mirror of
https://github.com/octoleo/restic.git
synced 2024-12-11 13:52:31 +00:00
121 lines
2.4 KiB
Go
121 lines
2.4 KiB
Go
// Copyright 2010 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 ripemd160 implements the RIPEMD-160 hash algorithm.
|
|
package ripemd160 // import "golang.org/x/crypto/ripemd160"
|
|
|
|
// RIPEMD-160 is designed by by Hans Dobbertin, Antoon Bosselaers, and Bart
|
|
// Preneel with specifications available at:
|
|
// http://homes.esat.kuleuven.be/~cosicart/pdf/AB-9601/AB-9601.pdf.
|
|
|
|
import (
|
|
"crypto"
|
|
"hash"
|
|
)
|
|
|
|
func init() {
|
|
crypto.RegisterHash(crypto.RIPEMD160, New)
|
|
}
|
|
|
|
// The size of the checksum in bytes.
|
|
const Size = 20
|
|
|
|
// The block size of the hash algorithm in bytes.
|
|
const BlockSize = 64
|
|
|
|
const (
|
|
_s0 = 0x67452301
|
|
_s1 = 0xefcdab89
|
|
_s2 = 0x98badcfe
|
|
_s3 = 0x10325476
|
|
_s4 = 0xc3d2e1f0
|
|
)
|
|
|
|
// digest represents the partial evaluation of a checksum.
|
|
type digest struct {
|
|
s [5]uint32 // running context
|
|
x [BlockSize]byte // temporary buffer
|
|
nx int // index into x
|
|
tc uint64 // total count of bytes processed
|
|
}
|
|
|
|
func (d *digest) Reset() {
|
|
d.s[0], d.s[1], d.s[2], d.s[3], d.s[4] = _s0, _s1, _s2, _s3, _s4
|
|
d.nx = 0
|
|
d.tc = 0
|
|
}
|
|
|
|
// New returns a new hash.Hash computing the checksum.
|
|
func New() hash.Hash {
|
|
result := new(digest)
|
|
result.Reset()
|
|
return result
|
|
}
|
|
|
|
func (d *digest) Size() int { return Size }
|
|
|
|
func (d *digest) BlockSize() int { return BlockSize }
|
|
|
|
func (d *digest) Write(p []byte) (nn int, err error) {
|
|
nn = len(p)
|
|
d.tc += uint64(nn)
|
|
if d.nx > 0 {
|
|
n := len(p)
|
|
if n > BlockSize-d.nx {
|
|
n = BlockSize - d.nx
|
|
}
|
|
for i := 0; i < n; i++ {
|
|
d.x[d.nx+i] = p[i]
|
|
}
|
|
d.nx += n
|
|
if d.nx == BlockSize {
|
|
_Block(d, d.x[0:])
|
|
d.nx = 0
|
|
}
|
|
p = p[n:]
|
|
}
|
|
n := _Block(d, p)
|
|
p = p[n:]
|
|
if len(p) > 0 {
|
|
d.nx = copy(d.x[:], p)
|
|
}
|
|
return
|
|
}
|
|
|
|
func (d0 *digest) Sum(in []byte) []byte {
|
|
// Make a copy of d0 so that caller can keep writing and summing.
|
|
d := *d0
|
|
|
|
// Padding. Add a 1 bit and 0 bits until 56 bytes mod 64.
|
|
tc := d.tc
|
|
var tmp [64]byte
|
|
tmp[0] = 0x80
|
|
if tc%64 < 56 {
|
|
d.Write(tmp[0 : 56-tc%64])
|
|
} else {
|
|
d.Write(tmp[0 : 64+56-tc%64])
|
|
}
|
|
|
|
// Length in bits.
|
|
tc <<= 3
|
|
for i := uint(0); i < 8; i++ {
|
|
tmp[i] = byte(tc >> (8 * i))
|
|
}
|
|
d.Write(tmp[0:8])
|
|
|
|
if d.nx != 0 {
|
|
panic("d.nx != 0")
|
|
}
|
|
|
|
var digest [Size]byte
|
|
for i, s := range d.s {
|
|
digest[i*4] = byte(s)
|
|
digest[i*4+1] = byte(s >> 8)
|
|
digest[i*4+2] = byte(s >> 16)
|
|
digest[i*4+3] = byte(s >> 24)
|
|
}
|
|
|
|
return append(in, digest[:]...)
|
|
}
|