2023-09-03 18:24:16 -07:00

322 lines
8.2 KiB
C

/* $OpenBSD: server.c,v 1.12 2023/02/01 14:39:09 tb Exp $ */
/*
* Copyright (c) 2018-2019 Alexander Bluhm <bluhm@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <err.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <openssl/err.h>
#include <openssl/ssl.h>
#include "util.h"
void __dead usage(void);
void __dead
usage(void)
{
fprintf(stderr, "usage: server [-Lsvv] [-C CA] [-c crt -k key] "
"[-l ciphers] [-p dhparam] [-V version] [host port]\n");
exit(2);
}
int
main(int argc, char *argv[])
{
const SSL_METHOD *method;
SSL_CTX *ctx;
SSL *ssl;
BIO *abio, *cbio;
SSL_SESSION *session;
int ch, error, listciphers = 0, sessionreuse = 0, verify = 0;
int version = 0;
char buf[256], *dhparam = NULL;
char *ca = NULL, *crt = NULL, *key = NULL, *ciphers = NULL;
char *host_port, *host = "127.0.0.1", *port = "0";
while ((ch = getopt(argc, argv, "C:c:k:Ll:p:sV:v")) != -1) {
switch (ch) {
case 'C':
ca = optarg;
break;
case 'c':
crt = optarg;
break;
case 'k':
key = optarg;
break;
case 'L':
listciphers = 1;
break;
case 'l':
ciphers = optarg;
break;
case 'p':
dhparam = optarg;
break;
case 's':
/* multiple reueses are possible */
sessionreuse++;
break;
case 'V':
if (strcmp(optarg, "TLS1") == 0) {
version = TLS1_VERSION;
} else if (strcmp(optarg, "TLS1_1") == 0) {
version = TLS1_1_VERSION;
} else if (strcmp(optarg, "TLS1_2") == 0) {
version = TLS1_2_VERSION;
} else if (strcmp(optarg, "TLS1_3") == 0) {
version = TLS1_3_VERSION;
} else {
errx(1, "unknown protocol version: %s", optarg);
}
break;
case 'v':
/* use twice to force client cert */
verify++;
break;
default:
usage();
}
}
argc -= optind;
argv += optind;
if (argc == 2) {
host = argv[0];
port = argv[1];
} else if (argc != 0 && !listciphers) {
usage();
}
if (asprintf(&host_port, strchr(host, ':') ? "[%s]:%s" : "%s:%s",
host, port) == -1)
err(1, "asprintf host port");
if ((crt == NULL && key != NULL) || (crt != NULL && key == NULL))
errx(1, "certificate and private key must be used together");
if (crt == NULL && asprintf(&crt, "%s.crt", host) == -1)
err(1, "asprintf crt");
if (key == NULL && asprintf(&key, "%s.key", host) == -1)
err(1, "asprintf key");
SSL_library_init();
SSL_load_error_strings();
print_version();
/* setup method and context */
#if OPENSSL_VERSION_NUMBER >= 0x1010000f
method = TLS_server_method();
if (method == NULL)
err_ssl(1, "TLS_server_method");
#else
switch (version) {
case TLS1_VERSION:
method = TLSv1_server_method();
break;
case TLS1_1_VERSION:
method = TLSv1_1_server_method();
break;
case TLS1_2_VERSION:
method = TLSv1_2_server_method();
break;
#ifdef TLS1_3_VERSION
case TLS1_3_VERSION:
err(1, "TLS1_3 not supported");
#endif
default:
method = SSLv23_server_method();
break;
}
if (method == NULL)
err_ssl(1, "SSLv23_server_method");
#endif
ctx = SSL_CTX_new(method);
if (ctx == NULL)
err_ssl(1, "SSL_CTX_new");
#if OPENSSL_VERSION_NUMBER >= 0x1010000f
if (version) {
if (SSL_CTX_set_min_proto_version(ctx, version) != 1)
err_ssl(1, "SSL_CTX_set_min_proto_version");
if (SSL_CTX_set_max_proto_version(ctx, version) != 1)
err_ssl(1, "SSL_CTX_set_max_proto_version");
}
#endif
#if OPENSSL_VERSION_NUMBER >= 0x10100000
/* needed to use DHE cipher with libressl */
if (SSL_CTX_set_dh_auto(ctx, 1) <= 0)
err_ssl(1, "SSL_CTX_set_dh_auto");
#endif
/* needed to use ADH, EDH, DHE cipher with openssl */
if (dhparam != NULL) {
DH *dh;
FILE *file;
file = fopen(dhparam, "r");
if (file == NULL)
err(1, "fopen %s", dhparam);
dh = PEM_read_DHparams(file, NULL, NULL, NULL);
if (dh == NULL)
err_ssl(1, "PEM_read_DHparams");
if (SSL_CTX_set_tmp_dh(ctx, dh) <= 0)
err_ssl(1, "SSL_CTX_set_tmp_dh");
fclose(file);
}
/* load server certificate */
if (SSL_CTX_use_certificate_file(ctx, crt, SSL_FILETYPE_PEM) <= 0)
err_ssl(1, "SSL_CTX_use_certificate_file");
if (SSL_CTX_use_PrivateKey_file(ctx, key, SSL_FILETYPE_PEM) <= 0)
err_ssl(1, "SSL_CTX_use_PrivateKey_file");
if (SSL_CTX_check_private_key(ctx) <= 0)
err_ssl(1, "SSL_CTX_check_private_key");
/* request client certificate and verify it */
if (ca != NULL) {
STACK_OF(X509_NAME) *x509stack;
x509stack = SSL_load_client_CA_file(ca);
if (x509stack == NULL)
err_ssl(1, "SSL_load_client_CA_file");
SSL_CTX_set_client_CA_list(ctx, x509stack);
if (SSL_CTX_load_verify_locations(ctx, ca, NULL) <= 0)
err_ssl(1, "SSL_CTX_load_verify_locations");
}
SSL_CTX_set_verify(ctx,
verify == 0 ? SSL_VERIFY_NONE :
verify == 1 ? SSL_VERIFY_PEER :
SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT,
verify_callback);
if (sessionreuse) {
uint32_t context;
SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_SERVER);
context = arc4random();
if (SSL_CTX_set_session_id_context(ctx,
(unsigned char *)&context, sizeof(context)) <= 0)
err_ssl(1, "SSL_CTX_set_session_id_context");
}
if (ciphers) {
if (SSL_CTX_set_cipher_list(ctx, ciphers) <= 0)
err_ssl(1, "SSL_CTX_set_cipher_list");
}
if (listciphers) {
STACK_OF(SSL_CIPHER) *supported_ciphers;
ssl = SSL_new(ctx);
if (ssl == NULL)
err_ssl(1, "SSL_new");
supported_ciphers = SSL_get1_supported_ciphers(ssl);
if (supported_ciphers == NULL)
err_ssl(1, "SSL_get1_supported_ciphers");
print_ciphers(supported_ciphers);
sk_SSL_CIPHER_free(supported_ciphers);
return 0;
}
/* setup bio for socket operations */
abio = BIO_new_accept(host_port);
if (abio == NULL)
err_ssl(1, "BIO_new_accept");
/* bind, listen */
if (BIO_do_accept(abio) <= 0)
err_ssl(1, "BIO_do_accept setup");
printf("listen ");
print_sockname(abio);
/* fork to background and set timeout */
if (daemon(1, 1) == -1)
err(1, "daemon");
alarm(10);
do {
/* accept connection */
if (BIO_do_accept(abio) <= 0)
err_ssl(1, "BIO_do_accept wait");
cbio = BIO_pop(abio);
printf("accept ");
print_sockname(cbio);
printf("accept ");
print_peername(cbio);
/* do ssl server handshake */
ssl = SSL_new(ctx);
if (ssl == NULL)
err_ssl(1, "SSL_new");
SSL_set_bio(ssl, cbio, cbio);
if ((error = SSL_accept(ssl)) <= 0)
err_ssl(1, "SSL_accept %d", error);
printf("session %d: %s\n", sessionreuse,
SSL_session_reused(ssl) ? "reuse" : "new");
if (fflush(stdout) != 0)
err(1, "fflush stdout");
/* print session statistics */
session = SSL_get_session(ssl);
if (session == NULL)
err_ssl(1, "SSL_get_session");
if (SSL_SESSION_print_fp(stdout, session) <= 0)
err_ssl(1, "SSL_SESSION_print_fp");
/* write server greeting and read client hello over TLS */
strlcpy(buf, "greeting\n", sizeof(buf));
printf(">>> %s", buf);
if (fflush(stdout) != 0)
err(1, "fflush stdout");
if ((error = SSL_write(ssl, buf, 9)) <= 0)
err_ssl(1, "SSL_write %d", error);
if (error != 9)
errx(1, "write not 9 bytes greeting: %d", error);
if ((error = SSL_read(ssl, buf, 6)) <= 0)
err_ssl(1, "SSL_read %d", error);
if (error != 6)
errx(1, "read not 6 bytes hello: %d", error);
buf[6] = '\0';
printf("<<< %s", buf);
if (fflush(stdout) != 0)
err(1, "fflush stdout");
/* shutdown connection */
if ((error = SSL_shutdown(ssl)) < 0)
err_ssl(1, "SSL_shutdown unidirectional %d", error);
if (error <= 0) {
if ((error = SSL_shutdown(ssl)) <= 0)
err_ssl(1, "SSL_shutdown bidirectional %d",
error);
}
SSL_free(ssl);
} while (sessionreuse--);
SSL_CTX_free(ctx);
printf("success\n");
return 0;
}