diff options
Diffstat (limited to 'crypto/random-platform.c')
-rw-r--r-- | crypto/random-platform.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/crypto/random-platform.c b/crypto/random-platform.c new file mode 100644 index 0000000..82b755a --- /dev/null +++ b/crypto/random-platform.c @@ -0,0 +1,64 @@ +/* + * 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" + +int qcrypto_random_bytes(uint8_t *buf G_GNUC_UNUSED, + size_t buflen G_GNUC_UNUSED, + Error **errp) +{ + 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; +} |