1/*
2 * Copyright 2013-2017 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the OpenSSL license (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 uses
12 * the SSL_CONF API with a configuration file. cc -I../../include saccept.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#include <openssl/conf.h>
23
24int main(int argc, char *argv[])
25{
26    char *port = "*:4433";
27    BIO *in = NULL;
28    BIO *ssl_bio, *tmp;
29    SSL_CTX *ctx;
30    SSL_CONF_CTX *cctx = NULL;
31    CONF *conf = NULL;
32    STACK_OF(CONF_VALUE) *sect = NULL;
33    CONF_VALUE *cnf;
34    long errline = -1;
35    char buf[512];
36    int ret = EXIT_FAILURE, i;
37
38    ctx = SSL_CTX_new(TLS_server_method());
39
40    conf = NCONF_new(NULL);
41
42    if (NCONF_load(conf, "accept.cnf", &errline) <= 0) {
43        if (errline <= 0)
44            fprintf(stderr, "Error processing config file\n");
45        else
46            fprintf(stderr, "Error on line %ld\n", errline);
47        goto err;
48    }
49
50    sect = NCONF_get_section(conf, "default");
51
52    if (sect == NULL) {
53        fprintf(stderr, "Error retrieving default section\n");
54        goto err;
55    }
56
57    cctx = SSL_CONF_CTX_new();
58    SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_SERVER);
59    SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_CERTIFICATE);
60    SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_FILE);
61    SSL_CONF_CTX_set_ssl_ctx(cctx, ctx);
62    for (i = 0; i < sk_CONF_VALUE_num(sect); i++) {
63        int rv;
64        cnf = sk_CONF_VALUE_value(sect, i);
65        rv = SSL_CONF_cmd(cctx, cnf->name, cnf->value);
66        if (rv > 0)
67            continue;
68        if (rv != -2) {
69            fprintf(stderr, "Error processing %s = %s\n",
70                    cnf->name, cnf->value);
71            ERR_print_errors_fp(stderr);
72            goto err;
73        }
74        if (strcmp(cnf->name, "Port") == 0) {
75            port = cnf->value;
76        } else {
77            fprintf(stderr, "Unknown configuration option %s\n", cnf->name);
78            goto err;
79        }
80    }
81
82    if (!SSL_CONF_CTX_finish(cctx)) {
83        fprintf(stderr, "Finish error\n");
84        ERR_print_errors_fp(stderr);
85        goto err;
86    }
87
88    /* Setup server side SSL bio */
89    ssl_bio = BIO_new_ssl(ctx, 0);
90
91    if ((in = BIO_new_accept(port)) == NULL)
92        goto err;
93
94    /*
95     * This means that when a new connection is accepted on 'in', The ssl_bio
96     * will be 'duplicated' and have the new socket BIO push into it.
97     * Basically it means the SSL BIO will be automatically setup
98     */
99    BIO_set_accept_bios(in, ssl_bio);
100
101 again:
102    /*
103     * The first call will setup the accept socket, and the second will get a
104     * socket.  In this loop, the first actual accept will occur in the
105     * BIO_read() function.
106     */
107
108    if (BIO_do_accept(in) <= 0)
109        goto err;
110
111    for (;;) {
112        i = BIO_read(in, buf, 512);
113        if (i == 0) {
114            /*
115             * If we have finished, remove the underlying BIO stack so the
116             * next time we call any function for this BIO, it will attempt
117             * to do an accept
118             */
119            printf("Done\n");
120            tmp = BIO_pop(in);
121            BIO_free_all(tmp);
122            goto again;
123        }
124        if (i < 0) {
125            if (BIO_should_retry(in))
126                continue;
127            goto err;
128        }
129        fwrite(buf, 1, i, stdout);
130        fflush(stdout);
131    }
132
133    ret = EXIT_SUCCESS;
134 err:
135    if (ret != EXIT_SUCCESS)
136        ERR_print_errors_fp(stderr);
137    BIO_free(in);
138    return ret;
139}
140