/*

 * Copyright 1998-2017 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the OpenSSL license (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

/*-

 * A minimal program to serve an SSL connection.

 * It uses blocking.

 * saccept host:port

 * host is the interface IP to use.  If any interface, use *:port

 * The default it *:4433

 *

 * cc -I../../include saccept.c -L../.. -lssl -lcrypto -ldl

 */

#include <stdio.h>

#include <signal.h>

#include <stdlib.h>

#include <openssl/err.h>

#include <openssl/ssl.h>

#define CERT_FILE       "server.pem"

static volatile int done = 0;

void interrupt(int sig)

{

    done = 1;

}

void sigsetup(void)

{

    struct sigaction sa;

    /*

     * Catch at most once, and don't restart the accept system call.

     */

    sa.sa_flags = SA_RESETHAND;

    sa.sa_handler = interrupt;

    sigemptyset(&sa.sa_mask);

    sigaction(SIGINT, &sa, NULL);

}

int main(int argc, char *argv[])

{

    char *port = NULL;

    BIO *in = NULL;

    BIO *ssl_bio, *tmp;

    SSL_CTX *ctx;

    char buf[512];

    int ret = EXIT_FAILURE, i;

    if (argc <= 1)

        port = "*:4433";

    else

        port = argv[1];

    ctx = SSL_CTX_new(TLS_server_method());

    if (!SSL_CTX_use_certificate_chain_file(ctx, CERT_FILE))

        goto err;

    if (!SSL_CTX_use_PrivateKey_file(ctx, CERT_FILE, SSL_FILETYPE_PEM))

        goto err;

    if (!SSL_CTX_check_private_key(ctx))

        goto err;

    /* Setup server side SSL bio */

    ssl_bio = BIO_new_ssl(ctx, 0);

    if ((in = BIO_new_accept(port)) == NULL)

        goto err;

    /*

     * This means that when a new connection is accepted on 'in', The ssl_bio

     * will be 'duplicated' and have the new socket BIO push into it.

     * Basically it means the SSL BIO will be automatically setup

     */

    BIO_set_accept_bios(in, ssl_bio);

    /* Arrange to leave server loop on interrupt */

    sigsetup();

 again:

    /*

     * The first call will setup the accept socket, and the second will get a

     * socket.  In this loop, the first actual accept will occur in the

     * BIO_read() function.

     */

    if (BIO_do_accept(in) <= 0)

        goto err;

    while (!done) {

        i = BIO_read(in, buf, 512);

        if (i == 0) {

            /*

             * If we have finished, remove the underlying BIO stack so the

             * next time we call any function for this BIO, it will attempt

             * to do an accept

             */

            printf("Done\n");

            tmp = BIO_pop(in);

            BIO_free_all(tmp);

            goto again;

        }

        if (i < 0)

            goto err;

        fwrite(buf, 1, i, stdout);

        fflush(stdout);

    }

    ret = EXIT_SUCCESS;

 err:

    if (ret != EXIT_SUCCESS)

        ERR_print_errors_fp(stderr);

    BIO_free(in);

    return ret;

}