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 "internal.h" 24 25#include <stddef.h> 26#include <dlfcn.h> 27 28typedef int (*uv__getentropy_cb)(void *, size_t); 29 30static uv__getentropy_cb uv__getentropy; 31static uv_once_t once = UV_ONCE_INIT; 32 33 34static void uv__random_getentropy_init(void) { 35 uv__getentropy = (uv__getentropy_cb) dlsym(RTLD_DEFAULT, "getentropy"); 36} 37 38 39int uv__random_getentropy(void* buf, size_t buflen) { 40 size_t pos; 41 size_t stride; 42 43 uv_once(&once, uv__random_getentropy_init); 44 45 if (uv__getentropy == NULL) 46 return UV_ENOSYS; 47 48 /* getentropy() returns an error for requests > 256 bytes. */ 49 for (pos = 0, stride = 256; pos + stride < buflen; pos += stride) 50 if (uv__getentropy((char *) buf + pos, stride)) 51 return UV__ERR(errno); 52 53 if (uv__getentropy((char *) buf + pos, buflen - pos)) 54 return UV__ERR(errno); 55 56 return 0; 57} 58