@@ -12,6 +12,7 @@ crypto-obj-y += tlssession.o
crypto-obj-y += secret.o
crypto-obj-$(CONFIG_GCRYPT) += random-gcrypt.o
crypto-obj-$(if $(CONFIG_GCRYPT),n,$(CONFIG_GNUTLS_RND)) += random-gnutls.o
+crypto-obj-$(if $(CONFIG_GCRYPT),n,$(if $(CONFIG_GNUTLS_RND),n,y)) += random-platform.o
crypto-obj-y += pbkdf.o
crypto-obj-$(CONFIG_NETTLE_KDF) += pbkdf-nettle.o
crypto-obj-$(if $(CONFIG_NETTLE_KDF),n,$(CONFIG_GCRYPT_KDF)) += pbkdf-gcrypt.o
@@ -28,6 +29,5 @@ crypto-obj-y += block-luks.o
# Let the userspace emulators avoid linking gnutls/etc
crypto-aes-obj-y = aes.o
-stub-obj-y += random-stub.o
stub-obj-y += pbkdf-stub.o
stub-obj-y += hash-stub.o
similarity index 52%
rename from crypto/random-stub.c
rename to crypto/random-platform.c
@@ -26,6 +26,39 @@ int qcrypto_random_bytes(uint8_t *buf G_GNUC_UNUSED,
size_t buflen G_GNUC_UNUSED,
Error **errp)
{
- error_setg(errp, "No random byte source provided in this build");
- return -1;
+ int fd;
+ int ret = -1;
+ int got;
+
+ /* TBD perhaps also add support for BSD getentropy / Linux
+ * getrandom syscalls directly */
+ fd = open("/dev/urandom", O_RDONLY);
+ if (fd == -1 && errno == ENOENT) {
+ fd = open("/dev/random", O_RDONLY);
+ }
+
+ if (fd < 0) {
+ error_setg(errp, "No /dev/urandom or /dev/random found");
+ return -1;
+ }
+
+ while (buflen > 0) {
+ got = read(fd, buf, buflen);
+ if (got < 0) {
+ error_setg_errno(errp, errno,
+ "Unable to read random bytes");
+ goto cleanup;
+ } else if (!got) {
+ error_setg(errp,
+ "Unexpected EOF reading random bytes");
+ goto cleanup;
+ }
+ buflen -= got;
+ buf += got;
+ }
+
+ ret = 0;
+ cleanup:
+ close(fd);
+ return ret;
}
If neither gcrypt or gnutls are available to provide a cryptographic random number generator, fallback to consuming bytes directly from /dev/[u]random. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> --- crypto/Makefile.objs | 2 +- crypto/{random-stub.c => random-platform.c} | 37 +++++++++++++++++++++++++++-- 2 files changed, 36 insertions(+), 3 deletions(-) rename crypto/{random-stub.c => random-platform.c} (52%)