/*

 * Copyright 2013-2017 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. It use the

 * SSL_CONF API with the command line. cc -I../../include server-arg.c

 * -L../.. -lssl -lcrypto -ldl

 */

#include <stdio.h>

#include <string.h>

#include <signal.h>

#include <stdlib.h>

#include <openssl/err.h>

#include <openssl/ssl.h>

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

{

    char *port = "*:4433";

    BIO *ssl_bio, *tmp;

    SSL_CTX *ctx;

    SSL_CONF_CTX *cctx;

    char buf[512];

    BIO *in = NULL;

    int ret = EXIT_FAILURE, i;

    char **args = argv + 1;

    int nargs = argc - 1;

    ctx = SSL_CTX_new(TLS_server_method());

    cctx = SSL_CONF_CTX_new();

    SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_SERVER);

    SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_CERTIFICATE);

    SSL_CONF_CTX_set_ssl_ctx(cctx, ctx);

    while (*args && **args == '-') {

        int rv;

        /* Parse standard arguments */

        rv = SSL_CONF_cmd_argv(cctx, &nargs, &args);

        if (rv == -3) {

            fprintf(stderr, "Missing argument for %s\n", *args);

            goto err;

        }

        if (rv < 0) {

            fprintf(stderr, "Error in command %s\n", *args);

            ERR_print_errors_fp(stderr);

            goto err;

        }

        /* If rv > 0 we processed something so proceed to next arg */

        if (rv > 0)

            continue;

        /* Otherwise application specific argument processing */

        if (strcmp(*args, "-port") == 0) {

            port = args[1];

            if (port == NULL) {

                fprintf(stderr, "Missing -port argument\n");

                goto err;

            }

            args += 2;

            nargs -= 2;

            continue;

        } else {

            fprintf(stderr, "Unknown argument %s\n", *args);

            goto err;

        }

    }

    if (!SSL_CONF_CTX_finish(cctx)) {

        fprintf(stderr, "Finish error\n");

        ERR_print_errors_fp(stderr);

        goto err;

    }

#ifdef ITERATE_CERTS

    /*

     * Demo of how to iterate over all certificates in an SSL_CTX structure.

     */

    {

        X509 *x;

        int rv;

        rv = SSL_CTX_set_current_cert(ctx, SSL_CERT_SET_FIRST);

        while (rv) {

            X509 *x = SSL_CTX_get0_certificate(ctx);

            X509_NAME_print_ex_fp(stdout, X509_get_subject_name(x), 0,

                                  XN_FLAG_ONELINE);

            printf("\n");

            rv = SSL_CTX_set_current_cert(ctx, SSL_CERT_SET_NEXT);

        }

        fflush(stdout);

    }

#endif

    /* 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);

 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;

    for (;;) {

        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;

}