minio/pkg/crypto/sha512/sha512_linux.go
2016-02-15 13:50:33 -08:00

167 lines
3.2 KiB
Go

// +build linux,amd64,cgo
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file of
// Golang project:
// https://github.com/golang/go/blob/master/LICENSE
// Using this part of Minio codebase under the license
// Apache License Version 2.0 with modifications
// Package sha512 implements the SHA512 hash algorithms as defined
// in FIPS 180-2.
package sha512
import (
"hash"
"github.com/klauspost/cpuid"
)
// Size - The size of a SHA512 checksum in bytes.
const Size = 64
// BlockSize - The blocksize of SHA512 in bytes.
const BlockSize = 128
const (
chunk = 128
init0 = 0x6a09e667f3bcc908
init1 = 0xbb67ae8584caa73b
init2 = 0x3c6ef372fe94f82b
init3 = 0xa54ff53a5f1d36f1
init4 = 0x510e527fade682d1
init5 = 0x9b05688c2b3e6c1f
init6 = 0x1f83d9abfb41bd6b
init7 = 0x5be0cd19137e2179
)
// digest represents the partial evaluation of a checksum.
type digest struct {
h [8]uint64
x [chunk]byte
nx int
len uint64
}
func block(dig *digest, p []byte) {
switch true {
case cpuid.CPU.AVX2():
blockAVX2(dig, p)
case cpuid.CPU.AVX():
blockAVX(dig, p)
case cpuid.CPU.SSSE3():
blockSSE(dig, p)
default:
blockGeneric(dig, p)
}
}
// Reset digest to its default value
func (d *digest) Reset() {
d.h[0] = init0
d.h[1] = init1
d.h[2] = init2
d.h[3] = init3
d.h[4] = init4
d.h[5] = init5
d.h[6] = init6
d.h[7] = init7
d.nx = 0
d.len = 0
}
// New returns a new hash.Hash computing the SHA512 checksum.
func New() hash.Hash {
d := new(digest)
d.Reset()
return d
}
// Sum512 - single caller sha512 helper
func Sum512(data []byte) [Size]byte {
var d digest
d.Reset()
d.Write(data)
return d.checkSum()
}
// Return output array byte size
func (d *digest) Size() int { return Size }
// Return blockSize
func (d *digest) BlockSize() int { return BlockSize }
// Write blocks
func (d *digest) Write(p []byte) (nn int, err error) {
nn = len(p)
d.len += uint64(nn)
if d.nx > 0 {
n := copy(d.x[d.nx:], p)
d.nx += n
if d.nx == chunk {
block(d, d.x[:])
d.nx = 0
}
p = p[n:]
}
if len(p) >= chunk {
n := len(p) &^ (chunk - 1)
block(d, p[:n])
p = p[n:]
}
if len(p) > 0 {
d.nx = copy(d.x[:], p)
}
return
}
// Calculate sha512
func (d *digest) Sum(in []byte) []byte {
// Make a copy of d0 so that caller can keep writing and summing.
d0 := *d
hash := d0.checkSum()
return append(in, hash[:]...)
}
// internal checksum calculation, returns [Size]byte
func (d *digest) checkSum() [Size]byte {
// Padding. Add a 1 bit and 0 bits until 112 bytes mod 128.
len := d.len
var tmp [128]byte
tmp[0] = 0x80
if len%128 < 112 {
d.Write(tmp[0 : 112-len%128])
} else {
d.Write(tmp[0 : 128+112-len%128])
}
// Length in bits.
len <<= 3
for i := uint(0); i < 16; i++ {
tmp[i] = byte(len >> (120 - 8*i))
}
d.Write(tmp[0:16])
if d.nx != 0 {
panic("d.nx != 0")
}
h := d.h[:]
var digest [Size]byte
for i, s := range h {
digest[i*8] = byte(s >> 56)
digest[i*8+1] = byte(s >> 48)
digest[i*8+2] = byte(s >> 40)
digest[i*8+3] = byte(s >> 32)
digest[i*8+4] = byte(s >> 24)
digest[i*8+5] = byte(s >> 16)
digest[i*8+6] = byte(s >> 8)
digest[i*8+7] = byte(s)
}
return digest
}