libc: Reintroduce getentropy.

This was introduced two years ago when the getrandom/getentropy API
question was still open, and removed because the discussion was
ongoing.  Now getentropy is more widely adopted and soon to be in
POSIX.  So reintroduce the symbol into libc since we'll be keeping it
anyway.  Discussion of details of the semantics, as interpreted by
NetBSD, is ongoing, but the symbol needs to get in before the
netbsd-10 branch.  The draft POSIX text is
(https://www.opengroup.org/austin/docs/austin_1110.pdf):

    SYNOPSIS
        #include <unistd.h>

        int getentropy(void *buffer, size_t length);

    DESCRIPTION
        The getentropy() function shall write length bytes of data
        starting at the location pointed to by buffer. The output
        shall be unpredictable high quality random data, generated by
        a cryptographically secure pseudo-random number
        generator. The maximum permitted value for the length
        argument is given by the {GETENTROPY_MAX} symbolic constant
        defined in <limits.h>.

    RETURN VALUES
        Upon successful completion, getentropy() shall return 0;
        otherwise, -1 shall be retunred and errno set to indicate the
        error.

    ERRORS
        The getentropy() function shall fail if:

        [EINVAL]        The value of length is greater than
                        {GETENTROPY_MAX}.

        The getentropy() function may fail if:

        [ENOSYS]        The system does not provide the necessary
                        source of entropy.

    RATIONALE
        The getentropy() function is not a cancellation point.

Minor changes from the previous introduction of getentropy into libc:

- Return EINVAL, not EIO, on buflen > 256.
- Define GETENTROPY_MAX in limits.h.

The declaration of getentropy in unistd.h and definition of
GETENTROPY_MAX in limits.h are currently conditional on
_NETBSD_SOURCE.  When the next revision of POSIX is finalized, we can
expose them also under _POSIX_C_SOURCE > 20yymmL as usual -- and this
can be done as a pullup without breaking existing compiled programs.
This commit is contained in:
riastradh 2022-05-31 13:42:58 +00:00
parent 4c33e72fa2
commit 2b5e567d9c
11 changed files with 372 additions and 13 deletions

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@ -1,4 +1,4 @@
# $NetBSD: mi,v 1.2414 2022/05/27 07:28:21 nia Exp $ # $NetBSD: mi,v 1.2415 2022/05/31 13:42:58 riastradh Exp $
# #
# Note: don't delete entries from here - mark them as "obsolete" instead. # Note: don't delete entries from here - mark them as "obsolete" instead.
./etc/mtree/set.comp comp-sys-root ./etc/mtree/set.comp comp-sys-root
@ -7698,7 +7698,7 @@
./usr/share/man/cat3/getdiskrawname.0 comp-c-catman .cat ./usr/share/man/cat3/getdiskrawname.0 comp-c-catman .cat
./usr/share/man/cat3/getdomainname.0 comp-c-catman .cat ./usr/share/man/cat3/getdomainname.0 comp-c-catman .cat
./usr/share/man/cat3/getdtablesize.0 comp-c-catman .cat ./usr/share/man/cat3/getdtablesize.0 comp-c-catman .cat
./usr/share/man/cat3/getentropy.0 comp-c-catman obsolete ./usr/share/man/cat3/getentropy.0 comp-c-catman .cat
./usr/share/man/cat3/getenv.0 comp-c-catman .cat ./usr/share/man/cat3/getenv.0 comp-c-catman .cat
./usr/share/man/cat3/getenv_r.0 comp-c-catman .cat ./usr/share/man/cat3/getenv_r.0 comp-c-catman .cat
./usr/share/man/cat3/getfsent.0 comp-c-catman .cat ./usr/share/man/cat3/getfsent.0 comp-c-catman .cat
@ -16018,7 +16018,7 @@
./usr/share/man/html3/getdiskrawname.html comp-c-htmlman html ./usr/share/man/html3/getdiskrawname.html comp-c-htmlman html
./usr/share/man/html3/getdomainname.html comp-c-htmlman html ./usr/share/man/html3/getdomainname.html comp-c-htmlman html
./usr/share/man/html3/getdtablesize.html comp-c-htmlman html ./usr/share/man/html3/getdtablesize.html comp-c-htmlman html
./usr/share/man/html3/getentropy.html comp-c-htmlman obsolete ./usr/share/man/html3/getentropy.html comp-c-htmlman html
./usr/share/man/html3/getenv.html comp-c-htmlman html ./usr/share/man/html3/getenv.html comp-c-htmlman html
./usr/share/man/html3/getenv_r.html comp-c-htmlman html ./usr/share/man/html3/getenv_r.html comp-c-htmlman html
./usr/share/man/html3/getfsent.html comp-c-htmlman html ./usr/share/man/html3/getfsent.html comp-c-htmlman html
@ -24276,7 +24276,7 @@
./usr/share/man/man3/getdiskrawname.3 comp-c-man .man ./usr/share/man/man3/getdiskrawname.3 comp-c-man .man
./usr/share/man/man3/getdomainname.3 comp-c-man .man ./usr/share/man/man3/getdomainname.3 comp-c-man .man
./usr/share/man/man3/getdtablesize.3 comp-c-man .man ./usr/share/man/man3/getdtablesize.3 comp-c-man .man
./usr/share/man/man3/getentropy.3 comp-c-man obsolete ./usr/share/man/man3/getentropy.3 comp-c-man .man
./usr/share/man/man3/getenv.3 comp-c-man .man ./usr/share/man/man3/getenv.3 comp-c-man .man
./usr/share/man/man3/getenv_r.3 comp-c-man .man ./usr/share/man/man3/getenv_r.3 comp-c-man .man
./usr/share/man/man3/getfsent.3 comp-c-man .man ./usr/share/man/man3/getfsent.3 comp-c-man .man

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@ -1,4 +1,4 @@
# $NetBSD: mi,v 1.385 2022/05/29 15:23:20 nia Exp $ # $NetBSD: mi,v 1.386 2022/05/31 13:42:59 riastradh Exp $
./etc/mtree/set.debug comp-sys-root ./etc/mtree/set.debug comp-sys-root
./usr/lib comp-sys-usr compatdir ./usr/lib comp-sys-usr compatdir
./usr/lib/i18n/libBIG5_g.a comp-c-debuglib debuglib,compatfile ./usr/lib/i18n/libBIG5_g.a comp-c-debuglib debuglib,compatfile
@ -2007,6 +2007,7 @@
./usr/libdata/debug/usr/tests/lib/libc/gen/t_fpsetround.debug tests-lib-debug debug,atf,compattestfile ./usr/libdata/debug/usr/tests/lib/libc/gen/t_fpsetround.debug tests-lib-debug debug,atf,compattestfile
./usr/libdata/debug/usr/tests/lib/libc/gen/t_ftok.debug tests-lib-debug debug,atf,compattestfile ./usr/libdata/debug/usr/tests/lib/libc/gen/t_ftok.debug tests-lib-debug debug,atf,compattestfile
./usr/libdata/debug/usr/tests/lib/libc/gen/t_getcwd.debug tests-lib-debug debug,atf,compattestfile ./usr/libdata/debug/usr/tests/lib/libc/gen/t_getcwd.debug tests-lib-debug debug,atf,compattestfile
./usr/libdata/debug/usr/tests/lib/libc/gen/t_getentropy.debug tests-lib-debug debug,atf,compattestfile
./usr/libdata/debug/usr/tests/lib/libc/gen/t_getgrent.debug tests-lib-debug debug,atf,compattestfile ./usr/libdata/debug/usr/tests/lib/libc/gen/t_getgrent.debug tests-lib-debug debug,atf,compattestfile
./usr/libdata/debug/usr/tests/lib/libc/gen/t_glob.debug tests-lib-debug debug,atf,compattestfile ./usr/libdata/debug/usr/tests/lib/libc/gen/t_glob.debug tests-lib-debug debug,atf,compattestfile
./usr/libdata/debug/usr/tests/lib/libc/gen/t_glob_star.debug tests-obsolete obsolete,compattestfile ./usr/libdata/debug/usr/tests/lib/libc/gen/t_glob_star.debug tests-obsolete obsolete,compattestfile

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@ -1,4 +1,4 @@
# $NetBSD: mi,v 1.1208 2022/05/27 07:28:22 nia Exp $ # $NetBSD: mi,v 1.1209 2022/05/31 13:42:59 riastradh Exp $
# #
# Note: don't delete entries from here - mark them as "obsolete" instead. # Note: don't delete entries from here - mark them as "obsolete" instead.
# #
@ -2867,6 +2867,7 @@
./usr/tests/lib/libc/gen/t_fpsetround tests-lib-tests compattestfile,atf ./usr/tests/lib/libc/gen/t_fpsetround tests-lib-tests compattestfile,atf
./usr/tests/lib/libc/gen/t_ftok tests-lib-tests compattestfile,atf ./usr/tests/lib/libc/gen/t_ftok tests-lib-tests compattestfile,atf
./usr/tests/lib/libc/gen/t_getcwd tests-lib-tests compattestfile,atf ./usr/tests/lib/libc/gen/t_getcwd tests-lib-tests compattestfile,atf
./usr/tests/lib/libc/gen/t_getentropy tests-lib-tests compattestfile,atf
./usr/tests/lib/libc/gen/t_getgrent tests-lib-tests compattestfile,atf ./usr/tests/lib/libc/gen/t_getgrent tests-lib-tests compattestfile,atf
./usr/tests/lib/libc/gen/t_glob tests-lib-tests compattestfile,atf ./usr/tests/lib/libc/gen/t_glob tests-lib-tests compattestfile,atf
./usr/tests/lib/libc/gen/t_glob_star tests-obsolete obsolete ./usr/tests/lib/libc/gen/t_glob_star tests-obsolete obsolete

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@ -1,4 +1,4 @@
/* $NetBSD: limits.h,v 1.42 2019/09/15 23:52:59 christos Exp $ */ /* $NetBSD: limits.h,v 1.43 2022/05/31 13:42:59 riastradh Exp $ */
/* /*
* Copyright (c) 1988, 1993 * Copyright (c) 1988, 1993
@ -144,6 +144,10 @@
#define MB_LEN_MAX 32 /* Allow ISO/IEC 2022 */ #define MB_LEN_MAX 32 /* Allow ISO/IEC 2022 */
#ifdef _NETBSD_SOURCE
#define GETENTROPY_MAX 256
#endif
#include <machine/limits.h> #include <machine/limits.h>
#ifdef __CHAR_UNSIGNED__ #ifdef __CHAR_UNSIGNED__

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@ -1,4 +1,4 @@
/* $NetBSD: unistd.h,v 1.162 2021/10/15 22:32:28 andvar Exp $ */ /* $NetBSD: unistd.h,v 1.163 2022/05/31 13:42:59 riastradh Exp $ */
/*- /*-
* Copyright (c) 1998, 1999, 2008 The NetBSD Foundation, Inc. * Copyright (c) 1998, 1999, 2008 The NetBSD Foundation, Inc.
@ -338,6 +338,7 @@ int fchroot(int);
int fdiscard(int, off_t, off_t); int fdiscard(int, off_t, off_t);
int fsync_range(int, int, off_t, off_t); int fsync_range(int, int, off_t, off_t);
int getdomainname(char *, size_t); int getdomainname(char *, size_t);
int getentropy(void *, size_t);
int getgrouplist(const char *, gid_t, gid_t *, int *); int getgrouplist(const char *, gid_t, gid_t *, int *);
int getgroupmembership(const char *, gid_t, gid_t *, int, int *); int getgroupmembership(const char *, gid_t, gid_t *, int, int *);
mode_t getmode(const void *, mode_t); mode_t getmode(const void *, mode_t);

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@ -1,4 +1,4 @@
# $NetBSD: Makefile.inc,v 1.215 2021/11/15 14:01:51 christos Exp $ # $NetBSD: Makefile.inc,v 1.216 2022/05/31 13:42:59 riastradh Exp $
# from: @(#)Makefile.inc 8.6 (Berkeley) 5/4/95 # from: @(#)Makefile.inc 8.6 (Berkeley) 5/4/95
# gen sources # gen sources
@ -15,7 +15,7 @@ SRCS+= alarm.c alphasort.c arc4random.c assert.c asysctl.c \
errc.c errlist.c errno.c execl.c execle.c execlp.c execv.c execvp.c \ errc.c errlist.c errno.c execl.c execle.c execlp.c execv.c execvp.c \
exect.c extattr.c fmtcheck.c fmtmsg.c fnmatch.c fstab.c ftok.c \ exect.c extattr.c fmtcheck.c fmtmsg.c fnmatch.c fstab.c ftok.c \
fts.c ftw.c getbsize.c getcap.c getcwd.c \ fts.c ftw.c getbsize.c getcap.c getcwd.c \
getdevmajor.c getdomainname.c getgrent.c \ getdevmajor.c getdomainname.c getentropy.c getgrent.c \
getgrouplist.c getgroupmembership.c gethostname.c \ getgrouplist.c getgroupmembership.c gethostname.c \
getloadavg.c getlogin.c getmntinfo.c \ getloadavg.c getlogin.c getmntinfo.c \
getnetgrent.c getpagesize.c \ getnetgrent.c getpagesize.c \
@ -61,7 +61,7 @@ MAN+= alarm.3 arc4random.3 basename.3 bsd_signal.3 bswap.3 \
fmtcheck.3 fmtmsg.3 fnmatch.3 fpclassify.3 fpgetmask.3 \ fmtcheck.3 fmtmsg.3 fnmatch.3 fpclassify.3 fpgetmask.3 \
ftok.3 fts.3 ftw.3 \ ftok.3 fts.3 ftw.3 \
getbsize.3 cgetcap.3 getcwd.3 getdevmajor.3 \ getbsize.3 cgetcap.3 getcwd.3 getdevmajor.3 \
getdomainname.3 getdiskbyname.3 getfsent.3 \ getdomainname.3 getdiskbyname.3 getentropy.3 getfsent.3 \
getgrent.3 getgrouplist.3 gethostname.3 getlastlogx.3 getloadavg.3 \ getgrent.3 getgrouplist.3 gethostname.3 getlastlogx.3 getloadavg.3 \
getmntinfo.3 getnetgrent.3 getpagesize.3 getpass.3 \ getmntinfo.3 getnetgrent.3 getpagesize.3 getpass.3 \
getprogname.3 getpwent.3 getttyent.3 getusershell.3 glob.3 \ getprogname.3 getpwent.3 getttyent.3 getusershell.3 glob.3 \

94
lib/libc/gen/getentropy.3 Normal file
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@ -0,0 +1,94 @@
.\" $NetBSD: getentropy.3,v 1.4 2022/05/31 13:42:59 riastradh Exp $ $
.\"
.\" Copyright (c) 2020 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Nia Alarie.
.\"
.\" 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.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
.\" ``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 FOUNDATION OR CONTRIBUTORS
.\" 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.
.\"
.Dd May 1, 2020
.Dt GETENTROPY 3
.Os
.Sh NAME
.Nm getentropy
.Nd fill a buffer with high quality random data
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In unistd.h
.Ft int
.Fn getentropy "void *buf" "size_t buflen"
.In limits.h
.Li #define GETENTROPY_MAX 256
.Sh DESCRIPTION
.Pp
The
.Fn getentropy
function fills a buffer with high quality random data, suitable for seeding
cryptographically secure psuedorandom number generators.
.Pp
.Fn getentropy
is only intended for seeding random number generators and is not intended
for use by regular code which simply needs secure random data.
For this purpose, please use
.Xr arc4random 3 .
.Pp
The maximum value for
.Li buflen
is 256 bytes.
.Sh IMPLEMENTATION NOTES
.Fn getentropy
reads from the
.Xr sysctl 7
variable
.Li kern.arandom .
.Sh RETURN VALUES
.Rv -std getentropy
.Sh ERRORS
.Fn getentropy
will succeed unless:
.Bl -tag -width Er
.It Bq Er EFAULT
The
.Fa buf
argument points to an invalid memory address.
.It Bq Er EINVAL
More than 256 bytes were requested.
.Sh SEE ALSO
.Xr arc4random 3 ,
.Xr rnd 4
.Sh STANDARDS
The
.Fn getentropy
function is non-standard.
However, it is likely to be included in the next revision of POSIX.
.Sh HISTORY
The
.Fn getentropy
function first appeared in
.Ox 5.6 ,
then in
.Fx 12.0 ,
and
.Nx 10 .

67
lib/libc/gen/getentropy.c Normal file
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@ -0,0 +1,67 @@
/* $NetBSD: getentropy.c,v 1.3 2022/05/31 13:42:59 riastradh Exp $ */
/*-
* Copyright (c) 2020 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Nia Alarie.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``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 FOUNDATION OR CONTRIBUTORS
* 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.
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: getentropy.c,v 1.3 2022/05/31 13:42:59 riastradh Exp $");
#include "namespace.h"
#include <sys/param.h>
#include <sys/sysctl.h>
#include <errno.h>
#include <limits.h>
#include <unistd.h>
#ifdef __weak_alias
__weak_alias(getentropy,_getentropy)
#endif
__CTASSERT(GETENTROPY_MAX == 256);
int
getentropy(void *buf, size_t buflen)
{
size_t len = buflen;
int name[2] = { CTL_KERN, KERN_ARND };
if (buf == NULL && buflen > 0) {
errno = EFAULT;
return -1;
}
if (buflen > 256) {
errno = EINVAL;
return -1;
}
return sysctl(name, 2, buf, &len, NULL, 0);
}

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@ -1,4 +1,4 @@
/* $NetBSD: namespace.h,v 1.202 2021/09/11 20:28:03 andvar Exp $ */ /* $NetBSD: namespace.h,v 1.203 2022/05/31 13:42:59 riastradh Exp $ */
/*- /*-
* Copyright (c) 1997-2004 The NetBSD Foundation, Inc. * Copyright (c) 1997-2004 The NetBSD Foundation, Inc.
@ -361,6 +361,7 @@
#define getdevmajor _getdevmajor #define getdevmajor _getdevmajor
#define getdiskbyname _getdiskbyname #define getdiskbyname _getdiskbyname
#define getdomainname _getdomainname #define getdomainname _getdomainname
#define getentropy _getentropy
#define getfsent _getfsent #define getfsent _getfsent
#define getfsfile _getfsfile #define getfsfile _getfsfile
#define getfsspec _getfsspec #define getfsspec _getfsspec

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@ -1,4 +1,4 @@
# $NetBSD: Makefile,v 1.54 2020/02/22 19:14:57 kamil Exp $ # $NetBSD: Makefile,v 1.55 2022/05/31 13:42:59 riastradh Exp $
.include <bsd.own.mk> .include <bsd.own.mk>
@ -21,6 +21,7 @@ TESTS_C+= t_fpsetmask
TESTS_C+= t_fpsetround TESTS_C+= t_fpsetround
TESTS_C+= t_ftok TESTS_C+= t_ftok
TESTS_C+= t_getcwd TESTS_C+= t_getcwd
TESTS_C+= t_getentropy
TESTS_C+= t_getgrent TESTS_C+= t_getgrent
TESTS_C+= t_glob TESTS_C+= t_glob
TESTS_C+= t_humanize_number TESTS_C+= t_humanize_number

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@ -0,0 +1,189 @@
/* $NetBSD: t_getentropy.c,v 1.1 2022/05/31 13:42:59 riastradh Exp $ */
/*-
* Copyright (c) 2022 The NetBSD Foundation, Inc.
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``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 FOUNDATION OR CONTRIBUTORS
* 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.
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: t_getentropy.c,v 1.1 2022/05/31 13:42:59 riastradh Exp $");
#include <sys/mman.h>
#include <atf-c.h>
#include <errno.h>
#include <limits.h>
#include <stdint.h>
#include <string.h>
#include <unistd.h>
static uint8_t buf[289];
static uint8_t zero[sizeof(buf)];
__CTASSERT(GETENTROPY_MAX == 256);
ATF_TC(getentropy_0);
ATF_TC_HEAD(getentropy_0, tc)
{
atf_tc_set_md_var(tc, "descr", "getentropy 0 bytes");
atf_tc_set_md_var(tc, "timeout", "2");
}
ATF_TC_BODY(getentropy_0, tc)
{
memset(buf, 0, sizeof(buf));
if (getentropy(buf, 0) == -1)
atf_tc_fail("getentropy: %d (%s)", errno, strerror(errno));
ATF_CHECK(memcmp(buf, zero, sizeof(buf)) == 0);
}
ATF_TC(getentropy_32);
ATF_TC_HEAD(getentropy_32, tc)
{
atf_tc_set_md_var(tc, "descr", "getentropy 32 bytes");
atf_tc_set_md_var(tc, "timeout", "2");
}
ATF_TC_BODY(getentropy_32, tc)
{
memset(buf, 0, sizeof(buf));
if (getentropy(buf + 1, 32) == -1)
atf_tc_fail("getentropy: %d (%s)", errno, strerror(errno));
ATF_CHECK(buf[0] == 0);
ATF_CHECK(memcmp(buf + 1, zero, 32) != 0);
ATF_CHECK(memcmp(buf + 1 + 32, zero, sizeof(buf) - 1 - 32) == 0);
}
ATF_TC(getentropy_256);
ATF_TC_HEAD(getentropy_256, tc)
{
atf_tc_set_md_var(tc, "descr", "getentropy 256 bytes");
atf_tc_set_md_var(tc, "timeout", "2");
}
ATF_TC_BODY(getentropy_256, tc)
{
memset(buf, 0, sizeof(buf));
if (getentropy(buf + 1, 256) == -1)
atf_tc_fail("getentropy: %d (%s)", errno, strerror(errno));
ATF_CHECK(buf[0] == 0);
ATF_CHECK(memcmp(buf + 1, zero, 256) != 0);
ATF_CHECK(memcmp(buf + 1 + 256, zero, sizeof(buf) - 1 - 256) == 0);
}
ATF_TC(getentropy_257);
ATF_TC_HEAD(getentropy_257, tc)
{
atf_tc_set_md_var(tc, "descr", "getentropy 257 bytes (beyond max)");
atf_tc_set_md_var(tc, "timeout", "2");
}
ATF_TC_BODY(getentropy_257, tc)
{
memset(buf, 0, sizeof(buf));
ATF_CHECK_ERRNO(EINVAL, getentropy(buf, 257) == -1);
ATF_CHECK(memcmp(buf, zero, sizeof(buf)) == 0);
}
ATF_TC(getentropy_null);
ATF_TC_HEAD(getentropy_null, tc)
{
atf_tc_set_md_var(tc, "descr", "getentropy with null buffer");
atf_tc_set_md_var(tc, "timeout", "2");
}
ATF_TC_BODY(getentropy_null, tc)
{
ATF_CHECK_ERRNO(EFAULT, getentropy(NULL, 32) == -1);
}
ATF_TC(getentropy_nearnull);
ATF_TC_HEAD(getentropy_nearnull, tc)
{
atf_tc_set_md_var(tc, "descr", "getentropy with nearly null buffer");
atf_tc_set_md_var(tc, "timeout", "2");
}
ATF_TC_BODY(getentropy_nearnull, tc)
{
ATF_CHECK_ERRNO(EFAULT, getentropy((char *)(uintptr_t)1, 32) == -1);
}
ATF_TC(getentropy_badaddr);
ATF_TC_HEAD(getentropy_badaddr, tc)
{
atf_tc_set_md_var(tc, "descr", "getentropy with bad address");
atf_tc_set_md_var(tc, "timeout", "2");
}
ATF_TC_BODY(getentropy_badaddr, tc)
{
size_t pagesize = sysconf(_SC_PAGESIZE);
char *p;
/*
* Allocate three consecutive pages and make the middle one
* nonwritable.
*/
p = mmap(NULL, 3*pagesize, PROT_READ|PROT_WRITE,
MAP_ANON|MAP_PRIVATE, -1, 0);
if (p == MAP_FAILED)
atf_tc_fail("mmap: %d (%s)", errno, strerror(errno));
if (mprotect(p + pagesize, pagesize, PROT_READ) == -1)
atf_tc_fail("mprotect: %d (%s)", errno, strerror(errno));
/* Verify that writing to the end of the first page works. */
if (getentropy(p + pagesize - 25, 25) == -1)
atf_tc_fail("getentropy 1: %d (%s)", errno, strerror(errno));
ATF_CHECK(memcmp(p + pagesize - 25, zero, 25) != 0);
/*
* Verify that writes into the middle page, whether straddling
* the surrounding pages or not, fail with EFAULT.
*/
ATF_CHECK_ERRNO(EFAULT, getentropy(p + pagesize - 1, 2) == -1);
ATF_CHECK_ERRNO(EFAULT, getentropy(p + pagesize, 32) == -1);
ATF_CHECK_ERRNO(EFAULT, getentropy(p + 2*pagesize - 1, 2) == -1);
/* Verify that writing to the start of the last page works. */
if (getentropy(p + 2*pagesize, 25) == -1)
atf_tc_fail("getentropy 2: %d (%s)", errno, strerror(errno));
ATF_CHECK(memcmp(p + pagesize - 25, zero, 25) != 0);
if (munmap(p, 3*pagesize) == -1)
atf_tc_fail("munmap: %d (%s)", errno, strerror(errno));
}
ATF_TP_ADD_TCS(tp)
{
ATF_TP_ADD_TC(tp, getentropy_0);
ATF_TP_ADD_TC(tp, getentropy_256);
ATF_TP_ADD_TC(tp, getentropy_257);
ATF_TP_ADD_TC(tp, getentropy_32);
ATF_TP_ADD_TC(tp, getentropy_badaddr);
ATF_TP_ADD_TC(tp, getentropy_nearnull);
ATF_TP_ADD_TC(tp, getentropy_null);
return atf_no_error();
}