qemu/crypto/init.c
Daniel P. Berrange 373166636b crypto: fix initialization of gcrypt threading
The gcrypt threads implementation must be set before calling
any other gcrypt APIs, especially gcry_check_version(),
since that triggers initialization of the random pool. After
that is initialized, changes to the threads impl won't be
honoured by the random pool code. This means that gcrypt
will think thread locking is needed and so try to acquire
the random pool mutex, but this is NULL as no threads impl
was set originally. This results in a crash in the random
pool code.

For the same reasons, we must set the gcrypt threads impl
before calling gnutls_init, since that will also trigger
gcry_check_version

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-10-20 12:19:35 +01:00

151 lines
3.8 KiB
C

/*
* QEMU Crypto initialization
*
* Copyright (c) 2015 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
*/
#include "qemu/osdep.h"
#include "crypto/init.h"
#include "qapi/error.h"
#include "qemu/thread.h"
#ifdef CONFIG_GNUTLS
#include <gnutls/gnutls.h>
#include <gnutls/crypto.h>
#endif
#ifdef CONFIG_GCRYPT
#include <gcrypt.h>
#endif
/* #define DEBUG_GNUTLS */
/*
* If GNUTLS is built against GCrypt then
*
* - When GNUTLS >= 2.12, we must not initialize gcrypt threading
* because GNUTLS will do that itself
* - When GNUTLS < 2.12 we must always initialize gcrypt threading
* - When GNUTLS is disabled we must always initialize gcrypt threading
*
* But....
*
* When gcrypt >= 1.6.0 we must not initialize gcrypt threading
* because gcrypt will do that itself.
*
* So we need to init gcrypt threading if
*
* - gcrypt < 1.6.0
* AND
* - gnutls < 2.12
* OR
* - gnutls is disabled
*
*/
#if (defined(CONFIG_GCRYPT) && \
(!defined(CONFIG_GNUTLS) || \
(LIBGNUTLS_VERSION_NUMBER < 0x020c00)) && \
(!defined(GCRYPT_VERSION_NUMBER) || \
(GCRYPT_VERSION_NUMBER < 0x010600)))
#define QCRYPTO_INIT_GCRYPT_THREADS
#else
#undef QCRYPTO_INIT_GCRYPT_THREADS
#endif
#ifdef DEBUG_GNUTLS
static void qcrypto_gnutls_log(int level, const char *str)
{
fprintf(stderr, "%d: %s", level, str);
}
#endif
#ifdef QCRYPTO_INIT_GCRYPT_THREADS
static int qcrypto_gcrypt_mutex_init(void **priv)
{ \
QemuMutex *lock = NULL;
lock = g_new0(QemuMutex, 1);
qemu_mutex_init(lock);
*priv = lock;
return 0;
}
static int qcrypto_gcrypt_mutex_destroy(void **priv)
{
QemuMutex *lock = *priv;
qemu_mutex_destroy(lock);
g_free(lock);
return 0;
}
static int qcrypto_gcrypt_mutex_lock(void **priv)
{
QemuMutex *lock = *priv;
qemu_mutex_lock(lock);
return 0;
}
static int qcrypto_gcrypt_mutex_unlock(void **priv)
{
QemuMutex *lock = *priv;
qemu_mutex_unlock(lock);
return 0;
}
static struct gcry_thread_cbs qcrypto_gcrypt_thread_impl = {
(GCRY_THREAD_OPTION_PTHREAD | (GCRY_THREAD_OPTION_VERSION << 8)),
NULL,
qcrypto_gcrypt_mutex_init,
qcrypto_gcrypt_mutex_destroy,
qcrypto_gcrypt_mutex_lock,
qcrypto_gcrypt_mutex_unlock,
NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
};
#endif /* QCRYPTO_INIT_GCRYPT */
int qcrypto_init(Error **errp)
{
#ifdef QCRYPTO_INIT_GCRYPT_THREADS
gcry_control(GCRYCTL_SET_THREAD_CBS, &qcrypto_gcrypt_thread_impl);
#endif /* QCRYPTO_INIT_GCRYPT_THREADS */
#ifdef CONFIG_GNUTLS
int ret;
ret = gnutls_global_init();
if (ret < 0) {
error_setg(errp,
"Unable to initialize GNUTLS library: %s",
gnutls_strerror(ret));
return -1;
}
#ifdef DEBUG_GNUTLS
gnutls_global_set_log_level(10);
gnutls_global_set_log_function(qcrypto_gnutls_log);
#endif
#endif
#ifdef CONFIG_GCRYPT
if (!gcry_check_version(GCRYPT_VERSION)) {
error_setg(errp, "Unable to initialize gcrypt");
return -1;
}
gcry_control(GCRYCTL_INITIALIZATION_FINISHED, 0);
#endif
return 0;
}