src/crypto/sha256/sha256.go - go - Git at Google

 // 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"
 )

 import "crypto/internal/boring"

 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 {
 	if boring.Enabled {
 		return boring.NewSHA256()
 	}
 	d := new(digest)
 	d.Reset()
 	return d
 }

 // New224 returns a new hash.Hash computing the SHA224 checksum.
 func New224() hash.Hash {
 	if boring.Enabled {
 		return boring.NewSHA224()
 	}
 	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) {
 	boring.Unreachable()
 	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 {
 	boring.Unreachable()
 	// 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 {
 	if boring.Enabled {
 		h := New()
 		h.Write(data)
 		var ret [Size]byte
 		h.Sum(ret[:0])
 		return ret
 	}
 	var d digest
 	d.Reset()
 	d.Write(data)
 	return d.checkSum()
 }

 // Sum224 returns the SHA224 checksum of the data.
 func Sum224(data []byte) (sum224 [Size224]byte) {
 	if boring.Enabled {
 		h := New224()
 		h.Write(data)
 		var ret [Size224]byte
 		h.Sum(ret[:0])
 		return ret
 	}
 	var d digest
 	d.is224 = true
 	d.Reset()
 	d.Write(data)
 	sum := d.checkSum()
 	copy(sum224[:], sum[:Size224])
 	return
 }
	// 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"
	)

	import "crypto/internal/boring"

	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 {
	if boring.Enabled {
	return boring.NewSHA256()
	}
	d := new(digest)
	d.Reset()
	return d
	}

	// New224 returns a new hash.Hash computing the SHA224 checksum.
	func New224() hash.Hash {
	if boring.Enabled {
	return boring.NewSHA224()
	}
	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) {
	boring.Unreachable()
	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 {
	boring.Unreachable()
	// 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 {
	if boring.Enabled {
	h := New()
	h.Write(data)
	var ret [Size]byte
	h.Sum(ret[:0])
	return ret
	}
	var d digest
	d.Reset()
	d.Write(data)
	return d.checkSum()
	}

	// Sum224 returns the SHA224 checksum of the data.
	func Sum224(data []byte) (sum224 [Size224]byte) {
	if boring.Enabled {
	h := New224()
	h.Write(data)
	var ret [Size224]byte
	h.Sum(ret[:0])
	return ret
	}
	var d digest
	d.is224 = true
	d.Reset()
	d.Write(data)
	sum := d.checkSum()
	copy(sum224[:], sum[:Size224])
	return
	}