src/shared/siphash24.c

   1 /*
   2    SipHash reference C implementation
   3
   4    Written in 2012 by
   5    Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com>
   6    Daniel J. Bernstein <djb@cr.yp.to>
   7
   8    To the extent possible under law, the author(s) have dedicated all copyright
   9    and related and neighboring rights to this software to the public domain
  10    worldwide. This software is distributed without any warranty.
  11
  12    You should have received a copy of the CC0 Public Domain Dedication along with
  13    this software. If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
  14
  15    (Minimal changes made by Lennart Poettering, to make clean for inclusion in systemd)
  16 */
  17 #include <stdint.h>
  18 #include <stdio.h>
  19 #include <string.h>
  20
  21 #include "siphash24.h"
  22
  23 typedef uint64_t u64;
  24 typedef uint32_t u32;
  25 typedef uint8_t u8;
  26
  27 #define ROTL(x,b) (u64)( ((x) << (b)) | ( (x) >> (64 - (b))) )
  28
  29 #define U32TO8_LE(p, v)         \
  30     (p)[0] = (u8)((v)      ); (p)[1] = (u8)((v) >>  8); \
  31     (p)[2] = (u8)((v) >> 16); (p)[3] = (u8)((v) >> 24);
  32
  33 #define U64TO8_LE(p, v)         \
  34   U32TO8_LE((p),     (u32)((v)      ));   \
  35   U32TO8_LE((p) + 4, (u32)((v) >> 32));
  36
  37 #define U8TO64_LE(p) \
  38   (((u64)((p)[0])      ) | \
  39    ((u64)((p)[1]) <<  8) | \
  40    ((u64)((p)[2]) << 16) | \
  41    ((u64)((p)[3]) << 24) | \
  42    ((u64)((p)[4]) << 32) | \
  43    ((u64)((p)[5]) << 40) | \
  44    ((u64)((p)[6]) << 48) | \
  45    ((u64)((p)[7]) << 56))
  46
  47 #define SIPROUND            \
  48   do {              \
  49     v0 += v1; v1=ROTL(v1,13); v1 ^= v0; v0=ROTL(v0,32); \
  50     v2 += v3; v3=ROTL(v3,16); v3 ^= v2;     \
  51     v0 += v3; v3=ROTL(v3,21); v3 ^= v0;     \
  52     v2 += v1; v1=ROTL(v1,17); v1 ^= v2; v2=ROTL(v2,32); \
  53   } while(0)
  54
  55 /* SipHash-2-4 */
  56 void siphash24(uint8_t out[8], const void *_in, size_t inlen, const uint8_t k[16])
  57 {
  58   /* "somepseudorandomlygeneratedbytes" */
  59   u64 v0 = 0x736f6d6570736575ULL;
  60   u64 v1 = 0x646f72616e646f6dULL;
  61   u64 v2 = 0x6c7967656e657261ULL;
  62   u64 v3 = 0x7465646279746573ULL;
  63   u64 b;
  64   u64 k0 = U8TO64_LE( k );
  65   u64 k1 = U8TO64_LE( k + 8 );
  66   u64 m;
  67   const u8 *in = _in;
  68   const u8 *end = in + inlen - ( inlen % sizeof( u64 ) );
  69   const int left = inlen & 7;
  70   b = ( ( u64 )inlen ) << 56;
  71   v3 ^= k1;
  72   v2 ^= k0;
  73   v1 ^= k1;
  74   v0 ^= k0;
  75
  76   for ( ; in != end; in += 8 )
  77   {
  78     m = U8TO64_LE( in );
  79 #ifdef DEBUG
  80     printf( "(%3d) v0 %08x %08x\n", ( int )inlen, ( u32 )( v0 >> 32 ), ( u32 )v0 );
  81     printf( "(%3d) v1 %08x %08x\n", ( int )inlen, ( u32 )( v1 >> 32 ), ( u32 )v1 );
  82     printf( "(%3d) v2 %08x %08x\n", ( int )inlen, ( u32 )( v2 >> 32 ), ( u32 )v2 );
  83     printf( "(%3d) v3 %08x %08x\n", ( int )inlen, ( u32 )( v3 >> 32 ), ( u32 )v3 );
  84     printf( "(%3d) compress %08x %08x\n", ( int )inlen, ( u32 )( m >> 32 ), ( u32 )m );
  85 #endif
  86     v3 ^= m;
  87     SIPROUND;
  88     SIPROUND;
  89     v0 ^= m;
  90   }
  91
  92   switch( left )
  93   {
  94   case 7: b |= ( ( u64 )in[ 6] )  << 48;
  95
  96   case 6: b |= ( ( u64 )in[ 5] )  << 40;
  97
  98   case 5: b |= ( ( u64 )in[ 4] )  << 32;
  99
 100   case 4: b |= ( ( u64 )in[ 3] )  << 24;
 101
 102   case 3: b |= ( ( u64 )in[ 2] )  << 16;
 103
 104   case 2: b |= ( ( u64 )in[ 1] )  <<  8;
 105
 106   case 1: b |= ( ( u64 )in[ 0] ); break;
 107
 108   case 0: break;
 109   }
 110
 111 #ifdef DEBUG
 112   printf( "(%3d) v0 %08x %08x\n", ( int )inlen, ( u32 )( v0 >> 32 ), ( u32 )v0 );
 113   printf( "(%3d) v1 %08x %08x\n", ( int )inlen, ( u32 )( v1 >> 32 ), ( u32 )v1 );
 114   printf( "(%3d) v2 %08x %08x\n", ( int )inlen, ( u32 )( v2 >> 32 ), ( u32 )v2 );
 115   printf( "(%3d) v3 %08x %08x\n", ( int )inlen, ( u32 )( v3 >> 32 ), ( u32 )v3 );
 116   printf( "(%3d) padding   %08x %08x\n", ( int )inlen, ( u32 )( b >> 32 ), ( u32 )b );
 117 #endif
 118   v3 ^= b;
 119   SIPROUND;
 120   SIPROUND;
 121   v0 ^= b;
 122 #ifdef DEBUG
 123   printf( "(%3d) v0 %08x %08x\n", ( int )inlen, ( u32 )( v0 >> 32 ), ( u32 )v0 );
 124   printf( "(%3d) v1 %08x %08x\n", ( int )inlen, ( u32 )( v1 >> 32 ), ( u32 )v1 );
 125   printf( "(%3d) v2 %08x %08x\n", ( int )inlen, ( u32 )( v2 >> 32 ), ( u32 )v2 );
 126   printf( "(%3d) v3 %08x %08x\n", ( int )inlen, ( u32 )( v3 >> 32 ), ( u32 )v3 );
 127 #endif
 128   v2 ^= 0xff;
 129   SIPROUND;
 130   SIPROUND;
 131   SIPROUND;
 132   SIPROUND;
 133   b = v0 ^ v1 ^ v2  ^ v3;
 134   U64TO8_LE( out, b );
 135 }