Commit Graph

7 Commits

Author SHA1 Message Date
Alan Somers
d14f60e9ba Misc compiler warning fixes in lib/libc
Reviewed by:	kevans, imp
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D26534
2020-09-27 22:26:41 +00:00
Conrad Meyer
0a3a36cd94 getentropy(3): Trap non-API errnos from getrandom(2) and abort
Additionally, reconcile our abort behavior with arc4random(3).  Unlike
SIGABRT, SIGKILL cannot be caught by the user program.  These failures
are fatal conditions and should not return to the caller, as they did in
the instance that resulted in D17049.

While here, fix some minor typos in a comment.

Reviewed by:	delphij
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D17050
2018-10-20 21:45:17 +00:00
Xin LI
59488f25ad In r331279 the code used ENOSYS to check the existence of getrandom(2).
This will only work if the caller already handles SIGSYS, which is not
always the case.

Address this by checking osreldate instead. Note that because there
was not __FreeBSD_version bump when the system call was added, use
1200061 (r332100) which is the first bump after the introduction of
the system call.

PR:		230762
Reported by:	Jenkins via Mark Millard
Reviewed by:	cem
Differential Revision:	https://reviews.freebsd.org/D16807
2018-08-20 02:17:55 +00:00
Xin LI
c1e80940f3 Update userland arc4random() with OpenBSD's Chacha20 based arc4random().
ObsoleteFiles.inc:

    Remove manual pages for arc4random_addrandom(3) and
    arc4random_stir(3).

  contrib/ntp/lib/isc/random.c:
  contrib/ntp/sntp/libevent/evutil_rand.c:

    Eliminate in-tree usage of arc4random_addrandom().

  crypto/heimdal/lib/roken/rand.c:
  crypto/openssh/config.h:

    Eliminate in-tree usage of arc4random_stir().

  include/stdlib.h:

    Remove arc4random_stir() and arc4random_addrandom() prototypes,
    provide temporary shims for transistion period.

  lib/libc/gen/Makefile.inc:

    Hook arc4random-compat.c to build, add hint for Chacha20 source for
    kernel, and remove arc4random_addrandom(3) and arc4random_stir(3)
    links.

  lib/libc/gen/arc4random.c:

    Adopt OpenBSD arc4random.c,v 1.54 with bare minimum changes, use the
    sys/crypto/chacha20 implementation of keystream.

  lib/libc/gen/Symbol.map:

    Remove arc4random_stir and arc4random_addrandom interfaces.

  lib/libc/gen/arc4random.h:

    Adopt OpenBSD arc4random.h,v 1.4 but provide _ARC4_LOCK of our own.

  lib/libc/gen/arc4random.3:

    Adopt OpenBSD arc4random.3,v 1.35 but keep FreeBSD r114444 and
    r118247.

  lib/libc/gen/arc4random-compat.c:

    Compatibility shims for arc4random_stir and arc4random_addrandom
    functions to preserve ABI.  Log once when called but do nothing
    otherwise.

  lib/libc/gen/getentropy.c:
  lib/libc/include/libc_private.h:

    Fold __arc4_sysctl into getentropy.c (renamed to arnd_sysctl).
    Remove from libc_private.h as a result.

  sys/crypto/chacha20/chacha.c:
  sys/crypto/chacha20/chacha.h:

    Make it possible to use the kernel implementation in libc.

PR:		182610
Reviewed by:	cem, markm
Obtained from:	OpenBSD
Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D16760
2018-08-19 17:40:50 +00:00
Xin LI
52809cc35b Workaround ECAPMODE for kernels between revision [331280, 337999)
where getrandom(2) is not available in capability mode.
2018-08-18 08:32:21 +00:00
Conrad Meyer
08a7e74c7c getentropy(3): Fallback to kern.arandom sysctl on older kernels
On older kernels, when userspace program disables SIGSYS, catch ENOSYS and
emulate getrandom(2) syscall with the kern.arandom sysctl (via existing
arc4_sysctl wrapper).

Special care is taken to faithfully emulate EFAULT on NULL pointers, because
sysctl(3) as used by kern.arandom ignores NULL oldp.  (This was caught by
getentropy(3) ATF tests.)

Reported by:	kib
Reviewed by:	kib
Discussed with:	delphij
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D14785
2018-03-21 23:52:37 +00:00
Conrad Meyer
e9ac27430c Implement getrandom(2) and getentropy(3)
The general idea here is to provide userspace programs with well-defined
sources of entropy, in a fashion that doesn't require opening a new file
descriptor (ulimits) or accessing paths (/dev/urandom may be restricted
by chroot or capsicum).

getrandom(2) is the more general API, and comes from the Linux world.
Since our urandom and random devices are identical, the GRND_RANDOM flag
is ignored.

getentropy(3) is added as a compatibility shim for the OpenBSD API.

truss(1) support is included.

Tests for both system calls are provided.  Coverage is believed to be at
least as comprehensive as LTP getrandom(2) test coverage.  Additionally,
instructions for running the LTP tests directly against FreeBSD are provided
in the "Test Plan" section of the Differential revision linked below.  (They
pass, of course.)

PR:		194204
Reported by:	David CARLIER <david.carlier AT hardenedbsd.org>
Discussed with:	cperciva, delphij, jhb, markj
Relnotes:	maybe
Differential Revision:	https://reviews.freebsd.org/D14500
2018-03-21 01:15:45 +00:00