func (sc *streamCipher) Partial(dst, src, key []byte) {
n := ints.Max(len(dst), len(src), len(key)) // bytes to process
// create our Stream cipher if needed
if sc.s == nil {
if sc.k == nil {
sc.k = make([]byte, sc.hashLen)
}
sc.s = sc.newStream(sc.k[:sc.keyLen])
}
// squeeze cryptographic output
ndst := ints.Min(n, len(dst)) // # bytes to write to dst
nsrc := ints.Min(ndst, len(src)) // # src bytes available
sc.s.XORKeyStream(dst[:nsrc], src[:nsrc])
if n > nsrc {
buf := make([]byte, n-nsrc)
sc.s.XORKeyStream(buf, buf)
copy(dst[nsrc:], buf)
}
// absorb cryptographic input (which may overlap with dst)
if key != nil {
nkey := ints.Min(n, len(key)) // # key bytes available
sc.h.Write(key[:nkey])
if n > nkey {
buf := make([]byte, n-nkey)
sc.h.Write(buf)
}
}
}
func (sc *spongeCipher) Partial(dst, src, key []byte) {
sp := sc.sponge
rate := sc.rate
buf := sc.buf
pos := sc.pos
rem := ints.Max(len(dst), len(src), len(key)) // bytes to process
for rem > 0 {
if pos == rate { // process next block if needed
sp.Transform(buf, buf[:rate])
pos = 0
}
n := ints.Min(rem, rate-pos) // bytes to process in this block
// squeeze cryptographic output
ndst := ints.Min(n, len(dst)) // # bytes to write to dst
nsrc := ints.Min(ndst, len(src)) // # src bytes available
for i := 0; i < nsrc; i++ { // XOR-encrypt from src to dst
dst[i] = src[i] ^ buf[pos+i]
}
copy(dst[nsrc:ndst], buf[pos+nsrc:]) // "XOR" with 0 bytes
dst = dst[ndst:]
src = src[nsrc:]
// absorb cryptographic input (which may overlap with dst)
nkey := ints.Min(n, len(key)) // # key bytes available
copy(buf[pos:], key[:nkey])
for i := nkey; i < n; i++ { // missing key bytes implicitly 0
buf[pos+i] = 0
}
key = key[nkey:]
pos += n
rem -= n
}
sc.pos = pos
//println("Decrypted",more,"\n" + hex.Dump(osrc) + "->\n" + hex.Dump(odst))
}
