270 lines
5.8 KiB
Go
270 lines
5.8 KiB
Go
// 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.
|
|
|
|
// Package sha256 implements the SHA224 and SHA256 hash algorithms as defined
|
|
// in FIPS 180-4.
|
|
package sha256
|
|
|
|
import (
|
|
"crypto"
|
|
"encoding/binary"
|
|
"errors"
|
|
"hash"
|
|
)
|
|
|
|
func init() {
|
|
crypto.RegisterHash(crypto.SHA224, New224)
|
|
crypto.RegisterHash(crypto.SHA256, New)
|
|
}
|
|
|
|
// The size of a SHA256 checksum in bytes.
|
|
const Size = 32
|
|
|
|
// The size of a SHA224 checksum in bytes.
|
|
const Size224 = 28
|
|
|
|
// The blocksize of SHA256 and SHA224 in bytes.
|
|
const BlockSize = 64
|
|
|
|
const (
|
|
chunk = 64
|
|
init0 = 0x6A09E667
|
|
init1 = 0xBB67AE85
|
|
init2 = 0x3C6EF372
|
|
init3 = 0xA54FF53A
|
|
init4 = 0x510E527F
|
|
init5 = 0x9B05688C
|
|
init6 = 0x1F83D9AB
|
|
init7 = 0x5BE0CD19
|
|
init0_224 = 0xC1059ED8
|
|
init1_224 = 0x367CD507
|
|
init2_224 = 0x3070DD17
|
|
init3_224 = 0xF70E5939
|
|
init4_224 = 0xFFC00B31
|
|
init5_224 = 0x68581511
|
|
init6_224 = 0x64F98FA7
|
|
init7_224 = 0xBEFA4FA4
|
|
)
|
|
|
|
// digest represents the partial evaluation of a checksum.
|
|
type digest struct {
|
|
h [8]uint32
|
|
x [chunk]byte
|
|
nx int
|
|
len uint64
|
|
is224 bool // mark if this digest is SHA-224
|
|
}
|
|
|
|
const (
|
|
magic224 = "sha\x02"
|
|
magic256 = "sha\x03"
|
|
marshaledSize = len(magic256) + 8*4 + chunk + 8
|
|
)
|
|
|
|
func (d *digest) MarshalBinary() ([]byte, error) {
|
|
b := make([]byte, 0, marshaledSize)
|
|
if d.is224 {
|
|
b = append(b, magic224...)
|
|
} else {
|
|
b = append(b, magic256...)
|
|
}
|
|
b = appendUint32(b, d.h[0])
|
|
b = appendUint32(b, d.h[1])
|
|
b = appendUint32(b, d.h[2])
|
|
b = appendUint32(b, d.h[3])
|
|
b = appendUint32(b, d.h[4])
|
|
b = appendUint32(b, d.h[5])
|
|
b = appendUint32(b, d.h[6])
|
|
b = appendUint32(b, d.h[7])
|
|
b = append(b, d.x[:d.nx]...)
|
|
b = b[:len(b)+len(d.x)-int(d.nx)] // already zero
|
|
b = appendUint64(b, d.len)
|
|
return b, nil
|
|
}
|
|
|
|
func (d *digest) UnmarshalBinary(b []byte) error {
|
|
if len(b) < len(magic224) || (d.is224 && string(b[:len(magic224)]) != magic224) || (!d.is224 && string(b[:len(magic256)]) != magic256) {
|
|
return errors.New("crypto/sha256: invalid hash state identifier")
|
|
}
|
|
if len(b) != marshaledSize {
|
|
return errors.New("crypto/sha256: invalid hash state size")
|
|
}
|
|
b = b[len(magic224):]
|
|
b, d.h[0] = consumeUint32(b)
|
|
b, d.h[1] = consumeUint32(b)
|
|
b, d.h[2] = consumeUint32(b)
|
|
b, d.h[3] = consumeUint32(b)
|
|
b, d.h[4] = consumeUint32(b)
|
|
b, d.h[5] = consumeUint32(b)
|
|
b, d.h[6] = consumeUint32(b)
|
|
b, d.h[7] = consumeUint32(b)
|
|
b = b[copy(d.x[:], b):]
|
|
b, d.len = consumeUint64(b)
|
|
d.nx = int(d.len % chunk)
|
|
return nil
|
|
}
|
|
|
|
func appendUint64(b []byte, x uint64) []byte {
|
|
var a [8]byte
|
|
binary.BigEndian.PutUint64(a[:], x)
|
|
return append(b, a[:]...)
|
|
}
|
|
|
|
func appendUint32(b []byte, x uint32) []byte {
|
|
var a [4]byte
|
|
binary.BigEndian.PutUint32(a[:], x)
|
|
return append(b, a[:]...)
|
|
}
|
|
|
|
func consumeUint64(b []byte) ([]byte, uint64) {
|
|
_ = b[7]
|
|
x := uint64(b[7]) | uint64(b[6])<<8 | uint64(b[5])<<16 | uint64(b[4])<<24 |
|
|
uint64(b[3])<<32 | uint64(b[2])<<40 | uint64(b[1])<<48 | uint64(b[0])<<56
|
|
return b[8:], x
|
|
}
|
|
|
|
func consumeUint32(b []byte) ([]byte, uint32) {
|
|
_ = b[3]
|
|
x := uint32(b[3]) | uint32(b[2])<<8 | uint32(b[1])<<16 | uint32(b[0])<<24
|
|
return b[4:], x
|
|
}
|
|
|
|
func (d *digest) Reset() {
|
|
if !d.is224 {
|
|
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
|
|
} else {
|
|
d.h[0] = init0_224
|
|
d.h[1] = init1_224
|
|
d.h[2] = init2_224
|
|
d.h[3] = init3_224
|
|
d.h[4] = init4_224
|
|
d.h[5] = init5_224
|
|
d.h[6] = init6_224
|
|
d.h[7] = init7_224
|
|
}
|
|
d.nx = 0
|
|
d.len = 0
|
|
}
|
|
|
|
// New returns a new hash.Hash computing the SHA256 checksum. The Hash
|
|
// also implements encoding.BinaryMarshaler and
|
|
// encoding.BinaryUnmarshaler to marshal and unmarshal the internal
|
|
// state of the hash.
|
|
func New() hash.Hash {
|
|
d := new(digest)
|
|
d.Reset()
|
|
return d
|
|
}
|
|
|
|
// New224 returns a new hash.Hash computing the SHA224 checksum.
|
|
func New224() hash.Hash {
|
|
d := new(digest)
|
|
d.is224 = true
|
|
d.Reset()
|
|
return d
|
|
}
|
|
|
|
func (d *digest) Size() int {
|
|
if !d.is224 {
|
|
return Size
|
|
}
|
|
return Size224
|
|
}
|
|
|
|
func (d *digest) BlockSize() int { return BlockSize }
|
|
|
|
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
|
|
}
|
|
|
|
func (d *digest) Sum(in []byte) []byte {
|
|
// Make a copy of d so that caller can keep writing and summing.
|
|
d0 := *d
|
|
hash := d0.checkSum()
|
|
if d0.is224 {
|
|
return append(in, hash[:Size224]...)
|
|
}
|
|
return append(in, hash[:]...)
|
|
}
|
|
|
|
func (d *digest) checkSum() [Size]byte {
|
|
len := d.len
|
|
// Padding. Add a 1 bit and 0 bits until 56 bytes mod 64.
|
|
var tmp [64]byte
|
|
tmp[0] = 0x80
|
|
if len%64 < 56 {
|
|
d.Write(tmp[0 : 56-len%64])
|
|
} else {
|
|
d.Write(tmp[0 : 64+56-len%64])
|
|
}
|
|
|
|
// Length in bits.
|
|
len <<= 3
|
|
binary.BigEndian.PutUint64(tmp[:], len)
|
|
d.Write(tmp[0:8])
|
|
|
|
if d.nx != 0 {
|
|
panic("d.nx != 0")
|
|
}
|
|
|
|
var digest [Size]byte
|
|
|
|
binary.BigEndian.PutUint32(digest[0:], d.h[0])
|
|
binary.BigEndian.PutUint32(digest[4:], d.h[1])
|
|
binary.BigEndian.PutUint32(digest[8:], d.h[2])
|
|
binary.BigEndian.PutUint32(digest[12:], d.h[3])
|
|
binary.BigEndian.PutUint32(digest[16:], d.h[4])
|
|
binary.BigEndian.PutUint32(digest[20:], d.h[5])
|
|
binary.BigEndian.PutUint32(digest[24:], d.h[6])
|
|
if !d.is224 {
|
|
binary.BigEndian.PutUint32(digest[28:], d.h[7])
|
|
}
|
|
|
|
return digest
|
|
}
|
|
|
|
// Sum256 returns the SHA256 checksum of the data.
|
|
func Sum256(data []byte) [Size]byte {
|
|
var d digest
|
|
d.Reset()
|
|
d.Write(data)
|
|
return d.checkSum()
|
|
}
|
|
|
|
// Sum224 returns the SHA224 checksum of the data.
|
|
func Sum224(data []byte) [Size224]byte {
|
|
var d digest
|
|
d.is224 = true
|
|
d.Reset()
|
|
d.Write(data)
|
|
sum := d.checkSum()
|
|
ap := (*[Size224]byte)(sum[:])
|
|
return *ap
|
|
}
|