/*
  *  OpenVPN -- An application to securely tunnel IP networks
  *             over a single UDP port, with support for SSL/TLS-based
  *             session authentication and key exchange,
  *             packet encryption, packet authentication, and
  *             packet compression.
  *

  *  Copyright (C) 2016-2017 Fox Crypto B.V. <openvpn@fox-it.com>

  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License version 2
  *  as published by the Free Software Foundation.
  *
  *  This program is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  *  GNU General Public License for more details.
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program (see the file COPYING included with this
  *  distribution); if not, write to the Free Software Foundation, Inc.,
  *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #elif defined(_MSC_VER)
 #include "config-msvc.h"
 #endif
 
 #ifdef ENABLE_CRYPTO
 
 #include "syshead.h"
 
 #include <stdio.h>
 #include <unistd.h>
 #include <stdlib.h>
 #include <stdarg.h>
 #include <string.h>
 #include <setjmp.h>
 #include <cmocka.h>
 
 #include "tls_crypt.h"
 
 #include "mock_msg.h"
 

 #define TESTBUF_SIZE            128

 
 const char plaintext_short[1];
 
 struct test_context {

     struct crypto_options co;
     struct key_type kt;
     struct buffer source;
     struct buffer ciphertext;
     struct buffer unwrapped;

 };
 

 static int
 setup(void **state) {

     struct test_context *ctx  = calloc(1, sizeof(*ctx));
 

     ctx->kt.cipher = cipher_kt_get("AES-256-CTR");
     ctx->kt.cipher_length = cipher_kt_key_size(ctx->kt.cipher);
     ctx->kt.digest = md_kt_get("SHA256");
     ctx->kt.hmac_length = md_kt_size(ctx->kt.digest);

 
     struct key key = { 0 };
 

     init_key_ctx(&ctx->co.key_ctx_bi.encrypt, &key, &ctx->kt, true, "TEST");
     init_key_ctx(&ctx->co.key_ctx_bi.decrypt, &key, &ctx->kt, false, "TEST");

     packet_id_init(&ctx->co.packet_id, 0, 0, "test", 0);

 
     ctx->source = alloc_buf(TESTBUF_SIZE);
     ctx->ciphertext = alloc_buf(TESTBUF_SIZE);
     ctx->unwrapped = alloc_buf(TESTBUF_SIZE);
 
     /* Write test plaintext */
     buf_write(&ctx->source, plaintext_short, sizeof(plaintext_short));
 
     /* Write dummy opcode and session id */
     buf_write(&ctx->ciphertext, "012345678", 1 + 8);
 
     *state = ctx;
 
     return 0;
 }
 

 static int
 teardown(void **state) {

     struct test_context *ctx = (struct test_context *) *state;
 

     free_buf(&ctx->source);
     free_buf(&ctx->ciphertext);
     free_buf(&ctx->unwrapped);

     free_key_ctx_bi(&ctx->co.key_ctx_bi);

 
     free(ctx);
 
     return 0;
 }
 
 /**
  * Check that short messages are successfully wrapped-and-unwrapped.
  */

 static void
 tls_crypt_loopback(void **state) {
     struct test_context *ctx = (struct test_context *) *state;
 
     assert_true(tls_crypt_wrap(&ctx->source, &ctx->ciphertext, &ctx->co));
     assert_true(BLEN(&ctx->source) < BLEN(&ctx->ciphertext));
     assert_true(tls_crypt_unwrap(&ctx->ciphertext, &ctx->unwrapped, &ctx->co));
     assert_int_equal(BLEN(&ctx->source), BLEN(&ctx->unwrapped));
     assert_memory_equal(BPTR(&ctx->source), BPTR(&ctx->unwrapped),
                         BLEN(&ctx->source));

 }
 
 /**
  * Check that zero-byte messages are successfully wrapped-and-unwrapped.
  */

 static void
 tls_crypt_loopback_zero_len(void **state) {
     struct test_context *ctx = (struct test_context *) *state;

     buf_clear(&ctx->source);

     assert_true(tls_crypt_wrap(&ctx->source, &ctx->ciphertext, &ctx->co));
     assert_true(BLEN(&ctx->source) < BLEN(&ctx->ciphertext));
     assert_true(tls_crypt_unwrap(&ctx->ciphertext, &ctx->unwrapped, &ctx->co));
     assert_int_equal(BLEN(&ctx->source), BLEN(&ctx->unwrapped));
     assert_memory_equal(BPTR(&ctx->source), BPTR(&ctx->unwrapped),
                         BLEN(&ctx->source));

 }
 
 /**
  * Check that max-length messages are successfully wrapped-and-unwrapped.
  */

 static void
 tls_crypt_loopback_max_len(void **state) {
     struct test_context *ctx = (struct test_context *) *state;
 
     buf_clear(&ctx->source);
     assert_non_null(buf_write_alloc(&ctx->source,
                                     TESTBUF_SIZE - BLEN(&ctx->ciphertext) - tls_crypt_buf_overhead()));
 
     assert_true(tls_crypt_wrap(&ctx->source, &ctx->ciphertext, &ctx->co));
     assert_true(BLEN(&ctx->source) < BLEN(&ctx->ciphertext));
     assert_true(tls_crypt_unwrap(&ctx->ciphertext, &ctx->unwrapped, &ctx->co));
     assert_int_equal(BLEN(&ctx->source), BLEN(&ctx->unwrapped));
     assert_memory_equal(BPTR(&ctx->source), BPTR(&ctx->unwrapped),
                         BLEN(&ctx->source));

 }
 
 /**
  * Check that too-long messages are gracefully rejected.
  */

 static void
 tls_crypt_fail_msg_too_long(void **state) {
     struct test_context *ctx = (struct test_context *) *state;

     buf_clear(&ctx->source);
     assert_non_null(buf_write_alloc(&ctx->source,
                                     TESTBUF_SIZE - BLEN(&ctx->ciphertext) - tls_crypt_buf_overhead() + 1));
     assert_false(tls_crypt_wrap(&ctx->source, &ctx->ciphertext, &ctx->co));

 }
 
 /**
  * Check that packets that were wrapped (or unwrapped) with a different key
  * are not accepted.
  */

 static void
 tls_crypt_fail_invalid_key(void **state) {
     struct test_context *ctx = (struct test_context *) *state;

     /* Change decrypt key */
     struct key key = { { 1 } };
     free_key_ctx(&ctx->co.key_ctx_bi.decrypt);
     init_key_ctx(&ctx->co.key_ctx_bi.decrypt, &key, &ctx->kt, false, "TEST");

     assert_true(tls_crypt_wrap(&ctx->source, &ctx->ciphertext, &ctx->co));
     assert_true(BLEN(&ctx->source) < BLEN(&ctx->ciphertext));
     assert_false(tls_crypt_unwrap(&ctx->ciphertext, &ctx->unwrapped, &ctx->co));

 }
 
 /**
  * Check that replayed packets are not accepted.
  */

 static void
 tls_crypt_fail_replay(void **state) {
     struct test_context *ctx = (struct test_context *) *state;
 
     assert_true(tls_crypt_wrap(&ctx->source, &ctx->ciphertext, &ctx->co));
     assert_true(BLEN(&ctx->source) < BLEN(&ctx->ciphertext));
     struct buffer tmp = ctx->ciphertext;
     assert_true(tls_crypt_unwrap(&tmp, &ctx->unwrapped, &ctx->co));
     buf_clear(&ctx->unwrapped);
     assert_false(tls_crypt_unwrap(&ctx->ciphertext, &ctx->unwrapped, &ctx->co));

 }
 
 /**
  * Check that packet replays are accepted when CO_IGNORE_PACKET_ID is set. This
  * is used for the first control channel packet that arrives, because we don't
  * know the packet ID yet.
  */

 static void
 tls_crypt_ignore_replay(void **state) {
     struct test_context *ctx = (struct test_context *) *state;

     ctx->co.flags |= CO_IGNORE_PACKET_ID;

     assert_true(tls_crypt_wrap(&ctx->source, &ctx->ciphertext, &ctx->co));
     assert_true(BLEN(&ctx->source) < BLEN(&ctx->ciphertext));
     struct buffer tmp = ctx->ciphertext;
     assert_true(tls_crypt_unwrap(&tmp, &ctx->unwrapped, &ctx->co));
     buf_clear(&ctx->unwrapped);
     assert_true(tls_crypt_unwrap(&ctx->ciphertext, &ctx->unwrapped, &ctx->co));

 }
 

 int
 main(void) {

     const struct CMUnitTest tests[] = {

         cmocka_unit_test_setup_teardown(tls_crypt_loopback, setup, teardown),
         cmocka_unit_test_setup_teardown(tls_crypt_loopback_zero_len,
                                         setup, teardown),
         cmocka_unit_test_setup_teardown(tls_crypt_loopback_max_len,
                                         setup, teardown),
         cmocka_unit_test_setup_teardown(tls_crypt_fail_msg_too_long,
                                         setup, teardown),
         cmocka_unit_test_setup_teardown(tls_crypt_fail_invalid_key,
                                         setup, teardown),
         cmocka_unit_test_setup_teardown(tls_crypt_fail_replay,
                                         setup, teardown),
         cmocka_unit_test_setup_teardown(tls_crypt_ignore_replay,
                                         setup, teardown),

     };
 
 #if defined(ENABLE_CRYPTO_OPENSSL)
     OpenSSL_add_all_algorithms();
 #endif
 
     int ret = cmocka_run_group_tests_name("tls-crypt tests", tests, NULL, NULL);
 
 #if defined(ENABLE_CRYPTO_OPENSSL)
     EVP_cleanup();
 #endif
 
     return ret;
 }
 
 #endif /* ENABLE_CRYPTO */