/*
 * 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 <errno.h>
#include <fcntl.h>
#include <stdint.h>
#include <sys/wait.h>
#include <unistd.h>

#include "api/s2n.h"
#include "s2n_test.h"
#include "testlib/s2n_testlib.h"
#include "tls/s2n_connection.h"
#include "tls/s2n_handshake.h"
#include "tls/s2n_tls.h"
#include "tls/s2n_tls_parameters.h"

#define ZERO_TO_THIRTY_ONE 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, \
                           0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F

int main(int argc, char **argv)
{
    char *cert_chain;
    char *private_key;
    BEGIN_TEST();
    EXPECT_SUCCESS(s2n_disable_tls13_in_test());

    EXPECT_NOT_NULL(cert_chain = malloc(S2N_MAX_TEST_PEM_SIZE));
    EXPECT_NOT_NULL(private_key = malloc(S2N_MAX_TEST_PEM_SIZE));
    EXPECT_SUCCESS(setenv("S2N_DONT_MLOCK", "1", 0));

    /* Server negotiates TLS1.2 */
    {
        struct s2n_connection *client_conn;
        struct s2n_config *client_config;
        s2n_blocked_status client_blocked;

        uint8_t server_hello_message[] = {
            /* Protocol version TLS 1.2 */
            0x03, 0x03,
            /* Server random */
            ZERO_TO_THIRTY_ONE,
            /* SessionID len - 32 bytes */
            0x20,
            /* Session ID */
            ZERO_TO_THIRTY_ONE,
            /* Cipher suite - TLS_RSA_WITH_AES_128_CBC_SHA256 */
            0x00, 0x3C,
            /* Compression method - none */
            0x00,
            /* Extensions len */
            0x00, 0x00
        };
        int body_len = sizeof(server_hello_message);
        uint8_t message_header[] = {
            /* Handshake message type SERVER HELLO */
            0x02,
            /* Body len */
            (body_len >> 16) & 0xff,
            (body_len >> 8) & 0xff,
            (body_len & 0xff),
        };
        int message_len = sizeof(message_header) + body_len;
        uint8_t record_header[] = {
            /* Record type HANDSHAKE */
            0x16,
            /* Protocol version TLS 1.2 */
            0x03,
            0x03,
            /* Message len */
            (message_len >> 8) & 0xff,
            (message_len & 0xff),
        };

        /* Create nonblocking pipes */
        struct s2n_test_io_pair io_pair;
        EXPECT_SUCCESS(s2n_io_pair_init_non_blocking(&io_pair));

        EXPECT_NOT_NULL(client_conn = s2n_connection_new(S2N_CLIENT));
        EXPECT_SUCCESS(s2n_connection_set_io_pair(client_conn, &io_pair));

        EXPECT_NOT_NULL(client_config = s2n_config_new());
        EXPECT_SUCCESS(s2n_config_set_cipher_preferences(client_config, "test_all"));
        EXPECT_SUCCESS(s2n_connection_set_config(client_conn, client_config));

        /* Send the client hello */
        EXPECT_EQUAL(s2n_negotiate(client_conn, &client_blocked), -1);
        EXPECT_EQUAL(s2n_errno, S2N_ERR_IO_BLOCKED);
        EXPECT_EQUAL(client_blocked, S2N_BLOCKED_ON_READ);

        /* Read ClientHello s2n wrote */
        uint8_t buf[1024];
        size_t buf_occupied = 0;

        /* we need only first 10 bytes to get to ClientHello protocol version */
        while (buf_occupied < 10) {
            ssize_t n = read(io_pair.server, buf + buf_occupied, sizeof(buf) - buf_occupied);

            /* We should be able to read 10 bytes without blocking */
            EXPECT_TRUE(n > 0);
            buf_occupied += n;
        }
        /* Record Type is Handshake */
        EXPECT_EQUAL(buf[0], 0x16);
        /* Protocol version is TLS1.0 */
        EXPECT_EQUAL(buf[1], 0x03);
        EXPECT_EQUAL(buf[2], 0x01);
        /* Handshake Type is ClientHello */
        EXPECT_EQUAL(buf[5], 0x01);
        /* Handshake Protocol Version is TLS1.2 */
        EXPECT_EQUAL(buf[9], 0x03);
        EXPECT_EQUAL(buf[10], 0x03);

        /* Read the rest of the pipe */
        while (1) {
            ssize_t n = read(io_pair.server, buf, sizeof(buf));

            if (n > 0) {
                continue;
            }

            EXPECT_EQUAL(n, -1);
            if (errno == EAGAIN || errno == EWOULDBLOCK) {
                break;
            }
        }

        /* Write the server hello */
        EXPECT_EQUAL(write(io_pair.server, record_header, sizeof(record_header)), sizeof(record_header));
        EXPECT_EQUAL(write(io_pair.server, message_header, sizeof(message_header)), sizeof(message_header));
        EXPECT_EQUAL(write(io_pair.server, server_hello_message, sizeof(server_hello_message)), sizeof(server_hello_message));

        /* Verify that we proceed with handshake */
        EXPECT_EQUAL(s2n_negotiate(client_conn, &client_blocked), -1);
        EXPECT_EQUAL(s2n_errno, S2N_ERR_IO_BLOCKED);
        EXPECT_EQUAL(client_blocked, S2N_BLOCKED_ON_READ);

        /* Verify that protocol versions are TLS1.2 now */
        EXPECT_EQUAL(client_conn->client_protocol_version, S2N_TLS12);
        EXPECT_EQUAL(client_conn->actual_protocol_version, S2N_TLS12);
        EXPECT_EQUAL(client_conn->server_protocol_version, S2N_TLS12);

        /* Now lets shutdown the connection and verify that alert is sent in record with protocol version TLS1.2 */
        EXPECT_SUCCESS(s2n_shutdown(client_conn, &client_blocked));

        /* Receive the next record from client and ensure that record protocol version is TLS1.2 */
        buf_occupied = 0;
        /* We need only first 5 bytes to get to record protocol version */
        while (buf_occupied < 5) {
            ssize_t n = read(io_pair.server, buf + buf_occupied, sizeof(buf) - buf_occupied);

            /* We should be able to read 5 bytes without blocking */
            EXPECT_TRUE(n > 0);
            buf_occupied += n;
        }
        /* Protocol version is TLS1.2 now */
        EXPECT_EQUAL(buf[1], 0x03);
        EXPECT_EQUAL(buf[2], 0x03);

        EXPECT_SUCCESS(s2n_connection_free(client_conn));
        EXPECT_SUCCESS(s2n_config_free(client_config));

        EXPECT_SUCCESS(s2n_io_pair_close(&io_pair));
    };

    /* Server negotiates SSLv3 */
    {
        struct s2n_connection *client_conn;
        struct s2n_config *client_config;
        s2n_blocked_status client_blocked;

        uint8_t server_hello_message[] = {
            /* Protocol version SSLv3 */
            0x03, 0x00,
            /* Server random */
            ZERO_TO_THIRTY_ONE,
            /* SessionID len - 32 bytes */
            0x20,
            /* Session ID */
            ZERO_TO_THIRTY_ONE,
            /* Cipher suite - DES-CBC3-SHA */
            0x00, 0x0A,
            /* Compression method - none */
            0x00,
            /* Extensions len */
            0x00, 0x00
        };
        int body_len = sizeof(server_hello_message);
        uint8_t message_header[] = {
            /* Handshake message type SERVER HELLO */
            0x02,
            /* Body len */
            (body_len >> 16) & 0xff,
            (body_len >> 8) & 0xff,
            (body_len & 0xff),
        };
        int message_len = sizeof(message_header) + body_len;
        uint8_t record_header[] = {
            /* Record type HANDSHAKE */
            0x16,
            /* Protocol version SSLv3 */
            0x03,
            0x00,
            /* Message len */
            (message_len >> 8) & 0xff,
            (message_len & 0xff),
        };

        /* Create nonblocking pipes */
        struct s2n_test_io_pair io_pair;
        EXPECT_SUCCESS(s2n_io_pair_init_non_blocking(&io_pair));

        EXPECT_NOT_NULL(client_conn = s2n_connection_new(S2N_CLIENT));
        EXPECT_SUCCESS(s2n_connection_set_io_pair(client_conn, &io_pair));

        EXPECT_NOT_NULL(client_config = s2n_config_new());
        EXPECT_SUCCESS(s2n_config_set_cipher_preferences(client_config, "test_all"));
        EXPECT_SUCCESS(s2n_connection_set_config(client_conn, client_config));

        /* Send the client hello */
        EXPECT_EQUAL(s2n_negotiate(client_conn, &client_blocked), -1);
        EXPECT_EQUAL(s2n_errno, S2N_ERR_IO_BLOCKED);
        EXPECT_EQUAL(client_blocked, S2N_BLOCKED_ON_READ);

        /* Read ClientHello s2n wrote */
        uint8_t buf[1024];
        size_t buf_occupied = 0;

        /* we need only first 10 bytes to get to ClientHello protocol version */
        while (buf_occupied < 10) {
            ssize_t n = read(io_pair.server, buf + buf_occupied, sizeof(buf) - buf_occupied);

            /* We should be able to read 10 bytes without blocking */
            EXPECT_TRUE(n > 0);
            buf_occupied += n;
        }
        /* Record Type is Handshake */
        EXPECT_EQUAL(buf[0], 0x16);
        /* Protocol version is TLS1.0 */
        EXPECT_EQUAL(buf[1], 0x03);
        EXPECT_EQUAL(buf[2], 0x01);
        /* Handshake Type is ClientHello */
        EXPECT_EQUAL(buf[5], 0x01);
        /* Handshake Protocol Version is TLS1.2 */
        EXPECT_EQUAL(buf[9], 0x03);
        EXPECT_EQUAL(buf[10], 0x03);

        /* Read the rest of the pipe */
        while (1) {
            ssize_t n = read(io_pair.server, buf, sizeof(buf));

            if (n > 0) {
                continue;
            }

            EXPECT_EQUAL(n, -1);
            if (errno == EAGAIN || errno == EWOULDBLOCK) {
                break;
            }
        }

        /* Write the server hello */
        EXPECT_EQUAL(write(io_pair.server, record_header, sizeof(record_header)), sizeof(record_header));
        EXPECT_EQUAL(write(io_pair.server, message_header, sizeof(message_header)), sizeof(message_header));
        EXPECT_EQUAL(write(io_pair.server, server_hello_message, sizeof(server_hello_message)), sizeof(server_hello_message));

        /* Verify that we proceed with handshake */
        EXPECT_EQUAL(s2n_negotiate(client_conn, &client_blocked), -1);
        EXPECT_EQUAL(s2n_errno, S2N_ERR_IO_BLOCKED);
        EXPECT_EQUAL(client_blocked, S2N_BLOCKED_ON_READ);

        /* Verify that protocol versions are SSLv3 with the exeption of client which supports TLS1.2 */
        EXPECT_EQUAL(client_conn->client_protocol_version, S2N_TLS12);
        EXPECT_EQUAL(client_conn->actual_protocol_version, S2N_SSLv3);
        EXPECT_EQUAL(client_conn->server_protocol_version, S2N_SSLv3);

        /* Now lets shutdown the connection and verify that alert is sent in record with protocol version SSLv3 */
        EXPECT_SUCCESS(s2n_shutdown(client_conn, &client_blocked));

        /* Receive the next record from client and ensure that record protocol version is SSLv3 */
        buf_occupied = 0;
        /* We need only first 5 bytes to get to record protocol version */
        while (buf_occupied < 5) {
            ssize_t n = read(io_pair.server, buf + buf_occupied, sizeof(buf) - buf_occupied);

            /* We should be able to read 5 bytes without blocking */
            EXPECT_TRUE(n > 0);
            buf_occupied += n;
        }
        /* Protocol version is SSLv3 now */
        EXPECT_EQUAL(buf[1], 0x03);
        EXPECT_EQUAL(buf[2], 0x00);

        EXPECT_SUCCESS(s2n_connection_free(client_conn));
        EXPECT_SUCCESS(s2n_config_free(client_config));

        EXPECT_SUCCESS(s2n_io_pair_close(&io_pair));
    };

    free(cert_chain);
    free(private_key);
    END_TEST();
    return 0;
}