tls: add openssl engine

Change-Id: I6c215858d2c9c620787632b570950b15274c0df2
Signed-off-by: Florin Coras <fcoras@cisco.com>
diff --git a/src/configure.ac b/src/configure.ac
index 74d5113..26c2eb5 100644
--- a/src/configure.ac
+++ b/src/configure.ac
@@ -231,6 +231,7 @@
 PLUGIN_ENABLED(srv6as)
 PLUGIN_ENABLED(stn)
 PLUGIN_ENABLED(tlsmbedtls)
+PLUGIN_ENABLED(tlsopenssl)
 
 ###############################################################################
 # Dependency checks
@@ -306,6 +307,12 @@
     ], [])
 ])
 
+AM_COND_IF([WITH_LIBSSL], [],
+[
+  AC_MSG_WARN([openssl not enabled. Disabling tlsopenssl plugin])
+  enable_tlsopenssl_plugin=no
+  AM_CONDITIONAL(ENABLE_TLSOPENSSL_PLUGIN, false)
+])
 
 ###############################################################################
 # JAVA
diff --git a/src/plugins/Makefile.am b/src/plugins/Makefile.am
index 8b46986..0381502 100644
--- a/src/plugins/Makefile.am
+++ b/src/plugins/Makefile.am
@@ -115,6 +115,10 @@
 include tlsmbedtls.am
 endif
 
+if ENABLE_TLSOPENSSL_PLUGIN
+include tlsopenssl.am
+endif
+
 include ../suffix-rules.mk
 
 # Remove *.la files
diff --git a/src/plugins/tlsmbedtls/tls_mbedtls.c b/src/plugins/tlsmbedtls/tls_mbedtls.c
index 1bae1f7..aaad99f 100644
--- a/src/plugins/tlsmbedtls/tls_mbedtls.c
+++ b/src/plugins/tlsmbedtls/tls_mbedtls.c
@@ -28,6 +28,7 @@
 typedef struct tls_ctx_mbedtls_
 {
   tls_ctx_t ctx;			/**< First */
+  u32 mbedtls_ctx_index;
   mbedtls_ssl_context ssl;
   mbedtls_ssl_config conf;
   mbedtls_x509_crt srvcert;
@@ -40,6 +41,8 @@
   mbedtls_ctr_drbg_context *ctr_drbgs;
   mbedtls_entropy_context *entropy_pools;
   mbedtls_x509_crt cacert;
+  u8 **rx_bufs;
+  u8 **tx_bufs;
 } mbedtls_main_t;
 
 static mbedtls_main_t mbedtls_main;
@@ -64,7 +67,7 @@
 }
 #endif
 
-u32
+static u32
 mbedtls_ctx_alloc (void)
 {
   u8 thread_index = vlib_get_thread_index ();
@@ -77,10 +80,12 @@
 
   memset (*ctx, 0, sizeof (mbedtls_ctx_t));
   (*ctx)->ctx.c_thread_index = thread_index;
-  return ctx - tm->ctx_pool[thread_index];
+  (*ctx)->ctx.tls_ctx_engine = TLS_ENGINE_MBEDTLS;
+  (*ctx)->mbedtls_ctx_index = ctx - tm->ctx_pool[thread_index];
+  return ((*ctx)->mbedtls_ctx_index);
 }
 
-void
+static void
 mbedtls_ctx_free (tls_ctx_t * ctx)
 {
   mbedtls_ctx_t *mc = (mbedtls_ctx_t *) ctx;
@@ -95,11 +100,11 @@
   mbedtls_ssl_free (&mc->ssl);
   mbedtls_ssl_config_free (&mc->conf);
 
-  pool_put_index (mbedtls_main.ctx_pool[vlib_get_thread_index ()],
-		  ctx->tls_ctx_idx);
+  pool_put_index (mbedtls_main.ctx_pool[ctx->c_thread_index],
+		  mc->mbedtls_ctx_index);
 }
 
-tls_ctx_t *
+static tls_ctx_t *
 mbedtls_ctx_get (u32 ctx_index)
 {
   mbedtls_ctx_t **ctx;
@@ -108,7 +113,7 @@
   return &(*ctx)->ctx;
 }
 
-tls_ctx_t *
+static tls_ctx_t *
 mbedtls_ctx_get_w_thread (u32 ctx_index, u8 thread_index)
 {
   mbedtls_ctx_t **ctx;
@@ -233,7 +238,7 @@
       return -1;
     }
 
-  ctx_ptr = uword_to_pointer (ctx->tls_ctx_idx, void *);
+  ctx_ptr = uword_to_pointer (mc->mbedtls_ctx_index, void *);
   mbedtls_ssl_set_bio (&mc->ssl, ctx_ptr, tls_net_send, tls_net_recv, NULL);
   mbedtls_debug_set_threshold (TLS_DEBUG_LEVEL_CLIENT);
 
@@ -241,7 +246,7 @@
    * 2. Do the first 2 steps in the handshake.
    */
   TLS_DBG (1, "Initiating handshake for [%u]%u", ctx->c_thread_index,
-	   ctx->tls_ctx_idx);
+	   mc->mbedtls_ctx_index);
   while (mc->ssl.state != MBEDTLS_SSL_HANDSHAKE_OVER)
     {
       rv = mbedtls_ssl_handshake_step (&mc->ssl);
@@ -249,7 +254,7 @@
 	break;
     }
   TLS_DBG (2, "tls state for [%u]%u is %u", ctx->c_thread_index,
-	   ctx->tls_ctx_idx, mc->ssl.state);
+	   mc->mbedtls_ctx_index, mc->ssl.state);
   return 0;
 }
 
@@ -332,7 +337,7 @@
     }
 
   mbedtls_ssl_session_reset (&mc->ssl);
-  ctx_ptr = uword_to_pointer (ctx->tls_ctx_idx, void *);
+  ctx_ptr = uword_to_pointer (mc->mbedtls_ctx_index, void *);
   mbedtls_ssl_set_bio (&mc->ssl, ctx_ptr, tls_net_send, tls_net_recv, NULL);
   mbedtls_debug_set_threshold (TLS_DEBUG_LEVEL_SERVER);
 
@@ -340,7 +345,7 @@
    * 3. Start handshake state machine
    */
   TLS_DBG (1, "Initiating handshake for [%u]%u", ctx->c_thread_index,
-	   ctx->tls_ctx_idx);
+	   mc->mbedtls_ctx_index);
   while (mc->ssl.state != MBEDTLS_SSL_HANDSHAKE_OVER)
     {
       rv = mbedtls_ssl_handshake_step (&mc->ssl);
@@ -349,7 +354,7 @@
     }
 
   TLS_DBG (2, "tls state for [%u]%u is %u", ctx->c_thread_index,
-	   ctx->tls_ctx_idx, mc->ssl.state);
+	   mc->mbedtls_ctx_index, mc->ssl.state);
   return 0;
 
 exit:
@@ -357,7 +362,7 @@
 }
 
 static int
-mbedtls_handshake_rx (tls_ctx_t * ctx)
+mbedtls_ctx_handshake_rx (tls_ctx_t * ctx)
 {
   mbedtls_ctx_t *mc = (mbedtls_ctx_t *) ctx;
   u32 flags;
@@ -368,10 +373,10 @@
       if (rv != 0)
 	break;
     }
-  TLS_DBG (2, "tls state for %u is %u", ctx->tls_ctx_idx, mc->ssl.state);
+  TLS_DBG (2, "tls state for %u is %u", mc->mbedtls_ctx_index, mc->ssl.state);
 
   if (mc->ssl.state != MBEDTLS_SSL_HANDSHAKE_OVER)
-    return HANDSHAKE_NOT_OVER;
+    return 0;
 
   /*
    * Handshake complete
@@ -392,32 +397,120 @@
 	   * Presence of hostname enforces strict certificate verification
 	   */
 	  if (ctx->srv_hostname)
-	    return CLIENT_HANDSHAKE_FAIL;
+	    {
+	      tls_notify_app_connected (ctx, /* is failed */ 0);
+	      return -1;
+	    }
 	}
-      rv = CLIENT_HANDSHAKE_OK;
+      tls_notify_app_connected (ctx, /* is failed */ 0);
     }
   else
     {
-      rv = SERVER_HANDSHAKE_OK;
+      tls_notify_app_accept (ctx);
     }
 
   TLS_DBG (1, "Handshake for %u complete. TLS cipher is %x",
-	   ctx->tls_ctx_idx, mc->ssl.session->ciphersuite);
-  return rv;
+	   mc->mbedtls_ctx_index, mc->ssl.session->ciphersuite);
+  return 0;
 }
 
 static int
-mbedtls_write (tls_ctx_t * ctx, u8 * buf, u32 len)
+mbedtls_ctx_write (tls_ctx_t * ctx, stream_session_t * app_session)
 {
   mbedtls_ctx_t *mc = (mbedtls_ctx_t *) ctx;
-  return mbedtls_ssl_write (&mc->ssl, buf, len);
+  u8 thread_index = ctx->c_thread_index;
+  mbedtls_main_t *mm = &mbedtls_main;
+  u32 enq_max, deq_max, deq_now;
+  stream_session_t *tls_session;
+  int wrote;
+
+  ASSERT (mc->ssl.state == MBEDTLS_SSL_HANDSHAKE_OVER);
+
+  deq_max = svm_fifo_max_dequeue (app_session->server_tx_fifo);
+  if (!deq_max)
+    return 0;
+
+  tls_session = session_get_from_handle (ctx->tls_session_handle);
+  enq_max = svm_fifo_max_enqueue (tls_session->server_tx_fifo);
+  deq_now = clib_min (deq_max, TLS_CHUNK_SIZE);
+
+  if (PREDICT_FALSE (enq_max == 0))
+    {
+      tls_add_vpp_q_evt (app_session->server_tx_fifo, FIFO_EVENT_APP_TX);
+      return 0;
+    }
+
+  vec_validate (mm->tx_bufs[thread_index], deq_now);
+  svm_fifo_peek (app_session->server_tx_fifo, 0, deq_now,
+		 mm->tx_bufs[thread_index]);
+
+  wrote = mbedtls_ssl_write (&mc->ssl, mm->tx_bufs[thread_index], deq_now);
+  if (wrote <= 0)
+    {
+      tls_add_vpp_q_evt (app_session->server_tx_fifo, FIFO_EVENT_APP_TX);
+      return 0;
+    }
+
+  svm_fifo_dequeue_drop (app_session->server_tx_fifo, wrote);
+  vec_reset_length (mm->tx_bufs[thread_index]);
+  tls_add_vpp_q_evt (tls_session->server_tx_fifo, FIFO_EVENT_APP_TX);
+
+  if (deq_now < deq_max)
+    tls_add_vpp_q_evt (app_session->server_tx_fifo, FIFO_EVENT_APP_TX);
+
+  return 0;
 }
 
 static int
-mbedtls_read (tls_ctx_t * ctx, u8 * buf, u32 len)
+mbedtls_ctx_read (tls_ctx_t * ctx, stream_session_t * tls_session)
 {
   mbedtls_ctx_t *mc = (mbedtls_ctx_t *) ctx;
-  return mbedtls_ssl_read (&mc->ssl, buf, len);
+  mbedtls_main_t *mm = &mbedtls_main;
+  u8 thread_index = ctx->c_thread_index;
+  u32 deq_max, enq_max, enq_now;
+  stream_session_t *app_session;
+  int read, enq;
+
+  if (PREDICT_FALSE (mc->ssl.state != MBEDTLS_SSL_HANDSHAKE_OVER))
+    {
+      mbedtls_ctx_handshake_rx (ctx);
+      return 0;
+    }
+
+  deq_max = svm_fifo_max_dequeue (tls_session->server_rx_fifo);
+  if (!deq_max)
+    return 0;
+
+  app_session = session_get_from_handle (ctx->app_session_handle);
+  enq_max = svm_fifo_max_enqueue (app_session->server_rx_fifo);
+  enq_now = clib_min (enq_max, TLS_CHUNK_SIZE);
+
+  if (PREDICT_FALSE (enq_now == 0))
+    {
+      tls_add_vpp_q_evt (tls_session->server_rx_fifo, FIFO_EVENT_BUILTIN_RX);
+      return 0;
+    }
+
+  vec_validate (mm->rx_bufs[thread_index], enq_now);
+  read = mbedtls_ssl_read (&mc->ssl, mm->rx_bufs[thread_index], enq_now);
+  if (read <= 0)
+    {
+      tls_add_vpp_q_evt (tls_session->server_rx_fifo, FIFO_EVENT_BUILTIN_RX);
+      return 0;
+    }
+
+  enq = svm_fifo_enqueue_nowait (app_session->server_rx_fifo, read,
+				 mm->rx_bufs[thread_index]);
+  ASSERT (enq == read);
+  vec_reset_length (mm->rx_bufs[thread_index]);
+
+  if (svm_fifo_max_dequeue (tls_session->server_rx_fifo))
+    tls_add_vpp_q_evt (tls_session->server_rx_fifo, FIFO_EVENT_BUILTIN_RX);
+
+  if (enq > 0)
+    tls_notify_app_enqueue (ctx, app_session);
+
+  return enq;
 }
 
 static u8
@@ -434,9 +527,8 @@
   .ctx_get_w_thread = mbedtls_ctx_get_w_thread,
   .ctx_init_server = mbedtls_ctx_init_server,
   .ctx_init_client = mbedtls_ctx_init_client,
-  .ctx_handshake_rx = mbedtls_handshake_rx,
-  .ctx_write = mbedtls_write,
-  .ctx_read = mbedtls_read,
+  .ctx_write = mbedtls_ctx_write,
+  .ctx_read = mbedtls_ctx_read,
   .ctx_handshake_is_over = mbedtls_handshake_is_over,
 };
 
@@ -526,6 +618,9 @@
     }
 
   vec_validate (mm->ctx_pool, num_threads - 1);
+  vec_validate (mm->rx_bufs, num_threads - 1);
+  vec_validate (mm->tx_bufs, num_threads - 1);
+
   tls_register_engine (&mbedtls_engine, TLS_ENGINE_MBEDTLS);
   return 0;
 }
diff --git a/src/plugins/tlsopenssl.am b/src/plugins/tlsopenssl.am
new file mode 100644
index 0000000..d4cab62
--- /dev/null
+++ b/src/plugins/tlsopenssl.am
@@ -0,0 +1,21 @@
+# Copyright (c) 2018 Cisco Systems, Inc.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+vppplugins_LTLIBRARIES += tlsopenssl_plugin.la
+
+tlsopenssl_plugin_la_SOURCES = tlsopenssl/tls_openssl.c
+tlsopenssl_plugin_la_LDFLAGS = $(AM_LDFLAGS) -lssl -lcrypto
+tlsopenssl_plugin_la_CFLAGS = $(AM_CFLAGS)
+
+# vi:syntax=automake
diff --git a/src/plugins/tlsopenssl/tls_openssl.c b/src/plugins/tlsopenssl/tls_openssl.c
new file mode 100644
index 0000000..0817f60
--- /dev/null
+++ b/src/plugins/tlsopenssl/tls_openssl.c
@@ -0,0 +1,675 @@
+/*
+ * Copyright (c) 2018 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <openssl/ssl.h>
+#include <openssl/conf.h>
+#include <openssl/err.h>
+#include <vnet/plugin/plugin.h>
+#include <vpp/app/version.h>
+#include <vnet/tls/tls.h>
+
+typedef struct tls_ctx_openssl_
+{
+  tls_ctx_t ctx;			/**< First */
+  u32 openssl_ctx_index;
+  SSL_CTX *ssl_ctx;
+  SSL *ssl;
+  BIO *rbio;
+  BIO *wbio;
+  X509 *srvcert;
+  EVP_PKEY *pkey;
+} openssl_ctx_t;
+
+typedef struct openssl_main_
+{
+  openssl_ctx_t ***ctx_pool;
+  X509_STORE *cert_store;
+} openssl_main_t;
+
+static openssl_main_t openssl_main;
+
+static u32
+openssl_ctx_alloc (void)
+{
+  u8 thread_index = vlib_get_thread_index ();
+  openssl_main_t *tm = &openssl_main;
+  openssl_ctx_t **ctx;
+
+  pool_get (tm->ctx_pool[thread_index], ctx);
+  if (!(*ctx))
+    *ctx = clib_mem_alloc (sizeof (openssl_ctx_t));
+
+  memset (*ctx, 0, sizeof (openssl_ctx_t));
+  (*ctx)->ctx.c_thread_index = thread_index;
+  (*ctx)->ctx.tls_ctx_engine = TLS_ENGINE_OPENSSL;
+  (*ctx)->ctx.app_session_handle = SESSION_INVALID_HANDLE;
+  (*ctx)->openssl_ctx_index = ctx - tm->ctx_pool[thread_index];
+  return ((*ctx)->openssl_ctx_index);
+}
+
+static void
+openssl_ctx_free (tls_ctx_t * ctx)
+{
+  openssl_ctx_t *oc = (openssl_ctx_t *) ctx;
+
+  if (SSL_is_init_finished (oc->ssl) && !ctx->is_passive_close)
+    SSL_shutdown (oc->ssl);
+
+  if (SSL_is_server (oc->ssl))
+    {
+      X509_free (oc->srvcert);
+      EVP_PKEY_free (oc->pkey);
+    }
+  SSL_free (oc->ssl);
+
+  pool_put_index (openssl_main.ctx_pool[ctx->c_thread_index],
+		  oc->openssl_ctx_index);
+}
+
+static tls_ctx_t *
+openssl_ctx_get (u32 ctx_index)
+{
+  openssl_ctx_t **ctx;
+  ctx = pool_elt_at_index (openssl_main.ctx_pool[vlib_get_thread_index ()],
+			   ctx_index);
+  return &(*ctx)->ctx;
+}
+
+static tls_ctx_t *
+openssl_ctx_get_w_thread (u32 ctx_index, u8 thread_index)
+{
+  openssl_ctx_t **ctx;
+  ctx = pool_elt_at_index (openssl_main.ctx_pool[thread_index], ctx_index);
+  return &(*ctx)->ctx;
+}
+
+static int
+openssl_try_handshake_read (openssl_ctx_t * oc,
+			    stream_session_t * tls_session)
+{
+  u32 deq_max, deq_now;
+  svm_fifo_t *f;
+  int wrote, rv;
+
+  f = tls_session->server_rx_fifo;
+  deq_max = svm_fifo_max_dequeue (f);
+  if (!deq_max)
+    return 0;
+
+  deq_now = clib_min (svm_fifo_max_read_chunk (f), deq_max);
+  wrote = BIO_write (oc->wbio, svm_fifo_head (f), deq_now);
+  if (wrote <= 0)
+    return 0;
+
+  svm_fifo_dequeue_drop (f, wrote);
+  if (wrote < deq_max)
+    {
+      deq_now = clib_min (svm_fifo_max_read_chunk (f), deq_max - wrote);
+      rv = BIO_write (oc->wbio, svm_fifo_head (f), deq_now);
+      if (rv > 0)
+	{
+	  svm_fifo_dequeue_drop (f, rv);
+	  wrote += rv;
+	}
+    }
+  return wrote;
+}
+
+static int
+openssl_try_handshake_write (openssl_ctx_t * oc,
+			     stream_session_t * tls_session)
+{
+  u32 enq_max, deq_now;
+  svm_fifo_t *f;
+  int read, rv;
+
+  if (BIO_ctrl_pending (oc->rbio) <= 0)
+    return 0;
+
+  f = tls_session->server_tx_fifo;
+  enq_max = svm_fifo_max_enqueue (f);
+  if (!enq_max)
+    return 0;
+
+  deq_now = clib_min (svm_fifo_max_write_chunk (f), enq_max);
+  read = BIO_read (oc->rbio, svm_fifo_tail (f), deq_now);
+  if (read <= 0)
+    return 0;
+
+  svm_fifo_enqueue_nocopy (f, read);
+  tls_add_vpp_q_evt (f, FIFO_EVENT_APP_TX);
+
+  if (read < enq_max)
+    {
+      deq_now = clib_min (svm_fifo_max_write_chunk (f), enq_max - read);
+      rv = BIO_read (oc->rbio, svm_fifo_tail (f), deq_now);
+      if (rv > 0)
+	{
+	  svm_fifo_enqueue_nocopy (f, rv);
+	  read += rv;
+	}
+    }
+
+  return read;
+}
+
+static int
+openssl_ctx_handshake_rx (tls_ctx_t * ctx, stream_session_t * tls_session)
+{
+  openssl_ctx_t *oc = (openssl_ctx_t *) ctx;
+  int rv = 0, err;
+  while (SSL_in_init (oc->ssl))
+    {
+      if (!openssl_try_handshake_read (oc, tls_session))
+	break;
+
+      rv = SSL_do_handshake (oc->ssl);
+      err = SSL_get_error (oc->ssl, rv);
+      openssl_try_handshake_write (oc, tls_session);
+      if (err != SSL_ERROR_WANT_WRITE)
+	{
+	  if (err == SSL_ERROR_SSL)
+	    {
+	      char buf[512];
+	      ERR_error_string (ERR_get_error (), buf);
+	      clib_warning ("Err: %s", buf);
+	    }
+	  break;
+	}
+    }
+  TLS_DBG (2, "tls state for %u is %s", oc->openssl_ctx_index,
+	   SSL_state_string_long (oc->ssl));
+
+  if (SSL_in_init (oc->ssl))
+    return 0;
+
+  /*
+   * Handshake complete
+   */
+  if (!SSL_is_server (oc->ssl))
+    {
+      /*
+       * Verify server certificate
+       */
+      if ((rv = SSL_get_verify_result (oc->ssl)) != X509_V_OK)
+	{
+	  TLS_DBG (1, " failed verify: %s\n",
+		   X509_verify_cert_error_string (rv));
+
+	  /*
+	   * Presence of hostname enforces strict certificate verification
+	   */
+	  if (ctx->srv_hostname)
+	    {
+	      tls_notify_app_connected (ctx, /* is failed */ 0);
+	      return -1;
+	    }
+	}
+      tls_notify_app_connected (ctx, /* is failed */ 0);
+    }
+  else
+    {
+      tls_notify_app_accept (ctx);
+    }
+
+  TLS_DBG (1, "Handshake for %u complete. TLS cipher is %s",
+	   oc->openssl_ctx_index, SSL_get_cipher (oc->ssl));
+  return rv;
+}
+
+static inline int
+openssl_ctx_write (tls_ctx_t * ctx, stream_session_t * app_session)
+{
+  openssl_ctx_t *oc = (openssl_ctx_t *) ctx;
+  int wrote = 0, rv, read, max_buf = 100 * TLS_CHUNK_SIZE, max_space;
+  u32 enq_max, deq_max, deq_now, to_write;
+  stream_session_t *tls_session;
+  svm_fifo_t *f;
+
+  f = app_session->server_tx_fifo;
+  deq_max = svm_fifo_max_dequeue (f);
+  if (!deq_max)
+    goto check_tls_fifo;
+
+  max_space = max_buf - BIO_ctrl_pending (oc->rbio);
+  max_space = (max_space < 0) ? 0 : max_space;
+  deq_now = clib_min (deq_max, (u32) max_space);
+  to_write = clib_min (svm_fifo_max_read_chunk (f), deq_now);
+  wrote = SSL_write (oc->ssl, svm_fifo_head (f), to_write);
+  if (wrote <= 0)
+    {
+      tls_add_vpp_q_evt (app_session->server_tx_fifo, FIFO_EVENT_APP_TX);
+      goto check_tls_fifo;
+    }
+  svm_fifo_dequeue_drop (app_session->server_tx_fifo, wrote);
+  if (wrote < deq_now)
+    {
+      to_write = clib_min (svm_fifo_max_read_chunk (f), deq_now - wrote);
+      rv = SSL_write (oc->ssl, svm_fifo_head (f), to_write);
+      if (rv > 0)
+	{
+	  svm_fifo_dequeue_drop (app_session->server_tx_fifo, rv);
+	  wrote += rv;
+	}
+    }
+
+  if (deq_now < deq_max)
+    tls_add_vpp_q_evt (app_session->server_tx_fifo, FIFO_EVENT_APP_TX);
+
+check_tls_fifo:
+
+  if (BIO_ctrl_pending (oc->rbio) <= 0)
+    return wrote;
+
+  tls_session = session_get_from_handle (ctx->tls_session_handle);
+  f = tls_session->server_tx_fifo;
+  enq_max = svm_fifo_max_enqueue (f);
+  if (!enq_max)
+    {
+      tls_add_vpp_q_evt (app_session->server_tx_fifo, FIFO_EVENT_APP_TX);
+      return wrote;
+    }
+
+  deq_now = clib_min (svm_fifo_max_write_chunk (f), enq_max);
+  read = BIO_read (oc->rbio, svm_fifo_tail (f), deq_now);
+  if (read <= 0)
+    {
+      tls_add_vpp_q_evt (app_session->server_tx_fifo, FIFO_EVENT_APP_TX);
+      return wrote;
+    }
+
+  svm_fifo_enqueue_nocopy (f, read);
+  tls_add_vpp_q_evt (f, FIFO_EVENT_APP_TX);
+
+  if (read < enq_max && BIO_ctrl_pending (oc->rbio) > 0)
+    {
+      deq_now = clib_min (svm_fifo_max_write_chunk (f), enq_max - read);
+      read = BIO_read (oc->rbio, svm_fifo_tail (f), deq_now);
+      if (read > 0)
+	svm_fifo_enqueue_nocopy (f, read);
+    }
+
+  if (BIO_ctrl_pending (oc->rbio) > 0)
+    tls_add_vpp_q_evt (app_session->server_tx_fifo, FIFO_EVENT_APP_TX);
+
+  return wrote;
+}
+
+static inline int
+openssl_ctx_read (tls_ctx_t * ctx, stream_session_t * tls_session)
+{
+  int read, wrote = 0, max_space, max_buf = 100 * TLS_CHUNK_SIZE, rv;
+  openssl_ctx_t *oc = (openssl_ctx_t *) ctx;
+  u32 deq_max, enq_max, deq_now, to_read;
+  stream_session_t *app_session;
+  svm_fifo_t *f;
+
+  if (PREDICT_FALSE (SSL_in_init (oc->ssl)))
+    {
+      openssl_ctx_handshake_rx (ctx, tls_session);
+      return 0;
+    }
+
+  f = tls_session->server_rx_fifo;
+  deq_max = svm_fifo_max_dequeue (f);
+  max_space = max_buf - BIO_ctrl_pending (oc->wbio);
+  max_space = max_space < 0 ? 0 : max_space;
+  deq_now = clib_min (deq_max, max_space);
+  if (!deq_now)
+    goto check_app_fifo;
+
+  to_read = clib_min (svm_fifo_max_read_chunk (f), deq_now);
+  wrote = BIO_write (oc->wbio, svm_fifo_head (f), to_read);
+  if (wrote <= 0)
+    {
+      tls_add_vpp_q_evt (tls_session->server_rx_fifo, FIFO_EVENT_BUILTIN_RX);
+      goto check_app_fifo;
+    }
+  svm_fifo_dequeue_drop (f, wrote);
+  if (wrote < deq_now)
+    {
+      to_read = clib_min (svm_fifo_max_read_chunk (f), deq_now - wrote);
+      rv = BIO_write (oc->wbio, svm_fifo_head (f), to_read);
+      if (rv > 0)
+	{
+	  svm_fifo_dequeue_drop (f, rv);
+	  wrote += rv;
+	}
+    }
+  if (svm_fifo_max_dequeue (f))
+    tls_add_vpp_q_evt (tls_session->server_rx_fifo, FIFO_EVENT_BUILTIN_RX);
+
+check_app_fifo:
+
+  if (BIO_ctrl_pending (oc->wbio) <= 0)
+    return wrote;
+
+  app_session = session_get_from_handle (ctx->app_session_handle);
+  f = app_session->server_rx_fifo;
+  enq_max = svm_fifo_max_enqueue (f);
+  if (!enq_max)
+    {
+      tls_add_vpp_q_evt (tls_session->server_rx_fifo, FIFO_EVENT_BUILTIN_RX);
+      return wrote;
+    }
+
+  deq_now = clib_min (svm_fifo_max_write_chunk (f), enq_max);
+  read = SSL_read (oc->ssl, svm_fifo_tail (f), deq_now);
+  if (read <= 0)
+    {
+      tls_add_vpp_q_evt (tls_session->server_rx_fifo, FIFO_EVENT_BUILTIN_RX);
+      return wrote;
+    }
+  svm_fifo_enqueue_nocopy (f, read);
+  if (read < enq_max && BIO_ctrl_pending (oc->wbio) > 0)
+    {
+      deq_now = clib_min (svm_fifo_max_write_chunk (f), enq_max - read);
+      read = SSL_read (oc->ssl, svm_fifo_tail (f), deq_now);
+      if (read > 0)
+	svm_fifo_enqueue_nocopy (f, read);
+    }
+
+  tls_notify_app_enqueue (ctx, app_session);
+  if (BIO_ctrl_pending (oc->wbio) > 0)
+    tls_add_vpp_q_evt (tls_session->server_rx_fifo, FIFO_EVENT_BUILTIN_RX);
+
+  return wrote;
+}
+
+static int
+openssl_ctx_init_client (tls_ctx_t * ctx)
+{
+  char *ciphers = "ALL:!ADH:!LOW:!EXP:!MD5:!RC4-SHA:!DES-CBC3-SHA:@STRENGTH";
+  long flags = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3 | SSL_OP_NO_COMPRESSION;
+  openssl_ctx_t *oc = (openssl_ctx_t *) ctx;
+  openssl_main_t *om = &openssl_main;
+  stream_session_t *tls_session;
+  const SSL_METHOD *method;
+  int rv, err;
+
+  method = SSLv23_client_method ();
+  if (method == NULL)
+    {
+      TLS_DBG (1, "SSLv23_method returned null");
+      return -1;
+    }
+
+  oc->ssl_ctx = SSL_CTX_new (method);
+  if (oc->ssl_ctx == NULL)
+    {
+      TLS_DBG (1, "SSL_CTX_new returned null");
+      return -1;
+    }
+
+  SSL_CTX_set_ecdh_auto (oc->ssl_ctx, 1);
+  SSL_CTX_set_mode (oc->ssl_ctx, SSL_MODE_ENABLE_PARTIAL_WRITE);
+  rv = SSL_CTX_set_cipher_list (oc->ssl_ctx, (const char *) ciphers);
+  if (rv != 1)
+    {
+      TLS_DBG (1, "Couldn't set cipher");
+      return -1;
+    }
+
+  SSL_CTX_set_options (oc->ssl_ctx, flags);
+  SSL_CTX_set_cert_store (oc->ssl_ctx, om->cert_store);
+
+  oc->ssl = SSL_new (oc->ssl_ctx);
+  if (oc->ssl == NULL)
+    {
+      TLS_DBG (1, "Couldn't initialize ssl struct");
+      return -1;
+    }
+
+  oc->rbio = BIO_new (BIO_s_mem ());
+  oc->wbio = BIO_new (BIO_s_mem ());
+
+  BIO_set_mem_eof_return (oc->rbio, -1);
+  BIO_set_mem_eof_return (oc->wbio, -1);
+
+  SSL_set_bio (oc->ssl, oc->wbio, oc->rbio);
+  SSL_set_connect_state (oc->ssl);
+
+  rv = SSL_set_tlsext_host_name (oc->ssl, ctx->srv_hostname);
+  if (rv != 1)
+    {
+      TLS_DBG (1, "Couldn't set hostname");
+      return -1;
+    }
+
+  /*
+   * 2. Do the first steps in the handshake.
+   */
+  TLS_DBG (1, "Initiating handshake for [%u]%u", ctx->c_thread_index,
+	   oc->openssl_ctx_index);
+
+  tls_session = session_get_from_handle (ctx->tls_session_handle);
+  while (1)
+    {
+      rv = SSL_do_handshake (oc->ssl);
+      err = SSL_get_error (oc->ssl, rv);
+      openssl_try_handshake_write (oc, tls_session);
+      if (err != SSL_ERROR_WANT_WRITE)
+	break;
+    }
+
+  TLS_DBG (2, "tls state for [%u]%u is su", ctx->c_thread_index,
+	   oc->openssl_ctx_index, SSL_state_string_long (oc->ssl));
+  return 0;
+}
+
+static int
+openssl_ctx_init_server (tls_ctx_t * ctx)
+{
+  char *ciphers = "ALL:!ADH:!LOW:!EXP:!MD5:!RC4-SHA:!DES-CBC3-SHA:@STRENGTH";
+  long flags = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3 | SSL_OP_NO_COMPRESSION;
+  openssl_ctx_t *oc = (openssl_ctx_t *) ctx;
+  stream_session_t *tls_session;
+  const SSL_METHOD *method;
+  application_t *app;
+  int rv, err;
+  BIO *cert_bio;
+
+  app = application_get (ctx->parent_app_index);
+  if (!app->tls_cert || !app->tls_key)
+    {
+      TLS_DBG (1, "tls cert and/or key not configured %d",
+	       ctx->parent_app_index);
+      return -1;
+    }
+
+  method = SSLv23_method ();
+  oc->ssl_ctx = SSL_CTX_new (method);
+  if (!oc->ssl_ctx)
+    {
+      clib_warning ("Unable to create SSL context");
+      return -1;
+    }
+
+  SSL_CTX_set_mode (oc->ssl_ctx, SSL_MODE_ENABLE_PARTIAL_WRITE);
+  SSL_CTX_set_options (oc->ssl_ctx, flags);
+  SSL_CTX_set_ecdh_auto (oc->ssl_ctx, 1);
+
+  rv = SSL_CTX_set_cipher_list (oc->ssl_ctx, (const char *) ciphers);
+  if (rv != 1)
+    {
+      TLS_DBG (1, "Couldn't set cipher");
+      return -1;
+    }
+
+  /*
+   * Set the key and cert
+   */
+  cert_bio = BIO_new (BIO_s_mem ());
+  BIO_write (cert_bio, app->tls_cert, vec_len (app->tls_cert));
+  oc->srvcert = PEM_read_bio_X509 (cert_bio, NULL, NULL, NULL);
+  if (!oc->srvcert)
+    {
+      clib_warning ("unable to parse certificate");
+      return -1;
+    }
+  BIO_free (cert_bio);
+  cert_bio = BIO_new (BIO_s_mem ());
+  BIO_write (cert_bio, app->tls_key, vec_len (app->tls_key));
+  oc->pkey = PEM_read_bio_PrivateKey (cert_bio, NULL, NULL, NULL);
+  if (!oc->pkey)
+    {
+      clib_warning ("unable to parse pkey");
+      return -1;
+    }
+
+  BIO_free (cert_bio);
+
+  oc->ssl = SSL_new (oc->ssl_ctx);
+  if (oc->ssl == NULL)
+    {
+      TLS_DBG (1, "Couldn't initialize ssl struct");
+      return -1;
+    }
+
+  oc->rbio = BIO_new (BIO_s_mem ());
+  oc->wbio = BIO_new (BIO_s_mem ());
+
+  BIO_set_mem_eof_return (oc->rbio, -1);
+  BIO_set_mem_eof_return (oc->wbio, -1);
+
+  SSL_set_bio (oc->ssl, oc->wbio, oc->rbio);
+  SSL_set_accept_state (oc->ssl);
+
+  TLS_DBG (1, "Initiating handshake for [%u]%u", ctx->c_thread_index,
+	   oc->openssl_ctx_index);
+
+  tls_session = session_get_from_handle (ctx->tls_session_handle);
+  while (1)
+    {
+      rv = SSL_do_handshake (oc->ssl);
+      err = SSL_get_error (oc->ssl, rv);
+      openssl_try_handshake_write (oc, tls_session);
+      if (err != SSL_ERROR_WANT_WRITE)
+	break;
+    }
+
+  TLS_DBG (2, "tls state for [%u]%u is su", ctx->c_thread_index,
+	   oc->openssl_ctx_index, SSL_state_string_long (oc->ssl));
+  return 0;
+}
+
+static u8
+openssl_handshake_is_over (tls_ctx_t * ctx)
+{
+  openssl_ctx_t *mc = (openssl_ctx_t *) ctx;
+  if (!mc->ssl)
+    return 0;
+  return SSL_is_init_finished (mc->ssl);
+}
+
+const static tls_engine_vft_t openssl_engine = {
+  .ctx_alloc = openssl_ctx_alloc,
+  .ctx_free = openssl_ctx_free,
+  .ctx_get = openssl_ctx_get,
+  .ctx_get_w_thread = openssl_ctx_get_w_thread,
+  .ctx_init_server = openssl_ctx_init_server,
+  .ctx_init_client = openssl_ctx_init_client,
+  .ctx_write = openssl_ctx_write,
+  .ctx_read = openssl_ctx_read,
+  .ctx_handshake_is_over = openssl_handshake_is_over,
+};
+
+int
+tls_init_ca_chain (void)
+{
+  openssl_main_t *om = &openssl_main;
+  tls_main_t *tm = vnet_tls_get_main ();
+  BIO *cert_bio;
+  X509 *testcert;
+  int rv;
+
+  if (access (tm->ca_cert_path, F_OK | R_OK) == -1)
+    {
+      clib_warning ("Could not initialize TLS CA certificates");
+      return -1;
+    }
+
+  if (!(om->cert_store = X509_STORE_new ()))
+    {
+      clib_warning ("failed to create cert store");
+      return -1;
+    }
+
+  rv = X509_STORE_load_locations (om->cert_store, tm->ca_cert_path, 0);
+  if (rv < 0)
+    {
+      clib_warning ("failed to load ca certificate");
+    }
+
+  if (tm->use_test_cert_in_ca)
+    {
+      cert_bio = BIO_new (BIO_s_mem ());
+      BIO_write (cert_bio, test_srv_crt_rsa, test_srv_crt_rsa_len);
+      testcert = PEM_read_bio_X509 (cert_bio, NULL, NULL, NULL);
+      if (!testcert)
+	{
+	  clib_warning ("unable to parse certificate");
+	  return -1;
+	}
+      X509_STORE_add_cert (om->cert_store, testcert);
+      rv = 0;
+    }
+  return (rv < 0 ? -1 : 0);
+}
+
+static clib_error_t *
+tls_openssl_init (vlib_main_t * vm)
+{
+  vlib_thread_main_t *vtm = vlib_get_thread_main ();
+  openssl_main_t *om = &openssl_main;
+  clib_error_t *error;
+  u32 num_threads;
+
+  num_threads = 1 /* main thread */  + vtm->n_threads;
+
+  if ((error = vlib_call_init_function (vm, tls_init)))
+    return error;
+
+  SSL_library_init ();
+  SSL_load_error_strings ();
+
+  if (tls_init_ca_chain ())
+    {
+      clib_warning ("failed to initialize TLS CA chain");
+      return 0;
+    }
+
+  vec_validate (om->ctx_pool, num_threads - 1);
+
+  tls_register_engine (&openssl_engine, TLS_ENGINE_OPENSSL);
+  return 0;
+}
+
+VLIB_INIT_FUNCTION (tls_openssl_init);
+
+/* *INDENT-OFF* */
+VLIB_PLUGIN_REGISTER () = {
+    .version = VPP_BUILD_VER,
+    .description = "openssl based TLS Engine",
+};
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/svm/svm_fifo.h b/src/svm/svm_fifo.h
index 0d85951..d06d77a 100644
--- a/src/svm/svm_fifo.h
+++ b/src/svm/svm_fifo.h
@@ -167,6 +167,49 @@
   f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
 }
 
+/**
+ * Max contiguous chunk of data that can be read
+ */
+always_inline u32
+svm_fifo_max_read_chunk (svm_fifo_t * f)
+{
+  return ((f->tail > f->head) ? (f->tail - f->head) : (f->nitems - f->head));
+}
+
+/**
+ * Max contiguous chunk of data that can be written
+ */
+always_inline u32
+svm_fifo_max_write_chunk (svm_fifo_t * f)
+{
+  return ((f->tail >= f->head) ? (f->nitems - f->tail) : (f->head - f->tail));
+}
+
+/**
+ * Advance tail pointer
+ *
+ * Useful for moving tail pointer after external enqueue.
+ */
+always_inline void
+svm_fifo_enqueue_nocopy (svm_fifo_t * f, u32 bytes)
+{
+  ASSERT (bytes <= svm_fifo_max_enqueue (f));
+  f->tail = (f->tail + bytes) % f->nitems;
+  f->cursize += bytes;
+}
+
+always_inline u8 *
+svm_fifo_head (svm_fifo_t * f)
+{
+  return (f->data + f->head);
+}
+
+always_inline u8 *
+svm_fifo_tail (svm_fifo_t * f)
+{
+  return (f->data + f->tail);
+}
+
 always_inline u32
 ooo_segment_distance_from_tail (svm_fifo_t * f, u32 pos)
 {
diff --git a/src/vnet/session-apps/echo_client.c b/src/vnet/session-apps/echo_client.c
index 5b70d49..2cfb471 100644
--- a/src/vnet/session-apps/echo_client.c
+++ b/src/vnet/session-apps/echo_client.c
@@ -458,8 +458,8 @@
   options[APP_OPTIONS_TX_FIFO_SIZE] = ecm->fifo_size;
   options[APP_OPTIONS_PRIVATE_SEGMENT_COUNT] = ecm->private_segment_count;
   options[APP_OPTIONS_PREALLOC_FIFO_PAIRS] = prealloc_fifos;
-
   options[APP_OPTIONS_FLAGS] = APP_OPTIONS_FLAGS_IS_BUILTIN;
+  options[APP_OPTIONS_TLS_ENGINE] = ecm->tls_engine;
   if (appns_id)
     {
       options[APP_OPTIONS_FLAGS] |= appns_flags;
@@ -575,6 +575,8 @@
   ecm->test_bytes = 0;
   ecm->test_failed = 0;
   ecm->vlib_main = vm;
+  ecm->tls_engine = TLS_ENGINE_OPENSSL;
+
   if (thread_main->n_vlib_mains > 1)
     clib_spinlock_init (&ecm->sessions_lock);
   vec_free (ecm->connect_uri);
@@ -632,6 +634,8 @@
 	ecm->no_output = 1;
       else if (unformat (input, "test-bytes"))
 	ecm->test_bytes = 1;
+      else if (unformat (input, "tls-engine %d", &ecm->tls_engine))
+	;
       else
 	return clib_error_return (0, "failed: unknown input `%U'",
 				  format_unformat_error, input);
diff --git a/src/vnet/session-apps/echo_client.h b/src/vnet/session-apps/echo_client.h
index 4ae63ec..5712da5 100644
--- a/src/vnet/session-apps/echo_client.h
+++ b/src/vnet/session-apps/echo_client.h
@@ -64,7 +64,7 @@
   u32 connections_per_batch;		/**< Connections to rx/tx at once */
   u32 private_segment_count;		/**< Number of private fifo segs */
   u32 private_segment_size;		/**< size of private fifo segs */
-
+  u32 tls_engine;			/**< TLS engine mbedtls/openssl */
   /*
    * Test state variables
    */
diff --git a/src/vnet/session-apps/echo_server.c b/src/vnet/session-apps/echo_server.c
index 39d848f..9f34d4c 100644
--- a/src/vnet/session-apps/echo_server.c
+++ b/src/vnet/session-apps/echo_server.c
@@ -40,7 +40,7 @@
   u32 private_segment_count;	/**< Number of private segments  */
   u32 private_segment_size;	/**< Size of private segments  */
   char *server_uri;		/**< Server URI */
-
+  u32 tls_engine;		/**< TLS engine: mbedtls/openssl */
   /*
    * Test state
    */
@@ -295,6 +295,7 @@
   a->options[APP_OPTIONS_RX_FIFO_SIZE] = esm->fifo_size;
   a->options[APP_OPTIONS_TX_FIFO_SIZE] = esm->fifo_size;
   a->options[APP_OPTIONS_PRIVATE_SEGMENT_COUNT] = esm->private_segment_count;
+  a->options[APP_OPTIONS_TLS_ENGINE] = esm->tls_engine;
   a->options[APP_OPTIONS_PREALLOC_FIFO_PAIRS] =
     esm->prealloc_fifos ? esm->prealloc_fifos : 1;
 
@@ -408,6 +409,7 @@
   esm->prealloc_fifos = 0;
   esm->private_segment_count = 0;
   esm->private_segment_size = 0;
+  esm->tls_engine = TLS_ENGINE_OPENSSL;
   vec_free (esm->server_uri);
 
   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
@@ -446,6 +448,8 @@
 	;
       else if (unformat (input, "stop"))
 	is_stop = 1;
+      else if (unformat (input, "tls-engine %d", &esm->tls_engine))
+	;
       else
 	return clib_error_return (0, "failed: unknown input `%U'",
 				  format_unformat_error, input);
diff --git a/src/vnet/session/application.c b/src/vnet/session/application.c
index 12f816b..14169fa 100644
--- a/src/vnet/session/application.c
+++ b/src/vnet/session/application.c
@@ -305,6 +305,8 @@
     props->tx_fifo_size = options[APP_OPTIONS_TX_FIFO_SIZE];
   if (options[APP_OPTIONS_EVT_QUEUE_SIZE])
     props->evt_q_size = options[APP_OPTIONS_EVT_QUEUE_SIZE];
+  if (options[APP_OPTIONS_TLS_ENGINE])
+    app->tls_engine = options[APP_OPTIONS_TLS_ENGINE];
   props->segment_type = seg_type;
 
   first_seg_size = options[APP_OPTIONS_SEGMENT_SIZE];
diff --git a/src/vnet/session/application.h b/src/vnet/session/application.h
index 8e5c2de..4050cb4 100644
--- a/src/vnet/session/application.h
+++ b/src/vnet/session/application.h
@@ -125,6 +125,9 @@
 
   /** PEM encoded key */
   u8 *tls_key;
+
+  /** Preferred tls engine */
+  u8 tls_engine;
 } application_t;
 
 #define APP_INVALID_INDEX ((u32)~0)
diff --git a/src/vnet/session/application_interface.h b/src/vnet/session/application_interface.h
index deddb64..f72a461 100644
--- a/src/vnet/session/application_interface.h
+++ b/src/vnet/session/application_interface.h
@@ -21,6 +21,7 @@
 #include <vnet/session/session.h>
 #include <vnet/session/application.h>
 #include <vnet/session/transport.h>
+#include <vnet/tls/tls.h>
 
 typedef struct _vnet_app_attach_args_t
 {
@@ -124,6 +125,7 @@
   APP_OPTIONS_NAMESPACE_SECRET,
   APP_OPTIONS_PROXY_TRANSPORT,
   APP_OPTIONS_ACCEPT_COOKIE,
+  APP_OPTIONS_TLS_ENGINE,
   APP_OPTIONS_N_OPTIONS
 } app_attach_options_index_t;
 
diff --git a/src/vnet/tls/tls.c b/src/vnet/tls/tls.c
index 65900c8..040db02 100644
--- a/src/vnet/tls/tls.c
+++ b/src/vnet/tls/tls.c
@@ -20,8 +20,23 @@
 static tls_main_t tls_main;
 static tls_engine_vft_t *tls_vfts;
 
-#define DEFAULT_ENGINE 0
-void tls_disconnect (u32 ctx_index, u32 thread_index);
+#define TLS_INVALID_HANDLE 	~0
+#define TLS_IDX_MASK 		0x00FFFFFF
+#define TLS_ENGINE_TYPE_SHIFT 	29
+
+void tls_disconnect (u32 ctx_handle, u32 thread_index);
+
+tls_engine_type_t
+tls_get_available_engine (void)
+{
+  int i;
+  for (i = 0; i < vec_len (tls_vfts); i++)
+    {
+      if (tls_vfts[i].ctx_alloc)
+	return i;
+    }
+  return TLS_ENGINE_NONE;
+}
 
 int
 tls_add_vpp_q_evt (svm_fifo_t * f, u8 evt_type)
@@ -169,7 +184,15 @@
   return (ctx - tls_main.half_open_ctx_pool);
 }
 
-static int
+void
+tls_notify_app_enqueue (tls_ctx_t * ctx, stream_session_t * app_session)
+{
+  application_t *app;
+  app = application_get_if_valid (app_session->app_index);
+  tls_add_app_q_evt (app, app_session);
+}
+
+int
 tls_notify_app_accept (tls_ctx_t * ctx)
 {
   stream_session_t *app_listener, *app_session;
@@ -185,7 +208,7 @@
 
   app_session = session_alloc (vlib_get_thread_index ());
   app_session->app_index = ctx->parent_app_index;
-  app_session->connection_index = ctx->tls_ctx_idx;
+  app_session->connection_index = ctx->tls_ctx_handle;
   app_session->session_type = app_listener->session_type;
   app_session->listener_index = app_listener->session_index;
   if ((rv = session_alloc_fifos (sm, app_session)))
@@ -198,7 +221,7 @@
   return app->cb_fns.session_accept_callback (app_session);
 }
 
-static int
+int
 tls_notify_app_connected (tls_ctx_t * ctx, u8 is_failed)
 {
   int (*cb_fn) (u32, u32, stream_session_t *, u8);
@@ -215,7 +238,7 @@
   sm = application_get_connect_segment_manager (app);
   app_session = session_alloc (vlib_get_thread_index ());
   app_session->app_index = ctx->parent_app_index;
-  app_session->connection_index = ctx->tls_ctx_idx;
+  app_session->connection_index = ctx->tls_ctx_handle;
   app_session->session_type =
     session_type_from_proto_and_ip (TRANSPORT_PROTO_TLS, ctx->tcp_is_ip4);
   if (session_alloc_fifos (sm, app_session))
@@ -228,93 +251,91 @@
 	     app_session, 0 /* not failed */ ))
     {
       TLS_DBG (1, "failed to notify app");
-      tls_disconnect (ctx->tls_ctx_idx, vlib_get_thread_index ());
+      tls_disconnect (ctx->tls_ctx_handle, vlib_get_thread_index ());
     }
 
   return 0;
 
 failed:
+  tls_disconnect (ctx->tls_ctx_handle, vlib_get_thread_index ());
   return cb_fn (ctx->parent_app_index, ctx->parent_app_api_context, 0,
 		1 /* failed */ );
 }
 
-static inline u32
-tls_ctx_alloc (void)
+static inline void
+tls_ctx_parse_handle (u32 ctx_handle, u32 * ctx_index, u32 * engine_type)
 {
-  return tls_vfts[DEFAULT_ENGINE].ctx_alloc ();
+  *ctx_index = ctx_handle & TLS_IDX_MASK;
+  *engine_type = ctx_handle >> TLS_ENGINE_TYPE_SHIFT;
+}
+
+static inline tls_engine_type_t
+tls_get_engine_type (tls_engine_type_t preferred)
+{
+  if (!tls_vfts[preferred].ctx_alloc)
+    return tls_get_available_engine ();
+  return preferred;
+}
+
+static inline u32
+tls_ctx_alloc (tls_engine_type_t engine_type)
+{
+  u32 ctx_index;
+  ctx_index = tls_vfts[engine_type].ctx_alloc ();
+  return (((u32) engine_type << TLS_ENGINE_TYPE_SHIFT) | ctx_index);
 }
 
 static inline void
 tls_ctx_free (tls_ctx_t * ctx)
 {
   vec_free (ctx->srv_hostname);
-  tls_vfts[DEFAULT_ENGINE].ctx_free (ctx);
+  tls_vfts[ctx->tls_ctx_engine].ctx_free (ctx);
 }
 
 static inline tls_ctx_t *
-tls_ctx_get (u32 ctx_index)
+tls_ctx_get (u32 ctx_handle)
 {
-  return tls_vfts[DEFAULT_ENGINE].ctx_get (ctx_index);
+  u32 ctx_index, engine_type;
+  tls_ctx_parse_handle (ctx_handle, &ctx_index, &engine_type);
+  return tls_vfts[engine_type].ctx_get (ctx_index);
 }
 
 static inline tls_ctx_t *
-tls_ctx_get_w_thread (u32 ctx_index, u8 thread_index)
+tls_ctx_get_w_thread (u32 ctx_handle, u8 thread_index)
 {
-  return tls_vfts[DEFAULT_ENGINE].ctx_get_w_thread (ctx_index, thread_index);
+  u32 ctx_index, engine_type;
+  tls_ctx_parse_handle (ctx_handle, &ctx_index, &engine_type);
+  return tls_vfts[engine_type].ctx_get_w_thread (ctx_index, thread_index);
 }
 
 static inline int
 tls_ctx_init_server (tls_ctx_t * ctx)
 {
-  return tls_vfts[DEFAULT_ENGINE].ctx_init_server (ctx);
+  return tls_vfts[ctx->tls_ctx_engine].ctx_init_server (ctx);
 }
 
 static inline int
 tls_ctx_init_client (tls_ctx_t * ctx)
 {
-  return tls_vfts[DEFAULT_ENGINE].ctx_init_client (ctx);
+  return tls_vfts[ctx->tls_ctx_engine].ctx_init_client (ctx);
 }
 
 static inline int
-tls_ctx_write (tls_ctx_t * ctx, u8 * buf, u32 len)
+tls_ctx_write (tls_ctx_t * ctx, stream_session_t * app_session)
 {
-  return tls_vfts[DEFAULT_ENGINE].ctx_write (ctx, buf, len);
+  return tls_vfts[ctx->tls_ctx_engine].ctx_write (ctx, app_session);
 }
 
 static inline int
-tls_ctx_read (tls_ctx_t * ctx, u8 * buf, u32 len)
+tls_ctx_read (tls_ctx_t * ctx, stream_session_t * tls_session)
 {
-  return tls_vfts[DEFAULT_ENGINE].ctx_read (ctx, buf, len);
+  return tls_vfts[ctx->tls_ctx_engine].ctx_read (ctx, tls_session);
 }
 
 static inline u8
 tls_ctx_handshake_is_over (tls_ctx_t * ctx)
 {
-  return tls_vfts[DEFAULT_ENGINE].ctx_handshake_is_over (ctx);
-}
-
-static inline int
-tls_handshake_rx (tls_ctx_t * ctx)
-{
-  int rv;
-  rv = tls_vfts[DEFAULT_ENGINE].ctx_handshake_rx (ctx);
-
-  switch (rv)
-    {
-    case CLIENT_HANDSHAKE_OK:
-      tls_notify_app_connected (ctx, /* is failed */ 0);
-      break;
-    case CLIENT_HANDSHAKE_FAIL:
-      tls_disconnect (ctx->tls_ctx_idx, vlib_get_thread_index ());
-      tls_notify_app_connected (ctx, /* is failed */ 1);
-      break;
-    case SERVER_HANDSHAKE_OK:
-      tls_notify_app_accept (ctx);
-      break;
-    default:
-      return 0;
-    }
-  return 0;
+  return tls_vfts[ctx->tls_ctx_engine].ctx_handshake_is_over (ctx);
 }
 
 void
@@ -360,23 +381,24 @@
 {
   stream_session_t *tls_listener;
   tls_ctx_t *lctx, *ctx;
-  u32 ctx_index;
+  u32 ctx_handle;
 
   tls_listener = listen_session_get (tls_session->session_type,
 				     tls_session->listener_index);
   lctx = tls_listener_ctx_get (tls_listener->opaque);
-  ctx_index = tls_ctx_alloc ();
-  ctx = tls_ctx_get (ctx_index);
+
+  ctx_handle = tls_ctx_alloc (lctx->tls_ctx_engine);
+  ctx = tls_ctx_get (ctx_handle);
   memcpy (ctx, lctx, sizeof (*lctx));
   ctx->c_thread_index = vlib_get_thread_index ();
-  ctx->tls_ctx_idx = ctx_index;
+  ctx->tls_ctx_handle = ctx_handle;
   tls_session->session_state = SESSION_STATE_READY;
-  tls_session->opaque = ctx_index;
+  tls_session->opaque = ctx_handle;
   ctx->tls_session_handle = session_handle (tls_session);
   ctx->listener_ctx_index = tls_listener->opaque;
 
-  TLS_DBG (1, "Accept on listener %u new connection [%u]%u",
-	   tls_listener->opaque, vlib_get_thread_index (), ctx_index);
+  TLS_DBG (1, "Accept on listener %u new connection [%u]%x",
+	   tls_listener->opaque, vlib_get_thread_index (), ctx_handle);
 
   return tls_ctx_init_server (ctx);
 }
@@ -384,95 +406,22 @@
 int
 tls_app_tx_callback (stream_session_t * app_session)
 {
-  stream_session_t *tls_session;
   tls_ctx_t *ctx;
-  static u8 *tmp_buf;
-  u32 enq_max, deq_max, deq_now;
-  int wrote;
-
-  ctx = tls_ctx_get (app_session->connection_index);
-  if (!tls_ctx_handshake_is_over (ctx))
-    tls_add_vpp_q_evt (app_session->server_tx_fifo, FIFO_EVENT_APP_TX);
-
-  deq_max = svm_fifo_max_dequeue (app_session->server_tx_fifo);
-  if (!deq_max)
+  if (PREDICT_FALSE (app_session->session_state == SESSION_STATE_CLOSED))
     return 0;
-
-  tls_session = session_get_from_handle (ctx->tls_session_handle);
-  enq_max = svm_fifo_max_enqueue (tls_session->server_tx_fifo);
-  deq_now = clib_min (deq_max, TLS_CHUNK_SIZE);
-
-  if (PREDICT_FALSE (enq_max == 0))
-    {
-      tls_add_vpp_q_evt (app_session->server_tx_fifo, FIFO_EVENT_APP_TX);
-      return 0;
-    }
-
-  vec_validate (tmp_buf, deq_now);
-  svm_fifo_peek (app_session->server_tx_fifo, 0, deq_now, tmp_buf);
-  wrote = tls_ctx_write (ctx, tmp_buf, deq_now);
-  if (wrote <= 0)
-    {
-      tls_add_vpp_q_evt (app_session->server_tx_fifo, FIFO_EVENT_APP_TX);
-      return 0;
-    }
-
-  svm_fifo_dequeue_drop (app_session->server_tx_fifo, wrote);
-  vec_reset_length (tmp_buf);
-
-  tls_add_vpp_q_evt (tls_session->server_tx_fifo, FIFO_EVENT_APP_TX);
-
-  if (deq_now < deq_max)
-    tls_add_vpp_q_evt (app_session->server_tx_fifo, FIFO_EVENT_APP_TX);
-
+  ctx = tls_ctx_get (app_session->connection_index);
+  tls_ctx_write (ctx, app_session);
   return 0;
 }
 
 int
 tls_app_rx_callback (stream_session_t * tls_session)
 {
-  stream_session_t *app_session;
-  u32 deq_max, enq_max, enq_now;
-  application_t *app;
-  static u8 *tmp_buf;
   tls_ctx_t *ctx;
-  int read, enq;
 
   ctx = tls_ctx_get (tls_session->opaque);
-  if (!tls_ctx_handshake_is_over (ctx))
-    return tls_handshake_rx (ctx);
-
-  deq_max = svm_fifo_max_dequeue (tls_session->server_rx_fifo);
-  if (!deq_max)
-    return 0;
-
-  app_session = session_get_from_handle (ctx->app_session_handle);
-  enq_max = svm_fifo_max_enqueue (app_session->server_rx_fifo);
-  enq_now = clib_min (enq_max, TLS_CHUNK_SIZE);
-
-  if (PREDICT_FALSE (enq_now == 0))
-    {
-      tls_add_vpp_q_evt (tls_session->server_rx_fifo, FIFO_EVENT_BUILTIN_RX);
-      return 0;
-    }
-
-  vec_validate (tmp_buf, enq_now);
-  read = tls_ctx_read (ctx, tmp_buf, enq_now);
-  if (read <= 0)
-    {
-      tls_add_vpp_q_evt (tls_session->server_rx_fifo, FIFO_EVENT_BUILTIN_RX);
-      return 0;
-    }
-
-  enq = svm_fifo_enqueue_nowait (app_session->server_rx_fifo, read, tmp_buf);
-  ASSERT (enq == read);
-  vec_reset_length (tmp_buf);
-
-  if (svm_fifo_max_dequeue (tls_session->server_rx_fifo))
-    tls_add_vpp_q_evt (tls_session->server_rx_fifo, FIFO_EVENT_BUILTIN_RX);
-
-  app = application_get_if_valid (app_session->app_index);
-  return tls_add_app_q_evt (app, app_session);
+  tls_ctx_read (ctx, tls_session);
+  return 0;
 }
 
 int
@@ -482,7 +431,7 @@
   int (*cb_fn) (u32, u32, stream_session_t *, u8);
   application_t *app;
   tls_ctx_t *ho_ctx, *ctx;
-  u32 ctx_index;
+  u32 ctx_handle;
 
   ho_ctx = tls_ctx_half_open_get (ho_ctx_index);
   app = application_get (ho_ctx->parent_app_index);
@@ -496,21 +445,21 @@
 		    1 /* failed */ );
     }
 
-  ctx_index = tls_ctx_alloc ();
-  ctx = tls_ctx_get (ctx_index);
+  ctx_handle = tls_ctx_alloc (ho_ctx->tls_ctx_engine);
+  ctx = tls_ctx_get (ctx_handle);
   clib_memcpy (ctx, ho_ctx, sizeof (*ctx));
   tls_ctx_half_open_reader_unlock ();
   tls_ctx_half_open_free (ho_ctx_index);
 
   ctx->c_thread_index = vlib_get_thread_index ();
-  ctx->tls_ctx_idx = ctx_index;
+  ctx->tls_ctx_handle = ctx_handle;
 
-  TLS_DBG (1, "TCP connect for %u returned %u. New connection [%u]%u",
+  TLS_DBG (1, "TCP connect for %u returned %u. New connection [%u]%x",
 	   ho_ctx_index, is_fail, vlib_get_thread_index (),
-	   (ctx) ? ctx_index : ~0);
+	   (ctx) ? ctx_handle : ~0);
 
   ctx->tls_session_handle = session_handle (tls_session);
-  tls_session->opaque = ctx_index;
+  tls_session->opaque = ctx_handle;
   tls_session->session_state = SESSION_STATE_READY;
 
   return tls_ctx_init_client (ctx);
@@ -533,6 +482,7 @@
 tls_connect (transport_endpoint_t * tep)
 {
   session_endpoint_extended_t *sep;
+  tls_engine_type_t engine_type;
   session_endpoint_t tls_sep;
   tls_main_t *tm = &tls_main;
   application_t *app;
@@ -541,6 +491,13 @@
   int rv;
 
   sep = (session_endpoint_extended_t *) tep;
+  app = application_get (sep->app_index);
+  engine_type = tls_get_engine_type (app->tls_engine);
+  if (engine_type == TLS_ENGINE_NONE)
+    {
+      clib_warning ("No tls engine_type available");
+      return -1;
+    }
 
   ctx_index = tls_ctx_half_open_alloc ();
   ctx = tls_ctx_half_open_get (ctx_index);
@@ -554,27 +511,27 @@
     }
   tls_ctx_half_open_reader_unlock ();
 
-  app = application_get (sep->app_index);
   application_alloc_connects_segment_manager (app);
+  ctx->tls_ctx_engine = engine_type;
 
   clib_memcpy (&tls_sep, sep, sizeof (tls_sep));
   tls_sep.transport_proto = TRANSPORT_PROTO_TCP;
   if ((rv = application_connect (tm->app_index, ctx_index, &tls_sep)))
     return rv;
 
-  TLS_DBG (1, "New connect request %u", ctx_index);
+  TLS_DBG (1, "New connect request %u engine %d", ctx_index, engine_type);
   return 0;
 }
 
 void
-tls_disconnect (u32 ctx_index, u32 thread_index)
+tls_disconnect (u32 ctx_handle, u32 thread_index)
 {
   stream_session_t *tls_session, *app_session;
   tls_ctx_t *ctx;
 
-  TLS_DBG (1, "Disconnecting %u", ctx_index);
+  TLS_DBG (1, "Disconnecting %x", ctx_handle);
 
-  ctx = tls_ctx_get (ctx_index);
+  ctx = tls_ctx_get (ctx_handle);
   tls_session = session_get_from_handle (ctx->tls_session_handle);
   stream_session_disconnect (tls_session);
 
@@ -593,7 +550,7 @@
 tls_start_listen (u32 app_listener_index, transport_endpoint_t * tep)
 {
   tls_main_t *tm = &tls_main;
-  application_t *tls_app;
+  application_t *tls_app, *app;
   session_handle_t tls_handle;
   session_endpoint_extended_t *sep;
   stream_session_t *tls_listener;
@@ -601,12 +558,18 @@
   u32 lctx_index;
   session_type_t st;
   stream_session_t *app_listener;
+  tls_engine_type_t engine_type;
 
   sep = (session_endpoint_extended_t *) tep;
+  app = application_get (sep->app_index);
+  engine_type = tls_get_engine_type (app->tls_engine);
+  if (engine_type == TLS_ENGINE_NONE)
+    {
+      clib_warning ("No tls engine_type available");
+      return -1;
+    }
+
   lctx_index = tls_listener_ctx_alloc ();
-  lctx = tls_listener_ctx_get (lctx_index);
-  st = session_type_from_proto_and_ip (sep->transport_proto, sep->is_ip4);
-  app_listener = listen_session_get (st, app_listener_index);
 
   tls_app = application_get (tm->app_index);
   sep->transport_proto = TRANSPORT_PROTO_TCP;
@@ -616,10 +579,19 @@
 
   tls_listener = listen_session_get_from_handle (tls_handle);
   tls_listener->opaque = lctx_index;
+
+  st = session_type_from_proto_and_ip (TRANSPORT_PROTO_TLS, sep->is_ip4);
+  app_listener = listen_session_get (st, app_listener_index);
+
+  lctx = tls_listener_ctx_get (lctx_index);
   lctx->parent_app_index = sep->app_index;
   lctx->tls_session_handle = tls_handle;
   lctx->app_session_handle = listen_session_get_handle (app_listener);
   lctx->tcp_is_ip4 = sep->is_ip4;
+  lctx->tls_ctx_engine = engine_type;
+
+  TLS_DBG (1, "Started listening %d, engine type %d", lctx_index,
+	   engine_type);
   return lctx_index;
 }
 
@@ -739,11 +711,15 @@
 clib_error_t *
 tls_init (vlib_main_t * vm)
 {
+  vlib_thread_main_t *vtm = vlib_get_thread_main ();
   vnet_app_attach_args_t _a, *a = &_a;
   u64 options[APP_OPTIONS_N_OPTIONS];
   u32 segment_size = 512 << 20;
   tls_main_t *tm = &tls_main;
   u32 fifo_size = 64 << 10;
+  u32 num_threads;
+
+  num_threads = 1 /* main thread */  + vtm->n_threads;
 
   memset (a, 0, sizeof (*a));
   memset (options, 0, sizeof (options));
@@ -769,6 +745,9 @@
   tm->app_index = a->app_index;
   clib_rwlock_init (&tm->half_open_rwlock);
 
+  vec_validate (tm->rx_bufs, num_threads - 1);
+  vec_validate (tm->tx_bufs, num_threads - 1);
+
   transport_register_protocol (TRANSPORT_PROTO_TLS, &tls_proto,
 			       FIB_PROTOCOL_IP4, ~0);
   transport_register_protocol (TRANSPORT_PROTO_TLS, &tls_proto,
diff --git a/src/vnet/tls/tls.h b/src/vnet/tls/tls.h
index 0dfc48b..c900b10 100644
--- a/src/vnet/tls/tls.h
+++ b/src/vnet/tls/tls.h
@@ -43,6 +43,7 @@
   session_handle_t tls_session_handle;
   u32 listener_ctx_index;
   u8 tcp_is_ip4;
+  u8 tls_engine_id;
 }) tls_ctx_id_t;
 /* *INDENT-ON* */
 
@@ -60,7 +61,8 @@
 #define tls_session_handle c_tls_ctx_id.tls_session_handle
 #define listener_ctx_index c_tls_ctx_id.listener_ctx_index
 #define tcp_is_ip4 c_tls_ctx_id.tcp_is_ip4
-#define tls_ctx_idx c_c_index
+#define tls_ctx_engine c_tls_ctx_id.tls_engine_id
+#define tls_ctx_handle c_c_index
   /* Temporary storage for session open opaque. Overwritten once
    * underlying tcp connection is established */
 #define parent_app_api_context c_s_index
@@ -75,6 +77,8 @@
   tls_ctx_t *listener_ctx_pool;
   tls_ctx_t *half_open_ctx_pool;
   clib_rwlock_t half_open_rwlock;
+  u8 **rx_bufs;
+  u8 **tx_bufs;
 
   /*
    * Config
@@ -91,22 +95,14 @@
   tls_ctx_t *(*ctx_get_w_thread) (u32 ctx_index, u8 thread_index);
   int (*ctx_init_client) (tls_ctx_t * ctx);
   int (*ctx_init_server) (tls_ctx_t * ctx);
-  int (*ctx_read) (tls_ctx_t * ctx, u8 * buf, u32 len);
-  int (*ctx_write) (tls_ctx_t * ctx, u8 * buf, u32 len);
-  int (*ctx_handshake_rx) (tls_ctx_t * ctx);
+  int (*ctx_read) (tls_ctx_t * ctx, stream_session_t * tls_session);
+  int (*ctx_write) (tls_ctx_t * ctx, stream_session_t * app_session);
     u8 (*ctx_handshake_is_over) (tls_ctx_t * ctx);
 } tls_engine_vft_t;
 
-enum tls_handshake_results_
-{
-  HANDSHAKE_NOT_OVER,
-  CLIENT_HANDSHAKE_OK,
-  CLIENT_HANDSHAKE_FAIL,
-  SERVER_HANDSHAKE_OK
-};
-
 typedef enum tls_engine_type_
 {
+  TLS_ENGINE_NONE,
   TLS_ENGINE_MBEDTLS,
   TLS_ENGINE_OPENSSL,
   TLS_N_ENGINES
@@ -116,7 +112,9 @@
 void tls_register_engine (const tls_engine_vft_t * vft,
 			  tls_engine_type_t type);
 int tls_add_vpp_q_evt (svm_fifo_t * f, u8 evt_type);
-
+int tls_notify_app_accept (tls_ctx_t * ctx);
+int tls_notify_app_connected (tls_ctx_t * ctx, u8 is_failed);
+void tls_notify_app_enqueue (tls_ctx_t * ctx, stream_session_t * app_session);
 #endif /* SRC_VNET_TLS_TLS_H_ */
 /*
  * fd.io coding-style-patch-verification: ON