1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
use std::collections::HashMap;
use std::iter::Iterator;
fn main() {
println!("pub const INVALID_VALUE: u8 = 255;");
// A-Z
let standard_alphabet: Vec<u8> = (0x41..0x5B)
// a-z
.chain(0x61..0x7B)
// 0-9
.chain(0x30..0x3A)
// +
.chain(0x2B..0x2C)
// /
.chain(0x2F..0x30)
.collect();
print_encode_table(&standard_alphabet, "STANDARD_ENCODE", 0);
print_decode_table(&standard_alphabet, "STANDARD_DECODE", 0);
// A-Z
let url_alphabet: Vec<u8> = (0x41..0x5B)
// a-z
.chain(0x61..0x7B)
// 0-9
.chain(0x30..0x3A)
// -
.chain(0x2D..0x2E)
// _
.chain(0x5F..0x60)
.collect();
print_encode_table(&url_alphabet, "URL_SAFE_ENCODE", 0);
print_decode_table(&url_alphabet, "URL_SAFE_DECODE", 0);
// ./0123456789
let crypt_alphabet: Vec<u8> = (b'.'..(b'9' + 1))
// A-Z
.chain(b'A'..(b'Z' + 1))
// a-z
.chain(b'a'..(b'z' + 1))
.collect();
print_encode_table(&crypt_alphabet, "CRYPT_ENCODE", 0);
print_decode_table(&crypt_alphabet, "CRYPT_DECODE", 0);
// A-Z
let imap_alphabet: Vec<u8> = (0x41..0x5B)
// a-z
.chain(0x61..0x7B)
// 0-9
.chain(0x30..0x3A)
// +
.chain(0x2B..0x2C)
// ,
.chain(0x2C..0x2D)
.collect();
print_encode_table(&imap_alphabet, "IMAP_MUTF7_ENCODE", 0);
print_decode_table(&imap_alphabet, "IMAP_MUTF7_DECODE", 0);
}
fn print_encode_table(alphabet: &[u8], const_name: &str, indent_depth: usize) {
println!("#[rustfmt::skip]");
println!(
"{:width$}pub const {}: &[u8; 64] = &[",
"",
const_name,
width = indent_depth
);
for (i, b) in alphabet.iter().enumerate() {
println!(
"{:width$}{}, // input {} (0x{:X}) => '{}' (0x{:X})",
"",
b,
i,
i,
String::from_utf8(vec![*b as u8]).unwrap(),
b,
width = indent_depth + 4
);
}
println!("{:width$}];", "", width = indent_depth);
}
fn print_decode_table(alphabet: &[u8], const_name: &str, indent_depth: usize) {
// map of alphabet bytes to 6-bit morsels
let mut input_to_morsel = HashMap::<u8, u8>::new();
// standard base64 alphabet bytes, in order
for (morsel, ascii_byte) in alphabet.iter().enumerate() {
// truncation cast is fine here
let _ = input_to_morsel.insert(*ascii_byte, morsel as u8);
}
println!("#[rustfmt::skip]");
println!(
"{:width$}pub const {}: &[u8; 256] = &[",
"",
const_name,
width = indent_depth
);
for ascii_byte in 0..256 {
let (value, comment) = match input_to_morsel.get(&(ascii_byte as u8)) {
None => (
"INVALID_VALUE".to_string(),
format!("input {} (0x{:X})", ascii_byte, ascii_byte),
),
Some(v) => (
format!("{}", *v),
format!(
"input {} (0x{:X} char '{}') => {} (0x{:X})",
ascii_byte,
ascii_byte,
String::from_utf8(vec![ascii_byte as u8]).unwrap(),
*v,
*v
),
),
};
println!(
"{:width$}{}, // {}",
"",
value,
comment,
width = indent_depth + 4
);
}
println!("{:width$}];", "", width = indent_depth);
}
|
