| /* 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/module.h> |
| #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->key[1]; \ |
| v2 ^= key->key[0]; \ |
| v1 ^= key->key[1]; \ |
| v0 ^= key->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); |