xemu/crypto/random-gnutls.c
Geert Martin Ijewski a37278169d crypto: qcrypto_random_bytes() now works on windows w/o any other crypto libs
If no crypto library is included in the build, QEMU uses
qcrypto_random_bytes() to generate random data. That function tried to open
/dev/urandom or /dev/random and if opening both files failed it errored out.

Those files obviously do not exist on windows, so there the code uses
CryptGenRandom().

Furthermore there was some refactoring and a new function
qcrypto_random_init() was introduced. If a proper crypto library (gnutls or
libgcrypt) is included in the build, this function does nothing. If neither
is included it initializes the (platform specific) handles that are used by
qcrypto_random_bytes().
Either:
* a handle to /dev/urandom | /dev/random on unix like systems
* a handle to a cryptographic service provider on windows

Signed-off-by: Geert Martin Ijewski <gm.ijewski@web.de>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-05-09 14:41:47 +01:00

47 lines
1.3 KiB
C

/*
* QEMU Crypto random number provider
*
* Copyright (c) 2015-2016 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/random.h"
#include <gnutls/gnutls.h>
#include <gnutls/crypto.h>
int qcrypto_random_bytes(uint8_t *buf,
size_t buflen,
Error **errp)
{
int ret;
ret = gnutls_rnd(GNUTLS_RND_RANDOM, buf, buflen);
if (ret < 0) {
error_setg(errp, "Cannot get random bytes: %s",
gnutls_strerror(ret));
return -1;
}
return 0;
}
int qcrypto_random_init(Error **errp G_GNUC_UNUSED) { return 0; }