SSL: disabled TLSv1 and TLSv1.1 by default.

TLSv1 and TLSv1.1 are formally deprecated and forbidden to negotiate due
to insufficient security reasons outlined in RFC 8996.

TLSv1 and TLSv1.1 are disabled in BoringSSL e95b0cad9 and LibreSSL 3.8.1
in the way they cannot be enabled in nginx configuration.  In OpenSSL 3.0,
they are only permitted at security level 0 (disabled by default).

The support is dropped in Chrome 84, Firefox 78, and deprecated in Safari.

This change disables TLSv1 and TLSv1.1 by default for OpenSSL 1.0.1 and
newer, where TLSv1.2 support is available.  For older library versions,
which do not have alternatives, these protocol versions remain enabled.

7 files changed, 14 insertions, 0 deletions

diff --git a/src/http/modules/ngx_http_grpc_module.c b/src/http/modules/ngx_http_grpc_module.c
index e7726f314..d9456843d 100644
--- a/src/http/modules/ngx_http_grpc_module.c
+++ b/src/http/modules/ngx_http_grpc_module.c
@@ -4477,7 +4477,9 @@ ngx_http_grpc_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child)
 
     ngx_conf_merge_bitmask_value(conf->ssl_protocols, prev->ssl_protocols,
                                  (NGX_CONF_BITMASK_SET
+#ifndef SSL_OP_NO_TLSv1_2
                                   |NGX_SSL_TLSv1|NGX_SSL_TLSv1_1
+#endif
                                   |NGX_SSL_TLSv1_2|NGX_SSL_TLSv1_3));
 
     ngx_conf_merge_str_value(conf->ssl_ciphers, prev->ssl_ciphers,
diff --git a/src/http/modules/ngx_http_proxy_module.c b/src/http/modules/ngx_http_proxy_module.c
index f9a373744..fe1952748 100644
--- a/src/http/modules/ngx_http_proxy_module.c
+++ b/src/http/modules/ngx_http_proxy_module.c
@@ -3944,7 +3944,9 @@ ngx_http_proxy_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child)
 
     ngx_conf_merge_bitmask_value(conf->ssl_protocols, prev->ssl_protocols,
                                  (NGX_CONF_BITMASK_SET
+#ifndef SSL_OP_NO_TLSv1_2
                                   |NGX_SSL_TLSv1|NGX_SSL_TLSv1_1
+#endif
                                   |NGX_SSL_TLSv1_2|NGX_SSL_TLSv1_3));
 
     ngx_conf_merge_str_value(conf->ssl_ciphers, prev->ssl_ciphers,
diff --git a/src/http/modules/ngx_http_ssl_module.c b/src/http/modules/ngx_http_ssl_module.c
index abc8d49ab..1fb1e6129 100644
--- a/src/http/modules/ngx_http_ssl_module.c
+++ b/src/http/modules/ngx_http_ssl_module.c
@@ -653,7 +653,9 @@ ngx_http_ssl_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
 
     ngx_conf_merge_bitmask_value(conf->protocols, prev->protocols,
                          (NGX_CONF_BITMASK_SET
+#ifndef SSL_OP_NO_TLSv1_2
                           |NGX_SSL_TLSv1|NGX_SSL_TLSv1_1
+#endif
                           |NGX_SSL_TLSv1_2|NGX_SSL_TLSv1_3));
 
     ngx_conf_merge_size_value(conf->buffer_size, prev->buffer_size,
diff --git a/src/http/modules/ngx_http_uwsgi_module.c b/src/http/modules/ngx_http_uwsgi_module.c
index c965d4bbd..f2a8dbe6a 100644
--- a/src/http/modules/ngx_http_uwsgi_module.c
+++ b/src/http/modules/ngx_http_uwsgi_module.c
@@ -1879,7 +1879,9 @@ ngx_http_uwsgi_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child)
 
     ngx_conf_merge_bitmask_value(conf->ssl_protocols, prev->ssl_protocols,
                                  (NGX_CONF_BITMASK_SET
+#ifndef SSL_OP_NO_TLSv1_2
                                   |NGX_SSL_TLSv1|NGX_SSL_TLSv1_1
+#endif
                                   |NGX_SSL_TLSv1_2|NGX_SSL_TLSv1_3));
 
     ngx_conf_merge_str_value(conf->ssl_ciphers, prev->ssl_ciphers,
diff --git a/src/mail/ngx_mail_ssl_module.c b/src/mail/ngx_mail_ssl_module.c
index b547dc101..2fee1adb8 100644
--- a/src/mail/ngx_mail_ssl_module.c
+++ b/src/mail/ngx_mail_ssl_module.c
@@ -345,7 +345,9 @@ ngx_mail_ssl_merge_conf(ngx_conf_t *cf, void *parent, void *child)
 
     ngx_conf_merge_bitmask_value(conf->protocols, prev->protocols,
                          (NGX_CONF_BITMASK_SET
+#ifndef SSL_OP_NO_TLSv1_2
                           |NGX_SSL_TLSv1|NGX_SSL_TLSv1_1
+#endif
                           |NGX_SSL_TLSv1_2|NGX_SSL_TLSv1_3));
 
     ngx_conf_merge_uint_value(conf->verify, prev->verify, 0);
diff --git a/src/stream/ngx_stream_proxy_module.c b/src/stream/ngx_stream_proxy_module.c
index ed275c009..bbf4f7ec0 100644
--- a/src/stream/ngx_stream_proxy_module.c
+++ b/src/stream/ngx_stream_proxy_module.c
@@ -2164,7 +2164,9 @@ ngx_stream_proxy_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
 
     ngx_conf_merge_bitmask_value(conf->ssl_protocols, prev->ssl_protocols,
                               (NGX_CONF_BITMASK_SET
+#ifndef SSL_OP_NO_TLSv1_2
                                |NGX_SSL_TLSv1|NGX_SSL_TLSv1_1
+#endif
                                |NGX_SSL_TLSv1_2|NGX_SSL_TLSv1_3));
 
     ngx_conf_merge_str_value(conf->ssl_ciphers, prev->ssl_ciphers, "DEFAULT");
diff --git a/src/stream/ngx_stream_ssl_module.c b/src/stream/ngx_stream_ssl_module.c
index 0233a9258..55bc54a44 100644
--- a/src/stream/ngx_stream_ssl_module.c
+++ b/src/stream/ngx_stream_ssl_module.c
@@ -884,7 +884,9 @@ ngx_stream_ssl_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
 
     ngx_conf_merge_bitmask_value(conf->protocols, prev->protocols,
                          (NGX_CONF_BITMASK_SET
+#ifndef SSL_OP_NO_TLSv1_2
                           |NGX_SSL_TLSv1|NGX_SSL_TLSv1_1
+#endif
                           |NGX_SSL_TLSv1_2|NGX_SSL_TLSv1_3));
 
     ngx_conf_merge_uint_value(conf->verify, prev->verify, 0);