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// 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 block
import (
"bytes"
"fmt"
"io"
"testing"
"testing/iotest"
)
// Simple "pseudo-random" stream for testing.
type incStream struct {
buf []byte
n byte
}
func newIncStream(blockSize int) *incStream {
x := new(incStream)
x.buf = make([]byte, blockSize)
return x
}
func (x *incStream) Next() []byte {
x.n++
for i := range x.buf {
x.buf[i] = x.n
x.n++
}
return x.buf
}
func testXorWriter(t *testing.T, maxio int) {
var plain, crypt [256]byte
for i := 0; i < len(plain); i++ {
plain[i] = byte(i)
}
b := new(bytes.Buffer)
for block := 1; block <= 64 && block <= maxio; block *= 2 {
// compute encrypted version
n := byte(0)
for i := 0; i < len(crypt); i++ {
if i%block == 0 {
n++
}
crypt[i] = plain[i] ^ n
n++
}
for frag := 0; frag < 2; frag++ {
test := fmt.Sprintf("block=%d frag=%d maxio=%d", block, frag, maxio)
b.Reset()
r := bytes.NewBuffer(plain[0:])
s := newIncStream(block)
w := newXorWriter(s, b)
// copy plain into w in increasingly large chunks: 1, 1, 2, 4, 8, ...
// if frag != 0, move the 1 to the end to cause fragmentation.
if frag == 0 {
_, err := io.Copyn(w, r, 1)
if err != nil {
t.Errorf("%s: first Copyn: %s", test, err)
continue
}
}
for n := 1; n <= len(plain)/2; n *= 2 {
_, err := io.Copyn(w, r, int64(n))
if err != nil {
t.Errorf("%s: Copyn %d: %s", test, n, err)
}
}
// check output
crypt := crypt[0 : len(crypt)-frag]
data := b.Bytes()
if len(data) != len(crypt) {
t.Errorf("%s: want %d bytes, got %d", test, len(crypt), len(data))
continue
}
if string(data) != string(crypt) {
t.Errorf("%s: want %x got %x", test, data, crypt)
}
}
}
}
func TestXorWriter(t *testing.T) {
// Do shorter I/O sizes first; they're easier to debug.
for n := 1; n <= 256 && !t.Failed(); n *= 2 {
testXorWriter(t, n)
}
}
func testXorReader(t *testing.T, maxio int) {
var readers = []func(io.Reader) io.Reader{
func(r io.Reader) io.Reader { return r },
iotest.OneByteReader,
iotest.HalfReader,
}
var plain, crypt [256]byte
for i := 0; i < len(plain); i++ {
plain[i] = byte(255 - i)
}
b := new(bytes.Buffer)
for block := 1; block <= 64 && block <= maxio; block *= 2 {
// compute encrypted version
n := byte(0)
for i := 0; i < len(crypt); i++ {
if i%block == 0 {
n++
}
crypt[i] = plain[i] ^ n
n++
}
for mode := 0; mode < len(readers); mode++ {
for frag := 0; frag < 2; frag++ {
test := fmt.Sprintf("block=%d mode=%d frag=%d maxio=%d", block, mode, frag, maxio)
s := newIncStream(block)
b.Reset()
r := newXorReader(s, readers[mode](bytes.NewBuffer(crypt[0:maxio])))
// read from crypt in increasingly large chunks: 1, 1, 2, 4, 8, ...
// if frag == 1, move the 1 to the end to cause fragmentation.
if frag == 0 {
_, err := io.Copyn(b, r, 1)
if err != nil {
t.Errorf("%s: first Copyn: %s", test, err)
continue
}
}
for n := 1; n <= maxio/2; n *= 2 {
_, err := io.Copyn(b, r, int64(n))
if err != nil {
t.Errorf("%s: Copyn %d: %s", test, n, err)
}
}
// check output
data := b.Bytes()
crypt := crypt[0 : maxio-frag]
plain := plain[0 : maxio-frag]
if len(data) != len(plain) {
t.Errorf("%s: want %d bytes, got %d", test, len(plain), len(data))
continue
}
if string(data) != string(plain) {
t.Errorf("%s: input=%x want %x got %x", test, crypt, plain, data)
}
}
}
}
}
func TestXorReader(t *testing.T) {
// Do shorter I/O sizes first; they're easier to debug.
for n := 1; n <= 256 && !t.Failed(); n *= 2 {
testXorReader(t, n)
}
}
// TODO(rsc): Test handling of writes after write errors.
|
