2 files changed, 100 insertions, 11 deletions

diff --git a/weed/util/cipher.go b/weed/util/cipher.go
new file mode 100644
index 000000000..f044c2ca3
--- /dev/null
+++ b/weed/util/cipher.go
@@ -0,0 +1,60 @@
+package util
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"errors"
+	"io"
+
+	"github.com/chrislusf/seaweedfs/weed/glog"
+)
+
+type CipherKey []byte
+
+func GenCipherKey() CipherKey {
+	key := make([]byte, 32)
+	if _, err := io.ReadFull(rand.Reader, key); err != nil {
+		glog.Fatalf("random key gen: %v", err)
+	}
+	return CipherKey(key)
+}
+
+func Encrypt(plaintext []byte, key CipherKey) ([]byte, error) {
+	c, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+
+	gcm, err := cipher.NewGCM(c)
+	if err != nil {
+		return nil, err
+	}
+
+	nonce := make([]byte, gcm.NonceSize())
+	if _, err = io.ReadFull(rand.Reader, nonce); err != nil {
+		return nil, err
+	}
+
+	return gcm.Seal(nonce, nonce, plaintext, nil), nil
+}
+
+func Decrypt(ciphertext []byte, key CipherKey) ([]byte, error) {
+	c, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+
+	gcm, err := cipher.NewGCM(c)
+	if err != nil {
+		return nil, err
+	}
+
+	nonceSize := gcm.NonceSize()
+	if len(ciphertext) < nonceSize {
+		return nil, errors.New("ciphertext too short")
+	}
+
+	nonce, ciphertext := ciphertext[:nonceSize], ciphertext[nonceSize:]
+	return gcm.Open(nil, nonce, ciphertext, nil)
+}
diff --git a/weed/util/http_util.go b/weed/util/http_util.go
index f819d8497..833db910c 100644
--- a/weed/util/http_util.go
+++ b/weed/util/http_util.go
@@ -189,13 +189,21 @@ func NormalizeUrl(url string) string {
 	return "http://" + url
 }
 
-func ReadUrl(fileUrl string, offset int64, size int, buf []byte, isReadRange bool) (int64, error) {
+func ReadUrl(fileUrl string, cipherKey []byte, isFullChunk bool, offset int64, size int, buf []byte) (int64, error) {
+
+	if cipherKey != nil {
+		var n int
+		err := readEncryptedUrl(fileUrl, cipherKey, offset, size, func(data []byte) {
+			n = copy(buf, data)
+		})
+		return int64(n), err
+	}
 
 	req, err := http.NewRequest("GET", fileUrl, nil)
 	if err != nil {
 		return 0, err
 	}
-	if isReadRange {
+	if !isFullChunk {
 		req.Header.Add("Range", fmt.Sprintf("bytes=%d-%d", offset, offset+int64(size)-1))
 	} else {
 		req.Header.Set("Accept-Encoding", "gzip")
@@ -250,43 +258,64 @@ func ReadUrl(fileUrl string, offset int64, size int, buf []byte, isReadRange boo
 	return n, err
 }
 
-func ReadUrlAsStream(fileUrl string, offset int64, size int, fn func(data []byte)) (int64, error) {
+func ReadUrlAsStream(fileUrl string, cipherKey []byte, isFullChunk bool, offset int64, size int, fn func(data []byte)) error {
+
+	if cipherKey != nil {
+		return readEncryptedUrl(fileUrl, cipherKey, offset, size, fn)
+	}
 
 	req, err := http.NewRequest("GET", fileUrl, nil)
 	if err != nil {
-		return 0, err
+		return err
+	}
+
+	if !isFullChunk {
+		req.Header.Add("Range", fmt.Sprintf("bytes=%d-%d", offset, offset+int64(size)-1))
 	}
-	req.Header.Add("Range", fmt.Sprintf("bytes=%d-%d", offset, offset+int64(size)-1))
 
 	r, err := client.Do(req)
 	if err != nil {
-		return 0, err
+		return err
 	}
 	defer CloseResponse(r)
 	if r.StatusCode >= 400 {
-		return 0, fmt.Errorf("%s: %s", fileUrl, r.Status)
+		return fmt.Errorf("%s: %s", fileUrl, r.Status)
 	}
 
 	var (
 		m int
-		n int64
 	)
 	buf := make([]byte, 64*1024)
 
 	for {
 		m, err = r.Body.Read(buf)
 		fn(buf[:m])
-		n += int64(m)
 		if err == io.EOF {
-			return n, nil
+			return nil
 		}
 		if err != nil {
-			return n, err
+			return err
 		}
 	}
 
 }
 
+func readEncryptedUrl(fileUrl string, cipherKey []byte, offset int64, size int, fn func(data []byte)) error {
+	encryptedData, err := Get(fileUrl)
+	if err != nil {
+		return fmt.Errorf("fetch %s: %v", fileUrl, err)
+	}
+	decryptedData, err := Decrypt(encryptedData, CipherKey(cipherKey))
+	if err != nil {
+		return fmt.Errorf("decrypt %s: %v", fileUrl, err)
+	}
+	if len(decryptedData) < int(offset)+size {
+		return fmt.Errorf("read decrypted %s size %d [%d, %d)", fileUrl, len(decryptedData), offset, int(offset)+size)
+	}
+	fn(decryptedData[int(offset) : int(offset)+size])
+	return nil
+}
+
 func ReadUrlAsReaderCloser(fileUrl string, rangeHeader string) (io.ReadCloser, error) {
 
 	req, err := http.NewRequest("GET", fileUrl, nil)