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+/*
+ SipHash reference C implementation
+
+ Copyright (c) 2012-2016 Jean-Philippe Aumasson
+ <jeanphilippe.aumasson@gmail.com>
+ Copyright (c) 2012-2014 Daniel J. Bernstein <djb@cr.yp.to>
+ Copyright (c) 2017 Salvatore Sanfilippo <antirez@gmail.com>
+
+ To the extent possible under law, the author(s) have dedicated all copyright
+ and related and neighboring rights to this software to the public domain
+ worldwide. This software is distributed without any warranty.
+
+ You should have received a copy of the CC0 Public Domain Dedication along
+ with this software. If not, see
+ <http://creativecommons.org/publicdomain/zero/1.0/>.
+
+ ----------------------------------------------------------------------------
+
+ This version was modified by Salvatore Sanfilippo <antirez@gmail.com>
+ in the following ways:
+
+ 1. We use SipHash 1-2. This is not believed to be as strong as the
+ suggested 2-4 variant, but AFAIK there are not trivial attacks
+ against this reduced-rounds version, and it runs at the same speed
+ as Murmurhash2 that we used previously, while the 2-4 variant slowed
+ down Redis by a 4% figure more or less.
+ 2. Hard-code rounds in the hope the compiler can optimize it more
+ in this raw from. Anyway we always want the standard 2-4 variant.
+ 3. Modify the prototype and implementation so that the function directly
+ returns an uint64_t value, the hash itself, instead of receiving an
+ output buffer. This also means that the output size is set to 8 bytes
+ and the 16 bytes output code handling was removed.
+ 4. Provide a case insensitive variant to be used when hashing strings that
+ must be considered identical by the hash table regardless of the case.
+ If we don't have directly a case insensitive hash function, we need to
+ perform a text transformation in some temporary buffer, which is costly.
+ 5. Remove debugging code.
+ 6. Modified the original test.c file to be a stand-alone function testing
+ the function in the new form (returning an uint64_t) using just the
+ relevant test vector.
+ */
+#include <assert.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+
+/* Fast tolower() alike function that does not care about locale
+ * but just returns a-z instead of A-Z. */
+int siptlw(int c) {
+ if (c >= 'A' && c <= 'Z') {
+ return c+('a'-'A');
+ } else {
+ return c;
+ }
+}
+
+#if defined(__has_attribute)
+#if __has_attribute(no_sanitize)
+#define NO_SANITIZE(sanitizer) __attribute__((no_sanitize(sanitizer)))
+#endif
+#endif
+
+#if !defined(NO_SANITIZE)
+#define NO_SANITIZE(sanitizer)
+#endif
+
+/* Test of the CPU is Little Endian and supports not aligned accesses.
+ * Two interesting conditions to speedup the function that happen to be
+ * in most of x86 servers. */
+#if defined(__X86_64__) || defined(__x86_64__) || defined (__i386__) \
+ || defined (__aarch64__) || defined (__arm64__)
+#define UNALIGNED_LE_CPU
+#endif
+
+#define ROTL(x, b) (uint64_t)(((x) << (b)) | ((x) >> (64 - (b))))
+
+#define U32TO8_LE(p, v) \
+ (p)[0] = (uint8_t)((v)); \
+ (p)[1] = (uint8_t)((v) >> 8); \
+ (p)[2] = (uint8_t)((v) >> 16); \
+ (p)[3] = (uint8_t)((v) >> 24);
+
+#define U64TO8_LE(p, v) \
+ U32TO8_LE((p), (uint32_t)((v))); \
+ U32TO8_LE((p) + 4, (uint32_t)((v) >> 32));
+
+#ifdef UNALIGNED_LE_CPU
+#define U8TO64_LE(p) (*((uint64_t*)(p)))
+#else
+#define U8TO64_LE(p) \
+ (((uint64_t)((p)[0])) | ((uint64_t)((p)[1]) << 8) | \
+ ((uint64_t)((p)[2]) << 16) | ((uint64_t)((p)[3]) << 24) | \
+ ((uint64_t)((p)[4]) << 32) | ((uint64_t)((p)[5]) << 40) | \
+ ((uint64_t)((p)[6]) << 48) | ((uint64_t)((p)[7]) << 56))
+#endif
+
+#define U8TO64_LE_NOCASE(p) \
+ (((uint64_t)(siptlw((p)[0]))) | \
+ ((uint64_t)(siptlw((p)[1])) << 8) | \
+ ((uint64_t)(siptlw((p)[2])) << 16) | \
+ ((uint64_t)(siptlw((p)[3])) << 24) | \
+ ((uint64_t)(siptlw((p)[4])) << 32) | \
+ ((uint64_t)(siptlw((p)[5])) << 40) | \
+ ((uint64_t)(siptlw((p)[6])) << 48) | \
+ ((uint64_t)(siptlw((p)[7])) << 56))
+
+#define SIPROUND \
+ do { \
+ v0 += v1; \
+ v1 = ROTL(v1, 13); \
+ v1 ^= v0; \
+ v0 = ROTL(v0, 32); \
+ v2 += v3; \
+ v3 = ROTL(v3, 16); \
+ v3 ^= v2; \
+ v0 += v3; \
+ v3 = ROTL(v3, 21); \
+ v3 ^= v0; \
+ v2 += v1; \
+ v1 = ROTL(v1, 17); \
+ v1 ^= v2; \
+ v2 = ROTL(v2, 32); \
+ } while (0)
+
+NO_SANITIZE("alignment")
+uint64_t siphash(const uint8_t *in, const size_t inlen, const uint8_t *k) {
+#ifndef UNALIGNED_LE_CPU
+ uint64_t hash;
+ uint8_t *out = (uint8_t*) &hash;
+#endif
+ uint64_t v0 = 0x736f6d6570736575ULL;
+ uint64_t v1 = 0x646f72616e646f6dULL;
+ uint64_t v2 = 0x6c7967656e657261ULL;
+ uint64_t v3 = 0x7465646279746573ULL;
+ uint64_t k0 = U8TO64_LE(k);
+ uint64_t k1 = U8TO64_LE(k + 8);
+ uint64_t m;
+ const uint8_t *end = in + inlen - (inlen % sizeof(uint64_t));
+ const int left = inlen & 7;
+ uint64_t b = ((uint64_t)inlen) << 56;
+ v3 ^= k1;
+ v2 ^= k0;
+ v1 ^= k1;
+ v0 ^= k0;
+
+ for (; in != end; in += 8) {
+ m = U8TO64_LE(in);
+ v3 ^= m;
+
+ SIPROUND;
+
+ v0 ^= m;
+ }
+
+ switch (left) {
+ case 7: b |= ((uint64_t)in[6]) << 48; /* fall-thru */
+ case 6: b |= ((uint64_t)in[5]) << 40; /* fall-thru */
+ case 5: b |= ((uint64_t)in[4]) << 32; /* fall-thru */
+ case 4: b |= ((uint64_t)in[3]) << 24; /* fall-thru */
+ case 3: b |= ((uint64_t)in[2]) << 16; /* fall-thru */
+ case 2: b |= ((uint64_t)in[1]) << 8; /* fall-thru */
+ case 1: b |= ((uint64_t)in[0]); break;
+ case 0: break;
+ }
+
+ v3 ^= b;
+
+ SIPROUND;
+
+ v0 ^= b;
+ v2 ^= 0xff;
+
+ SIPROUND;
+ SIPROUND;
+
+ b = v0 ^ v1 ^ v2 ^ v3;
+#ifndef UNALIGNED_LE_CPU
+ U64TO8_LE(out, b);
+ return hash;
+#else
+ return b;
+#endif
+}
+
+NO_SANITIZE("alignment")
+uint64_t siphash_nocase(const uint8_t *in, const size_t inlen, const uint8_t *k)
+{
+#ifndef UNALIGNED_LE_CPU
+ uint64_t hash;
+ uint8_t *out = (uint8_t*) &hash;
+#endif
+ uint64_t v0 = 0x736f6d6570736575ULL;
+ uint64_t v1 = 0x646f72616e646f6dULL;
+ uint64_t v2 = 0x6c7967656e657261ULL;
+ uint64_t v3 = 0x7465646279746573ULL;
+ uint64_t k0 = U8TO64_LE(k);
+ uint64_t k1 = U8TO64_LE(k + 8);
+ uint64_t m;
+ const uint8_t *end = in + inlen - (inlen % sizeof(uint64_t));
+ const int left = inlen & 7;
+ uint64_t b = ((uint64_t)inlen) << 56;
+ v3 ^= k1;
+ v2 ^= k0;
+ v1 ^= k1;
+ v0 ^= k0;
+
+ for (; in != end; in += 8) {
+ m = U8TO64_LE_NOCASE(in);
+ v3 ^= m;
+
+ SIPROUND;
+
+ v0 ^= m;
+ }
+
+ switch (left) {
+ case 7: b |= ((uint64_t)siptlw(in[6])) << 48; /* fall-thru */
+ case 6: b |= ((uint64_t)siptlw(in[5])) << 40; /* fall-thru */
+ case 5: b |= ((uint64_t)siptlw(in[4])) << 32; /* fall-thru */
+ case 4: b |= ((uint64_t)siptlw(in[3])) << 24; /* fall-thru */
+ case 3: b |= ((uint64_t)siptlw(in[2])) << 16; /* fall-thru */
+ case 2: b |= ((uint64_t)siptlw(in[1])) << 8; /* fall-thru */
+ case 1: b |= ((uint64_t)siptlw(in[0])); break;
+ case 0: break;
+ }
+
+ v3 ^= b;
+
+ SIPROUND;
+
+ v0 ^= b;
+ v2 ^= 0xff;
+
+ SIPROUND;
+ SIPROUND;
+
+ b = v0 ^ v1 ^ v2 ^ v3;
+#ifndef UNALIGNED_LE_CPU
+ U64TO8_LE(out, b);
+ return hash;
+#else
+ return b;
+#endif
+}
+
+
+/* --------------------------------- TEST ------------------------------------ */
+
+#ifdef SIPHASH_TEST
+
+const uint8_t vectors_sip64[64][8] = {
+ { 0x31, 0x0e, 0x0e, 0xdd, 0x47, 0xdb, 0x6f, 0x72, },
+ { 0xfd, 0x67, 0xdc, 0x93, 0xc5, 0x39, 0xf8, 0x74, },
+ { 0x5a, 0x4f, 0xa9, 0xd9, 0x09, 0x80, 0x6c, 0x0d, },
+ { 0x2d, 0x7e, 0xfb, 0xd7, 0x96, 0x66, 0x67, 0x85, },
+ { 0xb7, 0x87, 0x71, 0x27, 0xe0, 0x94, 0x27, 0xcf, },
+ { 0x8d, 0xa6, 0x99, 0xcd, 0x64, 0x55, 0x76, 0x18, },
+ { 0xce, 0xe3, 0xfe, 0x58, 0x6e, 0x46, 0xc9, 0xcb, },
+ { 0x37, 0xd1, 0x01, 0x8b, 0xf5, 0x00, 0x02, 0xab, },
+ { 0x62, 0x24, 0x93, 0x9a, 0x79, 0xf5, 0xf5, 0x93, },
+ { 0xb0, 0xe4, 0xa9, 0x0b, 0xdf, 0x82, 0x00, 0x9e, },
+ { 0xf3, 0xb9, 0xdd, 0x94, 0xc5, 0xbb, 0x5d, 0x7a, },
+ { 0xa7, 0xad, 0x6b, 0x22, 0x46, 0x2f, 0xb3, 0xf4, },
+ { 0xfb, 0xe5, 0x0e, 0x86, 0xbc, 0x8f, 0x1e, 0x75, },
+ { 0x90, 0x3d, 0x84, 0xc0, 0x27, 0x56, 0xea, 0x14, },
+ { 0xee, 0xf2, 0x7a, 0x8e, 0x90, 0xca, 0x23, 0xf7, },
+ { 0xe5, 0x45, 0xbe, 0x49, 0x61, 0xca, 0x29, 0xa1, },
+ { 0xdb, 0x9b, 0xc2, 0x57, 0x7f, 0xcc, 0x2a, 0x3f, },
+ { 0x94, 0x47, 0xbe, 0x2c, 0xf5, 0xe9, 0x9a, 0x69, },
+ { 0x9c, 0xd3, 0x8d, 0x96, 0xf0, 0xb3, 0xc1, 0x4b, },
+ { 0xbd, 0x61, 0x79, 0xa7, 0x1d, 0xc9, 0x6d, 0xbb, },
+ { 0x98, 0xee, 0xa2, 0x1a, 0xf2, 0x5c, 0xd6, 0xbe, },
+ { 0xc7, 0x67, 0x3b, 0x2e, 0xb0, 0xcb, 0xf2, 0xd0, },
+ { 0x88, 0x3e, 0xa3, 0xe3, 0x95, 0x67, 0x53, 0x93, },
+ { 0xc8, 0xce, 0x5c, 0xcd, 0x8c, 0x03, 0x0c, 0xa8, },
+ { 0x94, 0xaf, 0x49, 0xf6, 0xc6, 0x50, 0xad, 0xb8, },
+ { 0xea, 0xb8, 0x85, 0x8a, 0xde, 0x92, 0xe1, 0xbc, },
+ { 0xf3, 0x15, 0xbb, 0x5b, 0xb8, 0x35, 0xd8, 0x17, },
+ { 0xad, 0xcf, 0x6b, 0x07, 0x63, 0x61, 0x2e, 0x2f, },
+ { 0xa5, 0xc9, 0x1d, 0xa7, 0xac, 0xaa, 0x4d, 0xde, },
+ { 0x71, 0x65, 0x95, 0x87, 0x66, 0x50, 0xa2, 0xa6, },
+ { 0x28, 0xef, 0x49, 0x5c, 0x53, 0xa3, 0x87, 0xad, },
+ { 0x42, 0xc3, 0x41, 0xd8, 0xfa, 0x92, 0xd8, 0x32, },
+ { 0xce, 0x7c, 0xf2, 0x72, 0x2f, 0x51, 0x27, 0x71, },
+ { 0xe3, 0x78, 0x59, 0xf9, 0x46, 0x23, 0xf3, 0xa7, },
+ { 0x38, 0x12, 0x05, 0xbb, 0x1a, 0xb0, 0xe0, 0x12, },
+ { 0xae, 0x97, 0xa1, 0x0f, 0xd4, 0x34, 0xe0, 0x15, },
+ { 0xb4, 0xa3, 0x15, 0x08, 0xbe, 0xff, 0x4d, 0x31, },
+ { 0x81, 0x39, 0x62, 0x29, 0xf0, 0x90, 0x79, 0x02, },
+ { 0x4d, 0x0c, 0xf4, 0x9e, 0xe5, 0xd4, 0xdc, 0xca, },
+ { 0x5c, 0x73, 0x33, 0x6a, 0x76, 0xd8, 0xbf, 0x9a, },
+ { 0xd0, 0xa7, 0x04, 0x53, 0x6b, 0xa9, 0x3e, 0x0e, },
+ { 0x92, 0x59, 0x58, 0xfc, 0xd6, 0x42, 0x0c, 0xad, },
+ { 0xa9, 0x15, 0xc2, 0x9b, 0xc8, 0x06, 0x73, 0x18, },
+ { 0x95, 0x2b, 0x79, 0xf3, 0xbc, 0x0a, 0xa6, 0xd4, },
+ { 0xf2, 0x1d, 0xf2, 0xe4, 0x1d, 0x45, 0x35, 0xf9, },
+ { 0x87, 0x57, 0x75, 0x19, 0x04, 0x8f, 0x53, 0xa9, },
+ { 0x10, 0xa5, 0x6c, 0xf5, 0xdf, 0xcd, 0x9a, 0xdb, },
+ { 0xeb, 0x75, 0x09, 0x5c, 0xcd, 0x98, 0x6c, 0xd0, },
+ { 0x51, 0xa9, 0xcb, 0x9e, 0xcb, 0xa3, 0x12, 0xe6, },
+ { 0x96, 0xaf, 0xad, 0xfc, 0x2c, 0xe6, 0x66, 0xc7, },
+ { 0x72, 0xfe, 0x52, 0x97, 0x5a, 0x43, 0x64, 0xee, },
+ { 0x5a, 0x16, 0x45, 0xb2, 0x76, 0xd5, 0x92, 0xa1, },
+ { 0xb2, 0x74, 0xcb, 0x8e, 0xbf, 0x87, 0x87, 0x0a, },
+ { 0x6f, 0x9b, 0xb4, 0x20, 0x3d, 0xe7, 0xb3, 0x81, },
+ { 0xea, 0xec, 0xb2, 0xa3, 0x0b, 0x22, 0xa8, 0x7f, },
+ { 0x99, 0x24, 0xa4, 0x3c, 0xc1, 0x31, 0x57, 0x24, },
+ { 0xbd, 0x83, 0x8d, 0x3a, 0xaf, 0xbf, 0x8d, 0xb7, },
+ { 0x0b, 0x1a, 0x2a, 0x32, 0x65, 0xd5, 0x1a, 0xea, },
+ { 0x13, 0x50, 0x79, 0xa3, 0x23, 0x1c, 0xe6, 0x60, },
+ { 0x93, 0x2b, 0x28, 0x46, 0xe4, 0xd7, 0x06, 0x66, },
+ { 0xe1, 0x91, 0x5f, 0x5c, 0xb1, 0xec, 0xa4, 0x6c, },
+ { 0xf3, 0x25, 0x96, 0x5c, 0xa1, 0x6d, 0x62, 0x9f, },
+ { 0x57, 0x5f, 0xf2, 0x8e, 0x60, 0x38, 0x1b, 0xe5, },
+ { 0x72, 0x45, 0x06, 0xeb, 0x4c, 0x32, 0x8a, 0x95, },
+};
+
+
+/* Test siphash using a test vector. Returns 0 if the function passed
+ * all the tests, otherwise 1 is returned.
+ *
+ * IMPORTANT: The test vector is for SipHash 2-4. Before running
+ * the test revert back the siphash() function to 2-4 rounds since
+ * now it uses 1-2 rounds. */
+int siphash_test(void) {
+ uint8_t in[64], k[16];
+ int i;
+ int fails = 0;
+
+ for (i = 0; i < 16; ++i)
+ k[i] = i;
+
+ for (i = 0; i < 64; ++i) {
+ in[i] = i;
+ uint64_t hash = siphash(in, i, k);
+ const uint8_t *v = NULL;
+ v = (uint8_t *)vectors_sip64;
+ if (memcmp(&hash, v + (i * 8), 8)) {
+ /* printf("fail for %d bytes\n", i); */
+ fails++;
+ }
+ }
+
+ /* Run a few basic tests with the case insensitive version. */
+ uint64_t h1, h2;
+ h1 = siphash((uint8_t*)"hello world",11,(uint8_t*)"1234567812345678");
+ h2 = siphash_nocase((uint8_t*)"hello world",11,(uint8_t*)"1234567812345678");
+ if (h1 != h2) fails++;
+
+ h1 = siphash((uint8_t*)"hello world",11,(uint8_t*)"1234567812345678");
+ h2 = siphash_nocase((uint8_t*)"HELLO world",11,(uint8_t*)"1234567812345678");
+ if (h1 != h2) fails++;
+
+ h1 = siphash((uint8_t*)"HELLO world",11,(uint8_t*)"1234567812345678");
+ h2 = siphash_nocase((uint8_t*)"HELLO world",11,(uint8_t*)"1234567812345678");
+ if (h1 == h2) fails++;
+
+ if (!fails) return 0;
+ return 1;
+}
+
+int main(void) {
+ if (siphash_test() == 0) {
+ printf("SipHash test: OK\n");
+ return 0;
+ } else {
+ printf("SipHash test: FAILED\n");
+ return 1;
+ }
+}
+
+#endif
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