100 lines
2.0 KiB
Go
100 lines
2.0 KiB
Go
package keccak
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import "hash"
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const Size = 256 / 8
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const BlockSize = 1600/8 - Size*2
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func round(a *[25]uint64) { roundGo(a) }
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// digest implements hash.Hash
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type digest struct {
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a [25]uint64 // a[y][x][z]
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buf [200]byte
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dsbyte byte
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len int
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size int
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}
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func New256() hash.Hash { return &digest{size: 256 / 8, dsbyte: 0x06} }
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func New512() hash.Hash { return &digest{size: 512 / 8, dsbyte: 0x06} }
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func newKeccak256() hash.Hash { return &digest{size: 256 / 8, dsbyte: 0x01} }
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func newKeccak512() hash.Hash { return &digest{size: 512 / 8, dsbyte: 0x01} }
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func (d *digest) Size() int { return d.size }
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func (d *digest) BlockSize() int { return 200 - d.size*2 }
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func (d *digest) Reset() {
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//fmt.Println("resetting")
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d.a = [25]uint64{}
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d.buf = [200]byte{}
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d.len = 0
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}
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func (d *digest) Write(b []byte) (int, error) {
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written := len(b)
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bs := d.BlockSize()
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for len(b) > 0 {
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n := copy(d.buf[d.len:bs], b)
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d.len += n
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b = b[n:]
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if d.len == bs {
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d.flush()
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}
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}
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return written, nil
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}
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func (d *digest) flush() {
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//fmt.Printf("Flushing with %d bytes\n", d.len)
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b := d.buf[:d.len]
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for i := range d.a {
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if len(b) == 0 {
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break
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}
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d.a[i] ^= le64dec(b)
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b = b[8:]
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}
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keccakf(&d.a)
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d.len = 0
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}
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func keccakf(a *[25]uint64) {
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for i := 0; i < 24; i++ {
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round(a)
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a[0] ^= roundc[i]
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}
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}
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func (d *digest) clone() *digest {
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d0 := *d
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return &d0
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}
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func (d *digest) Sum(b []byte) []byte {
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d = d.clone()
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d.buf[d.len] = d.dsbyte
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bs := d.BlockSize()
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for i := d.len + 1; i < bs; i++ {
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d.buf[i] = 0
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}
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d.buf[bs-1] |= 0x80
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d.len = bs
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d.flush()
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for i := 0; i < d.size/8; i++ {
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b = le64enc(b, d.a[i])
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}
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return b
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}
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func le64dec(b []byte) uint64 {
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return uint64(b[0])<<0 | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56
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}
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func le64enc(b []byte, x uint64) []byte {
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return append(b, byte(x), byte(x>>8), byte(x>>16), byte(x>>24), byte(x>>32), byte(x>>40), byte(x>>48), byte(x>>56))
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}
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