1 // SPDX-License-Identifier: CDDL-1.0 2 /* 3 * CDDL HEADER START 4 * 5 * The contents of this file are subject to the terms of the 6 * Common Development and Distribution License (the "License"). 7 * You may not use this file except in compliance with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or https://opensource.org/licenses/CDDL-1.0. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 24 * Copyright (c) 2012, 2018 by Delphix. All rights reserved. 25 * Copyright (c) 2016 Actifio, Inc. All rights reserved. 26 * Copyright (c) 2025, Klara, Inc. 27 */ 28 29 #include <stdint.h> 30 #include <fcntl.h> 31 #include <assert.h> 32 #include <sys/random.h> 33 #include "libspl_impl.h" 34 35 #define RANDOM_PATH "/dev/random" 36 #define URANDOM_PATH "/dev/urandom" 37 38 static int random_fd = -1, urandom_fd = -1; 39 40 static boolean_t force_pseudo = B_FALSE; 41 42 void 43 random_init(void) 44 { 45 /* Handle multiple calls. */ 46 if (random_fd != -1) { 47 ASSERT3U(urandom_fd, !=, -1); 48 return; 49 } 50 51 VERIFY((random_fd = open(RANDOM_PATH, O_RDONLY | O_CLOEXEC)) != -1); 52 VERIFY((urandom_fd = open(URANDOM_PATH, O_RDONLY | O_CLOEXEC)) != -1); 53 } 54 55 void 56 random_fini(void) 57 { 58 close(random_fd); 59 close(urandom_fd); 60 61 random_fd = -1; 62 urandom_fd = -1; 63 } 64 65 void 66 random_force_pseudo(boolean_t onoff) 67 { 68 force_pseudo = onoff; 69 } 70 71 static int 72 random_get_bytes_common(uint8_t *ptr, size_t len, int fd) 73 { 74 size_t resid = len; 75 ssize_t bytes; 76 77 ASSERT(fd != -1); 78 79 while (resid != 0) { 80 bytes = read(fd, ptr, resid); 81 ASSERT3S(bytes, >=, 0); 82 ptr += bytes; 83 resid -= bytes; 84 } 85 86 return (0); 87 } 88 89 int 90 random_get_bytes(uint8_t *ptr, size_t len) 91 { 92 if (force_pseudo) 93 return (random_get_pseudo_bytes(ptr, len)); 94 return (random_get_bytes_common(ptr, len, random_fd)); 95 } 96 97 int 98 random_get_pseudo_bytes(uint8_t *ptr, size_t len) 99 { 100 return (random_get_bytes_common(ptr, len, urandom_fd)); 101 } 102