[Qemu-devel] [PATCH v1 01/15] crypto: add cryptographic random byte source

["Daniel P. Berrange" <berrange@redhat.com>]

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 crypto/Makefile.objs    |  1 +
 crypto/random.c         | 50 +++++++++++++++++++++++++++++++++++++++++++++++++
 include/crypto/random.h | 43 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 94 insertions(+)
 create mode 100644 crypto/random.c
 create mode 100644 include/crypto/random.h

diff --git a/crypto/Makefile.objs b/crypto/Makefile.objs
index a3135f1..5f38d2d 100644
--- a/crypto/Makefile.objs
+++ b/crypto/Makefile.objs
@@ -8,6 +8,7 @@ crypto-obj-y += tlscredsanon.o
 crypto-obj-y += tlscredsx509.o
 crypto-obj-y += tlssession.o
 crypto-obj-y += secret.o
+crypto-obj-y += random.o
 
 # Let the userspace emulators avoid linking gnutls/etc
 crypto-aes-obj-y = aes.o
diff --git a/crypto/random.c b/crypto/random.c
new file mode 100644
index 0000000..8257d24
--- /dev/null
+++ b/crypto/random.c
@@ -0,0 +1,50 @@
+/*
+ * QEMU Crypto random number provider
+ *
+ * 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 <config-host.h>
+
+#include "crypto/random.h"
+
+int qcrypto_random_bytes(uint8_t *buf,
+                         size_t buflen,
+                         Error **errp)
+{
+    ssize_t ret;
+    int fd = open("/dev/random", O_RDONLY);
+    if (fd < 0) {
+        error_setg_errno(errp, errno,
+                         "Unable to open /dev/random");
+        return -1;
+    }
+
+    while (buflen) {
+        ret = read(fd, buf, buflen);
+        if (ret < 0) {
+            error_setg_errno(errp, errno,
+                             "Unable to read random bytes");
+            close(fd);
+            return -1;
+        }
+        buflen -= ret;
+    }
+
+    close(fd);
+    return 0;
+}
diff --git a/include/crypto/random.h b/include/crypto/random.h
new file mode 100644
index 0000000..ce1626b
--- /dev/null
+++ b/include/crypto/random.h
@@ -0,0 +1,43 @@
+/*
+ * QEMU Crypto random number provider
+ *
+ * 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/>.
+ *
+ */
+
+#ifndef QCRYPTO_RANDOM_H__
+#define QCRYPTO_RANDOM_H__
+
+#include "qemu-common.h"
+#include "qapi/error.h"
+
+
+/**
+ * qcrypto_random_bytes:
+ * @buf: the buffer to fill
+ * @buflen: length of @buf in bytes
+ * @errp: pointer to uninitialized error objet
+ *
+ * Fill @buf with @buflen bytes of random data
+ *
+ * Returns 0 on sucess, -1 on error
+ */
+int qcrypto_random_bytes(uint8_t *buf,
+                         size_t buflen,
+                         Error **errp);
+
+
+#endif /* QCRYPTO_RANDOM_H__ */
-- 
2.5.0