diff options
Diffstat (limited to 'lib/siphash.c')
| -rw-r--r-- | lib/siphash.c | 321 |
1 files changed, 320 insertions, 1 deletions
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 <linux/siphash.h> @@ -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 |