+++ /dev/null
-/*
- * Minio Cloud Storage, (C) 2016 Minio, Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package sha256
-
-import (
- "crypto/sha256"
- "encoding/binary"
- "hash"
- "runtime"
-)
-
-// Size - The size of a SHA256 checksum in bytes.
-const Size = 32
-
-// BlockSize - The blocksize of SHA256 in bytes.
-const BlockSize = 64
-
-const (
- chunk = BlockSize
- init0 = 0x6A09E667
- init1 = 0xBB67AE85
- init2 = 0x3C6EF372
- init3 = 0xA54FF53A
- init4 = 0x510E527F
- init5 = 0x9B05688C
- init6 = 0x1F83D9AB
- init7 = 0x5BE0CD19
-)
-
-// digest represents the partial evaluation of a checksum.
-type digest struct {
- h [8]uint32
- x [chunk]byte
- nx int
- len uint64
-}
-
-// Reset digest back to default
-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
-}
-
-type blockfuncType int
-
-const (
- blockfuncGeneric blockfuncType = iota
- blockfuncAvx512 blockfuncType = iota
- blockfuncAvx2 blockfuncType = iota
- blockfuncAvx blockfuncType = iota
- blockfuncSsse blockfuncType = iota
- blockfuncSha blockfuncType = iota
- blockfuncArm blockfuncType = iota
-)
-
-var blockfunc blockfuncType
-
-func block(dig *digest, p []byte) {
- if blockfunc == blockfuncSha {
- blockShaGo(dig, p)
- } else if blockfunc == blockfuncAvx2 {
- blockAvx2Go(dig, p)
- } else if blockfunc == blockfuncAvx {
- blockAvxGo(dig, p)
- } else if blockfunc == blockfuncSsse {
- blockSsseGo(dig, p)
- } else if blockfunc == blockfuncArm {
- blockArmGo(dig, p)
- } else if blockfunc == blockfuncGeneric {
- blockGeneric(dig, p)
- }
-}
-
-func init() {
- is386bit := runtime.GOARCH == "386"
- isARM := runtime.GOARCH == "arm"
- switch {
- case is386bit || isARM:
- blockfunc = blockfuncGeneric
- case sha && ssse3 && sse41:
- blockfunc = blockfuncSha
- case avx2:
- blockfunc = blockfuncAvx2
- case avx:
- blockfunc = blockfuncAvx
- case ssse3:
- blockfunc = blockfuncSsse
- case armSha:
- blockfunc = blockfuncArm
- default:
- blockfunc = blockfuncGeneric
- }
-}
-
-// New returns a new hash.Hash computing the SHA256 checksum.
-func New() hash.Hash {
- if blockfunc != blockfuncGeneric {
- d := new(digest)
- d.Reset()
- return d
- }
- // Fallback to the standard golang implementation
- // if no features were found.
- return sha256.New()
-}
-
-// Sum256 - single caller sha256 helper
-func Sum256(data []byte) (result [Size]byte) {
- var d digest
- d.Reset()
- d.Write(data)
- result = d.checkSum()
- return
-}
-
-// Return size of checksum
-func (d *digest) Size() int { return Size }
-
-// Return blocksize of checksum
-func (d *digest) BlockSize() int { return BlockSize }
-
-// Write to digest
-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
-}
-
-// Return sha256 sum in bytes
-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[:]...)
-}
-
-// Intermediate checksum function
-func (d *digest) checkSum() (digest [Size]byte) {
- n := d.nx
-
- var k [64]byte
- copy(k[:], d.x[:n])
-
- k[n] = 0x80
-
- if n >= 56 {
- block(d, k[:])
-
- // clear block buffer - go compiles this to optimal 1x xorps + 4x movups
- // unfortunately expressing this more succinctly results in much worse code
- k[0] = 0
- k[1] = 0
- k[2] = 0
- k[3] = 0
- k[4] = 0
- k[5] = 0
- k[6] = 0
- k[7] = 0
- k[8] = 0
- k[9] = 0
- k[10] = 0
- k[11] = 0
- k[12] = 0
- k[13] = 0
- k[14] = 0
- k[15] = 0
- k[16] = 0
- k[17] = 0
- k[18] = 0
- k[19] = 0
- k[20] = 0
- k[21] = 0
- k[22] = 0
- k[23] = 0
- k[24] = 0
- k[25] = 0
- k[26] = 0
- k[27] = 0
- k[28] = 0
- k[29] = 0
- k[30] = 0
- k[31] = 0
- k[32] = 0
- k[33] = 0
- k[34] = 0
- k[35] = 0
- k[36] = 0
- k[37] = 0
- k[38] = 0
- k[39] = 0
- k[40] = 0
- k[41] = 0
- k[42] = 0
- k[43] = 0
- k[44] = 0
- k[45] = 0
- k[46] = 0
- k[47] = 0
- k[48] = 0
- k[49] = 0
- k[50] = 0
- k[51] = 0
- k[52] = 0
- k[53] = 0
- k[54] = 0
- k[55] = 0
- k[56] = 0
- k[57] = 0
- k[58] = 0
- k[59] = 0
- k[60] = 0
- k[61] = 0
- k[62] = 0
- k[63] = 0
- }
- binary.BigEndian.PutUint64(k[56:64], uint64(d.len)<<3)
- block(d, k[:])
-
- {
- const i = 0
- binary.BigEndian.PutUint32(digest[i*4:i*4+4], d.h[i])
- }
- {
- const i = 1
- binary.BigEndian.PutUint32(digest[i*4:i*4+4], d.h[i])
- }
- {
- const i = 2
- binary.BigEndian.PutUint32(digest[i*4:i*4+4], d.h[i])
- }
- {
- const i = 3
- binary.BigEndian.PutUint32(digest[i*4:i*4+4], d.h[i])
- }
- {
- const i = 4
- binary.BigEndian.PutUint32(digest[i*4:i*4+4], d.h[i])
- }
- {
- const i = 5
- binary.BigEndian.PutUint32(digest[i*4:i*4+4], d.h[i])
- }
- {
- const i = 6
- binary.BigEndian.PutUint32(digest[i*4:i*4+4], d.h[i])
- }
- {
- const i = 7
- binary.BigEndian.PutUint32(digest[i*4:i*4+4], d.h[i])
- }
-
- return
-}
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