From 61311e4954c596ad17a59c52b05dd8a6a4f81909 Mon Sep 17 00:00:00 2001 From: Tom Gundersen Date: Sat, 3 Oct 2015 20:09:43 +0200 Subject: siphash24: introduce state struct Encapsulate the four state variables in a struct so we can more easily pass them around. --- src/basic/siphash24.c | 96 +++++++++++++++++++++++++++++---------------------- 1 file changed, 54 insertions(+), 42 deletions(-) (limited to 'src') diff --git a/src/basic/siphash24.c b/src/basic/siphash24.c index f68bd283a..66e5a6105 100644 --- a/src/basic/siphash24.c +++ b/src/basic/siphash24.c @@ -44,49 +44,61 @@ typedef uint8_t u8; ((u64)((p)[6]) << 48) | \ ((u64)((p)[7]) << 56)) -#define SIPROUND \ +#define SIPROUND(state) \ 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); \ + (state)->v0 += (state)->v1; (state)->v1=ROTL((state)->v1,13); (state)->v1 ^= (state)->v0; (state)->v0=ROTL((state)->v0,32); \ + (state)->v2 += (state)->v3; (state)->v3=ROTL((state)->v3,16); (state)->v3 ^= (state)->v2; \ + (state)->v0 += (state)->v3; (state)->v3=ROTL((state)->v3,21); (state)->v3 ^= (state)->v0; \ + (state)->v2 += (state)->v1; (state)->v1=ROTL((state)->v1,17); (state)->v1 ^= (state)->v2; (state)->v2=ROTL((state)->v2,32); \ } while(0) +struct siphash { + u64 v0; + u64 v1; + u64 v2; + u64 v3; +}; + +static void siphash_init(struct siphash *state, const uint8_t k[16]) { + u64 k0, k1; + + k0 = U8TO64_LE( k ); + k1 = U8TO64_LE( k + 8 ); + + /* "somepseudorandomlygeneratedbytes" */ + state->v0 = 0x736f6d6570736575ULL ^ k0; + state->v1 = 0x646f72616e646f6dULL ^ k1; + state->v2 = 0x6c7967656e657261ULL ^ k0; + state->v3 = 0x7465646279746573ULL ^ k1; +} + /* SipHash-2-4 */ void siphash24(uint8_t out[8], const void *_in, size_t inlen, const uint8_t k[16]) { - /* "somepseudorandomlygeneratedbytes" */ - u64 v0 = 0x736f6d6570736575ULL; - u64 v1 = 0x646f72616e646f6dULL; - u64 v2 = 0x6c7967656e657261ULL; - u64 v3 = 0x7465646279746573ULL; + struct siphash state; u64 b; - u64 k0 = U8TO64_LE( k ); - u64 k1 = U8TO64_LE( k + 8 ); u64 m; const u8 *in = _in; const u8 *end = in + inlen - ( inlen % sizeof( u64 ) ); const int left = inlen & 7; b = ( ( u64 )inlen ) << 56; - v3 ^= k1; - v2 ^= k0; - v1 ^= k1; - v0 ^= k0; + + siphash_init(&state, k); for ( ; in != end; in += 8 ) { m = U8TO64_LE( in ); #ifdef DEBUG - printf( "(%3d) v0 %08x %08x\n", ( int )inlen, ( u32 )( v0 >> 32 ), ( u32 )v0 ); - printf( "(%3d) v1 %08x %08x\n", ( int )inlen, ( u32 )( v1 >> 32 ), ( u32 )v1 ); - printf( "(%3d) v2 %08x %08x\n", ( int )inlen, ( u32 )( v2 >> 32 ), ( u32 )v2 ); - printf( "(%3d) v3 %08x %08x\n", ( int )inlen, ( u32 )( v3 >> 32 ), ( u32 )v3 ); + printf( "(%3d) v0 %08x %08x\n", ( int )inlen, ( u32 )( state.v0 >> 32 ), ( u32 )state.v0 ); + printf( "(%3d) v1 %08x %08x\n", ( int )inlen, ( u32 )( state.v1 >> 32 ), ( u32 )state.v1 ); + printf( "(%3d) v2 %08x %08x\n", ( int )inlen, ( u32 )( state.v2 >> 32 ), ( u32 )state.v2 ); + printf( "(%3d) v3 %08x %08x\n", ( int )inlen, ( u32 )( state.v3 >> 32 ), ( u32 )state.v3 ); printf( "(%3d) compress %08x %08x\n", ( int )inlen, ( u32 )( m >> 32 ), ( u32 )m ); #endif - v3 ^= m; - SIPROUND; - SIPROUND; - v0 ^= m; + state.v3 ^= m; + SIPROUND(&state); + SIPROUND(&state); + state.v0 ^= m; } switch( left ) @@ -109,27 +121,27 @@ void siphash24(uint8_t out[8], const void *_in, size_t inlen, const uint8_t k[16 } #ifdef DEBUG - printf( "(%3d) v0 %08x %08x\n", ( int )inlen, ( u32 )( v0 >> 32 ), ( u32 )v0 ); - printf( "(%3d) v1 %08x %08x\n", ( int )inlen, ( u32 )( v1 >> 32 ), ( u32 )v1 ); - printf( "(%3d) v2 %08x %08x\n", ( int )inlen, ( u32 )( v2 >> 32 ), ( u32 )v2 ); - printf( "(%3d) v3 %08x %08x\n", ( int )inlen, ( u32 )( v3 >> 32 ), ( u32 )v3 ); + printf( "(%3d) v0 %08x %08x\n", ( int )inlen, ( u32 )( state.v0 >> 32 ), ( u32 )state.v0 ); + printf( "(%3d) v1 %08x %08x\n", ( int )inlen, ( u32 )( state.v1 >> 32 ), ( u32 )state.v1 ); + printf( "(%3d) v2 %08x %08x\n", ( int )inlen, ( u32 )( state.v2 >> 32 ), ( u32 )state.v2 ); + printf( "(%3d) v3 %08x %08x\n", ( int )inlen, ( u32 )( state.v3 >> 32 ), ( u32 )state.v3 ); printf( "(%3d) padding %08x %08x\n", ( int )inlen, ( u32 )( b >> 32 ), ( u32 )b ); #endif - v3 ^= b; - SIPROUND; - SIPROUND; - v0 ^= b; + state.v3 ^= b; + SIPROUND(&state); + SIPROUND(&state); + state.v0 ^= b; #ifdef DEBUG - printf( "(%3d) v0 %08x %08x\n", ( int )inlen, ( u32 )( v0 >> 32 ), ( u32 )v0 ); - printf( "(%3d) v1 %08x %08x\n", ( int )inlen, ( u32 )( v1 >> 32 ), ( u32 )v1 ); - printf( "(%3d) v2 %08x %08x\n", ( int )inlen, ( u32 )( v2 >> 32 ), ( u32 )v2 ); - printf( "(%3d) v3 %08x %08x\n", ( int )inlen, ( u32 )( v3 >> 32 ), ( u32 )v3 ); + printf( "(%3d) v0 %08x %08x\n", ( int )inlen, ( u32 )( state.v0 >> 32 ), ( u32 )state.v0 ); + printf( "(%3d) v1 %08x %08x\n", ( int )inlen, ( u32 )( state.v1 >> 32 ), ( u32 )state.v1 ); + printf( "(%3d) v2 %08x %08x\n", ( int )inlen, ( u32 )( state.v2 >> 32 ), ( u32 )state.v2 ); + printf( "(%3d) v3 %08x %08x\n", ( int )inlen, ( u32 )( state.v3 >> 32 ), ( u32 )state.v3 ); #endif - v2 ^= 0xff; - SIPROUND; - SIPROUND; - SIPROUND; - SIPROUND; - b = v0 ^ v1 ^ v2 ^ v3; + state.v2 ^= 0xff; + SIPROUND(&state); + SIPROUND(&state); + SIPROUND(&state); + SIPROUND(&state); + b = state.v0 ^ state.v1 ^ state.v2 ^ state.v3; U64TO8_LE( out, b ); } -- cgit v1.2.3