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authorTony Hutter <[email protected]>2016-06-15 15:47:05 -0700
committerTony Hutter <[email protected]>2016-10-03 14:51:15 -0700
commit3c67d83a8afb391f20bc53d36a0cebea6897b3e2 (patch)
tree2b862986c83414c7359c00219b43ad47dd73f81e /man/man5
parent62a65a654e15a1388bfb571727e69b46e7cc07ab (diff)
OpenZFS 4185 - add new cryptographic checksums to ZFS: SHA-512, Skein, Edon-R
Reviewed by: George Wilson <[email protected]> Reviewed by: Prakash Surya <[email protected]> Reviewed by: Saso Kiselkov <[email protected]> Reviewed by: Richard Lowe <[email protected]> Approved by: Garrett D'Amore <[email protected]> Ported by: Tony Hutter <[email protected]> OpenZFS-issue: https://www.illumos.org/issues/4185 OpenZFS-commit: https://github.com/openzfs/openzfs/commit/45818ee Porting Notes: This code is ported on top of the Illumos Crypto Framework code: https://github.com/zfsonlinux/zfs/pull/4329/commits/b5e030c8dbb9cd393d313571dee4756fbba8c22d The list of porting changes includes: - Copied module/icp/include/sha2/sha2.h directly from illumos - Removed from module/icp/algs/sha2/sha2.c: #pragma inline(SHA256Init, SHA384Init, SHA512Init) - Added 'ctx' to lib/libzfs/libzfs_sendrecv.c:zio_checksum_SHA256() since it now takes in an extra parameter. - Added CTASSERT() to assert.h from for module/zfs/edonr_zfs.c - Added skein & edonr to libicp/Makefile.am - Added sha512.S. It was generated from sha512-x86_64.pl in Illumos. - Updated ztest.c with new fletcher_4_*() args; used NULL for new CTX argument. - In icp/algs/edonr/edonr_byteorder.h, Removed the #if defined(__linux) section to not #include the non-existant endian.h. - In skein_test.c, renane NULL to 0 in "no test vector" array entries to get around a compiler warning. - Fixup test files: - Rename <sys/varargs.h> -> <varargs.h>, <strings.h> -> <string.h>, - Remove <note.h> and define NOTE() as NOP. - Define u_longlong_t - Rename "#!/usr/bin/ksh" -> "#!/bin/ksh -p" - Rename NULL to 0 in "no test vector" array entries to get around a compiler warning. - Remove "for isa in $($ISAINFO); do" stuff - Add/update Makefiles - Add some userspace headers like stdio.h/stdlib.h in places of sys/types.h. - EXPORT_SYMBOL *_Init/*_Update/*_Final... routines in ICP modules. - Update scripts/zfs2zol-patch.sed - include <sys/sha2.h> in sha2_impl.h - Add sha2.h to include/sys/Makefile.am - Add skein and edonr dirs to icp Makefile - Add new checksums to zpool_get.cfg - Move checksum switch block from zfs_secpolicy_setprop() to zfs_check_settable() - Fix -Wuninitialized error in edonr_byteorder.h on PPC - Fix stack frame size errors on ARM32 - Don't unroll loops in Skein on 32-bit to save stack space - Add memory barriers in sha2.c on 32-bit to save stack space - Add filetest_001_pos.ksh checksum sanity test - Add option to write psudorandom data in file_write utility
Diffstat (limited to 'man/man5')
-rw-r--r--man/man5/zpool-features.5108
1 files changed, 107 insertions, 1 deletions
diff --git a/man/man5/zpool-features.5 b/man/man5/zpool-features.5
index fa04d6e81..dcfb30d18 100644
--- a/man/man5/zpool-features.5
+++ b/man/man5/zpool-features.5
@@ -1,5 +1,5 @@
'\" te
-.\" Copyright (c) 2013 by Delphix. All rights reserved.
+.\" Copyright (c) 2012, 2015 by Delphix. All rights reserved.
.\" Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
.\" Copyright (c) 2014, Joyent, Inc. All rights reserved.
.\" The contents of this file are subject to the terms of the Common Development
@@ -457,5 +457,111 @@ allow more data to be stored in the bonus buffer, thus potentially
improving performance by avoiding the use of spill blocks.
.RE
+\fB\fBsha512\fR\fR
+.ad
+.RS 4n
+.TS
+l l .
+GUID org.illumos:sha512
+READ\-ONLY COMPATIBLE no
+DEPENDENCIES none
+.TE
+
+This feature enables the use of the SHA-512/256 truncated hash algorithm
+(FIPS 180-4) for checksum and dedup. The native 64-bit arithmetic of
+SHA-512 provides an approximate 50% performance boost over SHA-256 on
+64-bit hardware and is thus a good minimum-change replacement candidate
+for systems where hash performance is important, but these systems
+cannot for whatever reason utilize the faster \fBskein\fR and
+\fBedonr\fR algorithms.
+
+When the \fBsha512\fR feature is set to \fBenabled\fR, the administrator
+can turn on the \fBsha512\fR checksum on any dataset using the
+\fBzfs set checksum=sha512\fR(1M) command. This feature becomes
+\fBactive\fR once a \fBchecksum\fR property has been set to \fBsha512\fR,
+and will return to being \fBenabled\fR once all filesystems that have
+ever had their checksum set to \fBsha512\fR are destroyed.
+
+Booting off of pools utilizing SHA-512/256 is supported (provided that
+the updated GRUB stage2 module is installed).
+
+.RE
+
+.sp
+.ne 2
+.na
+\fB\fBskein\fR\fR
+.ad
+.RS 4n
+.TS
+l l .
+GUID org.illumos:skein
+READ\-ONLY COMPATIBLE no
+DEPENDENCIES none
+.TE
+
+This feature enables the use of the Skein hash algorithm for checksum
+and dedup. Skein is a high-performance secure hash algorithm that was a
+finalist in the NIST SHA-3 competition. It provides a very high security
+margin and high performance on 64-bit hardware (80% faster than
+SHA-256). This implementation also utilizes the new salted checksumming
+functionality in ZFS, which means that the checksum is pre-seeded with a
+secret 256-bit random key (stored on the pool) before being fed the data
+block to be checksummed. Thus the produced checksums are unique to a
+given pool, preventing hash collision attacks on systems with dedup.
+
+When the \fBskein\fR feature is set to \fBenabled\fR, the administrator
+can turn on the \fBskein\fR checksum on any dataset using the
+\fBzfs set checksum=skein\fR(1M) command. This feature becomes
+\fBactive\fR once a \fBchecksum\fR property has been set to \fBskein\fR,
+and will return to being \fBenabled\fR once all filesystems that have
+ever had their checksum set to \fBskein\fR are destroyed.
+
+Booting off of pools using \fBskein\fR is \fBNOT\fR supported
+-- any attempt to enable \fBskein\fR on a root pool will fail with an
+error.
+
+.RE
+
+.sp
+.ne 2
+.na
+\fB\fBedonr\fR\fR
+.ad
+.RS 4n
+.TS
+l l .
+GUID org.illumos:edonr
+READ\-ONLY COMPATIBLE no
+DEPENDENCIES none
+.TE
+
+This feature enables the use of the Edon-R hash algorithm for checksum,
+including for nopwrite (if compression is also enabled, an overwrite of
+a block whose checksum matches the data being written will be ignored).
+In an abundance of caution, Edon-R can not be used with dedup
+(without verification).
+
+Edon-R is a very high-performance hash algorithm that was part
+of the NIST SHA-3 competition. It provides extremely high hash
+performance (over 350% faster than SHA-256), but was not selected
+because of its unsuitability as a general purpose secure hash algorithm.
+This implementation utilizes the new salted checksumming functionality
+in ZFS, which means that the checksum is pre-seeded with a secret
+256-bit random key (stored on the pool) before being fed the data block
+to be checksummed. Thus the produced checksums are unique to a given
+pool.
+
+When the \fBedonr\fR feature is set to \fBenabled\fR, the administrator
+can turn on the \fBedonr\fR checksum on any dataset using the
+\fBzfs set checksum=edonr\fR(1M) command. This feature becomes
+\fBactive\fR once a \fBchecksum\fR property has been set to \fBedonr\fR,
+and will return to being \fBenabled\fR once all filesystems that have
+ever had their checksum set to \fBedonr\fR are destroyed.
+
+Booting off of pools using \fBedonr\fR is \fBNOT\fR supported
+-- any attempt to enable \fBedonr\fR on a root pool will fail with an
+error.
+
.SH "SEE ALSO"
\fBzpool\fR(8)