Exemplo n.º 1
0
// Parse reads a binary specification for a string-to-key transformation from r
// and returns a function which performs that transform.
func Parse(r io.Reader) (f func(out, in []byte), err error) {
	var buf [9]byte

	_, err = io.ReadFull(r, buf[:2])
	if err != nil {
		return
	}

	// GNU Extensions; handle them before we try to look for a hash, which won't
	// be needed in most cases anyway.
	if buf[0] == 101 {
		return parseGNUExtensions(r)
	}

	hash, ok := HashIdToHash(buf[1])
	if !ok {
		return nil, errors.UnsupportedError("hash for S2K function: " + strconv.Itoa(int(buf[1])))
	}
	if !hash.Available() {
		return nil, errors.UnsupportedError("hash not available: " + strconv.Itoa(int(hash)))
	}
	h := hash.New()

	switch buf[0] {
	case 0:
		f := func(out, in []byte) {
			Simple(out, h, in)
		}
		return f, nil
	case 1:
		_, err = io.ReadFull(r, buf[:8])
		if err != nil {
			return
		}
		f := func(out, in []byte) {
			Salted(out, h, in, buf[:8])
		}
		return f, nil
	case 3:
		_, err = io.ReadFull(r, buf[:9])
		if err != nil {
			return
		}
		count := decodeCount(buf[8])
		f := func(out, in []byte) {
			Iterated(out, h, in, buf[:8], count)
		}
		return f, nil
	}

	return nil, errors.UnsupportedError("S2K function")
}
Exemplo n.º 2
0
// Parse reads a binary specification for a string-to-key transformation from r
// and returns a function which performs that transform.
func Parse(r io.Reader) (f func(out, in []byte), err error) {
	var buf [9]byte

	_, err = io.ReadFull(r, buf[:2])
	if err != nil {
		return
	}

	hash, ok := HashIdToHash(buf[1])
	if !ok {
		return nil, errors.UnsupportedError("hash for S2K function: " + strconv.Itoa(int(buf[1])))
	}
	if !hash.Available() {
		return nil, errors.UnsupportedError("hash not available: " + strconv.Itoa(int(hash)))
	}
	h := hash.New()

	switch buf[0] {
	case 0:
		f := func(out, in []byte) {
			Simple(out, h, in)
		}
		return f, nil
	case 1:
		_, err = io.ReadFull(r, buf[:8])
		if err != nil {
			return
		}
		f := func(out, in []byte) {
			Salted(out, h, in, buf[:8])
		}
		return f, nil
	case 3:
		_, err = io.ReadFull(r, buf[:9])
		if err != nil {
			return
		}
		count := decodeCount(buf[8])
		f := func(out, in []byte) {
			Iterated(out, h, in, buf[:8], count)
		}
		return f, nil
	}

	return nil, errors.UnsupportedError("S2K function")
}
Exemplo n.º 3
0
// Parse reads a binary specification for a string-to-key transformation from r
// and returns a function which performs that transform.
func Parse(r io.Reader) (f func(out, in []byte), err error) {
	var buf [9]byte

	_, err = io.ReadFull(r, buf[:2])
	if err != nil {
		return
	}

	hash, ok := HashIdToHash(buf[1])
	if !ok {
		return nil, errors.UnsupportedError("hash for S2K function: " + strconv.Itoa(int(buf[1])))
	}
	if !hash.Available() {
		return nil, errors.UnsupportedError("hash not available: " + strconv.Itoa(int(hash)))
	}
	h := hash.New()

	switch buf[0] {
	case 0:
		f := func(out, in []byte) {
			Simple(out, h, in)
		}
		return f, nil
	case 1:
		_, err = io.ReadFull(r, buf[:8])
		if err != nil {
			return
		}
		f := func(out, in []byte) {
			Salted(out, h, in, buf[:8])
		}
		return f, nil
	case 3:
		_, err = io.ReadFull(r, buf[:9])
		if err != nil {
			return
		}
		count := decodeCount(buf[8])
		f := func(out, in []byte) {
			Iterated(out, h, in, buf[:8], count)
		}
		return f, nil

	// GNU Extensions
	case 101:

		// A three-byte string identifier
		_, err = io.ReadFull(r, buf[:3])
		if err != nil {
			return
		}
		gnuExt := string(buf[:3])

		if gnuExt != "GNU" {
			return nil, errors.UnsupportedError("Malformed GNU extension: " + gnuExt)
		}
		_, err = io.ReadFull(r, buf[:1])
		if err != nil {
			return
		}
		gnuExtType := int(buf[0])
		if gnuExtType != 1 {
			return nil, errors.UnsupportedError("unknown S2K GNU protection mode: " + strconv.Itoa(int(gnuExtType)))
		}
		return nil, nil
	}

	return nil, errors.UnsupportedError("S2K function")
}