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authorMarek Marczykowski-Górecki <marmarek@invisiblethingslab.com>2020-05-20 15:20:23 +0200
committerDaniel P. Berrangé <berrange@redhat.com>2020-06-15 11:33:50 +0100
commitb767d2578da4a46ff5e353f14da6364b97df1020 (patch)
treea9594e3e8e9e109203d905e88fe51039b801fa69 /crypto/random-none.c
parent7d3660e79830a069f1848bb4fa1cdf8f666424fb (diff)
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crypto: add "none" random provider
In case of not using random-number needing feature, it makes sense to skip RNG init too. This is especially helpful when QEMU is sandboxed in Stubdomain under Xen, where there is very little entropy so initial getrandom() call delays the startup several seconds. In that setup, no random bytes are needed at all. Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Diffstat (limited to 'crypto/random-none.c')
-rw-r--r--crypto/random-none.c38
1 files changed, 38 insertions, 0 deletions
diff --git a/crypto/random-none.c b/crypto/random-none.c
new file mode 100644
index 0000000..102f8a4
--- /dev/null
+++ b/crypto/random-none.c
@@ -0,0 +1,38 @@
+/*
+ * QEMU Crypto "none" random number provider
+ *
+ * Copyright (c) 2020 Marek Marczykowski-Górecki
+ * <marmarek@invisiblethingslab.com>
+ *
+ * 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 2.1 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 "qapi/error.h"
+
+int qcrypto_random_init(Error **errp)
+{
+ return 0;
+}
+
+int qcrypto_random_bytes(void *buf,
+ size_t buflen,
+ Error **errp)
+{
+ error_setg(errp, "Random bytes not available with \"none\" rng");
+ return -1;
+}