1/* Copyright libuv contributors. All rights reserved.
2 *
3 * Permission is hereby granted, free of charge, to any person obtaining a copy
4 * of this software and associated documentation files (the "Software"), to
5 * deal in the Software without restriction, including without limitation the
6 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
7 * sell copies of the Software, and to permit persons to whom the Software is
8 * furnished to do so, subject to the following conditions:
9 *
10 * The above copyright notice and this permission notice shall be included in
11 * all copies or substantial portions of the Software.
12 *
13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
18 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
19 * IN THE SOFTWARE.
20 */
21
22#include "uv.h"
23#include "uv-common.h"
24
25#ifdef _WIN32
26#  include "win/internal.h"
27#else
28#  include "unix/internal.h"
29#endif
30
31static int uv__random(void* buf, size_t buflen) {
32  int rc;
33
34#if defined(__PASE__)
35  rc = uv__random_readpath("/dev/urandom", buf, buflen);
36#elif defined(_AIX) || defined(__QNX__)
37  rc = uv__random_readpath("/dev/random", buf, buflen);
38#elif defined(__APPLE__) || defined(__OpenBSD__) || \
39     (defined(__ANDROID_API__) && __ANDROID_API__ >= 28)
40  rc = uv__random_getentropy(buf, buflen);
41  if (rc == UV_ENOSYS)
42    rc = uv__random_devurandom(buf, buflen);
43#elif defined(__NetBSD__)
44  rc = uv__random_sysctl(buf, buflen);
45#elif defined(__FreeBSD__) || defined(__linux__)
46  rc = uv__random_getrandom(buf, buflen);
47  if (rc == UV_ENOSYS)
48    rc = uv__random_devurandom(buf, buflen);
49# if defined(__linux__)
50  switch (rc) {
51    case UV_EACCES:
52    case UV_EIO:
53    case UV_ELOOP:
54    case UV_EMFILE:
55    case UV_ENFILE:
56    case UV_ENOENT:
57    case UV_EPERM:
58      rc = uv__random_sysctl(buf, buflen);
59      break;
60  }
61# endif
62#elif defined(_WIN32)
63  uv__once_init();
64  rc = uv__random_rtlgenrandom(buf, buflen);
65#else
66  rc = uv__random_devurandom(buf, buflen);
67#endif
68
69  return rc;
70}
71
72
73static void uv__random_work(struct uv__work* w) {
74  uv_random_t* req;
75
76  req = container_of(w, uv_random_t, work_req);
77  req->status = uv__random(req->buf, req->buflen);
78}
79
80
81static void uv__random_done(struct uv__work* w, int status) {
82  uv_random_t* req;
83
84  req = container_of(w, uv_random_t, work_req);
85  uv__req_unregister(req->loop, req);
86
87  if (status == 0)
88    status = req->status;
89
90  req->cb(req, status, req->buf, req->buflen);
91}
92
93
94int uv_random(uv_loop_t* loop,
95              uv_random_t* req,
96              void *buf,
97              size_t buflen,
98              unsigned flags,
99              uv_random_cb cb) {
100  if (buflen > 0x7FFFFFFFu)
101    return UV_E2BIG;
102
103  if (flags != 0)
104    return UV_EINVAL;
105
106  if (cb == NULL)
107    return uv__random(buf, buflen);
108
109  uv__req_init(loop, req, UV_RANDOM);
110  req->loop = loop;
111  req->status = 0;
112  req->cb = cb;
113  req->buf = buf;
114  req->buflen = buflen;
115
116  uv__work_submit(loop,
117                  &req->work_req,
118                  UV__WORK_CPU,
119                  uv__random_work,
120                  uv__random_done);
121
122  return 0;
123}
124