Commit 17650f22 authored by David S. Miller's avatar David S. Miller

Merge branch 'siphash'

Jason A. Donenfeld says:

====================
Introduce The SipHash PRF

This patch series introduces SipHash into the kernel. SipHash is a
cryptographically secure PRF, which serves a variety of functions, and is
introduced in patch #1. The following patch #2 introduces HalfSipHash,
an optimization suitable for hash tables only. Finally, the last two patches
in this series show two usages of the introduced siphash function family.
It is expected that after this initial introduction, other usages will follow.

Please read the extensive descriptions in patch #1 and patch #2 of what these
functions do and the various levels of assurances. They're products of intense
cryptographic research, and I believe they're suitable for the uses outlined
herein.

The use of SipHash is not limited to the networking subsystem -- indeed I
would like to use it in other places too in the kernel. But after discussing
with a few on this list and at Linus' suggestion, the initial import of these
functions is coming through the networking tree. After these are merged, it
will then be easier to expand use elsewhere.

Changes v2->v3:
  - hsiphash keys now simply use an unsigned long, in order to avoid
    a cluttered ifdef and make it a bit more clear what's happening.
  - A typo in the documentation has been fixed.
  - The documentation has been augmented with an example relating to struct
    packing and passing.
  - The net_secret variable is now __read_mostly.

Hopefully this is the last of the required revisions, and v3 can be merged
into net-next.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents eafea739 fe62d05b
SipHash - a short input PRF
-----------------------------------------------
Written by Jason A. Donenfeld <jason@zx2c4.com>
SipHash is a cryptographically secure PRF -- a keyed hash function -- that
performs very well for short inputs, hence the name. It was designed by
cryptographers Daniel J. Bernstein and Jean-Philippe Aumasson. It is intended
as a replacement for some uses of: `jhash`, `md5_transform`, `sha_transform`,
and so forth.
SipHash takes a secret key filled with randomly generated numbers and either
an input buffer or several input integers. It spits out an integer that is
indistinguishable from random. You may then use that integer as part of secure
sequence numbers, secure cookies, or mask it off for use in a hash table.
1. Generating a key
Keys should always be generated from a cryptographically secure source of
random numbers, either using get_random_bytes or get_random_once:
siphash_key_t key;
get_random_bytes(&key, sizeof(key));
If you're not deriving your key from here, you're doing it wrong.
2. Using the functions
There are two variants of the function, one that takes a list of integers, and
one that takes a buffer:
u64 siphash(const void *data, size_t len, const siphash_key_t *key);
And:
u64 siphash_1u64(u64, const siphash_key_t *key);
u64 siphash_2u64(u64, u64, const siphash_key_t *key);
u64 siphash_3u64(u64, u64, u64, const siphash_key_t *key);
u64 siphash_4u64(u64, u64, u64, u64, const siphash_key_t *key);
u64 siphash_1u32(u32, const siphash_key_t *key);
u64 siphash_2u32(u32, u32, const siphash_key_t *key);
u64 siphash_3u32(u32, u32, u32, const siphash_key_t *key);
u64 siphash_4u32(u32, u32, u32, u32, const siphash_key_t *key);
If you pass the generic siphash function something of a constant length, it
will constant fold at compile-time and automatically choose one of the
optimized functions.
3. Hashtable key function usage:
struct some_hashtable {
DECLARE_HASHTABLE(hashtable, 8);
siphash_key_t key;
};
void init_hashtable(struct some_hashtable *table)
{
get_random_bytes(&table->key, sizeof(table->key));
}
static inline hlist_head *some_hashtable_bucket(struct some_hashtable *table, struct interesting_input *input)
{
return &table->hashtable[siphash(input, sizeof(*input), &table->key) & (HASH_SIZE(table->hashtable) - 1)];
}
You may then iterate like usual over the returned hash bucket.
4. Security
SipHash has a very high security margin, with its 128-bit key. So long as the
key is kept secret, it is impossible for an attacker to guess the outputs of
the function, even if being able to observe many outputs, since 2^128 outputs
is significant.
Linux implements the "2-4" variant of SipHash.
5. Struct-passing Pitfalls
Often times the XuY functions will not be large enough, and instead you'll
want to pass a pre-filled struct to siphash. When doing this, it's important
to always ensure the struct has no padding holes. The easiest way to do this
is to simply arrange the members of the struct in descending order of size,
and to use offsetendof() instead of sizeof() for getting the size. For
performance reasons, if possible, it's probably a good thing to align the
struct to the right boundary. Here's an example:
const struct {
struct in6_addr saddr;
u32 counter;
u16 dport;
} __aligned(SIPHASH_ALIGNMENT) combined = {
.saddr = *(struct in6_addr *)saddr,
.counter = counter,
.dport = dport
};
u64 h = siphash(&combined, offsetofend(typeof(combined), dport), &secret);
6. Resources
Read the SipHash paper if you're interested in learning more:
https://131002.net/siphash/siphash.pdf
~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~
HalfSipHash - SipHash's insecure younger cousin
-----------------------------------------------
Written by Jason A. Donenfeld <jason@zx2c4.com>
On the off-chance that SipHash is not fast enough for your needs, you might be
able to justify using HalfSipHash, a terrifying but potentially useful
possibility. HalfSipHash cuts SipHash's rounds down from "2-4" to "1-3" and,
even scarier, uses an easily brute-forcable 64-bit key (with a 32-bit output)
instead of SipHash's 128-bit key. However, this may appeal to some
high-performance `jhash` users.
Danger!
Do not ever use HalfSipHash except for as a hashtable key function, and only
then when you can be absolutely certain that the outputs will never be
transmitted out of the kernel. This is only remotely useful over `jhash` as a
means of mitigating hashtable flooding denial of service attacks.
1. Generating a key
Keys should always be generated from a cryptographically secure source of
random numbers, either using get_random_bytes or get_random_once:
hsiphash_key_t key;
get_random_bytes(&key, sizeof(key));
If you're not deriving your key from here, you're doing it wrong.
2. Using the functions
There are two variants of the function, one that takes a list of integers, and
one that takes a buffer:
u32 hsiphash(const void *data, size_t len, const hsiphash_key_t *key);
And:
u32 hsiphash_1u32(u32, const hsiphash_key_t *key);
u32 hsiphash_2u32(u32, u32, const hsiphash_key_t *key);
u32 hsiphash_3u32(u32, u32, u32, const hsiphash_key_t *key);
u32 hsiphash_4u32(u32, u32, u32, u32, const hsiphash_key_t *key);
If you pass the generic hsiphash function something of a constant length, it
will constant fold at compile-time and automatically choose one of the
optimized functions.
3. Hashtable key function usage:
struct some_hashtable {
DECLARE_HASHTABLE(hashtable, 8);
hsiphash_key_t key;
};
void init_hashtable(struct some_hashtable *table)
{
get_random_bytes(&table->key, sizeof(table->key));
}
static inline hlist_head *some_hashtable_bucket(struct some_hashtable *table, struct interesting_input *input)
{
return &table->hashtable[hsiphash(input, sizeof(*input), &table->key) & (HASH_SIZE(table->hashtable) - 1)];
}
You may then iterate like usual over the returned hash bucket.
4. Performance
HalfSipHash is roughly 3 times slower than JenkinsHash. For many replacements,
this will not be a problem, as the hashtable lookup isn't the bottleneck. And
in general, this is probably a good sacrifice to make for the security and DoS
resistance of HalfSipHash.
...@@ -11304,6 +11304,13 @@ F: arch/arm/mach-s3c24xx/mach-bast.c ...@@ -11304,6 +11304,13 @@ F: arch/arm/mach-s3c24xx/mach-bast.c
F: arch/arm/mach-s3c24xx/bast-ide.c F: arch/arm/mach-s3c24xx/bast-ide.c
F: arch/arm/mach-s3c24xx/bast-irq.c F: arch/arm/mach-s3c24xx/bast-irq.c
SIPHASH PRF ROUTINES
M: Jason A. Donenfeld <Jason@zx2c4.com>
S: Maintained
F: lib/siphash.c
F: lib/test_siphash.c
F: include/linux/siphash.h
TI DAVINCI MACHINE SUPPORT TI DAVINCI MACHINE SUPPORT
M: Sekhar Nori <nsekhar@ti.com> M: Sekhar Nori <nsekhar@ti.com>
M: Kevin Hilman <khilman@kernel.org> M: Kevin Hilman <khilman@kernel.org>
......
/* Copyright (C) 2016 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*
* This file is provided under a dual BSD/GPLv2 license.
*
* SipHash: a fast short-input PRF
* https://131002.net/siphash/
*
* This implementation is specifically for SipHash2-4 for a secure PRF
* and HalfSipHash1-3/SipHash1-3 for an insecure PRF only suitable for
* hashtables.
*/
#ifndef _LINUX_SIPHASH_H
#define _LINUX_SIPHASH_H
#include <linux/types.h>
#include <linux/kernel.h>
#define SIPHASH_ALIGNMENT __alignof__(u64)
typedef struct {
u64 key[2];
} siphash_key_t;
u64 __siphash_aligned(const void *data, size_t len, const siphash_key_t *key);
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
u64 __siphash_unaligned(const void *data, size_t len, const siphash_key_t *key);
#endif
u64 siphash_1u64(const u64 a, const siphash_key_t *key);
u64 siphash_2u64(const u64 a, const u64 b, const siphash_key_t *key);
u64 siphash_3u64(const u64 a, const u64 b, const u64 c,
const siphash_key_t *key);
u64 siphash_4u64(const u64 a, const u64 b, const u64 c, const u64 d,
const siphash_key_t *key);
u64 siphash_1u32(const u32 a, const siphash_key_t *key);
u64 siphash_3u32(const u32 a, const u32 b, const u32 c,
const siphash_key_t *key);
static inline u64 siphash_2u32(const u32 a, const u32 b,
const siphash_key_t *key)
{
return siphash_1u64((u64)b << 32 | a, key);
}
static inline u64 siphash_4u32(const u32 a, const u32 b, const u32 c,
const u32 d, const siphash_key_t *key)
{
return siphash_2u64((u64)b << 32 | a, (u64)d << 32 | c, key);
}
static inline u64 ___siphash_aligned(const __le64 *data, size_t len,
const siphash_key_t *key)
{
if (__builtin_constant_p(len) && len == 4)
return siphash_1u32(le32_to_cpup((const __le32 *)data), key);
if (__builtin_constant_p(len) && len == 8)
return siphash_1u64(le64_to_cpu(data[0]), key);
if (__builtin_constant_p(len) && len == 16)
return siphash_2u64(le64_to_cpu(data[0]), le64_to_cpu(data[1]),
key);
if (__builtin_constant_p(len) && len == 24)
return siphash_3u64(le64_to_cpu(data[0]), le64_to_cpu(data[1]),
le64_to_cpu(data[2]), key);
if (__builtin_constant_p(len) && len == 32)
return siphash_4u64(le64_to_cpu(data[0]), le64_to_cpu(data[1]),
le64_to_cpu(data[2]), le64_to_cpu(data[3]),
key);
return __siphash_aligned(data, len, key);
}
/**
* siphash - compute 64-bit siphash PRF value
* @data: buffer to hash
* @size: size of @data
* @key: the siphash key
*/
static inline u64 siphash(const void *data, size_t len,
const siphash_key_t *key)
{
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
if (!IS_ALIGNED((unsigned long)data, SIPHASH_ALIGNMENT))
return __siphash_unaligned(data, len, key);
#endif
return ___siphash_aligned(data, len, key);
}
#define HSIPHASH_ALIGNMENT __alignof__(unsigned long)
typedef struct {
unsigned long key[2];
} hsiphash_key_t;
u32 __hsiphash_aligned(const void *data, size_t len,
const hsiphash_key_t *key);
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
u32 __hsiphash_unaligned(const void *data, size_t len,
const hsiphash_key_t *key);
#endif
u32 hsiphash_1u32(const u32 a, const hsiphash_key_t *key);
u32 hsiphash_2u32(const u32 a, const u32 b, const hsiphash_key_t *key);
u32 hsiphash_3u32(const u32 a, const u32 b, const u32 c,
const hsiphash_key_t *key);
u32 hsiphash_4u32(const u32 a, const u32 b, const u32 c, const u32 d,
const hsiphash_key_t *key);
static inline u32 ___hsiphash_aligned(const __le32 *data, size_t len,
const hsiphash_key_t *key)
{
if (__builtin_constant_p(len) && len == 4)
return hsiphash_1u32(le32_to_cpu(data[0]), key);
if (__builtin_constant_p(len) && len == 8)
return hsiphash_2u32(le32_to_cpu(data[0]), le32_to_cpu(data[1]),
key);
if (__builtin_constant_p(len) && len == 12)
return hsiphash_3u32(le32_to_cpu(data[0]), le32_to_cpu(data[1]),
le32_to_cpu(data[2]), key);
if (__builtin_constant_p(len) && len == 16)
return hsiphash_4u32(le32_to_cpu(data[0]), le32_to_cpu(data[1]),
le32_to_cpu(data[2]), le32_to_cpu(data[3]),
key);
return __hsiphash_aligned(data, len, key);
}
/**
* hsiphash - compute 32-bit hsiphash PRF value
* @data: buffer to hash
* @size: size of @data
* @key: the hsiphash key
*/
static inline u32 hsiphash(const void *data, size_t len,
const hsiphash_key_t *key)
{
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
if (!IS_ALIGNED((unsigned long)data, HSIPHASH_ALIGNMENT))
return __hsiphash_unaligned(data, len, key);
#endif
return ___hsiphash_aligned(data, len, key);
}
#endif /* _LINUX_SIPHASH_H */
...@@ -1819,9 +1819,9 @@ config TEST_HASH ...@@ -1819,9 +1819,9 @@ config TEST_HASH
tristate "Perform selftest on hash functions" tristate "Perform selftest on hash functions"
default n default n
help help
Enable this option to test the kernel's integer (<linux/hash,h>) Enable this option to test the kernel's integer (<linux/hash.h>),
and string (<linux/stringhash.h>) hash functions on boot string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
(or module load). hash functions on boot (or module load).
This is intended to help people writing architecture-specific This is intended to help people writing architecture-specific
optimized versions. If unsure, say N. optimized versions. If unsure, say N.
......
...@@ -22,7 +22,8 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ ...@@ -22,7 +22,8 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
sha1.o chacha20.o md5.o irq_regs.o argv_split.o \ sha1.o chacha20.o md5.o irq_regs.o argv_split.o \
flex_proportions.o ratelimit.o show_mem.o \ flex_proportions.o ratelimit.o show_mem.o \
is_single_threaded.o plist.o decompress.o kobject_uevent.o \ is_single_threaded.o plist.o decompress.o kobject_uevent.o \
earlycpio.o seq_buf.o nmi_backtrace.o nodemask.o win_minmax.o earlycpio.o seq_buf.o siphash.o \
nmi_backtrace.o nodemask.o win_minmax.o
lib-$(CONFIG_MMU) += ioremap.o lib-$(CONFIG_MMU) += ioremap.o
lib-$(CONFIG_SMP) += cpumask.o lib-$(CONFIG_SMP) += cpumask.o
...@@ -44,7 +45,7 @@ obj-$(CONFIG_TEST_HEXDUMP) += test_hexdump.o ...@@ -44,7 +45,7 @@ obj-$(CONFIG_TEST_HEXDUMP) += test_hexdump.o
obj-y += kstrtox.o obj-y += kstrtox.o
obj-$(CONFIG_TEST_BPF) += test_bpf.o obj-$(CONFIG_TEST_BPF) += test_bpf.o
obj-$(CONFIG_TEST_FIRMWARE) += test_firmware.o obj-$(CONFIG_TEST_FIRMWARE) += test_firmware.o
obj-$(CONFIG_TEST_HASH) += test_hash.o obj-$(CONFIG_TEST_HASH) += test_hash.o test_siphash.o
obj-$(CONFIG_TEST_KASAN) += test_kasan.o obj-$(CONFIG_TEST_KASAN) += test_kasan.o
obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o
obj-$(CONFIG_TEST_LKM) += test_module.o obj-$(CONFIG_TEST_LKM) += test_module.o
......
This diff is collapsed.
/* Test cases for siphash.c
*
* Copyright (C) 2016 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*
* This file is provided under a dual BSD/GPLv2 license.
*
* SipHash: a fast short-input PRF
* https://131002.net/siphash/
*
* This implementation is specifically for SipHash2-4 for a secure PRF
* and HalfSipHash1-3/SipHash1-3 for an insecure PRF only suitable for
* hashtables.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/siphash.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/module.h>
/* Test vectors taken from reference source available at:
* https://github.com/veorq/SipHash
*/
static const siphash_key_t test_key_siphash =
{{ 0x0706050403020100ULL, 0x0f0e0d0c0b0a0908ULL }};
static const u64 test_vectors_siphash[64] = {
0x726fdb47dd0e0e31ULL, 0x74f839c593dc67fdULL, 0x0d6c8009d9a94f5aULL,
0x85676696d7fb7e2dULL, 0xcf2794e0277187b7ULL, 0x18765564cd99a68dULL,
0xcbc9466e58fee3ceULL, 0xab0200f58b01d137ULL, 0x93f5f5799a932462ULL,
0x9e0082df0ba9e4b0ULL, 0x7a5dbbc594ddb9f3ULL, 0xf4b32f46226bada7ULL,
0x751e8fbc860ee5fbULL, 0x14ea5627c0843d90ULL, 0xf723ca908e7af2eeULL,
0xa129ca6149be45e5ULL, 0x3f2acc7f57c29bdbULL, 0x699ae9f52cbe4794ULL,
0x4bc1b3f0968dd39cULL, 0xbb6dc91da77961bdULL, 0xbed65cf21aa2ee98ULL,
0xd0f2cbb02e3b67c7ULL, 0x93536795e3a33e88ULL, 0xa80c038ccd5ccec8ULL,
0xb8ad50c6f649af94ULL, 0xbce192de8a85b8eaULL, 0x17d835b85bbb15f3ULL,
0x2f2e6163076bcfadULL, 0xde4daaaca71dc9a5ULL, 0xa6a2506687956571ULL,
0xad87a3535c49ef28ULL, 0x32d892fad841c342ULL, 0x7127512f72f27cceULL,
0xa7f32346f95978e3ULL, 0x12e0b01abb051238ULL, 0x15e034d40fa197aeULL,
0x314dffbe0815a3b4ULL, 0x027990f029623981ULL, 0xcadcd4e59ef40c4dULL,
0x9abfd8766a33735cULL, 0x0e3ea96b5304a7d0ULL, 0xad0c42d6fc585992ULL,
0x187306c89bc215a9ULL, 0xd4a60abcf3792b95ULL, 0xf935451de4f21df2ULL,
0xa9538f0419755787ULL, 0xdb9acddff56ca510ULL, 0xd06c98cd5c0975ebULL,
0xe612a3cb9ecba951ULL, 0xc766e62cfcadaf96ULL, 0xee64435a9752fe72ULL,
0xa192d576b245165aULL, 0x0a8787bf8ecb74b2ULL, 0x81b3e73d20b49b6fULL,
0x7fa8220ba3b2eceaULL, 0x245731c13ca42499ULL, 0xb78dbfaf3a8d83bdULL,
0xea1ad565322a1a0bULL, 0x60e61c23a3795013ULL, 0x6606d7e446282b93ULL,
0x6ca4ecb15c5f91e1ULL, 0x9f626da15c9625f3ULL, 0xe51b38608ef25f57ULL,
0x958a324ceb064572ULL
};
#if BITS_PER_LONG == 64
static const hsiphash_key_t test_key_hsiphash =
{{ 0x0706050403020100ULL, 0x0f0e0d0c0b0a0908ULL }};
static const u32 test_vectors_hsiphash[64] = {
0x050fc4dcU, 0x7d57ca93U, 0x4dc7d44dU,
0xe7ddf7fbU, 0x88d38328U, 0x49533b67U,
0xc59f22a7U, 0x9bb11140U, 0x8d299a8eU,
0x6c063de4U, 0x92ff097fU, 0xf94dc352U,
0x57b4d9a2U, 0x1229ffa7U, 0xc0f95d34U,
0x2a519956U, 0x7d908b66U, 0x63dbd80cU,
0xb473e63eU, 0x8d297d1cU, 0xa6cce040U,
0x2b45f844U, 0xa320872eU, 0xdae6c123U,
0x67349c8cU, 0x705b0979U, 0xca9913a5U,
0x4ade3b35U, 0xef6cd00dU, 0x4ab1e1f4U,
0x43c5e663U, 0x8c21d1bcU, 0x16a7b60dU,
0x7a8ff9bfU, 0x1f2a753eU, 0xbf186b91U,
0xada26206U, 0xa3c33057U, 0xae3a36a1U,
0x7b108392U, 0x99e41531U, 0x3f1ad944U,
0xc8138825U, 0xc28949a6U, 0xfaf8876bU,
0x9f042196U, 0x68b1d623U, 0x8b5114fdU,
0xdf074c46U, 0x12cc86b3U, 0x0a52098fU,
0x9d292f9aU, 0xa2f41f12U, 0x43a71ed0U,
0x73f0bce6U, 0x70a7e980U, 0x243c6d75U,
0xfdb71513U, 0xa67d8a08U, 0xb7e8f148U,
0xf7a644eeU, 0x0f1837f2U, 0x4b6694e0U,
0xb7bbb3a8U
};
#else
static const hsiphash_key_t test_key_hsiphash =
{{ 0x03020100U, 0x07060504U }};
static const u32 test_vectors_hsiphash[64] = {
0x5814c896U, 0xe7e864caU, 0xbc4b0e30U,
0x01539939U, 0x7e059ea6U, 0x88e3d89bU,
0xa0080b65U, 0x9d38d9d6U, 0x577999b1U,
0xc839caedU, 0xe4fa32cfU, 0x959246eeU,
0x6b28096cU, 0x66dd9cd6U, 0x16658a7cU,
0xd0257b04U, 0x8b31d501U, 0x2b1cd04bU,
0x06712339U, 0x522aca67U, 0x911bb605U,
0x90a65f0eU, 0xf826ef7bU, 0x62512debU,
0x57150ad7U, 0x5d473507U, 0x1ec47442U,
0xab64afd3U, 0x0a4100d0U, 0x6d2ce652U,
0x2331b6a3U, 0x08d8791aU, 0xbc6dda8dU,
0xe0f6c934U, 0xb0652033U, 0x9b9851ccU,
0x7c46fb7fU, 0x732ba8cbU, 0xf142997aU,
0xfcc9aa1bU, 0x05327eb2U, 0xe110131cU,
0xf9e5e7c0U, 0xa7d708a6U, 0x11795ab1U,
0x65671619U, 0x9f5fff91U, 0xd89c5267U,
0x007783ebU, 0x95766243U, 0xab639262U,
0x9c7e1390U, 0xc368dda6U, 0x38ddc455U,
0xfa13d379U, 0x979ea4e8U, 0x53ecd77eU,
0x2ee80657U, 0x33dbb66aU, 0xae3f0577U,
0x88b4c4ccU, 0x3e7f480bU, 0x74c1ebf8U,
0x87178304U
};
#endif
static int __init siphash_test_init(void)
{
u8 in[64] __aligned(SIPHASH_ALIGNMENT);
u8 in_unaligned[65] __aligned(SIPHASH_ALIGNMENT);
u8 i;
int ret = 0;
for (i = 0; i < 64; ++i) {
in[i] = i;
in_unaligned[i + 1] = i;
if (siphash(in, i, &test_key_siphash) !=
test_vectors_siphash[i]) {
pr_info("siphash self-test aligned %u: FAIL\n", i + 1);
ret = -EINVAL;
}
if (siphash(in_unaligned + 1, i, &test_key_siphash) !=
test_vectors_siphash[i]) {
pr_info("siphash self-test unaligned %u: FAIL\n", i + 1);
ret = -EINVAL;
}
if (hsiphash(in, i, &test_key_hsiphash) !=
test_vectors_hsiphash[i]) {
pr_info("hsiphash self-test aligned %u: FAIL\n", i + 1);
ret = -EINVAL;
}
if (hsiphash(in_unaligned + 1, i, &test_key_hsiphash) !=
test_vectors_hsiphash[i]) {
pr_info("hsiphash self-test unaligned %u: FAIL\n", i + 1);
ret = -EINVAL;
}
}
if (siphash_1u64(0x0706050403020100ULL, &test_key_siphash) !=
test_vectors_siphash[8]) {
pr_info("siphash self-test 1u64: FAIL\n");
ret = -EINVAL;
}
if (siphash_2u64(0x0706050403020100ULL, 0x0f0e0d0c0b0a0908ULL,
&test_key_siphash) != test_vectors_siphash[16]) {
pr_info("siphash self-test 2u64: FAIL\n");
ret = -EINVAL;
}
if (siphash_3u64(0x0706050403020100ULL, 0x0f0e0d0c0b0a0908ULL,
0x1716151413121110ULL, &test_key_siphash) !=
test_vectors_siphash[24]) {
pr_info("siphash self-test 3u64: FAIL\n");
ret = -EINVAL;
}
if (siphash_4u64(0x0706050403020100ULL, 0x0f0e0d0c0b0a0908ULL,
0x1716151413121110ULL, 0x1f1e1d1c1b1a1918ULL,
&test_key_siphash) != test_vectors_siphash[32]) {
pr_info("siphash self-test 4u64: FAIL\n");
ret = -EINVAL;
}
if (siphash_1u32(0x03020100U, &test_key_siphash) !=
test_vectors_siphash[4]) {
pr_info("siphash self-test 1u32: FAIL\n");
ret = -EINVAL;
}
if (siphash_2u32(0x03020100U, 0x07060504U, &test_key_siphash) !=
test_vectors_siphash[8]) {
pr_info("siphash self-test 2u32: FAIL\n");
ret = -EINVAL;
}
if (siphash_3u32(0x03020100U, 0x07060504U,
0x0b0a0908U, &test_key_siphash) !=
test_vectors_siphash[12]) {
pr_info("siphash self-test 3u32: FAIL\n");
ret = -EINVAL;
}
if (siphash_4u32(0x03020100U, 0x07060504U,
0x0b0a0908U, 0x0f0e0d0cU, &test_key_siphash) !=
test_vectors_siphash[16]) {
pr_info("siphash self-test 4u32: FAIL\n");
ret = -EINVAL;
}
if (hsiphash_1u32(0x03020100U, &test_key_hsiphash) !=
test_vectors_hsiphash[4]) {
pr_info("hsiphash self-test 1u32: FAIL\n");
ret = -EINVAL;
}
if (hsiphash_2u32(0x03020100U, 0x07060504U, &test_key_hsiphash) !=
test_vectors_hsiphash[8]) {
pr_info("hsiphash self-test 2u32: FAIL\n");
ret = -EINVAL;
}
if (hsiphash_3u32(0x03020100U, 0x07060504U,
0x0b0a0908U, &test_key_hsiphash) !=
test_vectors_hsiphash[12]) {
pr_info("hsiphash self-test 3u32: FAIL\n");
ret = -EINVAL;
}
if (hsiphash_4u32(0x03020100U, 0x07060504U,
0x0b0a0908U, 0x0f0e0d0cU, &test_key_hsiphash) !=
test_vectors_hsiphash[16]) {
pr_info("hsiphash self-test 4u32: FAIL\n");
ret = -EINVAL;
}
if (!ret)
pr_info("self-tests: pass\n");
return ret;
}
static void __exit siphash_test_exit(void)
{
}
module_init(siphash_test_init);
module_exit(siphash_test_exit);
MODULE_AUTHOR("Jason A. Donenfeld <Jason@zx2c4.com>");
MODULE_LICENSE("Dual BSD/GPL");
/*
* Copyright (C) 2016 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
#include <linux/kernel.h> #include <linux/kernel.h>
#include <linux/init.h> #include <linux/init.h>
#include <linux/cryptohash.h> #include <linux/cryptohash.h>
...@@ -8,18 +12,18 @@ ...@@ -8,18 +12,18 @@
#include <linux/ktime.h> #include <linux/ktime.h>
#include <linux/string.h> #include <linux/string.h>
#include <linux/net.h> #include <linux/net.h>
#include <linux/siphash.h>
#include <net/secure_seq.h> #include <net/secure_seq.h>
#if IS_ENABLED(CONFIG_IPV6) || IS_ENABLED(CONFIG_INET) #if IS_ENABLED(CONFIG_IPV6) || IS_ENABLED(CONFIG_INET)
#include <linux/in6.h>
#include <net/tcp.h> #include <net/tcp.h>
#define NET_SECRET_SIZE (MD5_MESSAGE_BYTES / 4)
static u32 net_secret[NET_SECRET_SIZE] ____cacheline_aligned; static siphash_key_t net_secret __read_mostly;
static __always_inline void net_secret_init(void) static __always_inline void net_secret_init(void)
{ {
net_get_random_once(net_secret, sizeof(net_secret)); net_get_random_once(&net_secret, sizeof(net_secret));
} }
#endif #endif
...@@ -44,80 +48,70 @@ static u32 seq_scale(u32 seq) ...@@ -44,80 +48,70 @@ static u32 seq_scale(u32 seq)
u32 secure_tcpv6_sequence_number(const __be32 *saddr, const __be32 *daddr, u32 secure_tcpv6_sequence_number(const __be32 *saddr, const __be32 *daddr,
__be16 sport, __be16 dport, u32 *tsoff) __be16 sport, __be16 dport, u32 *tsoff)
{ {
u32 secret[MD5_MESSAGE_BYTES / 4]; const struct {
u32 hash[MD5_DIGEST_WORDS]; struct in6_addr saddr;
u32 i; struct in6_addr daddr;
__be16 sport;
__be16 dport;
} __aligned(SIPHASH_ALIGNMENT) combined = {
.saddr = *(struct in6_addr *)saddr,
.daddr = *(struct in6_addr *)daddr,
.sport = sport,
.dport = dport
};
u64 hash;
net_secret_init(); net_secret_init();
memcpy(hash, saddr, 16); hash = siphash(&combined, offsetofend(typeof(combined), dport),
for (i = 0; i < 4; i++) &net_secret);
secret[i] = net_secret[i] + (__force u32)daddr[i]; *tsoff = sysctl_tcp_timestamps == 1 ? (hash >> 32) : 0;
secret[4] = net_secret[4] + return seq_scale(hash);
(((__force u16)sport << 16) + (__force u16)dport);
for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++)
secret[i] = net_secret[i];
md5_transform(hash, secret);
*tsoff = sysctl_tcp_timestamps == 1 ? hash[1] : 0;
return seq_scale(hash[0]);
} }
EXPORT_SYMBOL(secure_tcpv6_sequence_number); EXPORT_SYMBOL(secure_tcpv6_sequence_number);
u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr, u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr,
__be16 dport) __be16 dport)
{ {
u32 secret[MD5_MESSAGE_BYTES / 4]; const struct {
u32 hash[MD5_DIGEST_WORDS]; struct in6_addr saddr;
u32 i; struct in6_addr daddr;
__be16 dport;
} __aligned(SIPHASH_ALIGNMENT) combined = {
.saddr = *(struct in6_addr *)saddr,
.daddr = *(struct in6_addr *)daddr,
.dport = dport
};
net_secret_init(); net_secret_init();
memcpy(hash, saddr, 16); return siphash(&combined, offsetofend(typeof(combined), dport),
for (i = 0; i < 4; i++) &net_secret);
secret[i] = net_secret[i] + (__force u32) daddr[i];
secret[4] = net_secret[4] + (__force u32)dport;
for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++)
secret[i] = net_secret[i];
md5_transform(hash, secret);
return hash[0];
} }
EXPORT_SYMBOL(secure_ipv6_port_ephemeral); EXPORT_SYMBOL(secure_ipv6_port_ephemeral);
#endif #endif
#ifdef CONFIG_INET #ifdef CONFIG_INET
/* secure_tcp_sequence_number(a, b, 0, d) == secure_ipv4_port_ephemeral(a, b, d),
* but fortunately, `sport' cannot be 0 in any circumstances. If this changes,
* it would be easy enough to have the former function use siphash_4u32, passing
* the arguments as separate u32.
*/
u32 secure_tcp_sequence_number(__be32 saddr, __be32 daddr, u32 secure_tcp_sequence_number(__be32 saddr, __be32 daddr,
__be16 sport, __be16 dport, u32 *tsoff) __be16 sport, __be16 dport, u32 *tsoff)
{ {
u32 hash[MD5_DIGEST_WORDS]; u64 hash;
net_secret_init(); net_secret_init();
hash[0] = (__force u32)saddr; hash = siphash_3u32((__force u32)saddr, (__force u32)daddr,
hash[1] = (__force u32)daddr; (__force u32)sport << 16 | (__force u32)dport,
hash[2] = ((__force u16)sport << 16) + (__force u16)dport; &net_secret);
hash[3] = net_secret[15]; *tsoff = sysctl_tcp_timestamps == 1 ? (hash >> 32) : 0;
return seq_scale(hash);
md5_transform(hash, net_secret);
*tsoff = sysctl_tcp_timestamps == 1 ? hash[1] : 0;
return seq_scale(hash[0]);
} }
u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport) u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport)
{ {
u32 hash[MD5_DIGEST_WORDS];
net_secret_init(); net_secret_init();
hash[0] = (__force u32)saddr; return siphash_3u32((__force u32)saddr, (__force u32)daddr,
hash[1] = (__force u32)daddr; (__force u16)dport, &net_secret);
hash[2] = (__force u32)dport ^ net_secret[14];
hash[3] = net_secret[15];
md5_transform(hash, net_secret);
return hash[0];
} }
EXPORT_SYMBOL_GPL(secure_ipv4_port_ephemeral); EXPORT_SYMBOL_GPL(secure_ipv4_port_ephemeral);
#endif #endif
...@@ -126,21 +120,11 @@ EXPORT_SYMBOL_GPL(secure_ipv4_port_ephemeral); ...@@ -126,21 +120,11 @@ EXPORT_SYMBOL_GPL(secure_ipv4_port_ephemeral);
u64 secure_dccp_sequence_number(__be32 saddr, __be32 daddr, u64 secure_dccp_sequence_number(__be32 saddr, __be32 daddr,
__be16 sport, __be16 dport) __be16 sport, __be16 dport)
{ {
u32 hash[MD5_DIGEST_WORDS];
u64 seq; u64 seq;
net_secret_init(); net_secret_init();
hash[0] = (__force u32)saddr; seq = siphash_3u32(saddr, daddr, (u32)sport << 16 | dport, &net_secret);
hash[1] = (__force u32)daddr;
hash[2] = ((__force u16)sport << 16) + (__force u16)dport;
hash[3] = net_secret[15];
md5_transform(hash, net_secret);
seq = hash[0] | (((u64)hash[1]) << 32);
seq += ktime_get_real_ns(); seq += ktime_get_real_ns();
seq &= (1ull << 48) - 1; seq &= (1ull << 48) - 1;
return seq; return seq;
} }
EXPORT_SYMBOL(secure_dccp_sequence_number); EXPORT_SYMBOL(secure_dccp_sequence_number);
...@@ -149,26 +133,23 @@ EXPORT_SYMBOL(secure_dccp_sequence_number); ...@@ -149,26 +133,23 @@ EXPORT_SYMBOL(secure_dccp_sequence_number);
u64 secure_dccpv6_sequence_number(__be32 *saddr, __be32 *daddr, u64 secure_dccpv6_sequence_number(__be32 *saddr, __be32 *daddr,
__be16 sport, __be16 dport) __be16 sport, __be16 dport)
{ {
u32 secret[MD5_MESSAGE_BYTES / 4]; const struct {
u32 hash[MD5_DIGEST_WORDS]; struct in6_addr saddr;
struct in6_addr daddr;
__be16 sport;
__be16 dport;
} __aligned(SIPHASH_ALIGNMENT) combined = {
.saddr = *(struct in6_addr *)saddr,
.daddr = *(struct in6_addr *)daddr,
.sport = sport,
.dport = dport
};
u64 seq; u64 seq;
u32 i;
net_secret_init(); net_secret_init();
memcpy(hash, saddr, 16); seq = siphash(&combined, offsetofend(typeof(combined), dport),
for (i = 0; i < 4; i++) &net_secret);
secret[i] = net_secret[i] + (__force u32)daddr[i];
secret[4] = net_secret[4] +
(((__force u16)sport << 16) + (__force u16)dport);
for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++)
secret[i] = net_secret[i];
md5_transform(hash, secret);
seq = hash[0] | (((u64)hash[1]) << 32);
seq += ktime_get_real_ns(); seq += ktime_get_real_ns();
seq &= (1ull << 48) - 1; seq &= (1ull << 48) - 1;
return seq; return seq;
} }
EXPORT_SYMBOL(secure_dccpv6_sequence_number); EXPORT_SYMBOL(secure_dccpv6_sequence_number);
......
...@@ -13,13 +13,13 @@ ...@@ -13,13 +13,13 @@
#include <linux/tcp.h> #include <linux/tcp.h>
#include <linux/slab.h> #include <linux/slab.h>
#include <linux/random.h> #include <linux/random.h>
#include <linux/cryptohash.h> #include <linux/siphash.h>
#include <linux/kernel.h> #include <linux/kernel.h>
#include <linux/export.h> #include <linux/export.h>
#include <net/tcp.h> #include <net/tcp.h>
#include <net/route.h> #include <net/route.h>
static u32 syncookie_secret[2][16-4+SHA_DIGEST_WORDS] __read_mostly; static siphash_key_t syncookie_secret[2] __read_mostly;
#define COOKIEBITS 24 /* Upper bits store count */ #define COOKIEBITS 24 /* Upper bits store count */
#define COOKIEMASK (((__u32)1 << COOKIEBITS) - 1) #define COOKIEMASK (((__u32)1 << COOKIEBITS) - 1)
...@@ -48,24 +48,13 @@ static u32 syncookie_secret[2][16-4+SHA_DIGEST_WORDS] __read_mostly; ...@@ -48,24 +48,13 @@ static u32 syncookie_secret[2][16-4+SHA_DIGEST_WORDS] __read_mostly;
#define TSBITS 6 #define TSBITS 6
#define TSMASK (((__u32)1 << TSBITS) - 1) #define TSMASK (((__u32)1 << TSBITS) - 1)
static DEFINE_PER_CPU(__u32 [16 + 5 + SHA_WORKSPACE_WORDS], ipv4_cookie_scratch);
static u32 cookie_hash(__be32 saddr, __be32 daddr, __be16 sport, __be16 dport, static u32 cookie_hash(__be32 saddr, __be32 daddr, __be16 sport, __be16 dport,
u32 count, int c) u32 count, int c)
{ {
__u32 *tmp;
net_get_random_once(syncookie_secret, sizeof(syncookie_secret)); net_get_random_once(syncookie_secret, sizeof(syncookie_secret));
return siphash_4u32((__force u32)saddr, (__force u32)daddr,
tmp = this_cpu_ptr(ipv4_cookie_scratch); (__force u32)sport << 16 | (__force u32)dport,
memcpy(tmp + 4, syncookie_secret[c], sizeof(syncookie_secret[c])); count, &syncookie_secret[c]);
tmp[0] = (__force u32)saddr;
tmp[1] = (__force u32)daddr;
tmp[2] = ((__force u32)sport << 16) + (__force u32)dport;
tmp[3] = count;
sha_transform(tmp + 16, (__u8 *)tmp, tmp + 16 + 5);
return tmp[17];
} }
......
...@@ -16,7 +16,7 @@ ...@@ -16,7 +16,7 @@
#include <linux/tcp.h> #include <linux/tcp.h>
#include <linux/random.h> #include <linux/random.h>
#include <linux/cryptohash.h> #include <linux/siphash.h>
#include <linux/kernel.h> #include <linux/kernel.h>
#include <net/ipv6.h> #include <net/ipv6.h>
#include <net/tcp.h> #include <net/tcp.h>
...@@ -24,7 +24,7 @@ ...@@ -24,7 +24,7 @@
#define COOKIEBITS 24 /* Upper bits store count */ #define COOKIEBITS 24 /* Upper bits store count */
#define COOKIEMASK (((__u32)1 << COOKIEBITS) - 1) #define COOKIEMASK (((__u32)1 << COOKIEBITS) - 1)
static u32 syncookie6_secret[2][16-4+SHA_DIGEST_WORDS] __read_mostly; static siphash_key_t syncookie6_secret[2] __read_mostly;
/* RFC 2460, Section 8.3: /* RFC 2460, Section 8.3:
* [ipv6 tcp] MSS must be computed as the maximum packet size minus 60 [..] * [ipv6 tcp] MSS must be computed as the maximum packet size minus 60 [..]
...@@ -41,30 +41,27 @@ static __u16 const msstab[] = { ...@@ -41,30 +41,27 @@ static __u16 const msstab[] = {
9000 - 60, 9000 - 60,
}; };
static DEFINE_PER_CPU(__u32 [16 + 5 + SHA_WORKSPACE_WORDS], ipv6_cookie_scratch); static u32 cookie_hash(const struct in6_addr *saddr,
const struct in6_addr *daddr,
static u32 cookie_hash(const struct in6_addr *saddr, const struct in6_addr *daddr,
__be16 sport, __be16 dport, u32 count, int c) __be16 sport, __be16 dport, u32 count, int c)
{ {
__u32 *tmp; const struct {
struct in6_addr saddr;
struct in6_addr daddr;
u32 count;
__be16 sport;
__be16 dport;
} __aligned(SIPHASH_ALIGNMENT) combined = {
.saddr = *saddr,
.daddr = *daddr,
.count = count,
.sport = sport,
.dport = dport
};
net_get_random_once(syncookie6_secret, sizeof(syncookie6_secret)); net_get_random_once(syncookie6_secret, sizeof(syncookie6_secret));
return siphash(&combined, offsetofend(typeof(combined), dport),
tmp = this_cpu_ptr(ipv6_cookie_scratch); &syncookie6_secret[c]);
/*
* we have 320 bits of information to hash, copy in the remaining
* 192 bits required for sha_transform, from the syncookie6_secret
* and overwrite the digest with the secret
*/
memcpy(tmp + 10, syncookie6_secret[c], 44);
memcpy(tmp, saddr, 16);
memcpy(tmp + 4, daddr, 16);
tmp[8] = ((__force u32)sport << 16) + (__force u32)dport;
tmp[9] = count;
sha_transform(tmp + 16, (__u8 *)tmp, tmp + 16 + 5);
return tmp[17];
} }
static __u32 secure_tcp_syn_cookie(const struct in6_addr *saddr, static __u32 secure_tcp_syn_cookie(const struct in6_addr *saddr,
......
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