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package hash
import (
"crypto/md5"
"crypto/sha1"
"encoding/hex"
"fmt"
"hash"
"hash/crc32"
"io"
"strings"
"github.com/jzelinskie/whirlpool"
"github.com/pkg/errors"
"github.com/rclone/rclone/backend/dropbox/dbhash"
"github.com/rclone/rclone/backend/mailru/mrhash"
"github.com/rclone/rclone/backend/onedrive/quickxorhash"
)
// Type indicates a standard hashing algorithm
type Type int
// ErrUnsupported should be returned by filesystem,
// if it is requested to deliver an unsupported hash type.
var ErrUnsupported = errors.New("hash type not supported")
const (
// MD5 indicates MD5 support
MD5 Type = 1 << iota
// SHA1 indicates SHA-1 support
SHA1
// Dropbox indicates Dropbox special hash
// https://www.dropbox.com/developers/reference/content-hash
Dropbox
// QuickXorHash indicates Microsoft onedrive hash
// https://docs.microsoft.com/en-us/onedrive/developer/code-snippets/quickxorhash
QuickXorHash
// Whirlpool indicates Whirlpool support
Whirlpool
// CRC32 indicates CRC-32 support
CRC32
// Mailru indicates Mailru special hash
Mailru
// None indicates no hashes are supported
None Type = 0
)
// Supported returns a set of all the supported hashes by
// HashStream and MultiHasher.
var Supported = NewHashSet(MD5, SHA1, Dropbox, QuickXorHash, Whirlpool, CRC32, Mailru)
// Width returns the width in characters for any HashType
var Width = map[Type]int{
MD5: 32,
SHA1: 40,
Dropbox: 64,
QuickXorHash: 40,
Whirlpool: 128,
CRC32: 8,
Mailru: 40,
}
// Stream will calculate hashes of all supported hash types.
func Stream(r io.Reader) (map[Type]string, error) {
return StreamTypes(r, Supported)
}
// StreamTypes will calculate hashes of the requested hash types.
func StreamTypes(r io.Reader, set Set) (map[Type]string, error) {
hashers, err := fromTypes(set)
if err != nil {
return nil, err
}
_, err = io.Copy(toMultiWriter(hashers), r)
if err != nil {
return nil, err
}
var ret = make(map[Type]string)
for k, v := range hashers {
ret[k] = hex.EncodeToString(v.Sum(nil))
}
return ret, nil
}
// String returns a string representation of the hash type.
// The function will panic if the hash type is unknown.
func (h Type) String() string {
switch h {
case None:
return "None"
case MD5:
return "MD5"
case SHA1:
return "SHA-1"
case Dropbox:
return "DropboxHash"
case QuickXorHash:
return "QuickXorHash"
case Whirlpool:
return "Whirlpool"
case CRC32:
return "CRC-32"
case Mailru:
return "MailruHash"
default:
err := fmt.Sprintf("internal error: unknown hash type: 0x%x", int(h))
panic(err)
}
}
// Set a Type from a flag
func (h *Type) Set(s string) error {
switch s {
case "None":
*h = None
case "MD5":
*h = MD5
case "SHA-1":
*h = SHA1
case "DropboxHash":
*h = Dropbox
case "QuickXorHash":
*h = QuickXorHash
case "Whirlpool":
*h = Whirlpool
case "CRC-32":
*h = CRC32
case "MailruHash":
*h = Mailru
default:
return errors.Errorf("Unknown hash type %q", s)
}
return nil
}
// Type of the value
func (h Type) Type() string {
return "string"
}
// fromTypes will return hashers for all the requested types.
// The types must be a subset of SupportedHashes,
// and this function must support all types.
func fromTypes(set Set) (map[Type]hash.Hash, error) {
if !set.SubsetOf(Supported) {
return nil, errors.Errorf("requested set %08x contains unknown hash types", int(set))
}
var hashers = make(map[Type]hash.Hash)
types := set.Array()
for _, t := range types {
switch t {
case MD5:
hashers[t] = md5.New()
case SHA1:
hashers[t] = sha1.New()
case Dropbox:
hashers[t] = dbhash.New()
case QuickXorHash:
hashers[t] = quickxorhash.New()
case Whirlpool:
hashers[t] = whirlpool.New()
case CRC32:
hashers[t] = crc32.NewIEEE()
case Mailru:
hashers[t] = mrhash.New()
default:
err := fmt.Sprintf("internal error: Unsupported hash type %v", t)
panic(err)
}
}
return hashers, nil
}
// toMultiWriter will return a set of hashers into a
// single multiwriter, where one write will update all
// the hashers.
func toMultiWriter(h map[Type]hash.Hash) io.Writer {
// Convert to to slice
var w = make([]io.Writer, 0, len(h))
for _, v := range h {
w = append(w, v)
}
return io.MultiWriter(w...)
}
// A MultiHasher will construct various hashes on
// all incoming writes.
type MultiHasher struct {
w io.Writer
size int64
h map[Type]hash.Hash // Hashes
}
// NewMultiHasher will return a hash writer that will write all
// supported hash types.
func NewMultiHasher() *MultiHasher {
h, err := NewMultiHasherTypes(Supported)
if err != nil {
panic("internal error: could not create multihasher")
}
return h
}
// NewMultiHasherTypes will return a hash writer that will write
// the requested hash types.
func NewMultiHasherTypes(set Set) (*MultiHasher, error) {
hashers, err := fromTypes(set)
if err != nil {
return nil, err
}
m := MultiHasher{h: hashers, w: toMultiWriter(hashers)}
return &m, nil
}
func (m *MultiHasher) Write(p []byte) (n int, err error) {
n, err = m.w.Write(p)
m.size += int64(n)
return n, err
}
// Sums returns the sums of all accumulated hashes as hex encoded
// strings.
func (m *MultiHasher) Sums() map[Type]string {
dst := make(map[Type]string)
for k, v := range m.h {
dst[k] = hex.EncodeToString(v.Sum(nil))
}
return dst
}
// Size returns the number of bytes written
func (m *MultiHasher) Size() int64 {
return m.size
}
// A Set Indicates one or more hash types.
type Set int
// NewHashSet will create a new hash set with the hash types supplied
func NewHashSet(t ...Type) Set {
h := Set(None)
return h.Add(t...)
}
// Add one or more hash types to the set.
// Returns the modified hash set.
func (h *Set) Add(t ...Type) Set {
for _, v := range t {
*h |= Set(v)
}
return *h
}
// Contains returns true if the
func (h Set) Contains(t Type) bool {
return int(h)&int(t) != 0
}
// Overlap returns the overlapping hash types
func (h Set) Overlap(t Set) Set {
return Set(int(h) & int(t))
}
// SubsetOf will return true if all types of h
// is present in the set c
func (h Set) SubsetOf(c Set) bool {
return int(h)|int(c) == int(c)
}
// GetOne will return a hash type.
// Currently the first is returned, but it could be
// improved to return the strongest.
func (h Set) GetOne() Type {
v := int(h)
i := uint(0)
for v != 0 {
if v&1 != 0 {
return Type(1 << i)
}
i++
v >>= 1
}
return None
}
// Array returns an array of all hash types in the set
func (h Set) Array() (ht []Type) {
v := int(h)
i := uint(0)
for v != 0 {
if v&1 != 0 {
ht = append(ht, Type(1<<i))
}
i++
v >>= 1
}
return ht
}
// Count returns the number of hash types in the set
func (h Set) Count() int {
if int(h) == 0 {
return 0
}
// credit: https://code.google.com/u/arnehormann/
x := uint64(h)
x -= (x >> 1) & 0x5555555555555555
x = (x>>2)&0x3333333333333333 + x&0x3333333333333333
x += x >> 4
x &= 0x0f0f0f0f0f0f0f0f
x *= 0x0101010101010101
return int(x >> 56)
}
// String returns a string representation of the hash set.
// The function will panic if it contains an unknown type.
func (h Set) String() string {
a := h.Array()
var r []string
for _, v := range a {
r = append(r, v.String())
}
return "[" + strings.Join(r, ", ") + "]"
}
// Equals checks to see if src == dst, but ignores empty strings
// and returns true if either is empty.
func Equals(src, dst string) bool {
if src == "" || dst == "" {
return true
}
return src == dst
}
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