Attachment #149067 for bug #194204

Lines 581-586 off_t __syscall(quad_t, ...); Link Here

(-)b/include/unistd.h (+1 lines)
581	int undelete(const char *);	581	int undelete(const char *);
582	int unwhiteout(const char *);	582	int unwhiteout(const char *);
583	void valloc(size_t); / obsoleted by malloc() */	583	void valloc(size_t); / obsoleted by malloc() */
		584	int getentropy(void *, size_t);
584		585
585	#ifndef _OPTRESET_DECLARED	586	#ifndef _OPTRESET_DECLARED
586	#define _OPTRESET_DECLARED	587	#define _OPTRESET_DECLARED

Lines 123-128 MAN+= abort2.2 \ Link Here

(-)b/lib/libc/sys/Makefile.inc (+1 lines)
123	fsync.2 \	123	fsync.2 \
124	getdirentries.2 \	124	getdirentries.2 \
125	getdtablesize.2 \	125	getdtablesize.2 \
		126	getentropy.2 \
126	getfh.2 \	127	getfh.2 \
127	getfsstat.2 \	128	getfsstat.2 \
128	getgid.2 \	129	getgid.2 \

Lines 393-398 FBSD_1.3 { Link Here

(-)b/lib/libc/sys/Symbol.map (+3 lines)
393	ffclock_getcounter;	393	ffclock_getcounter;
394	ffclock_getestimate;	394	ffclock_getestimate;
395	ffclock_setestimate;	395	ffclock_setestimate;
		396	getentropy;
396	pipe2;	397	pipe2;
397	posix_fadvise;	398	posix_fadvise;
398	procctl;	399	procctl;
Lines 612-617 FBSDprivate_1.0 { Link Here
612	_getegid;	613	_getegid;
613	__sys_getegid;	614	__sys_getegid;
614	_geteuid;	615	_geteuid;
		616	__sys_getentropy;
		617	_getentropy;
615	__sys_geteuid;	618	__sys_geteuid;
616	_getfh;	619	_getfh;
617	__sys_getfh;	620	__sys_getfh;




.\"	$OpenBSD: getentropy.2,v 1.6 2014/07/18 18:20:17 deraadt Exp $
.\"
.\" Copyright (c) 2014 Theo de Raadt
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd $Mdocdate: July 18 2014 $
.Dt GETENTROPY 2
.Os
.Sh NAME
.Nm getentropy
.Nd get entropy
.Sh SYNOPSIS
.Fd #include <unistd.h>
.Ft int
.Fn getentropy "void *buf" "size_t buflen"
.Sh DESCRIPTION
.Nm
fills a buffer with high-quality entropy, which can be used
as input for process-context pseudorandom generators like
.Xr arc4random 3 .
.Pp
The maximum buffer size permitted is 256 bytes.
Even if
.Va buflen
exceeds this.
.Pp
.Nm
is not intended for regular code; please use the
.Xr arc4random 3
family of functions instead.
.Sh RETURN VALUES
Upon successful completion, a value of 0 is returned.
Otherwise, a value of \-1 is returned and
.Va errno
is set to indicate the error.
.Sh ERRORS
.Fn getentropy
will succeed unless:
.Bl -tag -width Er
.It Bq Er EFAULT
The
.Fa buf
parameter points to an
invalid address.
.El
.It Bq Er EIO
Too
.Fa many bytes
requested, or some other
fatal error occurred.
.El
.Sh SEE ALSO
.Xr arc4random 3
.Sh HISTORY
The
.Nm
function appeared in
.Ox 5.6 .

Lines 452-455 Link Here

(-)b/sys/compat/freebsd32/freebsd32_syscall.h (-1 / +2 lines)
452	#define FREEBSD32_SYS_freebsd32_aio_mlock 543	452	#define FREEBSD32_SYS_freebsd32_aio_mlock 543
453	#define FREEBSD32_SYS_freebsd32_procctl 544	453	#define FREEBSD32_SYS_freebsd32_procctl 544
454	#define FREEBSD32_SYS_freebsd32_procctl 544	454	#define FREEBSD32_SYS_freebsd32_procctl 544
455	#define FREEBSD32_SYS_MAXSYSCALL 545	455	#define FREEBSD32_SYS_getentropy 545
		456	#define FREEBSD32_SYS_MAXSYSCALL 546

Lines 578-581 const char *freebsd32_syscallnames[] = { Link Here

(-)b/sys/compat/freebsd32/freebsd32_syscalls.c (+1 lines)
578	#else	578	#else
579	"freebsd32_procctl", /* 544 = freebsd32_procctl */	579	"freebsd32_procctl", /* 544 = freebsd32_procctl */
580	#endif	580	#endif
		581	"getentropy", /* 545 = getentropy */
581	};	582	};

Lines 615-618 struct sysent freebsd32_sysent[] = { Link Here

(-)b/sys/compat/freebsd32/freebsd32_sysent.c (+1 lines)
615	#else	615	#else
616	{ AS(freebsd32_procctl_args), (sy_call_t )freebsd32_procctl, AUE_NULL, NULL, 0, 0, 0, SY_THR_STATIC }, / 544 = freebsd32_procctl */	616	{ AS(freebsd32_procctl_args), (sy_call_t )freebsd32_procctl, AUE_NULL, NULL, 0, 0, 0, SY_THR_STATIC }, / 544 = freebsd32_procctl */
617	#endif	617	#endif
		618	{ AS(getentropy_args), (sy_call_t )sys_getentropy, AUE_NULL, NULL, 0, 0, 0, SY_THR_STATIC }, / 545 = getentropy */
618	};	619	};

Lines 3299-3304 systrace_args(int sysnum, void params, uint64_t uarg, int *n_args) Link Here

(-)b/sys/compat/freebsd32/freebsd32_systrace_args.c (+26 lines)
3299	break;	3299	break;
3300	}	3300	}
3301	#endif	3301	#endif
		3302	/* getentropy */
		3303	case 545: {
		3304	struct getentropy_args *p = params;
		3305	uarg[0] = (intptr_t) p->ptr; /* void * */
		3306	uarg[1] = p->len; /* size_t */
		3307	*n_args = 2;
		3308	break;
		3309	}
3302	default:	3310	default:
3303	*n_args = 0;	3311	*n_args = 0;
3304	break;	3312	break;
Lines 8844-8849 systrace_entry_setargdesc(int sysnum, int ndx, char *desc, size_t descsz) Link Here
8844	};	8852	};
8845	break;	8853	break;
8846	#endif	8854	#endif
		8855	/* getentropy */
		8856	case 545:
		8857	switch(ndx) {
		8858	case 0:
		8859	p = "void *";
		8860	break;
		8861	case 1:
		8862	p = "size_t";
		8863	break;
		8864	default:
		8865	break;
		8866	};
		8867	break;
8847	default:	8868	default:
8848	break;	8869	break;
8849	};	8870	};
Lines 10717-10722 systrace_return_setargdesc(int sysnum, int ndx, char *desc, size_t descsz) Link Here
10717	p = "int";	10738	p = "int";
10718	break;	10739	break;
10719	#endif	10740	#endif
		10741	/* getentropy */
		10742	case 545:
		10743	if (ndx == 0 \|\| ndx == 1)
		10744	p = "int";
		10745	break;
10720	default:	10746	default:
10721	break;	10747	break;
10722	};	10748	};

Lines 1066-1068 Link Here

(-)b/sys/compat/freebsd32/syscalls.master (+2 lines)
1066	uint32_t id1, uint32_t id2, int com, \	1066	uint32_t id1, uint32_t id2, int com, \
1067	void *data); }	1067	void *data); }
1068	#endif	1068	#endif
		1069	545 AUE_NULL NOPROTO { int getentropy(void *ptr, \
		1070	size_t len); }

Lines 3068-3073 kern/sys_pipe.c standard Link Here

(-)b/sys/conf/files (+1 lines)
3068	kern/sys_procdesc.c standard	3068	kern/sys_procdesc.c standard
3069	kern/sys_process.c standard	3069	kern/sys_process.c standard
3070	kern/sys_socket.c standard	3070	kern/sys_socket.c standard
		3071	kern/sys_random.c standard
3071	kern/syscalls.c standard	3072	kern/syscalls.c standard
3072	kern/sysv_ipc.c standard	3073	kern/sysv_ipc.c standard
3073	kern/sysv_msg.c optional sysvmsg	3074	kern/sysv_msg.c optional sysvmsg

Lines 579-582 struct sysent sysent[] = { Link Here

(-)b/sys/kern/init_sysent.c (+1 lines)
579	{ AS(pipe2_args), (sy_call_t )sys_pipe2, AUE_PIPE, NULL, 0, 0, SYF_CAPENABLED, SY_THR_STATIC }, / 542 = pipe2 */	579	{ AS(pipe2_args), (sy_call_t )sys_pipe2, AUE_PIPE, NULL, 0, 0, SYF_CAPENABLED, SY_THR_STATIC }, / 542 = pipe2 */
580	{ AS(aio_mlock_args), (sy_call_t )lkmressys, AUE_NULL, NULL, 0, 0, 0, SY_THR_ABSENT }, / 543 = aio_mlock */	580	{ AS(aio_mlock_args), (sy_call_t )lkmressys, AUE_NULL, NULL, 0, 0, 0, SY_THR_ABSENT }, / 543 = aio_mlock */
581	{ AS(procctl_args), (sy_call_t )sys_procctl, AUE_NULL, NULL, 0, 0, 0, SY_THR_STATIC }, / 544 = procctl */	581	{ AS(procctl_args), (sy_call_t )sys_procctl, AUE_NULL, NULL, 0, 0, 0, SY_THR_STATIC }, / 544 = procctl */
		582	{ AS(getentropy_args), (sy_call_t )sys_getentropy, AUE_NULL, NULL, 0, 0, 0, SY_THR_STATIC }, / 545 = getentropy */
582	};	583	};




/*-
 * Copyright (c) 2014, by Theo de Raadt
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * $FreeBSD$
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/sysent.h>
#include <sys/sysproto.h>
#include <sys/libkern.h>
#include <sys/proc.h>

#ifndef	_SYS_SYSPROTO_H_
struct getentropy_args {
	void	*ptr;
	size_t	len;
};
#endif

int
sys_getentropy(struct thread *td, struct getentropy_args *uap)
{
	char buf[256];
	int error;

	if (uap->len > sizeof(buf))
		return (EIO);

	arc4rand(buf, uap->len, 1);
	if ((error = copyout(buf, uap->ptr, uap->len)) != 0)	
		return (error);

	explicit_bzero(buf, sizeof(buf));

	return (0);
}

Lines 552-555 const char *syscallnames[] = { Link Here

(-)b/sys/kern/syscalls.c (+1 lines)
552	"pipe2", /* 542 = pipe2 */	552	"pipe2", /* 542 = pipe2 */
553	"aio_mlock", /* 543 = aio_mlock */	553	"aio_mlock", /* 543 = aio_mlock */
554	"procctl", /* 544 = procctl */	554	"procctl", /* 544 = procctl */
		555	"getentropy", /* 545 = getentropy */
555	};	556	};

Lines 980-984 Link Here

(-)b/sys/kern/syscalls.master (+1 lines)
980	543 AUE_NULL NOSTD { int aio_mlock(struct aiocb *aiocbp); }	980	543 AUE_NULL NOSTD { int aio_mlock(struct aiocb *aiocbp); }
981	544 AUE_NULL STD { int procctl(idtype_t idtype, id_t id, \	981	544 AUE_NULL STD { int procctl(idtype_t idtype, id_t id, \
982	int com, void *data); }	982	int com, void *data); }
		983	545 AUE_NULL STD { int getentropy(void *ptr, size_t len); }
983	; Please copy any additions and changes to the following compatability tables:	984	; Please copy any additions and changes to the following compatability tables:
984	; sys/compat/freebsd32/syscalls.master	985	; sys/compat/freebsd32/syscalls.master

Lines 3372-3377 systrace_args(int sysnum, void params, uint64_t uarg, int *n_args) Link Here

(-)b/sys/kern/systrace_args.c (+26 lines)
3372	*n_args = 4;	3372	*n_args = 4;
3373	break;	3373	break;
3374	}	3374	}
		3375	/* getentropy */
		3376	case 545: {
		3377	struct getentropy_args *p = params;
		3378	uarg[0] = (intptr_t) p->ptr; /* void * */
		3379	uarg[1] = p->len; /* size_t */
		3380	*n_args = 2;
		3381	break;
		3382	}
3375	default:	3383	default:
3376	*n_args = 0;	3384	*n_args = 0;
3377	break;	3385	break;
Lines 8990-8995 systrace_entry_setargdesc(int sysnum, int ndx, char *desc, size_t descsz) Link Here
8990	break;	8998	break;
8991	};	8999	};
8992	break;	9000	break;
		9001	/* getentropy */
		9002	case 545:
		9003	switch(ndx) {
		9004	case 0:
		9005	p = "void *";
		9006	break;
		9007	case 1:
		9008	p = "size_t";
		9009	break;
		9010	default:
		9011	break;
		9012	};
		9013	break;
8993	default:	9014	default:
8994	break;	9015	break;
8995	};	9016	};
Lines 10928-10933 systrace_return_setargdesc(int sysnum, int ndx, char *desc, size_t descsz) Link Here
10928	if (ndx == 0 \|\| ndx == 1)	10949	if (ndx == 0 \|\| ndx == 1)
10929	p = "int";	10950	p = "int";
10930	break;	10951	break;
		10952	/* getentropy */
		10953	case 545:
		10954	if (ndx == 0 \|\| ndx == 1)
		10955	p = "int";
		10956	break;
10931	default:	10957	default:
10932	break;	10958	break;
10933	};	10959	};

Lines 462-465 Link Here

(-)b/sys/sys/syscall.h (-1 / +2 lines)
462	#define SYS_pipe2 542	462	#define SYS_pipe2 542
463	#define SYS_aio_mlock 543	463	#define SYS_aio_mlock 543
464	#define SYS_procctl 544	464	#define SYS_procctl 544
465	#define SYS_MAXSYSCALL 545	465	#define SYS_getentropy 545
		466	#define SYS_MAXSYSCALL 546

Lines 409-412 MIASM = \ Link Here

(-)b/sys/sys/syscall.mk (-1 / +2 lines)
409	accept4.o \	409	accept4.o \
410	pipe2.o \	410	pipe2.o \
411	aio_mlock.o \	411	aio_mlock.o \
412	procctl.o	412	procctl.o \
		413	getentropy.o

Lines 1813-1818 struct procctl_args { Link Here

(-)b/sys/sys/sysproto.h (+6 lines)
1813	char com_l_[PADL_(int)]; int com; char com_r_[PADR_(int)];	1813	char com_l_[PADL_(int)]; int com; char com_r_[PADR_(int)];
1814	char data_l_[PADL_(void )]; void data; char data_r_[PADR_(void *)];	1814	char data_l_[PADL_(void )]; void data; char data_r_[PADR_(void *)];
1815	};	1815	};
		1816	struct getentropy_args {
		1817	char ptr_l_[PADL_(void )]; void ptr; char ptr_r_[PADR_(void *)];
		1818	char len_l_[PADL_(size_t)]; size_t len; char len_r_[PADR_(size_t)];
		1819	};
1816	int nosys(struct thread , struct nosys_args );	1820	int nosys(struct thread , struct nosys_args );
1817	void sys_sys_exit(struct thread , struct sys_exit_args );	1821	void sys_sys_exit(struct thread , struct sys_exit_args );
1818	int sys_fork(struct thread , struct fork_args );	1822	int sys_fork(struct thread , struct fork_args );
Lines 2204-2209 int sys_accept4(struct thread , struct accept4_args ); Link Here
2204	int sys_pipe2(struct thread , struct pipe2_args );	2208	int sys_pipe2(struct thread , struct pipe2_args );
2205	int sys_aio_mlock(struct thread , struct aio_mlock_args );	2209	int sys_aio_mlock(struct thread , struct aio_mlock_args );
2206	int sys_procctl(struct thread , struct procctl_args );	2210	int sys_procctl(struct thread , struct procctl_args );
		2211	int sys_getentropy(struct thread , struct getentropy_args );
2207		2212
2208	#ifdef COMPAT_43	2213	#ifdef COMPAT_43
2209		2214
Lines 2909-2914 int freebsd7_shmctl(struct thread , struct freebsd7_shmctl_args ); Link Here
2909	#define SYS_AUE_pipe2 AUE_PIPE	2914	#define SYS_AUE_pipe2 AUE_PIPE
2910	#define SYS_AUE_aio_mlock AUE_NULL	2915	#define SYS_AUE_aio_mlock AUE_NULL
2911	#define SYS_AUE_procctl AUE_NULL	2916	#define SYS_AUE_procctl AUE_NULL
		2917	#define SYS_AUE_getentropy AUE_NULL
2912		2918
2913	#undef PAD_	2919	#undef PAD_
2914	#undef PADL_	2920	#undef PADL_

Return to bug 194204

Added Link Here

(-)b/lib/libc/sys/getentropy.2 (+69 lines)
1	.\" $OpenBSD: getentropy.2,v 1.6 2014/07/18 18:20:17 deraadt Exp $
2	.\"
3	.\" Copyright (c) 2014 Theo de Raadt
4	.\"
5	.\" Permission to use, copy, modify, and distribute this software for any
6	.\" purpose with or without fee is hereby granted, provided that the above
7	.\" copyright notice and this permission notice appear in all copies.
8	.\"
9	.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10	.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11	.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12	.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13	.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14	.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15	.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16	.\"
17	.Dd $Mdocdate: July 18 2014 $
18	.Dt GETENTROPY 2
19	.Os
20	.Sh NAME
21	.Nm getentropy
22	.Nd get entropy
23	.Sh SYNOPSIS
24	.Fd #include <unistd.h>
25	.Ft int
26	.Fn getentropy "void *buf" "size_t buflen"
27	.Sh DESCRIPTION
28	.Nm
29	fills a buffer with high-quality entropy, which can be used
30	as input for process-context pseudorandom generators like
31	.Xr arc4random 3 .
32	.Pp
33	The maximum buffer size permitted is 256 bytes.
34	Even if
35	.Va buflen
36	exceeds this.
37	.Pp
38	.Nm
39	is not intended for regular code; please use the
40	.Xr arc4random 3
41	family of functions instead.
42	.Sh RETURN VALUES
43	Upon successful completion, a value of 0 is returned.
44	Otherwise, a value of \-1 is returned and
45	.Va errno
46	is set to indicate the error.
47	.Sh ERRORS
48	.Fn getentropy
49	will succeed unless:
50	.Bl -tag -width Er
51	.It Bq Er EFAULT
52	The
53	.Fa buf
54	parameter points to an
55	invalid address.
56	.El
57	.It Bq Er EIO
58	Too
59	.Fa many bytes
60	requested, or some other
61	fatal error occurred.
62	.El
63	.Sh SEE ALSO
64	.Xr arc4random 3
65	.Sh HISTORY
66	The
67	.Nm
68	function appeared in
69	.Ox 5.6 .

Added Link Here

(-)b/sys/kern/sys_random.c (+61 lines)
1	/*-
2	* Copyright (c) 2014, by Theo de Raadt
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	* 2. Redistributions in binary form must reproduce the above copyright
11	* notice, this list of conditions and the following disclaimer in the
12	* documentation and/or other materials provided with the distribution.
13	* 3. The name of the author may not be used to endorse or promote products
14	* derived from this software without specific prior written permission.
15	*
16	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26	*
27	* $FreeBSD$
28	*/
29
30	#include <sys/cdefs.h>
31	__FBSDID("$FreeBSD$");
32
33	#include <sys/sysent.h>
34	#include <sys/sysproto.h>
35	#include <sys/libkern.h>
36	#include <sys/proc.h>
37
38	#ifndef _SYS_SYSPROTO_H_
39	struct getentropy_args {
40	void *ptr;
41	size_t len;
42	};
43	#endif
44
45	int
46	sys_getentropy(struct thread td, struct getentropy_args uap)
47	{
48	char buf[256];
49	int error;
50
51	if (uap->len > sizeof(buf))
52	return (EIO);
53
54	arc4rand(buf, uap->len, 1);
55	if ((error = copyout(buf, uap->ptr, uap->len)) != 0)
56	return (error);
57
58	explicit_bzero(buf, sizeof(buf));
59
60	return (0);
61	}