1 /*- 2 * Copyright (c) 2001 Mark R V Murray 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer 10 * in this position and unchanged. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 /* This header contains only those definitions that are global 30 * and non algorithm-specific for the entropy processor 31 */ 32 33 /* #define ENTROPYSOURCE nn entropy sources (actually classes) 34 * This is properly defined in 35 * an enum in sys/random.h 36 */ 37 38 /* Cryptographic block size in bits */ 39 #define BLOCKSIZE 256 40 41 /* The ring size _MUST_ be a power of 2 */ 42 #define HARVEST_RING_SIZE 1024 /* harvest ring buffer size */ 43 #define HARVEST_RING_MASK (HARVEST_RING_SIZE - 1) 44 45 #define HARVESTSIZE 16 /* max size of each harvested entropy unit */ 46 47 SYSCTL_DECL(_kern_random); 48 49 MALLOC_DECLARE(M_ENTROPY); 50 51 /* These are used to queue harvested packets of entropy. The entropy 52 * buffer size is pretty arbitrary. 53 */ 54 struct harvest { 55 uintmax_t somecounter; /* fast counter for clock jitter */ 56 u_char entropy[HARVESTSIZE]; /* the harvested entropy */ 57 u_int size, bits, frac; /* stats about the entropy */ 58 enum esource source; /* stats about the entropy */ 59 STAILQ_ENTRY(harvest) next; /* next item on the list */ 60 }; 61 62 void random_init(void); 63 void random_deinit(void); 64 void random_init_harvester(void (*)(u_int64_t, void *, u_int, u_int, u_int, enum esource), int (*)(void *, int)); 65 void random_deinit_harvester(void); 66 void random_set_wakeup_exit(void *); 67 void random_process_event(struct harvest *event); 68 void random_reseed(void); 69 void random_unblock(void); 70 71 int read_random_real(void *, int); 72 73 /* If this was c++, this would be a template */ 74 #define RANDOM_CHECK_UINT(name, min, max) \ 75 static int \ 76 random_check_uint_##name(SYSCTL_HANDLER_ARGS) \ 77 { \ 78 if (oidp->oid_arg1 != NULL) { \ 79 if (*(u_int *)(oidp->oid_arg1) <= (min)) \ 80 *(u_int *)(oidp->oid_arg1) = (min); \ 81 else if (*(u_int *)(oidp->oid_arg1) > (max)) \ 82 *(u_int *)(oidp->oid_arg1) = (max); \ 83 } \ 84 return sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, \ 85 req); \ 86 } 87