seaweedfs/weed/util/cipher.go

82 lines
1.7 KiB
Go

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
}