Commit Graph

43 Commits

Author SHA1 Message Date
Conrad Meyer
4647ce4fb6 EKCD: Preload error strings, PRNG seed; use OAEP padding
Preload OpenSSL ERR string data so that the formatted error messages are
vaguely meaningful. Add OpenSSL error information to the RSA_public_encrypt()
operation failure case in one-time key generation.

For obsolescent OpenSSL versions (*cough* FIPS *cough*), pre-seed the PRNG
before entering Cap mode, as old versions of OpenSSL are unaware of kernel
RNG interfaces aside from /dev/random (such as the long-supported kern.arnd, or
the slightly more recent getentropy(3) or getrandom(2)). (RSA_public_encrypt()
wants a seeded PRNG to randomize the "PS" portion of PKCS 1.5 padding or the
"MGF" pseudo-random function in OAEP padding.)

Switch dumpon to encrypt the one-time key with OAEP padding (recommended since
1998; RFC2437) rather than the obsolescent PKCS 1.5 padding (1993; RFC2313).

Switch decryptcore to attempt OAEP decryption first, and try PKCS 1.5
decryption on failure. This is intended only for transition convenience, and
we should obsolete support for non-OAEP padding in a release or two.

Reviewed by:	markj
MFC After:	2 weeks
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D24534
2020-04-23 17:56:48 +00:00
Eric van Gyzen
7bef70737b dumpon: skip size check if using zstd
As with gzip, let the dump device be smaller than physical memory
when using zstd and full dumps.

Also print the error message if the size check fails, even if -v
is not specified.  Failing silently is not friendly.

Reviewed by:	cem markj
MFC after:	2 weeks
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D23923
2020-03-03 22:14:23 +00:00
Conrad Meyer
8298529226 EKCD: Add Chacha20 encryption mode
Add Chacha20 mode to Encrypted Kernel Crash Dumps.

Chacha20 does not require messages to be multiples of block size, so it is
valid to use the cipher on non-block-sized messages without the explicit
padding AES-CBC would require.  Therefore, allow use with simultaneous dump
compression.  (Continue to disallow use of AES-CBC EKCD with compression.)

dumpon(8) gains a -C cipher flag to select between chacha and aes-cbc.
It defaults to chacha if no -C option is provided.  The man page documents this
behavior.

Relnotes:	sure
Sponsored by:	Dell EMC Isilon
2019-05-23 20:12:24 +00:00
Conrad Meyer
6b6e2954dd List-ify kernel dump device configuration
Allow users to specify multiple dump configurations in a prioritized list.
This enables fallback to secondary device(s) if primary dump fails.  E.g.,
one might configure a preference for netdump, but fallback to disk dump as a
second choice if netdump is unavailable.

This change does not list-ify netdump configuration, which is tracked
separately from ordinary disk dumps internally; only one netdump
configuration can be made at a time, for now.  It also does not implement
IPv6 netdump.

savecore(8) is already capable of scanning and iterating multiple devices
from /etc/fstab or passed on the command line.

This change doesn't update the rc or loader variables 'dumpdev' in any way;
it can still be set to configure a single dump device, and rc.d/savecore
still uses it as a single device.  Only dumpon(8) is updated to be able to
configure the more complicated configurations for now.

As part of revving the ABI, unify netdump and disk dump configuration ioctl
/ structure, and leave room for ipv6 netdump as a future possibility.
Backwards-compatibility ioctls are added to smooth ABI transition,
especially for developers who may not keep kernel and userspace perfectly
synced.

Reviewed by:	markj, scottl (earlier version)
Relnotes:	maybe
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D19996
2019-05-06 18:24:07 +00:00
Mark Johnston
79dd8f690a Avoid clobbering a user-specified -g value after r340547.
CID:		1396919
MFC with:	r340547
2018-11-20 18:10:56 +00:00
Mark Johnston
e5fff57dd0 Change dumpon(8)'s handling of -g.
Rather than using a special value to denote "use the default router",
treat the absence of the -g option to mean the same thing.  The
in-kernel netdump client will always attempt to reach the server
directly before falling back to the configured gateway anyway.  This
change makes it cleaner to support a hostname value for -g.

Reviewed by:	cem
MFC after:	3 days
Differential Revision:	https://reviews.freebsd.org/D18025
2018-11-18 01:58:48 +00:00
Conrad Meyer
f27d255c59 dumpon(8): Provide seatbelt against weak RSA keys
The premise of dumpon -k foo.pem is that dump contents will be confidential
except to anyone holding the corresponding RSA private key.

This guarantee breaks down when weak RSA keys are used.  Small RSA keys
(e.g. 512 bits) can be broken on a single personal computer in tractible
time.  Marginal RSA keys (768 bits) can be broken by EC2 and a few dollars.
Even 1024 bit keys can probably be broken by sophisticated and wealthy
attackers.

NIST SP800-57 (2016) recommends a minimum of 2048 bit RSA keys, and
estimates this provides 112 bits of security.

It would also be good to protect users from weak values of 'e' (i.e., 3) and
perhaps sanity check that their public key .pem does not accidentally
contain their private key as well.  These considerations are left as future
work.

Reviewed by:	markj, darius AT dons.net.au (previous version)
Discussed with:	bjk
Differential Revision:	https://reviews.freebsd.org/D17678
2018-10-26 19:53:59 +00:00
Mariusz Zaborski
7672a0148f Convert cap_enter() < 0 && errno != ENOSYS to caph_enter() < 0.
No functional change intended.
2018-06-19 23:43:14 +00:00
Sean Bruno
21a8e0b1d5 dumpon(8)
- fix the WITHOUT_CRYPTO buildworld case.  Its rare, but some of us do
  build this way.

Sponsored by:	Limelight Networks
2018-05-29 21:52:13 +00:00
Mark Johnston
0ff40d3d29 Add netdump support to dumpon(8).
A new usage is added so that parameters for netdump may be specified.
Specifically, one configures an interface for netdump with:

# dumpon -c <client IP> -s <server IP> [-g <gateway IP>] <iface name>

Reviewed by:	bdrewery, cem (earlier versions), sbruno
MFC after:	1 month
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D15254
2018-05-06 00:42:30 +00:00
Mark Johnston
6026dcd7ca Add support for zstd-compressed user and kernel core dumps.
This works similarly to the existing gzip compression support, but
zstd is typically faster and gives better compression ratios.

Support for this functionality must be configured by adding ZSTDIO to
one's kernel configuration file. dumpon(8)'s new -Z option is used to
configure zstd compression for kernel dumps. savecore(8) now recognizes
and saves zstd-compressed kernel dumps with a .zst extension.

Submitted by:	cem (original version)
Relnotes:	yes
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D13101,
			https://reviews.freebsd.org/D13633
2018-02-13 19:28:02 +00:00
Pedro F. Giffuni
8a16b7a18f General further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:49:47 +00:00
Mark Johnston
64a16434d8 Add support for compressed kernel dumps.
When using a kernel built with the GZIO config option, dumpon -z can be
used to configure gzip compression using the in-kernel copy of zlib.
This is useful on systems with large amounts of RAM, which require a
correspondingly large dump device. Recovery of compressed dumps is also
faster since fewer bytes need to be copied from the dump device.

Because we have no way of knowing the final size of a compressed dump
until it is written, the kernel will always attempt to dump when
compression is configured, regardless of the dump device size. If the
dump is aborted because we run out of space, an error is reported on
the console.

savecore(8) is modified to handle compressed dumps and save them to
vmcore.<index>.gz, as it does when given the -z option.

A new rc.conf variable, dumpon_flags, is added. Its value is added to
the boot-time dumpon(8) invocation that occurs when a dump device is
configured in rc.conf.

Reviewed by:	cem (earlier version)
Discussed with:	def, rgrimes
Relnotes:	yes
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D11723
2017-10-25 00:51:00 +00:00
Warner Losh
fbbd9655e5 Renumber copyright clause 4
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by:	Jan Schaumann <jschauma@stevens.edu>
Pull Request:	https://github.com/freebsd/freebsd/pull/96
2017-02-28 23:42:47 +00:00
Konrad Witaszczyk
480f31c214 Add support for encrypted kernel crash dumps.
Changes include modifications in kernel crash dump routines, dumpon(8) and
savecore(8). A new tool called decryptcore(8) was added.

A new DIOCSKERNELDUMP I/O control was added to send a kernel crash dump
configuration in the diocskerneldump_arg structure to the kernel.
The old DIOCSKERNELDUMP I/O control was renamed to DIOCSKERNELDUMP_FREEBSD11 for
backward ABI compatibility.

dumpon(8) generates an one-time random symmetric key and encrypts it using
an RSA public key in capability mode. Currently only AES-256-CBC is supported
but EKCD was designed to implement support for other algorithms in the future.
The public key is chosen using the -k flag. The dumpon rc(8) script can do this
automatically during startup using the dumppubkey rc.conf(5) variable.  Once the
keys are calculated dumpon sends them to the kernel via DIOCSKERNELDUMP I/O
control.

When the kernel receives the DIOCSKERNELDUMP I/O control it generates a random
IV and sets up the key schedule for the specified algorithm. Each time the
kernel tries to write a crash dump to the dump device, the IV is replaced by
a SHA-256 hash of the previous value. This is intended to make a possible
differential cryptanalysis harder since it is possible to write multiple crash
dumps without reboot by repeating the following commands:
# sysctl debug.kdb.enter=1
db> call doadump(0)
db> continue
# savecore

A kernel dump key consists of an algorithm identifier, an IV and an encrypted
symmetric key. The kernel dump key size is included in a kernel dump header.
The size is an unsigned 32-bit integer and it is aligned to a block size.
The header structure has 512 bytes to match the block size so it was required to
make a panic string 4 bytes shorter to add a new field to the header structure.
If the kernel dump key size in the header is nonzero it is assumed that the
kernel dump key is placed after the first header on the dump device and the core
dump is encrypted.

Separate functions were implemented to write the kernel dump header and the
kernel dump key as they need to be unencrypted. The dump_write function encrypts
data if the kernel was compiled with the EKCD option. Encrypted kernel textdumps
are not supported due to the way they are constructed which makes it impossible
to use the CBC mode for encryption. It should be also noted that textdumps don't
contain sensitive data by design as a user decides what information should be
dumped.

savecore(8) writes the kernel dump key to a key.# file if its size in the header
is nonzero. # is the number of the current core dump.

decryptcore(8) decrypts the core dump using a private RSA key and the kernel
dump key. This is performed by a child process in capability mode.
If the decryption was not successful the parent process removes a partially
decrypted core dump.

Description on how to encrypt crash dumps was added to the decryptcore(8),
dumpon(8), rc.conf(5) and savecore(8) manual pages.

EKCD was tested on amd64 using bhyve and i386, mipsel and sparc64 using QEMU.
The feature still has to be tested on arm and arm64 as it wasn't possible to run
FreeBSD due to the problems with QEMU emulation and lack of hardware.

Designed by:	def, pjd
Reviewed by:	cem, oshogbo, pjd
Partial review:	delphij, emaste, jhb, kib
Approved by:	pjd (mentor)
Differential Revision:	https://reviews.freebsd.org/D4712
2016-12-10 16:20:39 +00:00
Marcelo Araujo
0bfc2a1246 Use nitems() instead of sizeof(name) / sizeof(*name).
MFC after:	2 weeks.
2016-04-19 04:28:25 +00:00
Steven Hartland
45a9027de4 Fix dumpon compatibility with dumpdev kenv
The dumpdev kenv supports devices without the /dev/ prefix, fix dumpon to
also support this which is required after r288153.

MFC after:	1 week
Sponsored by:	Multiplay
2015-11-23 14:06:21 +00:00
Alfred Perlstein
4a790edd1b Document that you can use -v along with -l.
Noticed by: pjd
2012-11-02 17:30:08 +00:00
Alfred Perlstein
f6848434fe Add an option to display the current dump device via dumpon -l.
MFC after:	2 weeks
2012-11-01 18:59:19 +00:00
John Baldwin
b54a17cd2f Whitespace and style nits. 2006-10-31 22:36:49 +00:00
Paul Saab
ce893772bd With minidumps, the dumping partition could be smaller than physical
memory, so checking the size of the partition is not necessary.

Tested by:	kris
2006-04-27 19:01:54 +00:00
Dag-Erling Smørgrav
9872f15d75 Promote mediasize and physmem to uintmax_t when comparing them. 2004-10-04 06:54:19 +00:00
Dag-Erling Smørgrav
53504142a9 Whitespace nit. 2004-10-03 23:53:54 +00:00
Dag-Erling Smørgrav
c0046e261f Verify that the specified device is at least as large as hw.physmem. 2004-10-03 23:38:49 +00:00
Mark Murray
4c723140a4 Remove advertising clause from University of California Regent's license,
per letter dated July 22, 1999.

Approved by: core, imp
2004-04-09 19:58:40 +00:00
David E. O'Brien
c69284ca08 Use __FBSDID() to quiet GCC 3.3 warnings. 2003-05-03 18:41:59 +00:00
Alfred Perlstein
4a21733e2d unbreak build: include string.h for strcmp prototype. 2002-05-11 03:07:38 +00:00
Poul-Henning Kamp
7f086a0852 Rename DIOCGKERNELDUMP to DIOCSKERNELDUMP as it strictly speaking
is a "set" not a "get" operation.

Sponsored by:	DARPA & NAI Labs.
2002-04-09 10:04:09 +00:00
Poul-Henning Kamp
2dd527b3ac Move generic disk ioctls from <sys/disklabel.h> to <sys/disk.h>.
Sponsored by:	DARPA & NAI Labs
2002-04-08 09:20:07 +00:00
Poul-Henning Kamp
9e9c1cad4c Here follows the new kernel dumping infrastructure.
Caveats:

The new savecore program is not complete in the sense that it emulates
enough of the old savecores features to do the job, but implements none
of the options yet.

I would appreciate if a userland hacker could help me out getting savecore
to do what we want it to do from a users point of view, compression,
email-notification, space reservation etc etc.  (send me email if
you are interested).

Currently, savecore will scan all devices marked as "swap" or "dump" in
/etc/fstab _or_ any devices specified on the command-line.

All architectures but i386 lack an implementation of dumpsys(), but
looking at the i386 version it should be trivial for anybody familiar
with the platform(s) to provide this function.

Documentation is quite sparse at this time, more to come.

Sponsored by:   DARPA, NAI Labs

Details:

Dumpon now opens the device and uses ioctl(DIOCGKERNELDUMP) to set it
to be the dumpdevice.  When "off" is set, /dev/null is used.
2002-03-31 22:24:24 +00:00
Warner Losh
d1a939c146 o __P
o Strict ANSI declarations.
o return (foo);
o main (int, char *[])
2002-03-18 06:59:15 +00:00
Dima Dorfman
cafefe8c1b Include missing header files which define functions for which gcc has
builtins (e.g., exit, strcmp).
2001-06-24 23:04:23 +00:00
Jeroen Ruigrok van der Werven
219f5cc47b Remove unused #include. 2000-05-01 19:39:36 +00:00
Poul-Henning Kamp
9f68791143 The dumpon sysctl only accept cdevs thse days.
Submitted by:	bde
2000-01-04 12:52:52 +00:00
Andrey A. Chernov
c34957baa7 Accept both types of devices to work with older kernels too
Fix confusing message
1999-11-30 16:27:30 +00:00
Poul-Henning Kamp
ee072c08d0 Convert dumpon to work on character devices instead of block devices.
NB: You may need to change your /etc/rc.conf!
1999-11-28 16:25:17 +00:00
Peter Wemm
7f3dea244c $Id$ -> $FreeBSD$ 1999-08-28 00:22:10 +00:00
Philippe Charnier
8f034b11f2 Capitalize at the start of sentence. Add rcsid. Remove unused #includes.
Use `dumpon' instead of argv[0].
1998-06-15 07:03:47 +00:00
Warner Losh
8d64695c7c compare return value from getopt against -1 rather than EOF, per the final
posix standard on the topic.
1997-03-29 03:33:12 +00:00
Peter Wemm
c0ec1f37ef Revert $FreeBSD$ to $Id$ 1997-02-22 14:40:44 +00:00
Jordan K. Hubbard
1130b656e5 Make the long-awaited change from $Id$ to $FreeBSD$
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore.  This update would have been
insane otherwise.
1997-01-14 07:20:47 +00:00
Rodney W. Grimes
5ebc7e6281 Remove trailing whitespace. 1995-05-30 06:12:45 +00:00
Garrett Wollman
83f9dfab4d My utility to specify where you want crash dumps to go. More user
and kernel support to follow.
1995-05-12 19:10:09 +00:00