From 3dbe02182babb72a71bf5061b5dae5369a495092 Mon Sep 17 00:00:00 2001
From: Alexander Neumann <alexander@bumpern.de>
Date: Sun, 15 Feb 2015 23:38:45 +0100
Subject: [PATCH] Remove EncryptFrom*() methods, add Tests for EncryptTo()

---
 key.go      | 42 ------------------------------------------
 key_test.go | 29 +++++++++++++++++++----------
 2 files changed, 19 insertions(+), 52 deletions(-)

diff --git a/key.go b/key.go
index 8ab1b20c0..7cf5b92a5 100644
--- a/key.go
+++ b/key.go
@@ -334,48 +334,6 @@ func (k *Key) Encrypt(ciphertext, plaintext []byte) (int, error) {
 	return k.encrypt(k.master, ciphertext, plaintext)
 }
 
-// encryptFrom encrypts and signs data read from rd with ks. The returned
-// io.Reader reads IV || Ciphertext || HMAC. For the hash function, SHA256 is
-// used.
-func (k *Key) encryptFrom(ks *keys, rd io.Reader) io.Reader {
-	// create IV
-	iv := make([]byte, ivSize)
-
-	_, err := io.ReadFull(rand.Reader, iv)
-	if err != nil {
-		panic(fmt.Sprintf("unable to generate new random iv: %v", err))
-	}
-
-	c, err := aes.NewCipher(ks.Encrypt)
-	if err != nil {
-		panic(fmt.Sprintf("unable to create cipher: %v", err))
-	}
-
-	ivReader := bytes.NewReader(iv)
-
-	encryptReader := cipher.StreamReader{
-		R: rd,
-		S: cipher.NewCTR(c, iv),
-	}
-
-	return backend.NewHashAppendReader(io.MultiReader(ivReader, encryptReader),
-		hmac.New(sha256.New, ks.Sign))
-}
-
-// EncryptFrom encrypts and signs data read from rd with the master key. The
-// returned io.Reader reads IV || Ciphertext || HMAC. For the hash function,
-// SHA256 is used.
-func (k *Key) EncryptFrom(rd io.Reader) io.Reader {
-	return k.encryptFrom(k.master, rd)
-}
-
-// EncryptFrom encrypts and signs data read from rd with the user key. The
-// returned io.Reader reads IV || Ciphertext || HMAC. For the hash function,
-// SHA256 is used.
-func (k *Key) EncryptUserFrom(rd io.Reader) io.Reader {
-	return k.encryptFrom(k.user, rd)
-}
-
 type encryptWriter struct {
 	iv      []byte
 	wroteIV bool
diff --git a/key_test.go b/key_test.go
index 93a6395f4..9f2875de0 100644
--- a/key_test.go
+++ b/key_test.go
@@ -126,7 +126,7 @@ func TestLargeEncrypt(t *testing.T) {
 	}
 }
 
-func BenchmarkEncryptReader(b *testing.B) {
+func BenchmarkEncryptWriter(b *testing.B) {
 	size := 8 << 20 // 8MiB
 	rd := randomReader(23, size)
 
@@ -139,7 +139,8 @@ func BenchmarkEncryptReader(b *testing.B) {
 
 	for i := 0; i < b.N; i++ {
 		rd.Seek(0, 0)
-		_, err := io.Copy(ioutil.Discard, k.EncryptFrom(rd))
+		wr := k.EncryptTo(ioutil.Discard)
+		_, err := io.Copy(wr, rd)
 		ok(b, err)
 	}
 }
@@ -203,10 +204,16 @@ func BenchmarkEncryptDecryptReader(b *testing.B) {
 
 	for i := 0; i < b.N; i++ {
 		rd.Seek(0, 0)
-		decRd, err := k.DecryptFrom(k.EncryptFrom(rd))
+		buf := bytes.NewBuffer(nil)
+		wr := k.EncryptTo(buf)
+		_, err := io.Copy(wr, rd)
+		ok(b, err)
+		ok(b, wr.Close())
+
+		r, err := k.DecryptFrom(buf)
 		ok(b, err)
 
-		_, err = io.Copy(ioutil.Discard, decRd)
+		_, err = io.Copy(ioutil.Discard, r)
 		ok(b, err)
 	}
 }
@@ -233,7 +240,7 @@ func BenchmarkDecrypt(b *testing.B) {
 	restic.FreeChunkBuf("BenchmarkDecrypt", ciphertext)
 }
 
-func TestEncryptStreamReader(t *testing.T) {
+func TestEncryptStreamWriter(t *testing.T) {
 	s := setupBackend(t)
 	defer teardownBackend(t, s)
 	k := setupKey(t, s, testPassword)
@@ -248,18 +255,20 @@ func TestEncryptStreamReader(t *testing.T) {
 		_, err := io.ReadFull(randomReader(42, size), data)
 		ok(t, err)
 
-		erd := k.EncryptFrom(bytes.NewReader(data))
+		ciphertext := bytes.NewBuffer(nil)
+		wr := k.EncryptTo(ciphertext)
 
-		ciphertext, err := ioutil.ReadAll(erd)
+		_, err = io.Copy(wr, bytes.NewReader(data))
 		ok(t, err)
+		ok(t, wr.Close())
 
 		l := len(data) + restic.CiphertextExtension
-		assert(t, len(ciphertext) == l,
+		assert(t, len(ciphertext.Bytes()) == l,
 			"wrong ciphertext length: expected %d, got %d",
-			l, len(ciphertext))
+			l, len(ciphertext.Bytes()))
 
 		// decrypt with default function
-		plaintext, err := k.Decrypt(ciphertext)
+		plaintext, err := k.Decrypt(ciphertext.Bytes())
 		ok(t, err)
 		assert(t, bytes.Equal(data, plaintext),
 			"wrong plaintext after decryption: expected %02x, got %02x",