1 files changed, 81 insertions, 0 deletions
diff --git a/weed/util/cipher.go b/weed/util/cipher.go
new file mode 100644
index 000000000..7bcb6559a
--- /dev/null
+++ b/weed/util/cipher.go
@@ -0,0 +1,81 @@
+package util
+
+import (
+	"bytes"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+
+	"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)
+}
+
+func EncryptReader(clearReader io.Reader) (cipherKey CipherKey, encryptedReader io.ReadCloser, clearDataLen, encryptedDataLen int, err error) {
+	clearData, err := ioutil.ReadAll(clearReader)
+	if err != nil {
+		err = fmt.Errorf("read raw input: %v", err)
+		return
+	}
+	clearDataLen = len(clearData)
+	cipherKey = GenCipherKey()
+	encryptedData, err := Encrypt(clearData, cipherKey)
+	if err != nil {
+		err = fmt.Errorf("encrypt input: %v", err)
+		return
+	}
+	encryptedDataLen = len(encryptedData)
+	encryptedReader = ioutil.NopCloser(bytes.NewReader(encryptedData))
+	return
+}