1 /*
2 * Copyright 2013-2025 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. It uses blocking. It use the
12 * SSL_CONF API with the command line. cc -I../../include server-arg.c
13 * -L../.. -lssl -lcrypto -ldl
14 */
15
16 #include <stdio.h>
17 #include <string.h>
18 #include <signal.h>
19 #include <stdlib.h>
20 #include <openssl/err.h>
21 #include <openssl/ssl.h>
22
main(int argc,char * argv[])23 int main(int argc, char *argv[])
24 {
25 char *port = "*:4433";
26 BIO *ssl_bio = NULL;
27 BIO *tmp;
28 SSL_CTX *ctx;
29 SSL_CONF_CTX *cctx;
30 char buf[512];
31 BIO *in = NULL;
32 int ret = EXIT_FAILURE, i;
33 char **args = argv + 1;
34 int nargs = argc - 1;
35
36 ctx = SSL_CTX_new(TLS_server_method());
37
38 cctx = SSL_CONF_CTX_new();
39 SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_SERVER);
40 SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_CERTIFICATE);
41 SSL_CONF_CTX_set_ssl_ctx(cctx, ctx);
42 while (*args && **args == '-') {
43 int rv;
44 /* Parse standard arguments */
45 rv = SSL_CONF_cmd_argv(cctx, &nargs, &args);
46 if (rv == -3) {
47 fprintf(stderr, "Missing argument for %s\n", *args);
48 goto err;
49 }
50 if (rv < 0) {
51 fprintf(stderr, "Error in command %s\n", *args);
52 ERR_print_errors_fp(stderr);
53 goto err;
54 }
55 /* If rv > 0 we processed something so proceed to next arg */
56 if (rv > 0)
57 continue;
58 /* Otherwise application specific argument processing */
59 if (strcmp(*args, "-port") == 0) {
60 port = args[1];
61 if (port == NULL) {
62 fprintf(stderr, "Missing -port argument\n");
63 goto err;
64 }
65 args += 2;
66 nargs -= 2;
67 continue;
68 } else {
69 fprintf(stderr, "Unknown argument %s\n", *args);
70 goto err;
71 }
72 }
73
74 if (!SSL_CONF_CTX_finish(cctx)) {
75 fprintf(stderr, "Finish error\n");
76 ERR_print_errors_fp(stderr);
77 goto err;
78 }
79 #ifdef ITERATE_CERTS
80 /*
81 * Demo of how to iterate over all certificates in an SSL_CTX structure.
82 */
83 {
84 X509 *x;
85 int rv;
86 rv = SSL_CTX_set_current_cert(ctx, SSL_CERT_SET_FIRST);
87 while (rv) {
88 X509 *x = SSL_CTX_get0_certificate(ctx);
89 X509_NAME_print_ex_fp(stdout, X509_get_subject_name(x), 0,
90 XN_FLAG_ONELINE);
91 printf("\n");
92 rv = SSL_CTX_set_current_cert(ctx, SSL_CERT_SET_NEXT);
93 }
94 fflush(stdout);
95 }
96 #endif
97 /* Setup server side SSL bio */
98 ssl_bio = BIO_new_ssl(ctx, 0);
99
100 if ((in = BIO_new_accept(port)) == NULL)
101 goto err;
102
103 /*
104 * This means that when a new connection is accepted on 'in', The ssl_bio
105 * will be 'duplicated' and have the new socket BIO push into it.
106 * Basically it means the SSL BIO will be automatically setup
107 */
108 BIO_set_accept_bios(in, ssl_bio);
109 ssl_bio = NULL;
110
111 again:
112 /*
113 * The first call will setup the accept socket, and the second will get a
114 * socket. In this loop, the first actual accept will occur in the
115 * BIO_read() function.
116 */
117
118 if (BIO_do_accept(in) <= 0)
119 goto err;
120
121 for (;;) {
122 i = BIO_read(in, buf, 512);
123 if (i == 0) {
124 /*
125 * If we have finished, remove the underlying BIO stack so the
126 * next time we call any function for this BIO, it will attempt
127 * to do an accept
128 */
129 printf("Done\n");
130 tmp = BIO_pop(in);
131 BIO_free_all(tmp);
132 goto again;
133 }
134 if (i < 0)
135 goto err;
136 fwrite(buf, 1, i, stdout);
137 fflush(stdout);
138 }
139
140 ret = EXIT_SUCCESS;
141 err:
142 if (ret != EXIT_SUCCESS)
143 ERR_print_errors_fp(stderr);
144 BIO_free(in);
145 BIO_free_all(ssl_bio);
146 return ret;
147 }
148