File 499a3a7a612ad1e5ef5678bdb1bb6c059599419a.patch of Package unbound
From 499a3a7a612ad1e5ef5678bdb1bb6c059599419a Mon Sep 17 00:00:00 2001
From: Yorgos Thessalonikefs <yorgos@nlnetlabs.nl>
Date: Mon, 29 Sep 2025 12:03:56 +0200
Subject: [PATCH] Fix #1346: [FR] Please allow back TLS 1.2. (#1349)
* 'tls-use-system-policy-versions' is introduced to allow Unbound to use
any system available TLS version when serving TLS.
* Apply suggestions from code review
---------
Co-authored-by: Wouter Wijngaards <wcawijngaards@users.noreply.github.com>
---
daemon/remote.c | 2 +-
daemon/unbound.c | 2 +-
dnstap/unbound-dnstap-socket.c | 2 +-
doc/example.conf.in | 26 ++++++++++------
doc/unbound.conf.5.in | 55 +++++++++++++++++++++++++---------
doc/unbound.conf.rst | 32 +++++++++++++++-----
util/config_file.c | 3 ++
util/config_file.h | 2 ++
util/configlexer.lex | 1 +
util/configparser.y | 11 +++++++
util/net_help.c | 54 +++++++++++++++++----------------
util/net_help.h | 8 +++--
winrc/win_svc.c | 4 +--
13 files changed, 138 insertions(+), 64 deletions(-)
diff --git a/daemon/remote.c b/daemon/remote.c
index e10dadde7..8408e2273 100644
--- a/daemon/remote.c
+++ b/daemon/remote.c
@@ -153,7 +153,7 @@ remote_setup_ctx(struct daemon_remote* rc, struct config_file* cfg)
log_crypto_err("could not SSL_CTX_new");
return 0;
}
- if(!listen_sslctx_setup(rc->ctx)) {
+ if(!listen_sslctx_setup(rc->ctx, cfg->tls_use_system_policy_versions)) {
return 0;
}
diff --git a/daemon/unbound.c b/daemon/unbound.c
index 164d0fb89..688804743 100644
--- a/daemon/unbound.c
+++ b/daemon/unbound.c
@@ -473,7 +473,7 @@ setup_listen_sslctx(void** ctx, int is_dot, int is_doh, struct config_file* cfg)
cfg->tls_ciphers, cfg->tls_ciphersuites,
(cfg->tls_session_ticket_keys.first &&
cfg->tls_session_ticket_keys.first->str[0] != 0),
- is_dot, is_doh))) {
+ is_dot, is_doh, cfg->tls_use_system_policy_versions))) {
fatal_exit("could not set up listen SSL_CTX");
}
}
diff --git a/dnstap/unbound-dnstap-socket.c b/dnstap/unbound-dnstap-socket.c
index a01627de9..c0d344cbb 100644
--- a/dnstap/unbound-dnstap-socket.c
+++ b/dnstap/unbound-dnstap-socket.c
@@ -347,7 +347,7 @@ static struct tap_socket* tap_socket_new_tlsaccept(char* ip,
s->ev_cb = ev_cb;
s->data = data;
s->sslctx = listen_sslctx_create(server_key, server_cert, verifypem,
- NULL, NULL, 0, 0, 0);
+ NULL, NULL, 0, 0, 0, 0);
if(!s->sslctx) {
log_err("could not create ssl context");
free(s->ip);
diff --git a/doc/example.conf.in b/doc/example.conf.in
index 02f6ec774..54adee889 100644
--- a/doc/example.conf.in
+++ b/doc/example.conf.in
@@ -932,21 +932,26 @@ server:
# https-port: 443
# quic-port: 853
+ # Also serve tls on these port numbers (eg. 443, ...), by listing
+ # tls-additional-port: portno for each of the port numbers.
+
# cipher setting for TLSv1.2
# tls-ciphers: "DHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-SHA256:DHE-RSA-AES128-SHA256:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA256"
# cipher setting for TLSv1.3
# tls-ciphersuites: "TLS_AES_128_GCM_SHA256:TLS_AES_128_CCM_8_SHA256:TLS_AES_128_CCM_SHA256:TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256"
- # Pad responses to padded queries received over TLS
- # pad-responses: yes
-
- # Padded responses will be padded to the closest multiple of this size.
- # pad-responses-block-size: 468
-
# Use the SNI extension for TLS connections. Default is yes.
# Changing the value requires a reload.
# tls-use-sni: yes
+ # Allow general-purpose version-flexible TLS server configuration that
+ # may be further restricted by the system's policy.
+ # Use only if you want to support legacy TLS client connections.
+ # Default is no and Unbound will only use the latest available TLS
+ # version.
+ # Changing the value requires a reload.
+ # tls-use-system-policy-versions: no
+
# Add the secret file for TLS Session Ticket.
# Secret file must be 80 bytes of random data.
# First key use to encrypt and decrypt TLS session tickets.
@@ -967,15 +972,18 @@ server:
# and on other systems, the default openssl certificates
# tls-system-cert: no
+ # Pad responses to padded queries received over TLS
+ # pad-responses: yes
+
+ # Padded responses will be padded to the closest multiple of this size.
+ # pad-responses-block-size: 468
+
# Pad queries over TLS upstreams
# pad-queries: yes
# Padded queries will be padded to the closest multiple of this size.
# pad-queries-block-size: 128
- # Also serve tls on these port numbers (eg. 443, ...), by listing
- # tls-additional-port: portno for each of the port numbers.
-
# HTTP endpoint to provide DNS-over-HTTPS service on.
# http-endpoint: "/dns-query"
diff --git a/doc/unbound.conf.5.in b/doc/unbound.conf.5.in
index 0d2b5044b..08a926bd5 100644
--- a/doc/unbound.conf.5.in
+++ b/doc/unbound.conf.5.in
@@ -1218,6 +1218,47 @@ Default: \(dq\(dq
.UNINDENT
.INDENT 0.0
.TP
+.B tls\-use\-sni: \fI<yes or no>\fP
+Enable or disable sending the SNI extension on TLS connections.
+.sp
+\fBNOTE:\fP
+.INDENT 7.0
+.INDENT 3.5
+Changing the value requires a reload.
+.UNINDENT
+.UNINDENT
+.sp
+Default: yes
+.UNINDENT
+.INDENT 0.0
+.TP
+.B tls\-use\-system\-policy\-versions: \fI<yes or no>\fP
+Enable or disable general\-puspose version\-flexible TLS server configuration
+when serving TLS.
+This will allow the whole list of available TLS versions provided by the
+crypto library, which may have been further restricted by the system\(aqs
+crypto policy.
+.sp
+By default Unbound only uses the latest available TLS version.
+.sp
+\fBCAUTION:\fP
+.INDENT 7.0
+.INDENT 3.5
+Use only if you want to support legacy TLS client connections.
+.UNINDENT
+.UNINDENT
+.sp
+\fBNOTE:\fP
+.INDENT 7.0
+.INDENT 3.5
+Changing the value requires a reload.
+.UNINDENT
+.UNINDENT
+.sp
+Default: no
+.UNINDENT
+.INDENT 0.0
+.TP
.B pad\-responses: \fI<yes or no>\fP
If enabled, TLS serviced queries that contained an EDNS Padding option will
cause responses padded to the closest multiple of the size specified in
@@ -1251,20 +1292,6 @@ Default: 128
.UNINDENT
.INDENT 0.0
.TP
-.B tls\-use\-sni: \fI<yes or no>\fP
-Enable or disable sending the SNI extension on TLS connections.
-.sp
-\fBNOTE:\fP
-.INDENT 7.0
-.INDENT 3.5
-Changing the value requires a reload.
-.UNINDENT
-.UNINDENT
-.sp
-Default: yes
-.UNINDENT
-.INDENT 0.0
-.TP
.B https\-port: \fI<number>\fP
The port number on which to provide DNS\-over\-HTTPS service.
Only interfaces configured with that port number as @number get the HTTPS
diff --git a/doc/unbound.conf.rst b/doc/unbound.conf.rst
index bbc31fe50..f9f2dea8a 100644
--- a/doc/unbound.conf.rst
+++ b/doc/unbound.conf.rst
@@ -1103,6 +1103,30 @@ These options are part of the **server:** clause.
Default: ""
+@@UAHL@unbound.conf@tls-use-sni@@: *<yes or no>*
+ Enable or disable sending the SNI extension on TLS connections.
+
+ .. note:: Changing the value requires a reload.
+
+ Default: yes
+
+
+@@UAHL@unbound.conf@tls-use-system-policy-versions@@: *<yes or no>*
+ Enable or disable general-puspose version-flexible TLS server configuration
+ when serving TLS.
+ This will allow the whole list of available TLS versions provided by the
+ crypto library, which may have been further restricted by the system's
+ crypto policy.
+
+ By default Unbound only uses the latest available TLS version.
+
+ .. caution:: Use only if you want to support legacy TLS client connections.
+
+ .. note:: Changing the value requires a reload.
+
+ Default: no
+
+
@@UAHL@unbound.conf@pad-responses@@: *<yes or no>*
If enabled, TLS serviced queries that contained an EDNS Padding option will
cause responses padded to the closest multiple of the size specified in
@@ -1132,14 +1156,6 @@ These options are part of the **server:** clause.
Default: 128
-@@UAHL@unbound.conf@tls-use-sni@@: *<yes or no>*
- Enable or disable sending the SNI extension on TLS connections.
-
- .. note:: Changing the value requires a reload.
-
- Default: yes
-
-
@@UAHL@unbound.conf@https-port@@: *<number>*
The port number on which to provide DNS-over-HTTPS service.
Only interfaces configured with that port number as @number get the HTTPS
diff --git a/util/config_file.c b/util/config_file.c
index b1e767b3b..f611a96e4 100644
--- a/util/config_file.c
+++ b/util/config_file.c
@@ -129,6 +129,7 @@ config_create(void)
cfg->tls_cert_bundle = NULL;
cfg->tls_win_cert = 0;
cfg->tls_use_sni = 1;
+ cfg->tls_use_system_policy_versions = 0;
cfg->https_port = UNBOUND_DNS_OVER_HTTPS_PORT;
if(!(cfg->http_endpoint = strdup("/dns-query"))) goto error_exit;
cfg->http_max_streams = 100;
@@ -628,6 +629,7 @@ int config_set_option(struct config_file* cfg, const char* opt,
else S_STR("tls-ciphers:", tls_ciphers)
else S_STR("tls-ciphersuites:", tls_ciphersuites)
else S_YNO("tls-use-sni:", tls_use_sni)
+ else S_YNO("tls-use-system-policy-versions:", tls_use_system_policy_versions)
else S_NUMBER_NONZERO("https-port:", https_port)
else S_STR("http-endpoint:", http_endpoint)
else S_NUMBER_NONZERO("http-max-streams:", http_max_streams)
@@ -1179,6 +1181,7 @@ config_get_option(struct config_file* cfg, const char* opt,
else O_STR(opt, "tls-ciphers", tls_ciphers)
else O_STR(opt, "tls-ciphersuites", tls_ciphersuites)
else O_YNO(opt, "tls-use-sni", tls_use_sni)
+ else O_YNO(opt, "tls-use-system-policy-versions", tls_use_system_policy_versions)
else O_DEC(opt, "https-port", https_port)
else O_STR(opt, "http-endpoint", http_endpoint)
else O_UNS(opt, "http-max-streams", http_max_streams)
diff --git a/util/config_file.h b/util/config_file.h
index 44ac036b8..dd32f0d9f 100644
--- a/util/config_file.h
+++ b/util/config_file.h
@@ -148,6 +148,8 @@ struct config_file {
char* tls_ciphersuites;
/** if SNI is to be used */
int tls_use_sni;
+ /** if all TLS versions can be used; based on system policy (if any) */
+ int tls_use_system_policy_versions;
/** port on which to provide DNS over HTTPS service */
int https_port;
diff --git a/util/configlexer.lex b/util/configlexer.lex
index bc258673d..8e38ef468 100644
--- a/util/configlexer.lex
+++ b/util/configlexer.lex
@@ -262,6 +262,7 @@ tls-session-ticket-keys{COLON} { YDVAR(1, VAR_TLS_SESSION_TICKET_KEYS) }
tls-ciphers{COLON} { YDVAR(1, VAR_TLS_CIPHERS) }
tls-ciphersuites{COLON} { YDVAR(1, VAR_TLS_CIPHERSUITES) }
tls-use-sni{COLON} { YDVAR(1, VAR_TLS_USE_SNI) }
+tls-use-system-policy-versions{COLON} { YDVAR(1, VAR_TLS_USE_SYSTEM_POLICY_VERSIONS) }
https-port{COLON} { YDVAR(1, VAR_HTTPS_PORT) }
http-endpoint{COLON} { YDVAR(1, VAR_HTTP_ENDPOINT) }
http-max-streams{COLON} { YDVAR(1, VAR_HTTP_MAX_STREAMS) }
diff --git a/util/configparser.y b/util/configparser.y
index 82e1d8782..ced904669 100644
--- a/util/configparser.y
+++ b/util/configparser.y
@@ -199,6 +199,7 @@ extern struct config_parser_state* cfg_parser;
%token VAR_DISCARD_TIMEOUT VAR_WAIT_LIMIT VAR_WAIT_LIMIT_COOKIE
%token VAR_WAIT_LIMIT_NETBLOCK VAR_WAIT_LIMIT_COOKIE_NETBLOCK
%token VAR_STREAM_WAIT_SIZE VAR_TLS_CIPHERS VAR_TLS_CIPHERSUITES VAR_TLS_USE_SNI
+%token VAR_TLS_USE_SYSTEM_POLICY_VERSIONS
%token VAR_IPSET VAR_IPSET_NAME_V4 VAR_IPSET_NAME_V6
%token VAR_TLS_SESSION_TICKET_KEYS VAR_RPZ VAR_TAGS VAR_RPZ_ACTION_OVERRIDE
%token VAR_RPZ_CNAME_OVERRIDE VAR_RPZ_LOG VAR_RPZ_LOG_NAME
@@ -346,6 +347,7 @@ content_server: server_num_threads | server_verbosity | server_port |
server_tls_ciphersuites | server_tls_session_ticket_keys |
server_answer_cookie | server_cookie_secret | server_ip_ratelimit_cookie |
server_tls_use_sni | server_edns_client_string |
+ server_tls_use_system_policy_versions |
server_edns_client_string_opcode | server_nsid |
server_zonemd_permissive_mode | server_max_reuse_tcp_queries |
server_tcp_reuse_timeout | server_tcp_auth_query_timeout |
@@ -1154,6 +1156,15 @@ server_tls_use_sni: VAR_TLS_USE_SNI STRING_ARG
free($2);
}
;
+server_tls_use_system_policy_versions: VAR_TLS_USE_SYSTEM_POLICY_VERSIONS STRING_ARG
+ {
+ OUTYY(("P(server_tls_use_system_policy_versions:%s)\n", $2));
+ if(strcmp($2, "yes") != 0 && strcmp($2, "no") != 0)
+ yyerror("expected yes or no.");
+ else cfg_parser->cfg->tls_use_system_policy_versions = (strcmp($2, "yes")==0);
+ free($2);
+ }
+ ;
server_https_port: VAR_HTTPS_PORT STRING_ARG
{
OUTYY(("P(server_https_port:%s)\n", $2));
diff --git a/util/net_help.c b/util/net_help.c
index 6ce0d9131..426ace934 100644
--- a/util/net_help.c
+++ b/util/net_help.c
@@ -1226,7 +1226,7 @@ setup_ticket_keys_cb(void* sslctx)
#endif /* HAVE_SSL */
int
-listen_sslctx_setup(void* ctxt)
+listen_sslctx_setup(void* ctxt, int use_system_versions)
{
#ifdef HAVE_SSL
SSL_CTX* ctx = (SSL_CTX*)ctxt;
@@ -1238,35 +1238,37 @@ listen_sslctx_setup(void* ctxt)
return 0;
}
#endif
- if((SSL_CTX_set_options(ctx, SSL_OP_NO_SSLv3) & SSL_OP_NO_SSLv3)
- != SSL_OP_NO_SSLv3){
- log_crypto_err("could not set SSL_OP_NO_SSLv3");
- return 0;
- }
+ if(!use_system_versions) {
+ if((SSL_CTX_set_options(ctx, SSL_OP_NO_SSLv3) & SSL_OP_NO_SSLv3)
+ != SSL_OP_NO_SSLv3){
+ log_crypto_err("could not set SSL_OP_NO_SSLv3");
+ return 0;
+ }
#if defined(SSL_OP_NO_TLSv1) && defined(SSL_OP_NO_TLSv1_1)
- /* if we have tls 1.1 disable 1.0 */
- if((SSL_CTX_set_options(ctx, SSL_OP_NO_TLSv1) & SSL_OP_NO_TLSv1)
- != SSL_OP_NO_TLSv1){
- log_crypto_err("could not set SSL_OP_NO_TLSv1");
- return 0;
- }
+ /* if we have tls 1.1 disable 1.0 */
+ if((SSL_CTX_set_options(ctx, SSL_OP_NO_TLSv1) & SSL_OP_NO_TLSv1)
+ != SSL_OP_NO_TLSv1){
+ log_crypto_err("could not set SSL_OP_NO_TLSv1");
+ return 0;
+ }
#endif
#if defined(SSL_OP_NO_TLSv1_1) && defined(SSL_OP_NO_TLSv1_2)
- /* if we have tls 1.2 disable 1.1 */
- if((SSL_CTX_set_options(ctx, SSL_OP_NO_TLSv1_1) & SSL_OP_NO_TLSv1_1)
- != SSL_OP_NO_TLSv1_1){
- log_crypto_err("could not set SSL_OP_NO_TLSv1_1");
- return 0;
- }
+ /* if we have tls 1.2 disable 1.1 */
+ if((SSL_CTX_set_options(ctx, SSL_OP_NO_TLSv1_1) & SSL_OP_NO_TLSv1_1)
+ != SSL_OP_NO_TLSv1_1){
+ log_crypto_err("could not set SSL_OP_NO_TLSv1_1");
+ return 0;
+ }
#endif
#if defined(SSL_OP_NO_TLSv1_2) && defined(SSL_OP_NO_TLSv1_3)
- /* if we have tls 1.3 disable 1.2 */
- if((SSL_CTX_set_options(ctx, SSL_OP_NO_TLSv1_2) & SSL_OP_NO_TLSv1_2)
- != SSL_OP_NO_TLSv1_2){
- log_crypto_err("could not set SSL_OP_NO_TLSv1_2");
- return 0;
- }
+ /* if we have tls 1.3 disable 1.2 */
+ if((SSL_CTX_set_options(ctx, SSL_OP_NO_TLSv1_2) & SSL_OP_NO_TLSv1_2)
+ != SSL_OP_NO_TLSv1_2){
+ log_crypto_err("could not set SSL_OP_NO_TLSv1_2");
+ return 0;
+ }
#endif
+ }
#if defined(SSL_OP_NO_RENEGOTIATION)
/* disable client renegotiation */
if((SSL_CTX_set_options(ctx, SSL_OP_NO_RENEGOTIATION) &
@@ -1341,7 +1343,7 @@ listen_sslctx_setup_2(void* ctxt)
void* listen_sslctx_create(const char* key, const char* pem,
const char* verifypem, const char* tls_ciphers,
const char* tls_ciphersuites, int set_ticket_keys_cb,
- int is_dot, int is_doh)
+ int is_dot, int is_doh, int use_system_versions)
{
#ifdef HAVE_SSL
SSL_CTX* ctx = SSL_CTX_new(SSLv23_server_method());
@@ -1359,7 +1361,7 @@ void* listen_sslctx_create(const char* key, const char* pem,
SSL_CTX_free(ctx);
return NULL;
}
- if(!listen_sslctx_setup(ctx)) {
+ if(!listen_sslctx_setup(ctx, use_system_versions)) {
SSL_CTX_free(ctx);
return NULL;
}
diff --git a/util/net_help.h b/util/net_help.h
index 278e370a2..7b8a20642 100644
--- a/util/net_help.h
+++ b/util/net_help.h
@@ -478,9 +478,11 @@ void log_cert(unsigned level, const char* str, void* cert);
/**
* Set SSL_OP_NOxxx options on SSL context to disable bad crypto
* @param ctxt: SSL_CTX*
+ * @param use_system_versions: rely on the system policy (if any) for allowed
+ * TLS versions
* @return false on failure.
*/
-int listen_sslctx_setup(void* ctxt);
+int listen_sslctx_setup(void* ctxt, int use_system_versions);
/**
* Further setup of listening SSL context, after keys loaded.
@@ -499,12 +501,14 @@ void listen_sslctx_setup_2(void* ctxt);
* to be set.
* @param is_dot: if the TLS connection is for DoT to set the appropriate ALPN.
* @param is_doh: if the TLS connection is for DoH to set the appropriate ALPN.
+ * @param use_system_versions: rely on the system policy (if any) for allowed
+ * TLS versions
* return SSL_CTX* or NULL on failure (logged).
*/
void* listen_sslctx_create(const char* key, const char* pem,
const char* verifypem, const char* tls_ciphers,
const char* tls_ciphersuites, int set_ticket_keys_cb,
- int is_dot, int is_doh);
+ int is_dot, int is_doh, int use_system_versions);
/**
* create SSL connect context
diff --git a/winrc/win_svc.c b/winrc/win_svc.c
index 429b045dc..6fca0c7d5 100644
--- a/winrc/win_svc.c
+++ b/winrc/win_svc.c
@@ -369,7 +369,7 @@ service_init(int r, struct daemon** d, struct config_file** c)
cfg->tls_ciphers, cfg->tls_ciphersuites,
(cfg->tls_session_ticket_keys.first &&
cfg->tls_session_ticket_keys.first->str[0] != 0),
- 1, 0))) {
+ 1, 0, cfg->tls_use_system_policy_versions))) {
fatal_exit("could not set up listen SSL_CTX");
}
#ifdef HAVE_NGHTTP2_NGHTTP2_H
@@ -379,7 +379,7 @@ service_init(int r, struct daemon** d, struct config_file** c)
cfg->tls_ciphers, cfg->tls_ciphersuites,
(cfg->tls_session_ticket_keys.first &&
cfg->tls_session_ticket_keys.first->str[0] != 0),
- 0, 1))) {
+ 0, 1, cfg->tls_use_system_policy_versions))) {
fatal_exit("could not set up listen doh SSL_CTX");
}
}
