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[209.132.180.67]) by mx.google.com with ESMTP id l6si4669340pgg.489.2019.08.16.16.01.23; Fri, 16 Aug 2019 16:01:24 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=codethink.co.uk Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727831AbfHPXBX convert rfc822-to-8bit (ORCPT + 14 others); Fri, 16 Aug 2019 19:01:23 -0400 Received: from imap1.codethink.co.uk ([176.9.8.82]:51339 "EHLO imap1.codethink.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727765AbfHPXBX (ORCPT ); Fri, 16 Aug 2019 19:01:23 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126] helo=xylophone.i.decadent.org.uk) by imap1.codethink.co.uk with esmtpsa (Exim 4.84_2 #1 (Debian)) id 1hylDe-0004kl-4x; Sat, 17 Aug 2019 00:01:14 +0100 Date: Sat, 17 Aug 2019 00:01:12 +0100 From: Ben Hutchings To: Greg Kroah-Hartman , Sasha Levin Cc: stable Subject: [PATCH 4.9 10/13] siphash: add cryptographically secure PRF Message-ID: <20190816230112.GN9843@xylophone.i.decadent.org.uk> References: <20190816220431.GA9843@xylophone.i.decadent.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190816220431.GA9843@xylophone.i.decadent.org.uk> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jason A. Donenfeld commit 2c956a60778cbb6a27e0c7a8a52a91378c90e1d1 upstream. SipHash is a 64-bit keyed hash function that is actually a cryptographically secure PRF, like HMAC. Except SipHash is super fast, and is meant to be used as a hashtable keyed lookup function, or as a general PRF for short input use cases, such as sequence numbers or RNG chaining. For the first usage: There are a variety of attacks known as "hashtable poisoning" in which an attacker forms some data such that the hash of that data will be the same, and then preceeds to fill up all entries of a hashbucket. This is a realistic and well-known denial-of-service vector. Currently hashtables use jhash, which is fast but not secure, and some kind of rotating key scheme (or none at all, which isn't good). SipHash is meant as a replacement for jhash in these cases. There are a modicum of places in the kernel that are vulnerable to hashtable poisoning attacks, either via userspace vectors or network vectors, and there's not a reliable mechanism inside the kernel at the moment to fix it. The first step toward fixing these issues is actually getting a secure primitive into the kernel for developers to use. Then we can, bit by bit, port things over to it as deemed appropriate. While SipHash is extremely fast for a cryptographically secure function, it is likely a bit slower than the insecure jhash, and so replacements will be evaluated on a case-by-case basis based on whether or not the difference in speed is negligible and whether or not the current jhash usage poses a real security risk. For the second usage: A few places in the kernel are using MD5 or SHA1 for creating secure sequence numbers, syn cookies, port numbers, or fast random numbers. SipHash is a faster and more fitting, and more secure replacement for MD5 in those situations. Replacing MD5 and SHA1 with SipHash for these uses is obvious and straight-forward, and so is submitted along with this patch series. There shouldn't be much of a debate over its efficacy. Dozens of languages are already using this internally for their hash tables and PRFs. Some of the BSDs already use this in their kernels. SipHash is a widely known high-speed solution to a widely known set of problems, and it's time we catch-up. Signed-off-by: Jason A. Donenfeld Reviewed-by: Jean-Philippe Aumasson Cc: Linus Torvalds Cc: Eric Biggers Cc: David Laight Cc: Eric Dumazet Signed-off-by: David S. Miller [bwh: Backported to 4.9 as dependency of commits df453700e8d8 "inet: switch IP ID generator to siphash" and 3c79107631db "netfilter: ctnetlink: don't use conntrack/expect object addresses as id"] Signed-off-by: Ben Hutchings --- Documentation/siphash.txt | 100 ++++++++++++++++ MAINTAINERS | 7 ++ include/linux/siphash.h | 85 ++++++++++++++ lib/Kconfig.debug | 6 +- lib/Makefile | 5 +- lib/siphash.c | 232 ++++++++++++++++++++++++++++++++++++++ lib/test_siphash.c | 131 +++++++++++++++++++++ 7 files changed, 561 insertions(+), 5 deletions(-) create mode 100644 Documentation/siphash.txt create mode 100644 include/linux/siphash.h create mode 100644 lib/siphash.c create mode 100644 lib/test_siphash.c -- Ben Hutchings, Software Developer Codethink Ltd https://www.codethink.co.uk/ Dale House, 35 Dale Street Manchester, M1 2HF, United Kingdom diff --git a/Documentation/siphash.txt b/Documentation/siphash.txt new file mode 100644 index 000000000000..e8e6ddbbaab4 --- /dev/null +++ b/Documentation/siphash.txt @@ -0,0 +1,100 @@ + SipHash - a short input PRF +----------------------------------------------- +Written by Jason A. Donenfeld + +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 diff --git a/MAINTAINERS b/MAINTAINERS index 4f559f5b3a89..98ee40591a9b 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11068,6 +11068,13 @@ F: arch/arm/mach-s3c24xx/mach-bast.c F: arch/arm/mach-s3c24xx/bast-ide.c F: arch/arm/mach-s3c24xx/bast-irq.c +SIPHASH PRF ROUTINES +M: Jason A. Donenfeld +S: Maintained +F: lib/siphash.c +F: lib/test_siphash.c +F: include/linux/siphash.h + TI DAVINCI MACHINE SUPPORT M: Sekhar Nori M: Kevin Hilman diff --git a/include/linux/siphash.h b/include/linux/siphash.h new file mode 100644 index 000000000000..feeb29cd113e --- /dev/null +++ b/include/linux/siphash.h @@ -0,0 +1,85 @@ +/* Copyright (C) 2016 Jason A. Donenfeld . 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. + */ + +#ifndef _LINUX_SIPHASH_H +#define _LINUX_SIPHASH_H + +#include +#include + +#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); +} + +#endif /* _LINUX_SIPHASH_H */ diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 58a22ca10f33..4f561860bf41 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1822,9 +1822,9 @@ config TEST_HASH tristate "Perform selftest on hash functions" default n help - Enable this option to test the kernel's integer () - and string () hash functions on boot - (or module load). + Enable this option to test the kernel's integer (), + string (), and siphash () + hash functions on boot (or module load). This is intended to help people writing architecture-specific optimized versions. If unsure, say N. diff --git a/lib/Makefile b/lib/Makefile index 2447a218fff8..452d2956a5a2 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -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 \ flex_proportions.o ratelimit.o show_mem.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_SMP) += cpumask.o @@ -44,7 +45,7 @@ obj-$(CONFIG_TEST_HEXDUMP) += test_hexdump.o obj-y += kstrtox.o obj-$(CONFIG_TEST_BPF) += test_bpf.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 CFLAGS_test_kasan.o += -fno-builtin obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o diff --git a/lib/siphash.c b/lib/siphash.c new file mode 100644 index 000000000000..c43cf406e71b --- /dev/null +++ b/lib/siphash.c @@ -0,0 +1,232 @@ +/* Copyright (C) 2016 Jason A. Donenfeld . 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. + */ + +#include +#include + +#if defined(CONFIG_DCACHE_WORD_ACCESS) && BITS_PER_LONG == 64 +#include +#include +#endif + +#define SIPROUND \ + do { \ + v0 += v1; v1 = rol64(v1, 13); v1 ^= v0; v0 = rol64(v0, 32); \ + v2 += v3; v3 = rol64(v3, 16); v3 ^= v2; \ + v0 += v3; v3 = rol64(v3, 21); v3 ^= v0; \ + v2 += v1; v1 = rol64(v1, 17); v1 ^= v2; v2 = rol64(v2, 32); \ + } while (0) + +#define PREAMBLE(len) \ + u64 v0 = 0x736f6d6570736575ULL; \ + u64 v1 = 0x646f72616e646f6dULL; \ + u64 v2 = 0x6c7967656e657261ULL; \ + u64 v3 = 0x7465646279746573ULL; \ + u64 b = ((u64)(len)) << 56; \ + v3 ^= key->key[1]; \ + v2 ^= key->key[0]; \ + v1 ^= key->key[1]; \ + v0 ^= key->key[0]; + +#define POSTAMBLE \ + v3 ^= b; \ + SIPROUND; \ + SIPROUND; \ + v0 ^= b; \ + v2 ^= 0xff; \ + SIPROUND; \ + SIPROUND; \ + SIPROUND; \ + SIPROUND; \ + return (v0 ^ v1) ^ (v2 ^ v3); + +u64 __siphash_aligned(const void *data, size_t len, const siphash_key_t *key) +{ + const u8 *end = data + len - (len % sizeof(u64)); + const u8 left = len & (sizeof(u64) - 1); + u64 m; + PREAMBLE(len) + for (; data != end; data += sizeof(u64)) { + m = le64_to_cpup(data); + v3 ^= m; + SIPROUND; + SIPROUND; + v0 ^= m; + } +#if defined(CONFIG_DCACHE_WORD_ACCESS) && BITS_PER_LONG == 64 + if (left) + b |= le64_to_cpu((__force __le64)(load_unaligned_zeropad(data) & + bytemask_from_count(left))); +#else + switch (left) { + case 7: b |= ((u64)end[6]) << 48; + case 6: b |= ((u64)end[5]) << 40; + case 5: b |= ((u64)end[4]) << 32; + case 4: b |= le32_to_cpup(data); break; + case 3: b |= ((u64)end[2]) << 16; + case 2: b |= le16_to_cpup(data); break; + case 1: b |= end[0]; + } +#endif + POSTAMBLE +} +EXPORT_SYMBOL(__siphash_aligned); + +#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS +u64 __siphash_unaligned(const void *data, size_t len, const siphash_key_t *key) +{ + const u8 *end = data + len - (len % sizeof(u64)); + const u8 left = len & (sizeof(u64) - 1); + u64 m; + PREAMBLE(len) + for (; data != end; data += sizeof(u64)) { + m = get_unaligned_le64(data); + v3 ^= m; + SIPROUND; + SIPROUND; + v0 ^= m; + } +#if defined(CONFIG_DCACHE_WORD_ACCESS) && BITS_PER_LONG == 64 + if (left) + b |= le64_to_cpu((__force __le64)(load_unaligned_zeropad(data) & + bytemask_from_count(left))); +#else + switch (left) { + case 7: b |= ((u64)end[6]) << 48; + case 6: b |= ((u64)end[5]) << 40; + case 5: b |= ((u64)end[4]) << 32; + case 4: b |= get_unaligned_le32(end); break; + case 3: b |= ((u64)end[2]) << 16; + case 2: b |= get_unaligned_le16(end); break; + case 1: b |= end[0]; + } +#endif + POSTAMBLE +} +EXPORT_SYMBOL(__siphash_unaligned); +#endif + +/** + * siphash_1u64 - compute 64-bit siphash PRF value of a u64 + * @first: first u64 + * @key: the siphash key + */ +u64 siphash_1u64(const u64 first, const siphash_key_t *key) +{ + PREAMBLE(8) + v3 ^= first; + SIPROUND; + SIPROUND; + v0 ^= first; + POSTAMBLE +} +EXPORT_SYMBOL(siphash_1u64); + +/** + * siphash_2u64 - compute 64-bit siphash PRF value of 2 u64 + * @first: first u64 + * @second: second u64 + * @key: the siphash key + */ +u64 siphash_2u64(const u64 first, const u64 second, const siphash_key_t *key) +{ + PREAMBLE(16) + v3 ^= first; + SIPROUND; + SIPROUND; + v0 ^= first; + v3 ^= second; + SIPROUND; + SIPROUND; + v0 ^= second; + POSTAMBLE +} +EXPORT_SYMBOL(siphash_2u64); + +/** + * siphash_3u64 - compute 64-bit siphash PRF value of 3 u64 + * @first: first u64 + * @second: second u64 + * @third: third u64 + * @key: the siphash key + */ +u64 siphash_3u64(const u64 first, const u64 second, const u64 third, + const siphash_key_t *key) +{ + PREAMBLE(24) + v3 ^= first; + SIPROUND; + SIPROUND; + v0 ^= first; + v3 ^= second; + SIPROUND; + SIPROUND; + v0 ^= second; + v3 ^= third; + SIPROUND; + SIPROUND; + v0 ^= third; + POSTAMBLE +} +EXPORT_SYMBOL(siphash_3u64); + +/** + * siphash_4u64 - compute 64-bit siphash PRF value of 4 u64 + * @first: first u64 + * @second: second u64 + * @third: third u64 + * @forth: forth u64 + * @key: the siphash key + */ +u64 siphash_4u64(const u64 first, const u64 second, const u64 third, + const u64 forth, const siphash_key_t *key) +{ + PREAMBLE(32) + v3 ^= first; + SIPROUND; + SIPROUND; + v0 ^= first; + v3 ^= second; + SIPROUND; + SIPROUND; + v0 ^= second; + v3 ^= third; + SIPROUND; + SIPROUND; + v0 ^= third; + v3 ^= forth; + SIPROUND; + SIPROUND; + v0 ^= forth; + POSTAMBLE +} +EXPORT_SYMBOL(siphash_4u64); + +u64 siphash_1u32(const u32 first, const siphash_key_t *key) +{ + PREAMBLE(4) + b |= first; + POSTAMBLE +} +EXPORT_SYMBOL(siphash_1u32); + +u64 siphash_3u32(const u32 first, const u32 second, const u32 third, + const siphash_key_t *key) +{ + u64 combined = (u64)second << 32 | first; + PREAMBLE(12) + v3 ^= combined; + SIPROUND; + SIPROUND; + v0 ^= combined; + b |= third; + POSTAMBLE +} +EXPORT_SYMBOL(siphash_3u32); diff --git a/lib/test_siphash.c b/lib/test_siphash.c new file mode 100644 index 000000000000..d972acfc15e4 --- /dev/null +++ b/lib/test_siphash.c @@ -0,0 +1,131 @@ +/* Test cases for siphash.c + * + * Copyright (C) 2016 Jason A. Donenfeld . 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. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include + +/* Test vectors taken from official reference source available at: + * https://131002.net/siphash/siphash24.c + */ + +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 +}; + +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 (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 (!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 "); +MODULE_LICENSE("Dual BSD/GPL"); From patchwork Fri Aug 16 23:01:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Hutchings X-Patchwork-Id: 171520 Delivered-To: patch@linaro.org Received: by 2002:a92:d204:0:0:0:0:0 with SMTP id y4csp40069ily; Fri, 16 Aug 2019 16:01:26 -0700 (PDT) X-Google-Smtp-Source: APXvYqyoWo1lje131J8EikiHG/HkzXALFz1UYfLCTXfJCF5gt3q4ICpA4CkusPO1GfSp4WZ83CZX X-Received: by 2002:a17:90a:d793:: with SMTP id z19mr9269759pju.36.1565996486462; Fri, 16 Aug 2019 16:01:26 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1565996486; cv=none; d=google.com; s=arc-20160816; b=MlvTDm6oKm8c0PtMjziJ3IkkeTDUxU3Bjr8zsLG3SQt1gwTdEFYcMdlqhisjv6wOcg iq9KqiKIRyW370rX5+TJH3DNpZdrpNHElSW8ssT53qzNbDfZvRI8tSXqglVSvyW2CAeH 3Yqmg/KDuT/HHCjkhKqI4WwoRTgxwsosBjV88mMougEC6cuL4mDy4E4Dmdu2XHkywYZx R8jBFV2F5tTvA3cHjV4/fNVF9TlZYaNbD6L4sdqSnrCoC3Ovip4xXzc1UpGaF8X2z0IZ 3ETf1KgvBhy+hQs+NvajCWy4cjzsyuusWhQltuC1BgO/iSCt8X3papQIVPpioSMHX9z9 5RUQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-transfer-encoding:content-disposition:mime-version :references:message-id:subject:cc:to:from:date; bh=cf2qrjff/Wvb7phM+BTB7+dFNgt98q3J7G0rcdIf5Fc=; b=lMhPsaD4RrvNFUEG7f27GI9FjKfvLUyY1GFJ8Iwx9h0dV45yC0whiT0hP0xb05itK1 kMjJzdGGEaPnswU6OmukVQ4UZciwVRTeamqotLndmzfE69ImZY9znijgLVIFNMFjmHRt PeGo9GnJs1YOFaa3MNjDI5GivNRbBZL/0xjcXTN5NTfYlQsKoxnscZql3GyZnOoOEqaJ 1PuwBc6LtSZYMi41TGkKE+7JWcQdZGD4VZZZdEPYmaGxP/aqrTT1lQ8c1+04Mn8wTjkf k6IItGotbUQLcFb6VSjcpFd2HHMSLj8Ry3lLPyAUSuoa4q3QZx6iUvJ2hsWpv8S17AzK iltA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=codethink.co.uk Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id l6si4669340pgg.489.2019.08.16.16.01.26; Fri, 16 Aug 2019 16:01:26 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=codethink.co.uk Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727765AbfHPXBZ convert rfc822-to-8bit (ORCPT + 14 others); Fri, 16 Aug 2019 19:01:25 -0400 Received: from imap1.codethink.co.uk ([176.9.8.82]:51345 "EHLO imap1.codethink.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727796AbfHPXBZ (ORCPT ); Fri, 16 Aug 2019 19:01:25 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126] helo=xylophone.i.decadent.org.uk) by imap1.codethink.co.uk with esmtpsa (Exim 4.84_2 #1 (Debian)) id 1hylDk-0004kz-V5; Sat, 17 Aug 2019 00:01:21 +0100 Date: Sat, 17 Aug 2019 00:01:19 +0100 From: Ben Hutchings To: Greg Kroah-Hartman , Sasha Levin Cc: stable Subject: [PATCH 4.9 11/13] siphash: implement HalfSipHash1-3 for hash tables Message-ID: <20190816230119.GO9843@xylophone.i.decadent.org.uk> References: <20190816220431.GA9843@xylophone.i.decadent.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190816220431.GA9843@xylophone.i.decadent.org.uk> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jason A. Donenfeld commit 1ae2324f732c9c4e2fa4ebd885fa1001b70d52e1 upstream. HalfSipHash, or hsiphash, is a shortened version of SipHash, which generates 32-bit outputs using a weaker 64-bit key. It has *much* lower security margins, and shouldn't be used for anything too sensitive, but it could be used as a hashtable key function replacement, if the output is never exposed, and if the security requirement is not too high. The goal is to make this something that performance-critical jhash users would be willing to use. On 64-bit machines, HalfSipHash1-3 is slower than SipHash1-3, so we alias SipHash1-3 to HalfSipHash1-3 on those systems. 64-bit x86_64: [ 0.509409] test_siphash: SipHash2-4 cycles: 4049181 [ 0.510650] test_siphash: SipHash1-3 cycles: 2512884 [ 0.512205] test_siphash: HalfSipHash1-3 cycles: 3429920 [ 0.512904] test_siphash: JenkinsHash cycles: 978267 So, we map hsiphash() -> SipHash1-3 32-bit x86: [ 0.509868] test_siphash: SipHash2-4 cycles: 14812892 [ 0.513601] test_siphash: SipHash1-3 cycles: 9510710 [ 0.515263] test_siphash: HalfSipHash1-3 cycles: 3856157 [ 0.515952] test_siphash: JenkinsHash cycles: 1148567 So, we map hsiphash() -> HalfSipHash1-3 hsiphash() is roughly 3 times slower than jhash(), but comes with a considerable security improvement. Signed-off-by: Jason A. Donenfeld Reviewed-by: Jean-Philippe Aumasson Signed-off-by: David S. Miller [bwh: Backported to 4.9 to avoid regression for WireGuard with only half the siphash API present] Signed-off-by: Ben Hutchings --- Documentation/siphash.txt | 75 +++++++++ include/linux/siphash.h | 57 ++++++- lib/siphash.c | 321 +++++++++++++++++++++++++++++++++++++- lib/test_siphash.c | 98 +++++++++++- 4 files changed, 546 insertions(+), 5 deletions(-) -- Ben Hutchings, Software Developer Codethink Ltd https://www.codethink.co.uk/ Dale House, 35 Dale Street Manchester, M1 2HF, United Kingdom diff --git a/Documentation/siphash.txt b/Documentation/siphash.txt index e8e6ddbbaab4..908d348ff777 100644 --- a/Documentation/siphash.txt +++ b/Documentation/siphash.txt @@ -98,3 +98,78 @@ u64 h = siphash(&combined, offsetofend(typeof(combined), dport), &secret); 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 + +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. diff --git a/include/linux/siphash.h b/include/linux/siphash.h index feeb29cd113e..fa7a6b9cedbf 100644 --- a/include/linux/siphash.h +++ b/include/linux/siphash.h @@ -5,7 +5,9 @@ * SipHash: a fast short-input PRF * https://131002.net/siphash/ * - * This implementation is specifically for SipHash2-4. + * 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 @@ -82,4 +84,57 @@ static inline u64 siphash(const void *data, size_t len, 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 */ diff --git a/lib/siphash.c b/lib/siphash.c index c43cf406e71b..3ae58b4edad6 100644 --- a/lib/siphash.c +++ b/lib/siphash.c @@ -5,7 +5,9 @@ * SipHash: a fast short-input PRF * https://131002.net/siphash/ * - * This implementation is specifically for SipHash2-4. + * This implementation is specifically for SipHash2-4 for a secure PRF + * and HalfSipHash1-3/SipHash1-3 for an insecure PRF only suitable for + * hashtables. */ #include @@ -230,3 +232,320 @@ u64 siphash_3u32(const u32 first, const u32 second, const u32 third, POSTAMBLE } EXPORT_SYMBOL(siphash_3u32); + +#if BITS_PER_LONG == 64 +/* Note that on 64-bit, we make HalfSipHash1-3 actually be SipHash1-3, for + * performance reasons. On 32-bit, below, we actually implement HalfSipHash1-3. + */ + +#define HSIPROUND SIPROUND +#define HPREAMBLE(len) PREAMBLE(len) +#define HPOSTAMBLE \ + v3 ^= b; \ + HSIPROUND; \ + v0 ^= b; \ + v2 ^= 0xff; \ + HSIPROUND; \ + HSIPROUND; \ + HSIPROUND; \ + return (v0 ^ v1) ^ (v2 ^ v3); + +u32 __hsiphash_aligned(const void *data, size_t len, const hsiphash_key_t *key) +{ + const u8 *end = data + len - (len % sizeof(u64)); + const u8 left = len & (sizeof(u64) - 1); + u64 m; + HPREAMBLE(len) + for (; data != end; data += sizeof(u64)) { + m = le64_to_cpup(data); + v3 ^= m; + HSIPROUND; + v0 ^= m; + } +#if defined(CONFIG_DCACHE_WORD_ACCESS) && BITS_PER_LONG == 64 + if (left) + b |= le64_to_cpu((__force __le64)(load_unaligned_zeropad(data) & + bytemask_from_count(left))); +#else + switch (left) { + case 7: b |= ((u64)end[6]) << 48; + case 6: b |= ((u64)end[5]) << 40; + case 5: b |= ((u64)end[4]) << 32; + case 4: b |= le32_to_cpup(data); break; + case 3: b |= ((u64)end[2]) << 16; + case 2: b |= le16_to_cpup(data); break; + case 1: b |= end[0]; + } +#endif + HPOSTAMBLE +} +EXPORT_SYMBOL(__hsiphash_aligned); + +#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS +u32 __hsiphash_unaligned(const void *data, size_t len, + const hsiphash_key_t *key) +{ + const u8 *end = data + len - (len % sizeof(u64)); + const u8 left = len & (sizeof(u64) - 1); + u64 m; + HPREAMBLE(len) + for (; data != end; data += sizeof(u64)) { + m = get_unaligned_le64(data); + v3 ^= m; + HSIPROUND; + v0 ^= m; + } +#if defined(CONFIG_DCACHE_WORD_ACCESS) && BITS_PER_LONG == 64 + if (left) + b |= le64_to_cpu((__force __le64)(load_unaligned_zeropad(data) & + bytemask_from_count(left))); +#else + switch (left) { + case 7: b |= ((u64)end[6]) << 48; + case 6: b |= ((u64)end[5]) << 40; + case 5: b |= ((u64)end[4]) << 32; + case 4: b |= get_unaligned_le32(end); break; + case 3: b |= ((u64)end[2]) << 16; + case 2: b |= get_unaligned_le16(end); break; + case 1: b |= end[0]; + } +#endif + HPOSTAMBLE +} +EXPORT_SYMBOL(__hsiphash_unaligned); +#endif + +/** + * hsiphash_1u32 - compute 64-bit hsiphash PRF value of a u32 + * @first: first u32 + * @key: the hsiphash key + */ +u32 hsiphash_1u32(const u32 first, const hsiphash_key_t *key) +{ + HPREAMBLE(4) + b |= first; + HPOSTAMBLE +} +EXPORT_SYMBOL(hsiphash_1u32); + +/** + * hsiphash_2u32 - compute 32-bit hsiphash PRF value of 2 u32 + * @first: first u32 + * @second: second u32 + * @key: the hsiphash key + */ +u32 hsiphash_2u32(const u32 first, const u32 second, const hsiphash_key_t *key) +{ + u64 combined = (u64)second << 32 | first; + HPREAMBLE(8) + v3 ^= combined; + HSIPROUND; + v0 ^= combined; + HPOSTAMBLE +} +EXPORT_SYMBOL(hsiphash_2u32); + +/** + * hsiphash_3u32 - compute 32-bit hsiphash PRF value of 3 u32 + * @first: first u32 + * @second: second u32 + * @third: third u32 + * @key: the hsiphash key + */ +u32 hsiphash_3u32(const u32 first, const u32 second, const u32 third, + const hsiphash_key_t *key) +{ + u64 combined = (u64)second << 32 | first; + HPREAMBLE(12) + v3 ^= combined; + HSIPROUND; + v0 ^= combined; + b |= third; + HPOSTAMBLE +} +EXPORT_SYMBOL(hsiphash_3u32); + +/** + * hsiphash_4u32 - compute 32-bit hsiphash PRF value of 4 u32 + * @first: first u32 + * @second: second u32 + * @third: third u32 + * @forth: forth u32 + * @key: the hsiphash key + */ +u32 hsiphash_4u32(const u32 first, const u32 second, const u32 third, + const u32 forth, const hsiphash_key_t *key) +{ + u64 combined = (u64)second << 32 | first; + HPREAMBLE(16) + v3 ^= combined; + HSIPROUND; + v0 ^= combined; + combined = (u64)forth << 32 | third; + v3 ^= combined; + HSIPROUND; + v0 ^= combined; + HPOSTAMBLE +} +EXPORT_SYMBOL(hsiphash_4u32); +#else +#define HSIPROUND \ + do { \ + v0 += v1; v1 = rol32(v1, 5); v1 ^= v0; v0 = rol32(v0, 16); \ + v2 += v3; v3 = rol32(v3, 8); v3 ^= v2; \ + v0 += v3; v3 = rol32(v3, 7); v3 ^= v0; \ + v2 += v1; v1 = rol32(v1, 13); v1 ^= v2; v2 = rol32(v2, 16); \ + } while (0) + +#define HPREAMBLE(len) \ + u32 v0 = 0; \ + u32 v1 = 0; \ + u32 v2 = 0x6c796765U; \ + u32 v3 = 0x74656462U; \ + u32 b = ((u32)(len)) << 24; \ + v3 ^= key->key[1]; \ + v2 ^= key->key[0]; \ + v1 ^= key->key[1]; \ + v0 ^= key->key[0]; + +#define HPOSTAMBLE \ + v3 ^= b; \ + HSIPROUND; \ + v0 ^= b; \ + v2 ^= 0xff; \ + HSIPROUND; \ + HSIPROUND; \ + HSIPROUND; \ + return v1 ^ v3; + +u32 __hsiphash_aligned(const void *data, size_t len, const hsiphash_key_t *key) +{ + const u8 *end = data + len - (len % sizeof(u32)); + const u8 left = len & (sizeof(u32) - 1); + u32 m; + HPREAMBLE(len) + for (; data != end; data += sizeof(u32)) { + m = le32_to_cpup(data); + v3 ^= m; + HSIPROUND; + v0 ^= m; + } + switch (left) { + case 3: b |= ((u32)end[2]) << 16; + case 2: b |= le16_to_cpup(data); break; + case 1: b |= end[0]; + } + HPOSTAMBLE +} +EXPORT_SYMBOL(__hsiphash_aligned); + +#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS +u32 __hsiphash_unaligned(const void *data, size_t len, + const hsiphash_key_t *key) +{ + const u8 *end = data + len - (len % sizeof(u32)); + const u8 left = len & (sizeof(u32) - 1); + u32 m; + HPREAMBLE(len) + for (; data != end; data += sizeof(u32)) { + m = get_unaligned_le32(data); + v3 ^= m; + HSIPROUND; + v0 ^= m; + } + switch (left) { + case 3: b |= ((u32)end[2]) << 16; + case 2: b |= get_unaligned_le16(end); break; + case 1: b |= end[0]; + } + HPOSTAMBLE +} +EXPORT_SYMBOL(__hsiphash_unaligned); +#endif + +/** + * hsiphash_1u32 - compute 32-bit hsiphash PRF value of a u32 + * @first: first u32 + * @key: the hsiphash key + */ +u32 hsiphash_1u32(const u32 first, const hsiphash_key_t *key) +{ + HPREAMBLE(4) + v3 ^= first; + HSIPROUND; + v0 ^= first; + HPOSTAMBLE +} +EXPORT_SYMBOL(hsiphash_1u32); + +/** + * hsiphash_2u32 - compute 32-bit hsiphash PRF value of 2 u32 + * @first: first u32 + * @second: second u32 + * @key: the hsiphash key + */ +u32 hsiphash_2u32(const u32 first, const u32 second, const hsiphash_key_t *key) +{ + HPREAMBLE(8) + v3 ^= first; + HSIPROUND; + v0 ^= first; + v3 ^= second; + HSIPROUND; + v0 ^= second; + HPOSTAMBLE +} +EXPORT_SYMBOL(hsiphash_2u32); + +/** + * hsiphash_3u32 - compute 32-bit hsiphash PRF value of 3 u32 + * @first: first u32 + * @second: second u32 + * @third: third u32 + * @key: the hsiphash key + */ +u32 hsiphash_3u32(const u32 first, const u32 second, const u32 third, + const hsiphash_key_t *key) +{ + HPREAMBLE(12) + v3 ^= first; + HSIPROUND; + v0 ^= first; + v3 ^= second; + HSIPROUND; + v0 ^= second; + v3 ^= third; + HSIPROUND; + v0 ^= third; + HPOSTAMBLE +} +EXPORT_SYMBOL(hsiphash_3u32); + +/** + * hsiphash_4u32 - compute 32-bit hsiphash PRF value of 4 u32 + * @first: first u32 + * @second: second u32 + * @third: third u32 + * @forth: forth u32 + * @key: the hsiphash key + */ +u32 hsiphash_4u32(const u32 first, const u32 second, const u32 third, + const u32 forth, const hsiphash_key_t *key) +{ + HPREAMBLE(16) + v3 ^= first; + HSIPROUND; + v0 ^= first; + v3 ^= second; + HSIPROUND; + v0 ^= second; + v3 ^= third; + HSIPROUND; + v0 ^= third; + v3 ^= forth; + HSIPROUND; + v0 ^= forth; + HPOSTAMBLE +} +EXPORT_SYMBOL(hsiphash_4u32); +#endif diff --git a/lib/test_siphash.c b/lib/test_siphash.c index d972acfc15e4..a6d854d933bf 100644 --- a/lib/test_siphash.c +++ b/lib/test_siphash.c @@ -7,7 +7,9 @@ * SipHash: a fast short-input PRF * https://131002.net/siphash/ * - * This implementation is specifically for SipHash2-4. + * 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 @@ -18,8 +20,8 @@ #include #include -/* Test vectors taken from official reference source available at: - * https://131002.net/siphash/siphash24.c +/* Test vectors taken from reference source available at: + * https://github.com/veorq/SipHash */ static const siphash_key_t test_key_siphash = @@ -50,6 +52,64 @@ static const u64 test_vectors_siphash[64] = { 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); @@ -70,6 +130,16 @@ static int __init siphash_test_init(void) 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]) { @@ -115,6 +185,28 @@ static int __init siphash_test_init(void) 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;