wolf-crypto 0.1.0-alpha.15

Safe and thin API for wolfSSL's wolfcrypt
Documentation 
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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150


pub fn take_comment(raw: &[u8]) -> usize {
    if !matches!(raw.get(0), Some(b'#')) { return 0 }

    let mut pos: usize = 1;

    loop {
        match raw.get(pos) {
            Some(b'\n') | None => break,
            Some(_) => pos += 1,
        }
    }

    pos
}

pub fn take_ignorable(raw: &[u8]) -> &[u8] {
    let mut pos: usize = 0;

    loop {
        match raw.get(pos) {
            Some(b'#') => pos += take_comment(&raw[pos..]),
            Some(b' ' | b'\r' | b'\n') => pos += 1,
            _ => return &raw[pos..]
        }
    }
}

pub const fn take(ident: &[u8]) -> impl FnOnce(&[u8]) -> Option<&[u8]> + '_ {
    move |data: &[u8]| {
        if data.len() >= ident.len() && &data[..ident.len()] == ident {
            Some(&data[ident.len()..])
        } else {
            None
        }
    }
}

macro_rules! take_until {
    ($pat:pat, $data:expr) => {{
        let mut __pos: usize = 0;

        loop {
            match $data.get(__pos) {
                Some($pat) => break,
                Some(_) => __pos += 1,
                // eof
                None => break
            }
        }

        (&$data[..__pos], &$data[__pos + 1..])
    }}
}

#[inline]
pub const fn take_until(until: u8) -> impl FnOnce(&[u8]) -> (&[u8], &[u8]) {
    move |data: &[u8]| {
        let mut pos: usize = 0;

        loop {
            match data.get(pos) {
                Some(byte) if byte == &until => { break },
                Some(_) => pos += 1,
                // eof
                None => break
            }
        }

        (&data[..pos], &data[pos + 1..])
    }
}

#[inline]
pub fn take_until_break(raw: &[u8]) -> (&[u8], &[u8]) {
    take_until!(b'\n' | b'\r', raw)
}

#[inline]
pub const fn parse_until_assign(ident: &[u8]) -> impl FnOnce(&[u8]) -> Option<&[u8]> + '_ {
    let take_fn = take(ident);

    move |data: &[u8]| {
        take_fn(data)
            .map(take_ignorable)
            .and_then(take(b"="))
            .map(take_ignorable)
    }
}

#[inline]
pub const fn parse_assign(ident: &[u8]) -> impl FnOnce(&[u8]) -> Option<(&[u8], &[u8])> + '_ {
    let take_until_ass = parse_until_assign(ident);
    move |data: &[u8]| { take_until_ass(data).map(take_until_break) }
}

#[inline]
pub fn ignore_header(raw: &[u8]) -> &[u8] {
    take_length(raw).1
}

#[inline]
pub fn take_length(raw: &[u8]) -> (Option<&[u8]>, &[u8]) {
    let rem = take_ignorable(raw);

    match take(b"[")(rem) {
        Some(rem) => {
            let (inner, rem) = take_until(b']')(rem);
            (take(b"L=")(inner), rem)
        },
        None => (None, rem)
    }
}

#[inline]
const fn ascii_to_digit(byte: u8) -> Option<u32> {
    match byte {
        b'0' => Some(0),
        b'1' => Some(1),
        b'2' => Some(2),
        b'3' => Some(3),
        b'4' => Some(4),
        b'5' => Some(5),
        b'6' => Some(6),
        b'7' => Some(7),
        b'8' => Some(8),
        b'9' => Some(9),
        _ => None
    }
}

pub fn parse_u32(raw: &[u8]) -> Option<u32> {
    if raw.is_empty() { return None }

    let mut i = 0;
    let mut num = 0;

    while i < raw.len() {
        if let Some(digit) = ascii_to_digit(raw[i]) {
            num *= 10;
            num += digit;
            i += 1;
        } else {
            // we expect to be fed only valid numbers
            return None
        }
    }

    Some(num)
}