package tz import ( "hash" "github.com/nspcc-dev/tzhash/gf127" ) type digest2 struct { x [2]gf127.GF127x2 } var _ hash.Hash = (*digest2)(nil) func (d *digest2) Write(data []byte) (n int, err error) { n = len(data) for _, b := range data { mulBitRightx2(&d.x[0], &d.x[1], &minmax[(b>>7)&1]) mulBitRightx2(&d.x[0], &d.x[1], &minmax[(b>>6)&1]) mulBitRightx2(&d.x[0], &d.x[1], &minmax[(b>>5)&1]) mulBitRightx2(&d.x[0], &d.x[1], &minmax[(b>>4)&1]) mulBitRightx2(&d.x[0], &d.x[1], &minmax[(b>>3)&1]) mulBitRightx2(&d.x[0], &d.x[1], &minmax[(b>>2)&1]) mulBitRightx2(&d.x[0], &d.x[1], &minmax[(b>>1)&1]) mulBitRightx2(&d.x[0], &d.x[1], &minmax[(b>>0)&1]) } return } func (d *digest2) Sum(in []byte) []byte { // Make a copy of d so that caller can keep writing and summing. d0 := *d h := d0.checkSum() return append(in, h[:]...) } func (d *digest2) Reset() { d.x[0] = gf127.GF127x2{1, 0, 0, 0} d.x[1] = gf127.GF127x2{0, 0, 1, 0} } func (d *digest2) Size() int { return hashSize } func (d *digest2) BlockSize() int { return hashBlockSize } func (d *digest2) checkSum() (b [hashSize]byte) { // Matrix is stored transposed, // but we need to use order consistent with digest. h := d.x[0].ByteArray() copy(b[:], h[:16]) copy(b[32:], h[16:]) h = d.x[1].ByteArray() copy(b[16:], h[:16]) copy(b[48:], h[16:]) return } func mulBitRightx2(c00c10 *gf127.GF127x2, c01c11 *gf127.GF127x2, e *gf127.GF127)