Function GetReader

enc/util.go:43–62

GetReader wraps a crypto StreamReader using the input key on the input Reader.

(key x.Sensitive, r io.Reader)

// GetReader wraps a crypto StreamReader using the input key on the input Reader.
func GetReader(key x.Sensitive, r io.Reader) (io.Reader, error) {
	// No encryption, return input reader as is.
	if key == nil {
		return r, nil
	}

	// Encryption, wrap crypto StreamReader on input Reader.
	c, err := aes.NewCipher(key)
	if err != nil {
		return nil, err
	}
	var iv []byte = make([]byte, 16)
	cnt, err := r.Read(iv)
	if cnt != 16 || err != nil {
		err = errors.Errorf("unable to get IV from encrypted backup. Read %v bytes, err %v ",
			cnt, err)
		return nil, err
	}
	return cipher.StreamReader{S: cipher.NewCTR(c, iv), R: r}, nil
}