siphash24: make siphash24_compress decomposable

This allows the input to siphash24_compress to be decomposed into
smaller chunks and the function to be called on each individual
chunk.
This commit is contained in:
Tom Gundersen 2015-10-03 22:21:44 +02:00
parent f2936011c5
commit 2c4cc3bdcd

View file

@ -79,12 +79,39 @@ static void siphash_init(struct siphash *state, const uint8_t k[16]) {
static void siphash24_compress(const void *_in, size_t inlen, struct siphash *state) {
u64 m;
const u8 *in = _in;
const u8 *end = in + inlen - ( inlen % sizeof( u64 ) );
const int left = inlen & 7;
const u8 *end = in + inlen;
int left = state->inlen & 7;
state->inlen = inlen;
/* update total length */
state->inlen += inlen;
for ( ; in != end; in += 8 )
/* if padding exists, fill it out */
if (left > 0) {
for ( ; in < end && left < 8; in ++, left ++ )
state->padding |= ( ( u64 )*in ) << (left * 8);
if (in == end && left < 8)
/* we did not have enough input to fill out the padding completely */
return;
#ifdef DEBUG
printf( "(%3d) v0 %08x %08x\n", ( int )state->inlen, ( u32 )( state->v0 >> 32 ), ( u32 )state->v0 );
printf( "(%3d) v1 %08x %08x\n", ( int )state->inlen, ( u32 )( state->v1 >> 32 ), ( u32 )state->v1 );
printf( "(%3d) v2 %08x %08x\n", ( int )state->inlen, ( u32 )( state->v2 >> 32 ), ( u32 )state->v2 );
printf( "(%3d) v3 %08x %08x\n", ( int )state->inlen, ( u32 )( state->v3 >> 32 ), ( u32 )state->v3 );
printf( "(%3d) compress padding %08x %08x\n", ( int )state->inlen, ( u32 )( state->padding >> 32 ), ( u32 )state->padding );
#endif
state->v3 ^= state->padding;
SIPROUND(state);
SIPROUND(state);
state->v0 ^= state->padding;
state->padding = 0;
}
end -= ( state->inlen % sizeof (u64) );
for ( ; in < end; in += 8 )
{
m = U8TO64_LE( in );
#ifdef DEBUG
@ -100,6 +127,8 @@ static void siphash24_compress(const void *_in, size_t inlen, struct siphash *st
state->v0 ^= m;
}
left = state->inlen & 7;
switch( left )
{
case 7: state->padding |= ( ( u64 )in[ 6] ) << 48;