ktls interface

tests/unit/s2n_ktls_test.c

@@ -0,0 +1,188 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file 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 "tls/s2n_ktls.h"
+
+#include <stdlib.h>
+
+#include "api/s2n.h"
+#include "crypto/s2n_fips.h"
+#include "s2n_test.h"
+#include "testlib/s2n_testlib.h"
+#include "tls/s2n_config.h"
+#include "tls/s2n_connection.h"
+#include "tls/s2n_record.h"
+#include "tls/s2n_security_policies.h"
+#include "tls/s2n_tls13.h"
+
+int main(int argc, char **argv)
+{
+    BEGIN_TEST();
+    EXPECT_SUCCESS(s2n_disable_tls13_in_test());
+
+    const struct s2n_security_policy *default_security_policy, *tls13_security_policy, *fips_security_policy;
+    EXPECT_SUCCESS(s2n_find_security_policy_from_version("default_tls13", &tls13_security_policy));
+    EXPECT_SUCCESS(s2n_find_security_policy_from_version("default_fips", &fips_security_policy));
+    EXPECT_SUCCESS(s2n_find_security_policy_from_version("default", &default_security_policy));
+
+    char cert[S2N_MAX_TEST_PEM_SIZE] = { 0 };
+    EXPECT_SUCCESS(s2n_read_test_pem(S2N_DEFAULT_TEST_CERT_CHAIN, cert, S2N_MAX_TEST_PEM_SIZE));
+    char key[S2N_MAX_TEST_PEM_SIZE] = { 0 };
+    EXPECT_SUCCESS(s2n_read_test_pem(S2N_DEFAULT_TEST_PRIVATE_KEY, key, S2N_MAX_TEST_PEM_SIZE));
+
+    /* config default kTLS mode */
+    {
+        DEFER_CLEANUP(struct s2n_config *config = s2n_config_new(), s2n_config_ptr_free);
+        EXPECT_NOT_NULL(config);
+        EXPECT_EQUAL(config->ktls_mode_requested, S2N_KTLS_MODE_DISABLED);
+        EXPECT_TRUE(s2n_config_is_ktls_requested(config, S2N_KTLS_MODE_DISABLED));
+        EXPECT_FALSE(s2n_config_is_ktls_requested(config, S2N_KTLS_MODE_SEND));
+        EXPECT_FALSE(s2n_config_is_ktls_requested(config, S2N_KTLS_MODE_RECV));
+        EXPECT_FALSE(s2n_config_is_ktls_requested(config, S2N_KTLS_MODE_DUPLEX));
+    };
+
+    /* request config kTLS mode
+     *
+     * Requesting Duplex means the Send and Recv are also requested
+     */
+    {
+        DEFER_CLEANUP(struct s2n_config *config = s2n_config_new(), s2n_config_ptr_free);
+        EXPECT_NOT_NULL(config);
+
+        EXPECT_SUCCESS(s2n_config_ktls_enable(config, S2N_KTLS_MODE_SEND));
+        EXPECT_FALSE(s2n_config_is_ktls_requested(config, S2N_KTLS_MODE_DISABLED));
+        EXPECT_TRUE(s2n_config_is_ktls_requested(config, S2N_KTLS_MODE_SEND));
+        EXPECT_FALSE(s2n_config_is_ktls_requested(config, S2N_KTLS_MODE_RECV));
+        EXPECT_FALSE(s2n_config_is_ktls_requested(config, S2N_KTLS_MODE_DUPLEX));
+
+        EXPECT_SUCCESS(s2n_config_ktls_enable(config, S2N_KTLS_MODE_RECV));
+        EXPECT_FALSE(s2n_config_is_ktls_requested(config, S2N_KTLS_MODE_DISABLED));
+        EXPECT_FALSE(s2n_config_is_ktls_requested(config, S2N_KTLS_MODE_SEND));
+        EXPECT_TRUE(s2n_config_is_ktls_requested(config, S2N_KTLS_MODE_RECV));
+        EXPECT_FALSE(s2n_config_is_ktls_requested(config, S2N_KTLS_MODE_DUPLEX));
+
+        EXPECT_SUCCESS(s2n_config_ktls_enable(config, S2N_KTLS_MODE_DUPLEX));
+        EXPECT_FALSE(s2n_config_is_ktls_requested(config, S2N_KTLS_MODE_DISABLED));
+        EXPECT_TRUE(s2n_config_is_ktls_requested(config, S2N_KTLS_MODE_SEND));
+        EXPECT_TRUE(s2n_config_is_ktls_requested(config, S2N_KTLS_MODE_RECV));
+        EXPECT_TRUE(s2n_config_is_ktls_requested(config, S2N_KTLS_MODE_DUPLEX));
+
+        EXPECT_SUCCESS(s2n_config_ktls_enable(config, S2N_KTLS_MODE_DISABLED));
+        EXPECT_TRUE(s2n_config_is_ktls_requested(config, S2N_KTLS_MODE_DISABLED));
+        EXPECT_FALSE(s2n_config_is_ktls_requested(config, S2N_KTLS_MODE_SEND));
+        EXPECT_FALSE(s2n_config_is_ktls_requested(config, S2N_KTLS_MODE_RECV));
+        EXPECT_FALSE(s2n_config_is_ktls_requested(config, S2N_KTLS_MODE_DUPLEX));
+    };
+
+    /* connection default kTLS mode */
+    {
+        DEFER_CLEANUP(struct s2n_connection *conn = s2n_connection_new(S2N_CLIENT),
+                s2n_connection_ptr_free);
+        EXPECT_NOT_NULL(conn);
+        DEFER_CLEANUP(struct s2n_test_io_pair io_pair = { 0 }, s2n_io_pair_close);
+        EXPECT_SUCCESS(s2n_io_pair_init_non_blocking(&io_pair));
+        EXPECT_SUCCESS(s2n_connection_set_io_pair(conn, &io_pair));
+        EXPECT_TRUE(conn->managed_send_io);
+        EXPECT_TRUE(conn->managed_recv_io);
+
+        EXPECT_EQUAL(conn->ktls_mode_enabled, S2N_KTLS_MODE_DISABLED);
+        EXPECT_TRUE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_DISABLED));
+        EXPECT_FALSE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_SEND));
+        EXPECT_FALSE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_RECV));
+        EXPECT_FALSE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_DUPLEX));
+    };
+
+    /* enable kTLS modes
+     *
+     * Enabling TX and RX modes is additive and equals Duplex
+     */
+    {
+        DEFER_CLEANUP(struct s2n_connection *conn = s2n_connection_new(S2N_CLIENT),
+                s2n_connection_ptr_free);
+        EXPECT_NOT_NULL(conn);
+        DEFER_CLEANUP(struct s2n_test_io_pair io_pair = { 0 }, s2n_io_pair_close);
+        EXPECT_SUCCESS(s2n_io_pair_init_non_blocking(&io_pair));
+        EXPECT_SUCCESS(s2n_connection_set_io_pair(conn, &io_pair));
+        EXPECT_TRUE(conn->managed_send_io);
+        EXPECT_TRUE(conn->managed_recv_io);
+
+        EXPECT_EQUAL(conn->ktls_mode_enabled, S2N_KTLS_MODE_DISABLED);
+
+        EXPECT_OK(s2n_connection_mark_ktls_enabled(conn, S2N_KTLS_MODE_RECV));
+        EXPECT_FALSE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_DISABLED));
+        EXPECT_TRUE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_RECV));
+        EXPECT_FALSE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_SEND));
+        EXPECT_FALSE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_DUPLEX));
+
+        EXPECT_OK(s2n_connection_mark_ktls_enabled(conn, S2N_KTLS_MODE_SEND));
+        EXPECT_FALSE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_DISABLED));
+        EXPECT_TRUE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_RECV));
+        EXPECT_TRUE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_SEND));
+        EXPECT_TRUE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_DUPLEX));
+    };
+
+    /* enable kTLS duplex */
+    {
+        DEFER_CLEANUP(struct s2n_connection *conn = s2n_connection_new(S2N_CLIENT),
+                s2n_connection_ptr_free);
+        EXPECT_NOT_NULL(conn);
+        DEFER_CLEANUP(struct s2n_test_io_pair io_pair = { 0 }, s2n_io_pair_close);
+        EXPECT_SUCCESS(s2n_io_pair_init_non_blocking(&io_pair));
+        EXPECT_SUCCESS(s2n_connection_set_io_pair(conn, &io_pair));
+        EXPECT_TRUE(conn->managed_send_io);
+        EXPECT_TRUE(conn->managed_recv_io);
+
+        EXPECT_EQUAL(conn->ktls_mode_enabled, S2N_KTLS_MODE_DISABLED);
+
+        EXPECT_OK(s2n_connection_mark_ktls_enabled(conn, S2N_KTLS_MODE_DUPLEX));
+        EXPECT_FALSE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_DISABLED));
+        EXPECT_TRUE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_SEND));
+        EXPECT_TRUE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_RECV));
+        EXPECT_TRUE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_DUPLEX));
+    };
+
+    /* DISALLOW kTLS disable on connection
+     *
+     * kTLS cannot be disabled once it has been enabled
+     *
+     * Note: This behavior might change if we introduce a kernel patch which
+     * support user space fallback from kTLS.
+     */
+    {
+        DEFER_CLEANUP(struct s2n_connection *conn = s2n_connection_new(S2N_CLIENT),
+                s2n_connection_ptr_free);
+        EXPECT_NOT_NULL(conn);
+        DEFER_CLEANUP(struct s2n_test_io_pair io_pair = { 0 }, s2n_io_pair_close);
+        EXPECT_SUCCESS(s2n_io_pair_init_non_blocking(&io_pair));
+        EXPECT_SUCCESS(s2n_connection_set_io_pair(conn, &io_pair));
+        EXPECT_TRUE(conn->managed_send_io);
+        EXPECT_TRUE(conn->managed_recv_io);
+
+        EXPECT_EQUAL(conn->ktls_mode_enabled, S2N_KTLS_MODE_DISABLED);
+
+        EXPECT_OK(s2n_connection_mark_ktls_enabled(conn, S2N_KTLS_MODE_DUPLEX));
+        EXPECT_TRUE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_SEND));
+        EXPECT_TRUE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_RECV));
+        EXPECT_TRUE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_DUPLEX));
+
+        EXPECT_OK(s2n_connection_mark_ktls_enabled(conn, S2N_KTLS_MODE_DISABLED));
+        EXPECT_FALSE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_DISABLED));
+        EXPECT_TRUE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_SEND));
+        EXPECT_TRUE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_RECV));
+        EXPECT_TRUE(s2n_connection_matches_ktls_mode(conn, S2N_KTLS_MODE_DUPLEX));
+    };
+
+    END_TEST();
+}

tls/s2n_config.c

@@ -13,6 +13,8 @@
  * permissions and limitations under the License.
  */
 
+#include "tls/s2n_config.h"
+
 #include <strings.h>
 #include <time.h>
 
@@ -22,6 +24,7 @@
 #include "error/s2n_errno.h"
 #include "tls/s2n_cipher_preferences.h"
 #include "tls/s2n_internal.h"
+#include "tls/s2n_ktls.h"
 #include "tls/s2n_security_policies.h"
 #include "tls/s2n_tls13.h"
 #include "utils/s2n_blob.h"
@@ -1067,3 +1070,24 @@ int s2n_config_set_recv_multi_record(struct s2n_config *config, bool enabled)
 
     return S2N_SUCCESS;
 }
+
+int s2n_config_ktls_enable(struct s2n_config *config, s2n_ktls_mode ktls_mode)
+{
+    POSIX_ENSURE_REF(config);
+
+    config->ktls_mode_requested = ktls_mode;
+    return S2N_SUCCESS;
+}
+
+bool s2n_config_is_ktls_requested(struct s2n_config *config, s2n_ktls_mode ktls_mode)
+{
+    POSIX_ENSURE_REF(config);
+
+    if (ktls_mode == S2N_KTLS_MODE_DUPLEX) {
+        return config->ktls_mode_requested == S2N_KTLS_MODE_DUPLEX;
+    }
+    if (ktls_mode == S2N_KTLS_MODE_DISABLED) {
+        return config->ktls_mode_requested == S2N_KTLS_MODE_DISABLED;
+    }
+    return config->ktls_mode_requested & ktls_mode;
+}

tls/s2n_config.h

@@ -19,6 +19,7 @@
 #include "crypto/s2n_certificate.h"
 #include "crypto/s2n_dhe.h"
 #include "tls/s2n_crl.h"
+#include "tls/s2n_ktls.h"
 #include "tls/s2n_psk.h"
 #include "tls/s2n_renegotiate.h"
 #include "tls/s2n_resume.h"
@@ -175,6 +176,11 @@ struct s2n_config {
 
     void *renegotiate_request_ctx;
     s2n_renegotiate_request_cb renegotiate_request_cb;
+
+    /* Depending on OS and configuration it is possible to use kTLS.
+     *
+     * This option indicates if connections should attempt to use kTLS. */
+    s2n_ktls_mode ktls_mode_requested;
 };
 
 S2N_CLEANUP_RESULT s2n_config_ptr_free(struct s2n_config **config);
@@ -190,3 +196,4 @@ void s2n_wipe_static_configs(void);
 extern struct s2n_cert_chain_and_key *s2n_config_get_single_default_cert(struct s2n_config *config);
 int s2n_config_get_num_default_certs(struct s2n_config *config);
 S2N_RESULT s2n_config_wall_clock(struct s2n_config *config, uint64_t *output);
+bool s2n_config_is_ktls_requested(struct s2n_config *config, s2n_ktls_mode ktls_mode);

tls/s2n_connection.c

@@ -37,6 +37,7 @@
 #include "tls/s2n_handshake.h"
 #include "tls/s2n_internal.h"
 #include "tls/s2n_kem.h"
+#include "tls/s2n_ktls.h"
 #include "tls/s2n_prf.h"
 #include "tls/s2n_record.h"
 #include "tls/s2n_resume.h"
@@ -1517,3 +1518,38 @@ S2N_RESULT s2n_connection_dynamic_free_in_buffer(struct s2n_connection *conn)
 
     return S2N_RESULT_OK;
 }
+
+/* Marks s2n_ktls_mode enabled for the connection.
+ *
+ * Note: currently, kTLS cannot be disabled once enabled.
+ */
+S2N_RESULT s2n_connection_mark_ktls_enabled(struct s2n_connection *conn, s2n_ktls_mode ktls_mode)
+{
+    RESULT_ENSURE_REF(conn);
+
+    /* kTLS I/O functionality is managed by s2n-tls. kTLS cannot be enabled
+     * if the application sets custom I/O. */
+    if ((ktls_mode == S2N_KTLS_MODE_SEND || ktls_mode == S2N_KTLS_MODE_DUPLEX) && !conn->managed_send_io) {
+        return S2N_RESULT_ERROR;
+    }
+    if ((ktls_mode == S2N_KTLS_MODE_RECV || ktls_mode == S2N_KTLS_MODE_DUPLEX) && !conn->managed_recv_io) {
+        return S2N_RESULT_ERROR;
+    }
+
+    conn->ktls_mode_enabled |= ktls_mode;
+
+    return S2N_RESULT_OK;
+}
+
+bool s2n_connection_matches_ktls_mode(struct s2n_connection *conn, s2n_ktls_mode ktls_mode)
+{
+    POSIX_ENSURE_REF(conn);
+
+    if (ktls_mode == S2N_KTLS_MODE_DUPLEX) {
+        return conn->ktls_mode_enabled == S2N_KTLS_MODE_DUPLEX;
+    }
+    if (ktls_mode == S2N_KTLS_MODE_DISABLED) {
+        return conn->ktls_mode_enabled == S2N_KTLS_MODE_DISABLED;
+    }
+    return conn->ktls_mode_enabled & ktls_mode;
+}

tls/s2n_connection.h

@@ -282,8 +282,8 @@ struct s2n_connection {
      */
     uint16_t max_outgoing_fragment_length;
 
-    /* The number of bytes to send before changing the record size. 
-     * If this value > 0 then dynamic TLS record size is enabled. Otherwise, the feature is disabled (default). 
+    /* The number of bytes to send before changing the record size.
+     * If this value > 0 then dynamic TLS record size is enabled. Otherwise, the feature is disabled (default).
      */
     uint32_t dynamic_record_resize_threshold;
 
@@ -385,6 +385,9 @@ struct s2n_connection {
     uint32_t server_keying_material_lifetime;
 
     struct s2n_post_handshake post_handshake;
+
+    /* Marks if kTLS has been enabled for this connection. */
+    s2n_ktls_mode ktls_mode_enabled;
 };
 
 S2N_CLEANUP_RESULT s2n_connection_ptr_free(struct s2n_connection **s2n_connection);
@@ -417,3 +420,4 @@ int s2n_connection_get_client_cert_chain(struct s2n_connection *conn, uint8_t **
 int s2n_connection_get_peer_cert_chain(const struct s2n_connection *conn, struct s2n_cert_chain_and_key *cert_chain_and_key);
 uint8_t s2n_connection_get_protocol_version(const struct s2n_connection *conn);
 S2N_RESULT s2n_connection_set_max_fragment_length(struct s2n_connection *conn, uint16_t length);
+S2N_RESULT s2n_connection_mark_ktls_enabled(struct s2n_connection *conn, s2n_ktls_mode mode);

tls/s2n_ktls.c

@@ -0,0 +1,26 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file 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 "s2n_ktls.h"
+
+/*
+ * TODO implement
+ */
+S2N_RESULT s2n_ktls_enable(struct s2n_connection *conn, s2n_ktls_mode mode)
+{
+    /* TODO perform managed_send_io and managed_recv_io checks */
+
+    return S2N_RESULT_OK;
+}