2 * random.h -- A strong random number generator
4 * $FreeBSD: src/sys/sys/random.h,v 1.19.2.2 2002/09/17 17:11:54 sam Exp $
6 * Version 0.95, last modified 18-Oct-95
8 * Copyright Theodore Ts'o, 1994, 1995. All rights reserved.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, and the entire permission notice in its entirety,
15 * including the disclaimer of warranties.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. The name of the author may not be used to endorse or promote
20 * products derived from this software without specific prior
23 * ALTERNATIVELY, this product may be distributed under the terms of
24 * the GNU Public License, in which case the provisions of the GPL are
25 * required INSTEAD OF the above restrictions. (This clause is
26 * necessary due to a potential bad interaction between the GPL and
27 * the restrictions contained in a BSD-style copyright.)
29 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
30 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
31 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
32 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
33 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
34 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
35 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
37 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
38 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
39 * OF THE POSSIBILITY OF SUCH DAMAGE.
44 * Many kernel routines will have a use for good random numbers,
45 * for example, for truely random TCP sequence numbers, which prevent
46 * certain forms of TCP spoofing attacks.
50 #ifndef _SYS_RANDOM_H_
51 #define _SYS_RANDOM_H_
54 #include <sys/types.h>
56 #ifndef _SYS_INTERRUPT_H_
57 #include <sys/interrupt.h>
59 #ifndef _SYS_IOCCOM_H_
60 #include <sys/ioccom.h>
63 #define MEM_SETIRQ _IOW('r', 1, u_int16_t) /* set interrupt */
64 #define MEM_CLEARIRQ _IOW('r', 2, u_int16_t) /* clear interrupt */
65 #define MEM_RETURNIRQ _IOR('r', 3, u_int16_t) /* obsolete */
66 #define MEM_FINDIRQ _IOWR('r', 4, u_int16_t) /* next interrupt */
70 /* Type of the cookie passed to add_interrupt_randomness. */
77 /* Exported functions */
79 void rand_initialize(void);
80 void add_keyboard_randomness(u_char scancode);
81 void add_interrupt_randomness(int intr);
83 void add_blkdev_randomness(int major);
85 void add_true_randomness(int);
86 int add_buffer_randomness(const char *, int);
89 void get_random_bytes(void *buf, u_int nbytes);
91 u_int read_random(void *buf, u_int size);
92 u_int read_random_unlimited(void *buf, u_int size);
94 u_int write_random(const char *buf, u_int nbytes);
98 int random_filter_read(struct knote *kn, long hint);
102 #endif /* !_SYS_RANDOM_H_ */