Merge pull request #1465 from teg/siphash24

hashmap/siphash24: refactor hash functions

3 files changed, 82 insertions, 7 deletions

diff --git a/src/test/test-hashmap-plain.c b/src/test/test-hashmap-plain.c
index 057b6c1dc1..78f9c19f5b 100644
--- a/src/test/test-hashmap-plain.c
+++ b/src/test/test-hashmap-plain.c
@@ -692,8 +692,8 @@ static void test_hashmap_get2(void) {
         hashmap_free_free_free(m);
 }
 
-static unsigned long crippled_hashmap_func(const void *p, const uint8_t hash_key[HASH_KEY_SIZE]) {
-        return trivial_hash_func(p, hash_key) & 0xff;
+static void crippled_hashmap_func(const void *p, struct siphash *state) {
+        return trivial_hash_func(INT_TO_PTR(PTR_TO_INT(p) & 0xff), state);
 }
 
 static const struct hash_ops crippled_hashmap_ops = {
diff --git a/src/test/test-prioq.c b/src/test/test-prioq.c
index dfedc9b8dc..1e2e42cbca 100644
--- a/src/test/test-prioq.c
+++ b/src/test/test-prioq.c
@@ -89,13 +89,10 @@ static int test_compare(const void *a, const void *b) {
         return 0;
 }
 
-static unsigned long test_hash(const void *a, const uint8_t hash_key[HASH_KEY_SIZE]) {
+static void test_hash(const void *a, struct siphash *state) {
         const struct test *x = a;
-        uint64_t u;
 
-        siphash24((uint8_t*) &u, &x->value, sizeof(x->value), hash_key);
-
-        return (unsigned long) u;
+        siphash24_compress(&x->value, sizeof(x->value), state);
 }
 
 static const struct hash_ops test_hash_ops = {
diff --git a/src/test/test-siphash24.c b/src/test/test-siphash24.c
new file mode 100644
index 0000000000..65eb2b6f35
--- /dev/null
+++ b/src/test/test-siphash24.c
@@ -0,0 +1,78 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2015 Tom Gundersen
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "util.h"
+#include "siphash24.h"
+
+#define ITERATIONS 10000000ULL
+
+/* see https://131002.net/siphash/siphash.pdf, Appendix A */
+int main(int argc, char *argv[]) {
+        struct siphash state = {};
+        const uint8_t in[15]  = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+                                  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e };
+        const uint8_t key[16] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+                                  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f};
+        uint64_t out = 0;
+        unsigned i, j, k;
+        usec_t ts;
+
+        siphash24((uint8_t *)&out, in, sizeof(in), key);
+        assert_se(out == 0xa129ca6149be45e5);
+
+        assert_se(out == 0xa129ca6149be45e5ULL);
+
+        ts = now(CLOCK_MONOTONIC);
+        for (k = 0; k < ITERATIONS; k++)
+                siphash24((uint8_t *)&out, in, sizeof(in), key);
+        ts = now(CLOCK_MONOTONIC) - ts;
+
+        log_info("%llu iterations per second", (ITERATIONS * USEC_PER_SEC) / ts);
+
+        /* verify the internal state as given in the above paper */
+        siphash_init(&state, key);
+        assert_se(state.v0 == 0x7469686173716475);
+        assert_se(state.v1 == 0x6b617f6d656e6665);
+        assert_se(state.v2 == 0x6b7f62616d677361);
+        assert_se(state.v3 == 0x7b6b696e727e6c7b);
+        siphash24_compress(in, sizeof(in), &state);
+        assert_se(state.v0 == 0x4a017198de0a59e0);
+        assert_se(state.v1 == 0x0d52f6f62a4f59a4);
+        assert_se(state.v2 == 0x634cb3577b01fd3d);
+        assert_se(state.v3 == 0xa5224d6f55c7d9c8);
+        assert_se(siphash24_finalize(&state) == 0xa129ca6149be45e5);
+        assert_se(state.v0 == 0xf6bcd53893fecff1);
+        assert_se(state.v1 == 0x54b9964c7ea0d937);
+        assert_se(state.v2 == 0x1b38329c099bb55a);
+        assert_se(state.v3 == 0x1814bb89ad7be679);
+
+        /* verify that decomposing the input in three chunks gives the
+           same result */
+        for (i = 0; i < sizeof(in); i++) {
+                for (j = i; j < sizeof(in); j++) {
+                        siphash_init(&state, key);
+                        siphash24_compress(in, i, &state);
+                        siphash24_compress(&in[i], j - i, &state);
+                        siphash24_compress(&in[j], sizeof(in) - j, &state);
+                        assert_se(siphash24_finalize(&state) == 0xa129ca6149be45e5);
+                }
+        }
+}