validate.gno

 1package skins
 2
 3// The string rules below are what makes the hand-built JSON and the markdown
 4// of this realm safe: every string that is stored and later printed went
 5// through one of them, and none of them lets a quote, a backslash, a pipe, a
 6// bracket or a control character in.
 7
 8const (
 9	maxIDLen    = 32
10	maxModelLen = 16
11	maxNameLen  = 40
12)
13
14// validID reports whether s matches [a-z0-9-]{1,32}.
15func validID(s string) bool {
16	return isSlug(s, maxIDLen)
17}
18
19// validModel reports whether s matches [a-z0-9-]{1,16}.
20func validModel(s string) bool {
21	return isSlug(s, maxModelLen)
22}
23
24// validName reports whether s matches [A-Za-z0-9 '.!-]{1,40}. The charset is
25// deliberately narrow so that a name can be embedded in JSON and markdown
26// without escaping.
27func validName(s string) bool {
28	if len(s) == 0 || len(s) > maxNameLen {
29		return false
30	}
31	for i := 0; i < len(s); i++ {
32		c := s[i]
33		switch {
34		case c >= 'a' && c <= 'z', c >= 'A' && c <= 'Z', c >= '0' && c <= '9':
35		case c == ' ', c == '\'', c == '.', c == '!', c == '-':
36		default:
37			return false
38		}
39	}
40	return true
41}
42
43// validColor reports whether s is "#rrggbb" with lowercase hex digits.
44func validColor(s string) bool {
45	if len(s) != 7 || s[0] != '#' {
46		return false
47	}
48	for i := 1; i < len(s); i++ {
49		c := s[i]
50		if !(c >= '0' && c <= '9') && !(c >= 'a' && c <= 'f') {
51			return false
52		}
53	}
54	return true
55}
56
57// validAddress reports whether addr is a valid address in its canonical,
58// lowercase form.
59//
60// Bech32 can also be written in all capitals, and address.IsValid accepts
61// that. To this realm the capitals would be a second key for the same
62// account: a second player record, a second line on a leaderboard, an admin
63// who can never be matched to a caller. Bech32 does not allow mixing cases,
64// so looking at the first character is enough.
65func validAddress(addr address) bool {
66	return addr.IsValid() && addr[0] == 'g'
67}
68
69// isSlug reports whether s is 1 to max characters of [a-z0-9-].
70func isSlug(s string, max int) bool {
71	if len(s) == 0 || len(s) > max {
72		return false
73	}
74	for i := 0; i < len(s); i++ {
75		c := s[i]
76		if !(c >= 'a' && c <= 'z') && !(c >= '0' && c <= '9') && c != '-' {
77			return false
78		}
79	}
80	return true
81}