}
		i += 3
	}
	if percents == 0 {
		return s, nil
	}

	t := make([]byte, len(s)-2*percents)
	j := 0
	for i := 0; i < len(s); {
		switch s[i] {
		case '%':
			t[j] = unhex(s[i+1])<<4 | unhex(s[i+2])
			j++
			i += 3
		default:
			t[j] = s[i]
			j++
			i++
		}
	}
	return string(t), nil
}

func ishex(c byte) bool {
	switch {
	case '0' <= c && c <= '9':

				// That is, you can use escaping in the zone identifier but not
				// to introduce bytes you couldn't just write directly.
				// But Windows puts spaces here! Yay.
				v := unhex(s[i+1])<<4 | unhex(s[i+2])
				if s[i:i+3] != "%25" && v != ' ' && shouldEscape(v, encodeHost) {
					return "", EscapeError(s[i : i+3])
				}
			}
			i += 3
		case '+':
			hasPlus = mode == encodeQueryComponent

		}
		if r == utf8.RuneError {
			return false
		}
		if (r < ' ' && r != '\t') || r == '`' || r == '\u007F' {
			return false
		}
	}
	return true
}

func unhex(b byte) (v rune, ok bool) {
	c := rune(b)
	switch {
	case '0' <= c && c <= '9':
		return c - '0', true
	case 'a' <= c && c <= 'f':
		return c - 'a' + 10, true
	case 'A' <= c && c <= 'F':

					break Switch
				}
				nhex++
			}
			if nhex == 0 {
				break Switch
			}
			return r, t, nil
		}

		// Easy case: two hex digits.
		x := unhex(c)
		if c, t, err = nextRune(t); err != nil {
			return 0, "", err
		}
		y := unhex(c)
		if x < 0 || y < 0 {
			break
		}
		return x*16 + y, t, nil

	// C escapes. There is no case 'b', to avoid misparsing

	opts := &PSSOptions{
		SaltLength: PSSSaltLengthEqualsHash,
	}

	for marker := range values {
		switch marker {
		case newKeyMarker:
			key = new(PublicKey)
			nHex, ok := <-values
			if !ok {
				continue
			}
			key.N = bigFromHex(nHex)
			key.E = intFromHex(<-values)
			// We don't care for d, p, q, dP, dQ or qInv.
			for i := 0; i < 6; i++ {
				<-values
			}
		case newSignatureMarker: