8b892e3347
While the PSK cipher suites do not use any ECDHE/RSA signatures, in the future someone may change the code. In that case, as a robustness measure, already set the acceptable signature algorithms now. Additionally upgrade to OpenSSL v1.1.0e and include the comment to include X448 once it becomes available for TLS ECDHE (it's not yet, unfortunately).
112 lines
3.6 KiB
C
112 lines
3.6 KiB
C
/*
|
|
luksrku - Tool to remotely unlock LUKS disks using TLS.
|
|
Copyright (C) 2016-2016 Johannes Bauer
|
|
|
|
This file is part of luksrku.
|
|
|
|
luksrku is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; this program is ONLY licensed under
|
|
version 3 of the License, later versions are explicitly excluded.
|
|
|
|
luksrku is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with luksrku; if not, write to the Free Software
|
|
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
|
|
Johannes Bauer <JohannesBauer@gmx.de>
|
|
*/
|
|
|
|
#include <stdbool.h>
|
|
#include <string.h>
|
|
#include <openssl/evp.h>
|
|
#include <openssl/ssl.h>
|
|
#include <openssl/err.h>
|
|
#include "openssl.h"
|
|
#include "log.h"
|
|
|
|
bool openssl_init(void) {
|
|
OpenSSL_add_all_algorithms();
|
|
ERR_load_ERR_strings();
|
|
ERR_load_SSL_strings();
|
|
return true;
|
|
}
|
|
|
|
bool create_generic_ssl_context(struct generic_ssl_ctx_t *gctx, bool server) {
|
|
memset(gctx, 0, sizeof(struct generic_ssl_ctx_t));
|
|
|
|
gctx->conf_ctx = SSL_CONF_CTX_new();
|
|
if (!gctx->conf_ctx) {
|
|
log_openssl(LLVL_FATAL, "Cannot initialize SSL generic context config context.");
|
|
return false;
|
|
}
|
|
|
|
if (server) {
|
|
gctx->method = TLS_server_method();
|
|
if (!gctx->method) {
|
|
log_openssl(LLVL_FATAL, "Cannot initialize SSL server method.");
|
|
return false;
|
|
}
|
|
} else {
|
|
gctx->method = TLS_client_method();
|
|
if (!gctx->method) {
|
|
log_openssl(LLVL_FATAL, "Cannot initialize SSL client method.");
|
|
return false;
|
|
}
|
|
}
|
|
|
|
gctx->ctx = SSL_CTX_new(gctx->method);
|
|
if (!gctx->ctx) {
|
|
log_openssl(LLVL_FATAL, "Cannot initialize SSL generic context context.");
|
|
return false;
|
|
}
|
|
|
|
/* Disable insecure previous protocol variants */
|
|
/* Disable compression (not secure, should be disabled everywhere) */
|
|
/* Disable DH param reuse (we use ECDH and this doesn't affect us, but in case someone changes to EDH) */
|
|
/* Disable session resumption (unnecessary attack surface) */
|
|
/* Disable resumption on renegotiation (unnecessary attack surface) */
|
|
/* TODO: Disable renegotiation altogether! How? */
|
|
const long flags = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3 | SSL_OP_NO_TLSv1 | SSL_OP_NO_TLSv1_1 | SSL_OP_NO_COMPRESSION | SSL_OP_SINGLE_DH_USE | SSL_OP_NO_TICKET | SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION;
|
|
SSL_CTX_set_options(gctx->ctx, flags);
|
|
|
|
if (!SSL_CTX_set_min_proto_version(gctx->ctx, TLS1_2_VERSION)) {
|
|
log_openssl(LLVL_FATAL, "Cannot set SSL generic context minimal version.");
|
|
return false;
|
|
}
|
|
|
|
if (!SSL_CTX_set_cipher_list(gctx->ctx, "ECDHE-PSK-CHACHA20-POLY1305")) {
|
|
log_openssl(LLVL_FATAL, "Cannot set SSL generic context cipher suites.");
|
|
return false;
|
|
}
|
|
|
|
/* In the cipher suite we're using, none of these should be used anyways
|
|
* (PSK); however for the future we want to have proper crypto here as
|
|
* well. */
|
|
if (!SSL_CTX_set1_sigalgs_list(gctx->ctx, "ECDSA+SHA256:RSA+SHA256:ECDSA+SHA384:RSA+SHA384:ECDSA+SHA512:RSA+SHA512")) {
|
|
log_openssl(LLVL_FATAL, "Cannot set SSL signature algorithms.");
|
|
return false;
|
|
}
|
|
|
|
/* TODO: When X448 becomes available, include it here. */
|
|
if (!SSL_CTX_set1_curves_list(gctx->ctx, "X25519")) {
|
|
log_openssl(LLVL_FATAL, "Cannot set SSL generic context ECDHE curves.");
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
void free_generic_ssl_context(struct generic_ssl_ctx_t *gctx) {
|
|
SSL_CTX_free(gctx->ctx);
|
|
gctx->ctx = NULL;
|
|
|
|
SSL_CONF_CTX_free(gctx->conf_ctx);
|
|
gctx->conf_ctx = NULL;
|
|
}
|
|
|