `sed -n 's/listen sock: //p' ${@:S/^run/server/}.out`
+	grep -q '^success$$' ${@:S/^run/server/}.out || \
+	    { sleep 1; grep -q '^success$$' ${@:S/^run/server/}.out; }
+	grep -q '^success$$' ${@:S/^run/client/}.out
+
+REGRESS_TARGETS +=	check-cipher-${cipher}-client-${clib}-server-${slib}
+check-cipher-${cipher}-client-${clib}-server-${slib}: \
+    client-cipher-${cipher}-client-${clib}-server-${slib}.out \
+    server-cipher-${cipher}-client-${clib}-server-${slib}.out
+	@echo '\n======== $@ ========'
+	grep -q ' Cipher *: ${cipher}$$' ${@:S/^check/server/}.out
+	grep -q ' Cipher *: ${cipher}$$' ${@:S/^check/client/}.out
+
+.endfor
+.endfor
+.endfor
+
+.include <bsd.regress.mk>
diff --git a/regress/lib/libssl/interop/client.c b/regress/lib/libssl/interop/client.c
index 6f148378955..136dc38d099 100644
--- a/regress/lib/libssl/interop/client.c
+++ b/regress/lib/libssl/interop/client.c
@@ -1,6 +1,6 @@
-/*	$OpenBSD: client.c,v 1.6 2019/02/11 12:22:44 bluhm Exp $	*/
+/*	$OpenBSD: client.c,v 1.7 2019/02/21 23:06:33 bluhm Exp $	*/
 /*
- * Copyright (c) 2018 Alexander Bluhm <bluhm@openbsd.org>
+ * Copyright (c) 2018-2019 Alexander Bluhm <bluhm@openbsd.org>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -34,8 +34,8 @@ void __dead usage(void);
 void __dead
 usage(void)
 {
-	fprintf(stderr,
-	    "usage: client [-sv] [-C CA] [-c crt -k key] host port");
+	fprintf(stderr, "usage: client [-Lsv] [-C CA] [-c crt -k key] "
+	    "[-l cipers] host port\n");
 	exit(2);
 }
 
@@ -47,12 +47,13 @@ main(int argc, char *argv[])
 	SSL *ssl;
 	BIO *bio;
 	SSL_SESSION *session = NULL;
-	int ch, error, sessionreuse = 0, verify = 0;
+	int ch, error, listciphers = 0, sessionreuse = 0, verify = 0;
 	char buf[256];
-	char *ca = NULL, *crt = NULL, *key = NULL;
-	char *host_port, *host, *port;
+	char *ca = NULL, *crt = NULL, *key = NULL, *ciphers = NULL;
+	char *host_port, *host = "127.0.0.1", *port = "0";
 
-	while ((ch = getopt(argc, argv, "C:c:k:sv")) != -1) {
+
+	while ((ch = getopt(argc, argv, "C:c:k:Ll:sv")) != -1) {
 		switch (ch) {
 		case 'C':
 			ca = optarg;
@@ -63,6 +64,12 @@ main(int argc, char *argv[])
 		case 'k':
 			key = optarg;
 			break;
+		case 'L':
+			listciphers = 1;
+			break;
+		case 'l':
+			ciphers = optarg;
+			break;
 		case 's':
 			/* multiple reueses are possible */
 			sessionreuse++;
@@ -79,7 +86,7 @@ main(int argc, char *argv[])
 	if (argc == 2) {
 		host = argv[0];
 		port = argv[1];
-	} else {
+	} else if (!listciphers) {
 		usage();
 	}
 	if (asprintf(&host_port, strchr(host, ':') ? "[%s]:%s" : "%s:%s",
@@ -130,6 +137,19 @@ main(int argc, char *argv[])
 		SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_CLIENT);
 	}
 
+	if (ciphers) {
+		if (SSL_CTX_set_cipher_list(ctx, ciphers) <= 0)
+			err_ssl(1, "SSL_CTX_set_cipher_list");
+	}
+
+	if (listciphers) {
+		ssl = SSL_new(ctx);
+		if (ssl == NULL)
+			err_ssl(1, "SSL_new");
+		print_ciphers(SSL_get_ciphers(ssl));
+		return 0;
+	}
+
 	do {
 		/* setup bio for socket operations */
 		bio = BIO_new_connect(host_port);
@@ -148,7 +168,6 @@ main(int argc, char *argv[])
 		ssl = SSL_new(ctx);
 		if (ssl == NULL)
 			err_ssl(1, "SSL_new");
-		print_ciphers(SSL_get_ciphers(ssl));
 		SSL_set_bio(ssl, bio, bio);
 		/* resuse session if possible */
 		if (session != NULL) {
diff --git a/regress/lib/libssl/interop/server.c b/regress/lib/libssl/interop/server.c
index 3cbadda4c5b..ee9c7c70a09 100644
--- a/regress/lib/libssl/interop/server.c
+++ b/regress/lib/libssl/interop/server.c
@@ -1,6 +1,6 @@
-/*	$OpenBSD: server.c,v 1.6 2019/02/11 12:22:44 bluhm Exp $	*/
+/*	$OpenBSD: server.c,v 1.7 2019/02/21 23:06:33 bluhm Exp $	*/
 /*
- * Copyright (c) 2018 Alexander Bluhm <bluhm@openbsd.org>
+ * Copyright (c) 2018-2019 Alexander Bluhm <bluhm@openbsd.org>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -35,8 +35,8 @@ void __dead usage(void);
 void __dead
 usage(void)
 {
-	fprintf(stderr,
-	    "usage: server [-svv] [-C CA] [-c crt -k key] [host port]");
+	fprintf(stderr, "usage: server [-Lsvv] [-C CA] [-c crt -k key] "
+	    "[-l cipers] [-p dhparam] [host port]\n");
 	exit(2);
 }
 
@@ -48,12 +48,12 @@ main(int argc, char *argv[])
 	SSL *ssl;
 	BIO *abio, *cbio;
 	SSL_SESSION *session;
-	int ch, error, sessionreuse = 0, verify = 0;
-	char buf[256];
-	char *ca = NULL, *crt = NULL, *key = NULL;
+	int ch, error, listciphers = 0, sessionreuse = 0, verify = 0;
+	char buf[256], *dhparam = NULL;
+	char *ca = NULL, *crt = NULL, *key = NULL, *ciphers = NULL;
 	char *host_port, *host = "127.0.0.1", *port = "0";
 
-	while ((ch = getopt(argc, argv, "C:c:k:sv")) != -1) {
+	while ((ch = getopt(argc, argv, "C:c:k:Ll:p:sv")) != -1) {
 		switch (ch) {
 		case 'C':
 			ca = optarg;
@@ -64,6 +64,15 @@ main(int argc, char *argv[])
 		case 'k':
 			key = optarg;
 			break;
+		case 'L':
+			listciphers = 1;
+			break;
+		case 'l':
+			ciphers = optarg;
+			break;
+		case 'p':
+			dhparam = optarg;
+			break;
 		case 's':
 			/* multiple reueses are possible */
 			sessionreuse++;
@@ -81,7 +90,7 @@ main(int argc, char *argv[])
 	if (argc == 2) {
 		host = argv[0];
 		port = argv[1];
-	} else if (argc != 0) {
+	} else if (argc != 0 && !listciphers) {
 		usage();
 	}
 	if (asprintf(&host_port, strchr(host, ':') ? "[%s]:%s" : "%s:%s",
@@ -112,6 +121,27 @@ main(int argc, char *argv[])
 	if (ctx == NULL)
 		err_ssl(1, "SSL_CTX_new");
 
+#if OPENSSL_VERSION_NUMBER >= 0x10100000
+	/* needed to use DHE cipher with libressl */
+	if (SSL_CTX_set_dh_auto(ctx, 1) <= 0)
+		err_ssl(1, "SSL_CTX_set_dh_auto");
+#endif
+	/* needed to use ADH, EDH, DHE cipher with openssl */
+	if (dhparam != NULL) {
+		DH *dh;
+		FILE *file;
+
+		file = fopen(dhparam, "r");
+		if (file == NULL)
+			err(1, "fopen %s", dhparam);
+		dh = PEM_read_DHparams(file, NULL, NULL, NULL);
+		if (dh == NULL)
+			err_ssl(1, "PEM_read_DHparams");
+		if (SSL_CTX_set_tmp_dh(ctx, dh) <= 0)
+			err_ssl(1, "SSL_CTX_set_tmp_dh");
+		fclose(file);
+	}
+
 	/* needed when linking with OpenSSL 1.0.2p */
 	if (SSL_CTX_set_ecdh_auto(ctx, 1) <= 0)
 		err_ssl(1, "SSL_CTX_set_ecdh_auto");
@@ -151,6 +181,19 @@ main(int argc, char *argv[])
 			err_ssl(1, "SSL_CTX_set_session_id_context");
 	}
 
+	if (ciphers) {
+		if (SSL_CTX_set_cipher_list(ctx, ciphers) <= 0)
+			err_ssl(1, "SSL_CTX_set_cipher_list");
+	}
+
+	if (listciphers) {
+		ssl = SSL_new(ctx);
+		if (ssl == NULL)
+			err_ssl(1, "SSL_new");
+		print_ciphers(SSL_get_ciphers(ssl));
+		return 0;
+	}
+
 	/* setup bio for socket operations */
 	abio = BIO_new_accept(host_port);
 	if (abio == NULL)
@@ -182,7 +225,6 @@ main(int argc, char *argv[])
 		ssl = SSL_new(ctx);
 		if (ssl == NULL)
 			err_ssl(1, "SSL_new");
-		print_ciphers(SSL_get_ciphers(ssl));
 		SSL_set_bio(ssl, cbio, cbio);
 		if ((error = SSL_accept(ssl)) <= 0)
 			err_ssl(1, "SSL_accept %d", error);