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-rw-r--r--crypto/random-platform.c37
1 files changed, 32 insertions, 5 deletions
diff --git a/crypto/random-platform.c b/crypto/random-platform.c
index 6df40744c7..cb3ca1bc09 100644
--- a/crypto/random-platform.c
+++ b/crypto/random-platform.c
@@ -27,7 +27,11 @@
#include <wincrypt.h>
static HCRYPTPROV hCryptProv;
#else
-static int fd; /* a file handle to either /dev/urandom or /dev/random */
+# ifdef CONFIG_GETRANDOM
+# include <sys/random.h>
+# endif
+/* This is -1 for getrandom(), or a file handle for /dev/{u,}random. */
+static int fd;
#endif
int qcrypto_random_init(Error **errp)
@@ -40,15 +44,20 @@ int qcrypto_random_init(Error **errp)
return -1;
}
#else
- /* TBD perhaps also add support for BSD getentropy / Linux
- * getrandom syscalls directly */
+# ifdef CONFIG_GETRANDOM
+ if (getrandom(NULL, 0, 0) == 0) {
+ /* Use getrandom() */
+ fd = -1;
+ return 0;
+ }
+ /* Fall through to /dev/urandom case. */
+# endif
fd = open("/dev/urandom", O_RDONLY | O_CLOEXEC);
if (fd == -1 && errno == ENOENT) {
fd = open("/dev/random", O_RDONLY | O_CLOEXEC);
}
-
if (fd < 0) {
- error_setg(errp, "No /dev/urandom or /dev/random found");
+ error_setg_errno(errp, errno, "No /dev/urandom or /dev/random");
return -1;
}
#endif
@@ -66,6 +75,24 @@ int qcrypto_random_bytes(uint8_t *buf G_GNUC_UNUSED,
return -1;
}
#else
+# ifdef CONFIG_GETRANDOM
+ if (likely(fd < 0)) {
+ while (1) {
+ ssize_t got = getrandom(buf, buflen, 0);
+ if (likely(got == buflen)) {
+ return 0;
+ }
+ if (got >= 0) {
+ buflen -= got;
+ buf += got;
+ } else if (errno != EINTR) {
+ error_setg_errno(errp, errno, "getrandom");
+ return -1;
+ }
+ }
+ }
+ /* Fall through to /dev/urandom case. */
+# endif
while (1) {
ssize_t got = read(fd, buf, buflen);
if (likely(got == buflen)) {