Method newEncrypter

backend/crypt/cipher.go:694–716

newEncrypter creates a new file handle encrypting on the fly

(in io.Reader, nonce *nonce)

// newEncrypter creates a new file handle encrypting on the fly
func (c *Cipher) newEncrypter(in io.Reader, nonce *nonce) (*encrypter, error) {
	fh := &encrypter{
		in:      in,
		c:       c,
		buf:     c.getBlock(),
		readBuf: c.getBlock(),
		bufSize: fileHeaderSize,
	}
	// Initialise nonce
	if nonce != nil {
		fh.nonce = *nonce
	} else {
		err := fh.nonce.fromReader(c.cryptoRand)
		if err != nil {
			return nil, err
		}
	}
	// Copy magic into buffer
	copy((*fh.buf)[:], fileMagicBytes)
	// Copy nonce into buffer
	copy((*fh.buf)[fileMagicSize:], fh.nonce[:])
	return fh, nil
}

// Read as per io.Reader
func (fh *encrypter) Read(p []byte) (n int, err error) {