diff --git a/auto/lib/openssl/conf b/auto/lib/openssl/conf
index 4fb52df..fb8e04c 100644
--- a/auto/lib/openssl/conf
+++ b/auto/lib/openssl/conf
@@ -62,8 +62,35 @@ else
         ngx_feature_path=
         ngx_feature_libs="-lssl -lcrypto $NGX_LIBDL $NGX_LIBPTHREAD"
         ngx_feature_test="SSL_CTX_set_options(NULL, 0)"
+
+        if [ $WOLFSSL != NONE ]; then
+            ngx_feature="wolfSSL library in $WOLFSSL"
+            ngx_feature_path="$WOLFSSL/include/wolfssl $WOLFSSL/include"
+            ngx_feature_incs="#include <wolfssl/options.h
+                              #include <openssl/ssl.h>"
+
+            if [ $NGX_RPATH = YES ]; then
+                ngx_feature_libs="-R$WOLFSSL/lib -L$WOLFSSL/lib -lwolfssl $NGX_LIBDL"
+            else
+                ngx_feature_libs="-L$WOLFSSL/lib -lwolfssl $NGX_LIBDL"
+            fi
+
+            CORE_INCS="$CORE_INCS $WOLFSSL/include/wolfssl"
+            CFLAGS="$CFLAGS -DWOLFSSL_NGINX"
+        fi
+
         . auto/feature
 
+        if [ $WOLFSSL != NONE -a $ngx_found = no ]; then
+cat << END
+
+$0: error: Could not find wolfSSL at $WOLFSSL/include/wolfssl.
+SSL modules require the wolfSSL library.
+
+END
+            exit 1
+        fi
+
         if [ $ngx_found = no ]; then
 
             # FreeBSD port
diff --git a/auto/options b/auto/options
index d8b421b..ef1401d 100644
--- a/auto/options
+++ b/auto/options
@@ -147,6 +147,7 @@ PCRE_JIT=NO
 
 USE_OPENSSL=NO
 OPENSSL=NONE
+WOLFSSL=NONE
 
 USE_ZLIB=NO
 ZLIB=NONE
@@ -355,6 +356,7 @@ use the \"--with-mail_ssl_module\" option instead"
         --with-pcre-opt=*)               PCRE_OPT="$value"          ;;
         --with-pcre-jit)                 PCRE_JIT=YES               ;;
 
+        --with-wolfssl=*)                WOLFSSL="$value"           ;;
         --with-openssl=*)                OPENSSL="$value"           ;;
         --with-openssl-opt=*)            OPENSSL_OPT="$value"       ;;
 
@@ -579,6 +581,7 @@ cat << END
   --with-libatomic                   force libatomic_ops library usage
   --with-libatomic=DIR               set path to libatomic_ops library sources
 
+  --with-wolfssl=DIR                 set path to wolfSSL headers and library
   --with-openssl=DIR                 set path to OpenSSL library sources
   --with-openssl-opt=OPTIONS         set additional build options for OpenSSL
 
diff --git a/src/event/ngx_event_openssl.c b/src/event/ngx_event_openssl.c
index a281fba..c36196d 100644
--- a/src/event/ngx_event_openssl.c
+++ b/src/event/ngx_event_openssl.c
@@ -375,6 +375,10 @@ ngx_ssl_create(ngx_ssl_t *ssl, ngx_uint_t protocols, void *data)
 
     SSL_CTX_set_info_callback(ssl->ctx, ngx_ssl_info_callback);
 
+#ifdef WOLFSSL_NGINX
+    SSL_CTX_set_verify(ssl->ctx, SSL_VERIFY_NONE, NULL);
+#endif
+
     return NGX_OK;
 }
 
@@ -683,6 +687,14 @@ ngx_ssl_ciphers(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *ciphers,
 
 
 ngx_int_t
+ngx_ssl_set_verify_on(ngx_conf_t *cf, ngx_ssl_t *ssl)
+{
+    SSL_CTX_set_verify(ssl->ctx, SSL_VERIFY_PEER, ngx_ssl_verify_callback);
+
+    return NGX_OK;
+}
+
+ngx_int_t
 ngx_ssl_client_certificate(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *cert,
     ngx_int_t depth)
 {
@@ -1124,7 +1136,8 @@ ngx_ssl_ecdh_curve(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *name)
      * maximum interoperability.
      */
 
-#if (defined SSL_CTX_set1_curves_list || defined SSL_CTRL_SET_CURVES_LIST)
+#if (defined SSL_CTX_set1_curves_list || defined SSL_CTRL_SET_CURVES_LIST) || \
+    defined(WOLFSSL_NGINX)
 
     /*
      * OpenSSL 1.0.2+ allows configuring a curve list instead of a single
@@ -3613,7 +3626,8 @@ ngx_ssl_session_ticket_key_callback(ngx_ssl_conn_t *ssl_conn,
             return -1;
         }
 
-#if OPENSSL_VERSION_NUMBER >= 0x10000000L
+#if OPENSSL_VERSION_NUMBER >= 0x10000000L && \
+    (!defined(WOLFSSL_NGINX) || !defined(HAVE_FIPS))
         if (HMAC_Init_ex(hctx, key[0].hmac_key, size, digest, NULL) != 1) {
             ngx_ssl_error(NGX_LOG_ALERT, c->log, 0, "HMAC_Init_ex() failed");
             return -1;
@@ -3657,7 +3671,8 @@ ngx_ssl_session_ticket_key_callback(ngx_ssl_conn_t *ssl_conn,
             size = 32;
         }
 
-#if OPENSSL_VERSION_NUMBER >= 0x10000000L
+#if OPENSSL_VERSION_NUMBER >= 0x10000000L && \
+    (!defined(WOLFSSL_NGINX) || !defined(HAVE_FIPS))
         if (HMAC_Init_ex(hctx, key[i].hmac_key, size, digest, NULL) != 1) {
             ngx_ssl_error(NGX_LOG_ALERT, c->log, 0, "HMAC_Init_ex() failed");
             return -1;
diff --git a/src/event/ngx_event_openssl.h b/src/event/ngx_event_openssl.h
index abd84cc..18267f8 100644
--- a/src/event/ngx_event_openssl.h
+++ b/src/event/ngx_event_openssl.h
@@ -12,6 +12,10 @@
 #include <ngx_config.h>
 #include <ngx_core.h>
 
+#ifdef WOLFSSL_NGINX
+#include <wolfssl/options.h>
+#include <openssl/pem.h>
+#endif
 #include <openssl/ssl.h>
 #include <openssl/err.h>
 #include <openssl/bn.h>
@@ -59,7 +63,7 @@
 #define ngx_ssl_conn_t          SSL
 
 
-#if (OPENSSL_VERSION_NUMBER < 0x10002000L)
+#if (OPENSSL_VERSION_NUMBER < 0x10002000L) && !defined(WOLFSSL_NGINX)
 #define SSL_is_server(s)        (s)->server
 #endif
 
@@ -166,6 +170,7 @@ ngx_int_t ngx_ssl_certificate(ngx_conf_t *cf, ngx_ssl_t *ssl,
     ngx_str_t *cert, ngx_str_t *key, ngx_array_t *passwords);
 ngx_int_t ngx_ssl_ciphers(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *ciphers,
     ngx_uint_t prefer_server_ciphers);
+ngx_int_t ngx_ssl_set_verify_on(ngx_conf_t *cf, ngx_ssl_t *ssl);
 ngx_int_t ngx_ssl_client_certificate(ngx_conf_t *cf, ngx_ssl_t *ssl,
     ngx_str_t *cert, ngx_int_t depth);
 ngx_int_t ngx_ssl_trusted_certificate(ngx_conf_t *cf, ngx_ssl_t *ssl,
diff --git a/src/event/ngx_event_openssl_stapling.c b/src/event/ngx_event_openssl_stapling.c
index 0bea5e7..aee5786 100644
--- a/src/event/ngx_event_openssl_stapling.c
+++ b/src/event/ngx_event_openssl_stapling.c
@@ -313,7 +313,9 @@ ngx_ssl_stapling_issuer(ngx_conf_t *cf, ngx_ssl_t *ssl,
     for (i = 0; i < n; i++) {
         issuer = sk_X509_value(chain, i);
         if (X509_check_issued(issuer, cert) == X509_V_OK) {
-#if OPENSSL_VERSION_NUMBER >= 0x10100001L
+#ifdef WOLFSSL_NGINX
+            issuer = X509_dup(issuer);
+#elif OPENSSL_VERSION_NUMBER >= 0x10100001L
             X509_up_ref(issuer);
 #else
             CRYPTO_add(&issuer->references, 1, CRYPTO_LOCK_X509);
diff --git a/src/http/modules/ngx_http_proxy_module.c b/src/http/modules/ngx_http_proxy_module.c
index d6a8922..94c1a34 100644
--- a/src/http/modules/ngx_http_proxy_module.c
+++ b/src/http/modules/ngx_http_proxy_module.c
@@ -4306,6 +4306,8 @@ ngx_http_proxy_set_ssl(ngx_conf_t *cf, ngx_http_proxy_loc_conf_t *plcf)
             return NGX_ERROR;
         }
 
+        ngx_ssl_set_verify_on(cf, plcf->upstream.ssl);
+
         if (ngx_ssl_trusted_certificate(cf, plcf->upstream.ssl,
                                         &plcf->ssl_trusted_certificate,
                                         plcf->ssl_verify_depth)
diff --git a/src/http/modules/ngx_http_ssl_module.c b/src/http/modules/ngx_http_ssl_module.c
index 9e243ea..3bef37b 100644
--- a/src/http/modules/ngx_http_ssl_module.c
+++ b/src/http/modules/ngx_http_ssl_module.c
@@ -14,7 +14,11 @@ typedef ngx_int_t (*ngx_ssl_variable_handler_pt)(ngx_connection_t *c,
     ngx_pool_t *pool, ngx_str_t *s);
 
 
+#ifndef WOLFSSL_NGINX
 #define NGX_DEFAULT_CIPHERS     "HIGH:!aNULL:!MD5"
+#else
+#define NGX_DEFAULT_CIPHERS     "ALL"
+#endif
 #define NGX_DEFAULT_ECDH_CURVE  "auto"
 
 #define NGX_HTTP_NPN_ADVERTISE  "\x08http/1.1"
@@ -780,8 +784,10 @@ ngx_http_ssl_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
         return NGX_CONF_ERROR;
     }
 
+#ifndef WOLFSSL_NGINX
     ngx_conf_merge_value(conf->builtin_session_cache,
                          prev->builtin_session_cache, NGX_SSL_NONE_SCACHE);
+#endif
 
     if (conf->shm_zone == NULL) {
         conf->shm_zone = prev->shm_zone;
diff --git a/src/http/ngx_http_request.c b/src/http/ngx_http_request.c
index 7dd28b8..0bff124 100644
--- a/src/http/ngx_http_request.c
+++ b/src/http/ngx_http_request.c
@@ -834,6 +834,12 @@ ngx_http_ssl_handshake_handler(ngx_connection_t *c)
 }
 
 #ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
+#ifndef SSL_AD_NO_RENEGOTIATION
+#define SSL_AD_NO_RENEGOTIATION     100
+#endif
+#ifndef SSL_AD_INTERNAL_ERROR
+#define SSL_AD_INTERNAL_ERROR       80
+#endif
 
 int
 ngx_http_ssl_servername(ngx_ssl_conn_t *ssl_conn, int *ad, void *arg)
diff --git a/src/mail/ngx_mail_ssl_module.c b/src/mail/ngx_mail_ssl_module.c
index 4509597..7b7ae03 100644
--- a/src/mail/ngx_mail_ssl_module.c
+++ b/src/mail/ngx_mail_ssl_module.c
@@ -10,7 +10,11 @@
 #include <ngx_mail.h>
 
 
+#ifndef WOLFSSL_NGINX
 #define NGX_DEFAULT_CIPHERS     "HIGH:!aNULL:!MD5"
+#else
+#define NGX_DEFAULT_CIPHERS     "ALL"
+#endif
 #define NGX_DEFAULT_ECDH_CURVE  "auto"
 
 
diff --git a/src/stream/ngx_stream_proxy_module.c b/src/stream/ngx_stream_proxy_module.c
index 0949313..b752d2d 100644
--- a/src/stream/ngx_stream_proxy_module.c
+++ b/src/stream/ngx_stream_proxy_module.c
@@ -2130,6 +2130,8 @@ ngx_stream_proxy_set_ssl(ngx_conf_t *cf, ngx_stream_proxy_srv_conf_t *pscf)
             return NGX_ERROR;
         }
 
+        ngx_ssl_set_verify_on(cf, pscf->ssl);
+
         if (ngx_ssl_trusted_certificate(cf, pscf->ssl,
                                         &pscf->ssl_trusted_certificate,
                                         pscf->ssl_verify_depth)
diff --git a/src/stream/ngx_stream_ssl_module.c b/src/stream/ngx_stream_ssl_module.c
index dcc33e1..e38eba3 100644
--- a/src/stream/ngx_stream_ssl_module.c
+++ b/src/stream/ngx_stream_ssl_module.c
@@ -14,7 +14,11 @@ typedef ngx_int_t (*ngx_ssl_variable_handler_pt)(ngx_connection_t *c,
     ngx_pool_t *pool, ngx_str_t *s);
 
 
+#ifndef WOLFSSL_NGINX
 #define NGX_DEFAULT_CIPHERS     "HIGH:!aNULL:!MD5"
+#else
+#define NGX_DEFAULT_CIPHERS     "ALL"
+#endif
 #define NGX_DEFAULT_ECDH_CURVE  "auto"