siphash: implement HalfSipHash1-3 for hash tables
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 <Jason@zx2c4.com>
Reviewed-by: Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/lib/test_siphash.c b/lib/test_siphash.c
index d972acf..a6d854d 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 <linux/errno.h>
#include <linux/module.h>
-/* 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 @@
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 @@
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 @@
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;