demos/bio/saccept.c

   1 /*
   2  * Copyright 1998-2025 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 /*-
  11  * A minimal program to serve an SSL connection.
  12  * It uses blocking.
  13  * saccept host:port
  14  * host is the interface IP to use.  If any interface, use *:port
  15  * The default it *:4433
  16  *
  17  * cc -I../../include saccept.c -L../.. -lssl -lcrypto -ldl
  18  */
  19
  20 #include <stdio.h>
  21 #include <signal.h>
  22 #include <stdlib.h>
  23 #include <openssl/err.h>
  24 #include <openssl/ssl.h>
  25
  26 #define CERT_FILE       "server.pem"
  27
  28 static volatile int done = 0;
  29
  30 static void interrupt(int sig)
  31 {
  32     done = 1;
  33 }
  34
  35 static void sigsetup(void)
  36 {
  37 #if defined(OPENSSL_SYS_WINDOWS)
  38     signal(SIGINT, interrupt);
  39 #else
  40     struct sigaction sa;
  41
  42     /*
  43      * Catch at most once, and don't restart the accept system call.
  44      */
  45     sa.sa_flags = SA_RESETHAND;
  46     sa.sa_handler = interrupt;
  47     sigemptyset(&sa.sa_mask);
  48     sigaction(SIGINT, &sa, NULL);
  49 #endif
  50 }
  51
  52 int main(int argc, char *argv[])
  53 {
  54     char *port = NULL;
  55     BIO *in = NULL;
  56     BIO *ssl_bio = NULL;
  57     BIO *tmp;
  58     SSL_CTX *ctx;
  59     char buf[512];
  60     int ret = EXIT_FAILURE, i;
  61
  62     if (argc <= 1)
  63         port = "*:4433";
  64     else
  65         port = argv[1];
  66
  67     ctx = SSL_CTX_new(TLS_server_method());
  68     if (!SSL_CTX_use_certificate_chain_file(ctx, CERT_FILE))
  69         goto err;
  70     if (!SSL_CTX_use_PrivateKey_file(ctx, CERT_FILE, SSL_FILETYPE_PEM))
  71         goto err;
  72     if (!SSL_CTX_check_private_key(ctx))
  73         goto err;
  74
  75     /* Setup server side SSL bio */
  76     ssl_bio = BIO_new_ssl(ctx, 0);
  77
  78     if ((in = BIO_new_accept(port)) == NULL)
  79         goto err;
  80
  81     /*
  82      * This means that when a new connection is accepted on 'in', The ssl_bio
  83      * will be 'duplicated' and have the new socket BIO push into it.
  84      * Basically it means the SSL BIO will be automatically setup
  85      */
  86     BIO_set_accept_bios(in, ssl_bio);
  87     ssl_bio = NULL;
  88
  89     /* Arrange to leave server loop on interrupt */
  90     sigsetup();
  91
  92  again:
  93     /*
  94      * The first call will setup the accept socket, and the second will get a
  95      * socket.  In this loop, the first actual accept will occur in the
  96      * BIO_read() function.
  97      */
  98
  99     if (BIO_do_accept(in) <= 0)
 100         goto err;
 101
 102     while (!done) {
 103         i = BIO_read(in, buf, 512);
 104         if (i == 0) {
 105             /*
 106              * If we have finished, remove the underlying BIO stack so the
 107              * next time we call any function for this BIO, it will attempt
 108              * to do an accept
 109              */
 110             printf("Done\n");
 111             tmp = BIO_pop(in);
 112             BIO_free_all(tmp);
 113             goto again;
 114         }
 115         if (i < 0)
 116             goto err;
 117         fwrite(buf, 1, i, stdout);
 118         fflush(stdout);
 119     }
 120
 121     ret = EXIT_SUCCESS;
 122  err:
 123     if (ret != EXIT_SUCCESS)
 124         ERR_print_errors_fp(stderr);
 125     BIO_free(in);
 126     BIO_free_all(ssl_bio);
 127     return ret;
 128 }