mirror of
https://github.com/superseriousbusiness/gotosocial.git
synced 2024-11-01 06:50:00 +00:00
286 lines
6.1 KiB
Go
286 lines
6.1 KiB
Go
package blake3
|
|
|
|
import (
|
|
"math/bits"
|
|
"unsafe"
|
|
|
|
"github.com/zeebo/blake3/internal/alg"
|
|
"github.com/zeebo/blake3/internal/consts"
|
|
"github.com/zeebo/blake3/internal/utils"
|
|
)
|
|
|
|
//
|
|
// hasher contains state for a blake3 hash
|
|
//
|
|
|
|
type hasher struct {
|
|
len uint64
|
|
chunks uint64
|
|
flags uint32
|
|
key [8]uint32
|
|
stack cvstack
|
|
buf [8192]byte
|
|
}
|
|
|
|
func (a *hasher) reset() {
|
|
a.len = 0
|
|
a.chunks = 0
|
|
a.stack.occ = 0
|
|
a.stack.lvls = [8]uint8{}
|
|
a.stack.bufn = 0
|
|
}
|
|
|
|
func (a *hasher) update(buf []byte) {
|
|
// relies on the first two words of a string being the same as a slice
|
|
a.updateString(*(*string)(unsafe.Pointer(&buf)))
|
|
}
|
|
|
|
func (a *hasher) updateString(buf string) {
|
|
var input *[8192]byte
|
|
|
|
for len(buf) > 0 {
|
|
if a.len == 0 && len(buf) > 8192 {
|
|
// relies on the data pointer being the first word in the string header
|
|
input = (*[8192]byte)(*(*unsafe.Pointer)(unsafe.Pointer(&buf)))
|
|
buf = buf[8192:]
|
|
} else if a.len < 8192 {
|
|
n := copy(a.buf[a.len:], buf)
|
|
a.len += uint64(n)
|
|
buf = buf[n:]
|
|
continue
|
|
} else {
|
|
input = &a.buf
|
|
}
|
|
|
|
a.consume(input)
|
|
a.len = 0
|
|
a.chunks += 8
|
|
}
|
|
}
|
|
|
|
func (a *hasher) consume(input *[8192]byte) {
|
|
var out chainVector
|
|
var chain [8]uint32
|
|
alg.HashF(input, 8192, a.chunks, a.flags, &a.key, &out, &chain)
|
|
a.stack.pushN(0, &out, 8, a.flags, &a.key)
|
|
}
|
|
|
|
func (a *hasher) finalize(p []byte) {
|
|
var d Digest
|
|
a.finalizeDigest(&d)
|
|
_, _ = d.Read(p)
|
|
}
|
|
|
|
func (a *hasher) finalizeDigest(d *Digest) {
|
|
if a.chunks == 0 && a.len <= consts.ChunkLen {
|
|
compressAll(d, a.buf[:a.len], a.flags, a.key)
|
|
return
|
|
}
|
|
|
|
d.chain = a.key
|
|
d.flags = a.flags | consts.Flag_ChunkEnd
|
|
|
|
if a.len > 64 {
|
|
var buf chainVector
|
|
alg.HashF(&a.buf, a.len, a.chunks, a.flags, &a.key, &buf, &d.chain)
|
|
|
|
if a.len > consts.ChunkLen {
|
|
complete := (a.len - 1) / consts.ChunkLen
|
|
a.stack.pushN(0, &buf, int(complete), a.flags, &a.key)
|
|
a.chunks += complete
|
|
a.len = uint64(copy(a.buf[:], a.buf[complete*consts.ChunkLen:a.len]))
|
|
}
|
|
}
|
|
|
|
if a.len <= 64 {
|
|
d.flags |= consts.Flag_ChunkStart
|
|
}
|
|
|
|
d.counter = a.chunks
|
|
d.blen = uint32(a.len) % 64
|
|
|
|
base := a.len / 64 * 64
|
|
if a.len > 0 && d.blen == 0 {
|
|
d.blen = 64
|
|
base -= 64
|
|
}
|
|
|
|
if consts.IsLittleEndian {
|
|
copy((*[64]byte)(unsafe.Pointer(&d.block[0]))[:], a.buf[base:a.len])
|
|
} else {
|
|
var tmp [64]byte
|
|
copy(tmp[:], a.buf[base:a.len])
|
|
utils.BytesToWords(&tmp, &d.block)
|
|
}
|
|
|
|
for a.stack.bufn > 0 {
|
|
a.stack.flush(a.flags, &a.key)
|
|
}
|
|
|
|
var tmp [16]uint32
|
|
for occ := a.stack.occ; occ != 0; occ &= occ - 1 {
|
|
col := uint(bits.TrailingZeros64(occ)) % 64
|
|
|
|
alg.Compress(&d.chain, &d.block, d.counter, d.blen, d.flags, &tmp)
|
|
|
|
*(*[8]uint32)(unsafe.Pointer(&d.block[0])) = a.stack.stack[col]
|
|
*(*[8]uint32)(unsafe.Pointer(&d.block[8])) = *(*[8]uint32)(unsafe.Pointer(&tmp[0]))
|
|
|
|
if occ == a.stack.occ {
|
|
d.chain = a.key
|
|
d.counter = 0
|
|
d.blen = consts.BlockLen
|
|
d.flags = a.flags | consts.Flag_Parent
|
|
}
|
|
}
|
|
|
|
d.flags |= consts.Flag_Root
|
|
}
|
|
|
|
//
|
|
// chain value stack
|
|
//
|
|
|
|
type chainVector = [64]uint32
|
|
|
|
type cvstack struct {
|
|
occ uint64 // which levels in stack are occupied
|
|
lvls [8]uint8 // what level the buf input was in
|
|
bufn int // how many pairs are loaded into buf
|
|
buf [2]chainVector
|
|
stack [64][8]uint32
|
|
}
|
|
|
|
func (a *cvstack) pushN(l uint8, cv *chainVector, n int, flags uint32, key *[8]uint32) {
|
|
for i := 0; i < n; i++ {
|
|
a.pushL(l, cv, i)
|
|
for a.bufn == 8 {
|
|
a.flush(flags, key)
|
|
}
|
|
}
|
|
}
|
|
|
|
func (a *cvstack) pushL(l uint8, cv *chainVector, n int) {
|
|
bit := uint64(1) << (l & 63)
|
|
if a.occ&bit == 0 {
|
|
readChain(cv, n, &a.stack[l&63])
|
|
a.occ ^= bit
|
|
return
|
|
}
|
|
|
|
a.lvls[a.bufn&7] = l
|
|
writeChain(&a.stack[l&63], &a.buf[0], a.bufn)
|
|
copyChain(cv, n, &a.buf[1], a.bufn)
|
|
a.bufn++
|
|
a.occ ^= bit
|
|
}
|
|
|
|
func (a *cvstack) flush(flags uint32, key *[8]uint32) {
|
|
var out chainVector
|
|
alg.HashP(&a.buf[0], &a.buf[1], flags|consts.Flag_Parent, key, &out, a.bufn)
|
|
|
|
bufn, lvls := a.bufn, a.lvls
|
|
a.bufn, a.lvls = 0, [8]uint8{}
|
|
|
|
for i := 0; i < bufn; i++ {
|
|
a.pushL(lvls[i]+1, &out, i)
|
|
}
|
|
}
|
|
|
|
//
|
|
// helpers to deal with reading/writing transposed values
|
|
//
|
|
|
|
func copyChain(in *chainVector, icol int, out *chainVector, ocol int) {
|
|
type u = uintptr
|
|
type p = unsafe.Pointer
|
|
type a = *uint32
|
|
|
|
i := p(u(p(in)) + u(icol*4))
|
|
o := p(u(p(out)) + u(ocol*4))
|
|
|
|
*a(p(u(o) + 0*32)) = *a(p(u(i) + 0*32))
|
|
*a(p(u(o) + 1*32)) = *a(p(u(i) + 1*32))
|
|
*a(p(u(o) + 2*32)) = *a(p(u(i) + 2*32))
|
|
*a(p(u(o) + 3*32)) = *a(p(u(i) + 3*32))
|
|
*a(p(u(o) + 4*32)) = *a(p(u(i) + 4*32))
|
|
*a(p(u(o) + 5*32)) = *a(p(u(i) + 5*32))
|
|
*a(p(u(o) + 6*32)) = *a(p(u(i) + 6*32))
|
|
*a(p(u(o) + 7*32)) = *a(p(u(i) + 7*32))
|
|
}
|
|
|
|
func readChain(in *chainVector, col int, out *[8]uint32) {
|
|
type u = uintptr
|
|
type p = unsafe.Pointer
|
|
type a = *uint32
|
|
|
|
i := p(u(p(in)) + u(col*4))
|
|
|
|
out[0] = *a(p(u(i) + 0*32))
|
|
out[1] = *a(p(u(i) + 1*32))
|
|
out[2] = *a(p(u(i) + 2*32))
|
|
out[3] = *a(p(u(i) + 3*32))
|
|
out[4] = *a(p(u(i) + 4*32))
|
|
out[5] = *a(p(u(i) + 5*32))
|
|
out[6] = *a(p(u(i) + 6*32))
|
|
out[7] = *a(p(u(i) + 7*32))
|
|
}
|
|
|
|
func writeChain(in *[8]uint32, out *chainVector, col int) {
|
|
type u = uintptr
|
|
type p = unsafe.Pointer
|
|
type a = *uint32
|
|
|
|
o := p(u(p(out)) + u(col*4))
|
|
|
|
*a(p(u(o) + 0*32)) = in[0]
|
|
*a(p(u(o) + 1*32)) = in[1]
|
|
*a(p(u(o) + 2*32)) = in[2]
|
|
*a(p(u(o) + 3*32)) = in[3]
|
|
*a(p(u(o) + 4*32)) = in[4]
|
|
*a(p(u(o) + 5*32)) = in[5]
|
|
*a(p(u(o) + 6*32)) = in[6]
|
|
*a(p(u(o) + 7*32)) = in[7]
|
|
}
|
|
|
|
//
|
|
// compress <= chunkLen bytes in one shot
|
|
//
|
|
|
|
func compressAll(d *Digest, in []byte, flags uint32, key [8]uint32) {
|
|
var compressed [16]uint32
|
|
|
|
d.chain = key
|
|
d.flags = flags | consts.Flag_ChunkStart
|
|
|
|
for len(in) > 64 {
|
|
buf := (*[64]byte)(unsafe.Pointer(&in[0]))
|
|
|
|
var block *[16]uint32
|
|
if consts.IsLittleEndian {
|
|
block = (*[16]uint32)(unsafe.Pointer(buf))
|
|
} else {
|
|
block = &d.block
|
|
utils.BytesToWords(buf, block)
|
|
}
|
|
|
|
alg.Compress(&d.chain, block, 0, consts.BlockLen, d.flags, &compressed)
|
|
|
|
d.chain = *(*[8]uint32)(unsafe.Pointer(&compressed[0]))
|
|
d.flags &^= consts.Flag_ChunkStart
|
|
|
|
in = in[64:]
|
|
}
|
|
|
|
if consts.IsLittleEndian {
|
|
copy((*[64]byte)(unsafe.Pointer(&d.block[0]))[:], in)
|
|
} else {
|
|
var tmp [64]byte
|
|
copy(tmp[:], in)
|
|
utils.BytesToWords(&tmp, &d.block)
|
|
}
|
|
|
|
d.blen = uint32(len(in))
|
|
d.flags |= consts.Flag_ChunkEnd | consts.Flag_Root
|
|
}
|