Rename HashReader -> HashAppendReader, add HashingReader

This commit is contained in:
Alexander Neumann 2015-02-11 19:37:48 +01:00
parent 842dea173c
commit 64f7b4e5e9
4 changed files with 105 additions and 51 deletions

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@ -1,46 +0,0 @@
package backend_test
import (
"bytes"
"crypto/rand"
"crypto/sha256"
"io"
"testing"
"github.com/restic/restic/backend"
)
func TestHashReader(t *testing.T) {
tests := []int{5, 23, 2<<18 + 23, 1 << 20}
for _, size := range tests {
data := make([]byte, size)
_, err := io.ReadFull(rand.Reader, data)
if err != nil {
t.Fatalf("ReadFull: %v", err)
}
expectedHash := sha256.Sum256(data)
rd := backend.NewHashReader(bytes.NewReader(data), sha256.New())
target := bytes.NewBuffer(nil)
n, err := io.Copy(target, rd)
ok(t, err)
assert(t, n == int64(size)+int64(len(expectedHash)),
"HashReader: invalid number of bytes read: got %d, expected %d",
n, size+len(expectedHash))
r := target.Bytes()
resultingHash := r[len(r)-len(expectedHash):]
assert(t, bytes.Equal(expectedHash[:], resultingHash),
"HashReader: hashes do not match: expected %02x, got %02x",
expectedHash, resultingHash)
// try to read again, must return io.EOF
n2, err := rd.Read(make([]byte, 100))
assert(t, n2 == 0, "HashReader returned %d additional bytes", n)
assert(t, err == io.EOF, "HashReader returned %v instead of EOF", err)
}
}

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@ -5,22 +5,22 @@ import (
"io"
)
type HashReader struct {
type HashAppendReader struct {
r io.Reader
h hash.Hash
sum []byte
closed bool
}
func NewHashReader(r io.Reader, h hash.Hash) *HashReader {
return &HashReader{
func NewHashAppendReader(r io.Reader, h hash.Hash) *HashAppendReader {
return &HashAppendReader{
h: h,
r: io.TeeReader(r, h),
sum: make([]byte, 0, h.Size()),
}
}
func (h *HashReader) Read(p []byte) (n int, err error) {
func (h *HashAppendReader) Read(p []byte) (n int, err error) {
if !h.closed {
n, err = h.r.Read(p)
@ -51,3 +51,23 @@ func (h *HashReader) Read(p []byte) (n int, err error) {
return
}
type HashingReader struct {
r io.Reader
h hash.Hash
}
func NewHashingReader(r io.Reader, h hash.Hash) *HashingReader {
return &HashingReader{
h: h,
r: io.TeeReader(r, h),
}
}
func (h *HashingReader) Read(p []byte) (int, error) {
return h.r.Read(p)
}
func (h *HashingReader) Sum(d []byte) []byte {
return h.h.Sum(d)
}

80
backend/reader_test.go Normal file
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@ -0,0 +1,80 @@
package backend_test
import (
"bytes"
"crypto/rand"
"crypto/sha256"
"io"
"io/ioutil"
"testing"
"github.com/restic/restic/backend"
)
func TestHashAppendReader(t *testing.T) {
tests := []int{5, 23, 2<<18 + 23, 1 << 20}
for _, size := range tests {
data := make([]byte, size)
_, err := io.ReadFull(rand.Reader, data)
if err != nil {
t.Fatalf("ReadFull: %v", err)
}
expectedHash := sha256.Sum256(data)
rd := backend.NewHashAppendReader(bytes.NewReader(data), sha256.New())
target := bytes.NewBuffer(nil)
n, err := io.Copy(target, rd)
ok(t, err)
assert(t, n == int64(size)+int64(len(expectedHash)),
"HashAppendReader: invalid number of bytes read: got %d, expected %d",
n, size+len(expectedHash))
r := target.Bytes()
resultingHash := r[len(r)-len(expectedHash):]
assert(t, bytes.Equal(expectedHash[:], resultingHash),
"HashAppendReader: hashes do not match: expected %02x, got %02x",
expectedHash, resultingHash)
// try to read again, must return io.EOF
n2, err := rd.Read(make([]byte, 100))
assert(t, n2 == 0, "HashAppendReader returned %d additional bytes", n)
assert(t, err == io.EOF, "HashAppendReader returned %v instead of EOF", err)
}
}
func TestHashingReader(t *testing.T) {
tests := []int{5, 23, 2<<18 + 23, 1 << 20}
for _, size := range tests {
data := make([]byte, size)
_, err := io.ReadFull(rand.Reader, data)
if err != nil {
t.Fatalf("ReadFull: %v", err)
}
expectedHash := sha256.Sum256(data)
rd := backend.NewHashingReader(bytes.NewReader(data), sha256.New())
n, err := io.Copy(ioutil.Discard, rd)
ok(t, err)
assert(t, n == int64(size),
"HashAppendReader: invalid number of bytes read: got %d, expected %d",
n, size+len(expectedHash))
resultingHash := rd.Sum(nil)
assert(t, bytes.Equal(expectedHash[:], resultingHash),
"HashAppendReader: hashes do not match: expected %02x, got %02x",
expectedHash, resultingHash)
// try to read again, must return io.EOF
n2, err := rd.Read(make([]byte, 100))
assert(t, n2 == 0, "HashAppendReader returned %d additional bytes", n)
assert(t, err == io.EOF, "HashAppendReader returned %v instead of EOF", err)
}
}

2
key.go
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@ -341,7 +341,7 @@ func (k *Key) encryptFrom(ks *keys, rd io.Reader) io.Reader {
S: cipher.NewCTR(c, iv),
}
return backend.NewHashReader(io.MultiReader(ivReader, encryptReader),
return backend.NewHashAppendReader(io.MultiReader(ivReader, encryptReader),
hmac.New(sha256.New, ks.Sign))
}