qxl: check release info object
[qemu.git] / crypto / random-platform.c
1 /*
2 * QEMU Crypto random number provider
3 *
4 * Copyright (c) 2015-2016 Red Hat, Inc.
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18 *
19 */
20
21 #include "qemu/osdep.h"
22
23 #include "crypto/random.h"
24 #include "qapi/error.h"
25
26 #ifdef _WIN32
27 #include <wincrypt.h>
28 static HCRYPTPROV hCryptProv;
29 #else
30 static int fd; /* a file handle to either /dev/urandom or /dev/random */
31 #endif
32
33 int qcrypto_random_init(Error **errp)
34 {
35 #ifndef _WIN32
36 /* TBD perhaps also add support for BSD getentropy / Linux
37 * getrandom syscalls directly */
38 fd = open("/dev/urandom", O_RDONLY);
39 if (fd == -1 && errno == ENOENT) {
40 fd = open("/dev/random", O_RDONLY);
41 }
42
43 if (fd < 0) {
44 error_setg(errp, "No /dev/urandom or /dev/random found");
45 return -1;
46 }
47 #else
48 if (!CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_FULL,
49 CRYPT_SILENT | CRYPT_VERIFYCONTEXT)) {
50 error_setg_win32(errp, GetLastError(),
51 "Unable to create cryptographic provider");
52 return -1;
53 }
54 #endif
55
56 return 0;
57 }
58
59 int qcrypto_random_bytes(uint8_t *buf G_GNUC_UNUSED,
60 size_t buflen G_GNUC_UNUSED,
61 Error **errp)
62 {
63 #ifndef _WIN32
64 int ret = -1;
65 int got;
66
67 while (buflen > 0) {
68 got = read(fd, buf, buflen);
69 if (got < 0) {
70 error_setg_errno(errp, errno,
71 "Unable to read random bytes");
72 goto cleanup;
73 } else if (!got) {
74 error_setg(errp,
75 "Unexpected EOF reading random bytes");
76 goto cleanup;
77 }
78 buflen -= got;
79 buf += got;
80 }
81
82 ret = 0;
83 cleanup:
84 return ret;
85 #else
86 if (!CryptGenRandom(hCryptProv, buflen, buf)) {
87 error_setg_win32(errp, GetLastError(),
88 "Unable to read random bytes");
89 return -1;
90 }
91
92 return 0;
93 #endif
94 }