[PATCH net-next 1/4] siphash: add cryptographically secure PRF

@@ -0,0 +1,79 @@
+         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, siphash_key_t key);
+
+And:
+
+u64 siphash_1u64(u64, siphash_key_t key);
+u64 siphash_2u64(u64, u64, siphash_key_t key);
+u64 siphash_3u64(u64, u64, u64, siphash_key_t key);
+u64 siphash_4u64(u64, u64, u64, u64, siphash_key_t key);
+u64 siphash_1u32(u32, siphash_key_t key);
+u64 siphash_2u32(u32, u32, siphash_key_t key);
+u64 siphash_3u32(u32, u32, u32, siphash_key_t key);
+u64 siphash_4u32(u32, u32, u32, u32, 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. Resources
+
+Read the SipHash paper if you're interested in learning more:
+https://131002.net/siphash/siphash.pdf

@@ -11291,6 +11291,13 @@ 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 <Jason@zx2c4.com>
+S:	Maintained
+F:	lib/siphash.c
+F:	lib/test_siphash.c
+F:	include/linux/siphash.h
+
 TI DAVINCI MACHINE SUPPORT
 M:	Sekhar Nori <nsekhar@ti.com>
 M:	Kevin Hilman <khilman@kernel.org>

@@ -0,0 +1,79 @@
+/* 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.
+ */
+
+#ifndef _LINUX_SIPHASH_H
+#define _LINUX_SIPHASH_H
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+
+#define SIPHASH_ALIGNMENT __alignof__(u64)
+typedef u64 siphash_key_t[2];
+
+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_cpu(data[0]), 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 */

@@ -1819,9 +1819,9 @@ config TEST_HASH
 	tristate "Perform selftest on hash functions"
 	default n
 	help
-	  Enable this option to test the kernel's integer (<linux/hash,h>)
-	  and string (<linux/stringhash.h>) hash functions on boot
-	  (or module load).
+	  Enable this option to test the kernel's integer (<linux/hash.h>),
+	  string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
+	  hash functions on boot (or module load).
 
 	  This is intended to help people writing architecture-specific
 	  optimized versions.  If unsure, say N.

@@ -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
 obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o
 obj-$(CONFIG_TEST_LKM) += test_module.o

@@ -0,0 +1,232 @@
+/* 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.
+ */
+
+#include <linux/siphash.h>
+#include <asm/unaligned.h>
+
+#if defined(CONFIG_DCACHE_WORD_ACCESS) && BITS_PER_LONG == 64
+#include <linux/dcache.h>
+#include <asm/word-at-a-time.h>
+#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[1]; \
+	v2 ^= key[0]; \
+	v1 ^= key[1]; \
+	v0 ^= 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);

@@ -0,0 +1,119 @@
+/* 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.
+ */
+
+#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 official reference source available at:
+ *     https://131002.net/siphash/siphash24.c
+ */
+static const u64 test_vectors[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 const siphash_key_t test_key =
+	{ 0x0706050403020100ULL , 0x0f0e0d0c0b0a0908ULL };
+
+static int __init siphash_test_init(void)
+{
+	u8 in[64] __aligned(SIPHASH_ALIGNMENT);
+	u8 in_unaligned[65];
+	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) != test_vectors[i]) {
+			pr_info("self-test aligned %u: FAIL\n", i + 1);
+			ret = -EINVAL;
+		}
+		if (siphash(in_unaligned + 1, i, test_key) != test_vectors[i]) {
+			pr_info("self-test unaligned %u: FAIL\n", i + 1);
+			ret = -EINVAL;
+		}
+	}
+	if (siphash_1u64(0x0706050403020100ULL, test_key) != test_vectors[8]) {
+		pr_info("self-test 1u64: FAIL\n");
+		ret = -EINVAL;
+	}
+	if (siphash_2u64(0x0706050403020100ULL, 0x0f0e0d0c0b0a0908ULL, test_key) != test_vectors[16]) {
+		pr_info("self-test 2u64: FAIL\n");
+		ret = -EINVAL;
+	}
+	if (siphash_3u64(0x0706050403020100ULL, 0x0f0e0d0c0b0a0908ULL,
+			 0x1716151413121110ULL, test_key) != test_vectors[24]) {
+		pr_info("self-test 3u64: FAIL\n");
+		ret = -EINVAL;
+	}
+	if (siphash_4u64(0x0706050403020100ULL, 0x0f0e0d0c0b0a0908ULL,
+			 0x1716151413121110ULL, 0x1f1e1d1c1b1a1918ULL, test_key) != test_vectors[32]) {
+		pr_info("self-test 4u64: FAIL\n");
+		ret = -EINVAL;
+	}
+	if (siphash_1u32(0x03020100U, test_key) != test_vectors[4]) {
+		pr_info("self-test 1u32: FAIL\n");
+		ret = -EINVAL;
+	}
+	if (siphash_2u32(0x03020100U, 0x07060504U, test_key) != test_vectors[8]) {
+		pr_info("self-test 2u32: FAIL\n");
+		ret = -EINVAL;
+	}
+	if (siphash_3u32(0x03020100U, 0x07060504U,
+			 0x0b0a0908U, test_key) != test_vectors[12]) {
+		pr_info("self-test 3u32: FAIL\n");
+		ret = -EINVAL;
+	}
+	if (siphash_4u32(0x03020100U, 0x07060504U,
+			 0x0b0a0908U, 0x0f0e0d0cU, test_key) != test_vectors[16]) {
+		pr_info("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");

@@ -1,3 +1,5 @@
+/* Copyright (C) 2016 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. */
+
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/cryptohash.h>

@@ -8,14 +10,14 @@
 #include <linux/ktime.h>
 #include <linux/string.h>
 #include <linux/net.h>
-
+#include <linux/siphash.h>
 #include <net/secure_seq.h>
 
 #if IS_ENABLED(CONFIG_IPV6) || IS_ENABLED(CONFIG_INET)
+#include <linux/in6.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;
 
 static __always_inline void net_secret_init(void)
 {

@@ -44,80 +46,65 @@ static u32 seq_scale(u32 seq)
 u32 secure_tcpv6_sequence_number(const __be32 *saddr, const __be32 *daddr,
 				 __be16 sport, __be16 dport, u32 *tsoff)
 {
-	u32 secret[MD5_MESSAGE_BYTES / 4];
-	u32 hash[MD5_DIGEST_WORDS];
-	u32 i;
-
+	const struct {
+		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 hash;
 	net_secret_init();
-	memcpy(hash, saddr, 16);
-	for (i = 0; i < 4; i++)
-		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);
-
-	*tsoff = sysctl_tcp_timestamps == 1 ? hash[1] : 0;
-	return seq_scale(hash[0]);
+	hash = siphash(&combined, offsetofend(typeof(combined), dport), net_secret);
+	*tsoff = sysctl_tcp_timestamps == 1 ? (hash >> 32) : 0;
+	return seq_scale(hash);
 }
 EXPORT_SYMBOL(secure_tcpv6_sequence_number);
 
 u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr,
 			       __be16 dport)
 {
-	u32 secret[MD5_MESSAGE_BYTES / 4];
-	u32 hash[MD5_DIGEST_WORDS];
-	u32 i;
-
+	const struct {
+		struct in6_addr saddr;
+		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();
-	memcpy(hash, saddr, 16);
-	for (i = 0; i < 4; i++)
-		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];
+	return siphash(&combined, offsetofend(typeof(combined), dport), net_secret);
 }
 EXPORT_SYMBOL(secure_ipv6_port_ephemeral);
 #endif
 
 #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,
 			       __be16 sport, __be16 dport, u32 *tsoff)
 {
-	u32 hash[MD5_DIGEST_WORDS];
-
+	u64 hash;
 	net_secret_init();
-	hash[0] = (__force u32)saddr;
-	hash[1] = (__force u32)daddr;
-	hash[2] = ((__force u16)sport << 16) + (__force u16)dport;
-	hash[3] = net_secret[15];
-
-	md5_transform(hash, net_secret);
-
-	*tsoff = sysctl_tcp_timestamps == 1 ? hash[1] : 0;
-	return seq_scale(hash[0]);
+	hash = siphash_3u32(saddr, daddr, (u32)sport << 16 | dport, net_secret);
+	*tsoff = sysctl_tcp_timestamps == 1 ? (hash >> 32) : 0;
+	return seq_scale(hash);
 }
 
 u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport)
 {
-	u32 hash[MD5_DIGEST_WORDS];
-
 	net_secret_init();
-	hash[0] = (__force u32)saddr;
-	hash[1] = (__force u32)daddr;
-	hash[2] = (__force u32)dport ^ net_secret[14];
-	hash[3] = net_secret[15];
-
-	md5_transform(hash, net_secret);
-
-	return hash[0];
+	return siphash_3u32(saddr, daddr, dport, net_secret);
 }
 EXPORT_SYMBOL_GPL(secure_ipv4_port_ephemeral);
 #endif

@@ -126,21 +113,11 @@ EXPORT_SYMBOL_GPL(secure_ipv4_port_ephemeral);
 u64 secure_dccp_sequence_number(__be32 saddr, __be32 daddr,
 				__be16 sport, __be16 dport)
 {
-	u32 hash[MD5_DIGEST_WORDS];
 	u64 seq;
-
 	net_secret_init();
-	hash[0] = (__force u32)saddr;
-	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 = siphash_3u32(saddr, daddr, (u32)sport << 16 | dport, net_secret);
 	seq += ktime_get_real_ns();
 	seq &= (1ull << 48) - 1;
-
 	return seq;
 }
 EXPORT_SYMBOL(secure_dccp_sequence_number);

@@ -149,26 +126,22 @@ EXPORT_SYMBOL(secure_dccp_sequence_number);
 u64 secure_dccpv6_sequence_number(__be32 *saddr, __be32 *daddr,
 				  __be16 sport, __be16 dport)
 {
-	u32 secret[MD5_MESSAGE_BYTES / 4];
-	u32 hash[MD5_DIGEST_WORDS];
+	const struct {
+		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;
-	u32 i;
-
 	net_secret_init();
-	memcpy(hash, saddr, 16);
-	for (i = 0; i < 4; i++)
-		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 = siphash(&combined, offsetofend(typeof(combined), dport), net_secret);
 	seq += ktime_get_real_ns();
 	seq &= (1ull << 48) - 1;
-
 	return seq;
 }
 EXPORT_SYMBOL(secure_dccpv6_sequence_number);

@@ -77,3 +77,78 @@ Linux implements the "2-4" variant of SipHash.
 
 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, siphash_key_t key);
+
+And:
+
+u32 hsiphash_1u32(u32, hsiphash_key_t key);
+u32 hsiphash_2u32(u32, u32, hsiphash_key_t key);
+u32 hsiphash_3u32(u32, u32, u32, hsiphash_key_t key);
+u32 hsiphash_4u32(u32, u32, u32, u32, 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.

@@ -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

@@ -76,4 +78,56 @@ static inline u64 siphash(const void *data, size_t len, const siphash_key_t key)
 	return ___siphash_aligned(data, len, key);
 }
 
+#if BITS_PER_LONG == 64
+typedef siphash_key_t hsiphash_key_t;
+#define HSIPHASH_ALIGNMENT SIPHASH_ALIGNMENT
+#else
+typedef u32 hsiphash_key_t[2];
+#define HSIPHASH_ALIGNMENT __alignof__(u32)
+#endif
+
+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 */

@@ -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 <linux/siphash.h>

@@ -230,3 +232,317 @@ u64 siphash_3u32(const u32 first, const u32 second, const u32 third,
 	POSTAMBLE
 }
 EXPORT_SYMBOL(siphash_3u32);
+
+#if BITS_PER_LONG == 64
+/* Note that this HalfSipHash1-3 implementation on 64-bit
+ * isn't actually HalfSipHash1-3 but rather SipHash1-3. */
+
+#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[1]; \
+	v2 ^= key[0]; \
+	v1 ^= key[1]; \
+	v0 ^= 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