1 /* 2 * Copyright 2015-2025 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 TLS server it ses SSL_CTX_config and a configuration file to 12 * set most server parameters. 13 */ 14 15 #include <stdio.h> 16 #include <signal.h> 17 #include <stdlib.h> 18 #include <openssl/err.h> 19 #include <openssl/ssl.h> 20 #include <openssl/conf.h> 21 22 int main(int argc, char *argv[]) 23 { 24 unsigned char buf[512]; 25 char *port = "*:4433"; 26 BIO *in = NULL; 27 BIO *ssl_bio = NULL; 28 BIO *tmp; 29 SSL_CTX *ctx; 30 int ret = EXIT_FAILURE, i; 31 32 ctx = SSL_CTX_new(TLS_server_method()); 33 34 if (CONF_modules_load_file("cmod.cnf", "testapp", 0) <= 0) { 35 fprintf(stderr, "Error processing config file\n"); 36 goto err; 37 } 38 39 if (SSL_CTX_config(ctx, "server") == 0) { 40 fprintf(stderr, "Error configuring server.\n"); 41 goto err; 42 } 43 44 /* Setup server side SSL bio */ 45 ssl_bio = BIO_new_ssl(ctx, 0); 46 47 if ((in = BIO_new_accept(port)) == NULL) 48 goto err; 49 50 /* 51 * This means that when a new connection is accepted on 'in', The ssl_bio 52 * will be 'duplicated' and have the new socket BIO push into it. 53 * Basically it means the SSL BIO will be automatically setup 54 */ 55 BIO_set_accept_bios(in, ssl_bio); 56 ssl_bio = NULL; 57 58 again: 59 /* 60 * The first call will setup the accept socket, and the second will get a 61 * socket. In this loop, the first actual accept will occur in the 62 * BIO_read() function. 63 */ 64 65 if (BIO_do_accept(in) <= 0) 66 goto err; 67 68 for (;;) { 69 i = BIO_read(in, buf, sizeof(buf)); 70 if (i == 0) { 71 /* 72 * If we have finished, remove the underlying BIO stack so the 73 * next time we call any function for this BIO, it will attempt 74 * to do an accept 75 */ 76 printf("Done\n"); 77 tmp = BIO_pop(in); 78 BIO_free_all(tmp); 79 goto again; 80 } 81 if (i < 0) { 82 if (BIO_should_retry(in)) 83 continue; 84 goto err; 85 } 86 fwrite(buf, 1, i, stdout); 87 fflush(stdout); 88 } 89 90 ret = EXIT_SUCCESS; 91 err: 92 if (ret != EXIT_SUCCESS) 93 ERR_print_errors_fp(stderr); 94 BIO_free(in); 95 BIO_free_all(ssl_bio); 96 return ret; 97 } 98