structured-pkix 0.9.2

Borrowed X.509 certificates and provider-neutral certification path validation
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
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181

//! Scoped attribute preparation must fund all deferred work in the query.

use std::sync::Arc;
use structured_asn1::memory::{Memory, MemoryAccount};
use structured_asn1::{Encoding, Limits, Parser};

fn memory(capacity: usize, work: usize) -> Memory {
    Memory::new(Arc::new(MemoryAccount::new(capacity, work)))
}

fn tlv(tag: u8, contents: &[u8]) -> Vec<u8> {
    let mut bytes = vec![tag, u8::try_from(contents.len()).unwrap()];
    bytes.extend_from_slice(contents);
    bytes
}

fn named(kind: &[u8], value: &[u8]) -> Vec<u8> {
    let mut attribute = tlv(6, kind);
    attribute.extend_from_slice(value);
    tlv(0x30, &tlv(0x31, &tlv(0x30, &attribute)))
}

#[test]
fn unicode_attribute_preparation_cannot_ignore_current_local_work() {
    // The retained Memory-only API has no query ceiling. The new entry must
    // refuse before a Unicode scan even while the account has abundant slack.
    let bytes = [
        0x30, 13, 0x31, 11, 0x30, 9, 6, 3, 0x55, 4, 3, 12, 2, 0xc3, 0x9f,
    ];
    let parser = Parser::der(memory(65536, 65536));
    let mut parent = parser.read(&bytes, 400).unwrap();
    let element = parent.next_element().unwrap().unwrap();
    let name = structured_pkix::name::read(&parent, &element, "subject").unwrap();
    let attribute = name.parts()[0].attributes()[0];
    let current = memory(65536, 65536);
    let query_parser = Parser::new(
        Encoding::Ber,
        Limits {
            max_work: 0,
            ..Limits::default()
        },
        current.clone(),
    );
    let query = query_parser.read(&[], 900).unwrap();
    let error = attribute.folds_in(&query).unwrap_err();
    assert!(error.is_resource());
    assert_eq!(error.offset(), 411);
    assert_eq!(current.work_used(), 0);
    assert_eq!(current.used(), 0);
}

#[test]
fn scoped_attribute_folding_uses_the_retained_semantic_core() {
    // Scoped funding must not change supported/opaque/prohibited preparation.
    // Original Name storage remains on its own account; all query scratch dies.
    for (kind, text, expected) in [
        (&[0x55, 4, 3][..], "Example", true),
        (&[0x55, 4, 3][..], "Straße", true),
        (&[0x55, 4, 3][..], "\u{e000}", false),
        (&[42][..], "opaque", false),
    ] {
        let bytes = named(kind, &tlv(12, text.as_bytes()));
        let origin = memory(65536, 65536);
        let parser = Parser::der(origin.clone());
        let mut parent = parser.read(&bytes, 400).unwrap();
        let element = parent.next_element().unwrap().unwrap();
        let name = structured_pkix::name::read(&parent, &element, "subject").unwrap();
        let attribute = name.parts()[0].attributes()[0];
        let before = (origin.used(), origin.work_used());
        let retained_query = memory(65536, 65536);
        assert_eq!(attribute.folds(&retained_query).unwrap(), expected);
        let current = memory(65536, 65536);
        let query = parent.try_clone().unwrap().with_execution(&current);
        assert_eq!(attribute.folds_in(&query).unwrap(), expected);
        assert_eq!(current.work_used(), retained_query.work_used());
        assert_eq!(current.used(), 0);
        assert_eq!((origin.used(), origin.work_used()), before);
        assert_eq!(name.as_bytes(), bytes);
    }
}

#[test]
fn scoped_folding_enforces_exact_work_and_rolls_back_unicode_scratch() {
    // Primitive preparation has identical work under retained/scoped ownership.
    // Exact succeeds; local/global one-less and zero scratch capacity refuse.
    let bytes = named(&[0x55, 4, 3], &tlv(12, "Straße".as_bytes()));
    let origin = memory(65536, 65536);
    let parser = Parser::der(origin.clone());
    let mut parent = parser.read(&bytes, 400).unwrap();
    let element = parent.next_element().unwrap().unwrap();
    let name = structured_pkix::name::read(&parent, &element, "subject").unwrap();
    let attribute = name.parts()[0].attributes()[0];
    let measured = memory(65536, 65536);
    assert!(attribute.folds(&measured).unwrap());
    let cost = measured.work_used();
    assert!(cost > 1);
    let before = (origin.used(), origin.work_used());
    let mut lower = 0;
    let mut upper = 65536;
    while lower < upper {
        let capacity = lower + (upper - lower) / 2;
        let current = memory(capacity, 65536);
        let query = parent.try_clone().unwrap().with_execution(&current);
        match attribute.folds_in(&query) {
            Ok(folds) => {
                assert!(folds);
                upper = capacity;
            }
            Err(error) => {
                assert!(error.is_resource());
                lower = capacity + 1;
            }
        }
        assert_eq!(current.used(), 0);
    }
    let peak = lower;
    assert!(peak > 0);
    for (capacity, local, aggregate, succeeds) in [
        (peak, cost, cost, true),
        (peak, cost - 1, cost, false),
        (peak, cost, cost - 1, false),
        (peak - 1, cost, cost, false),
        (0, cost, cost, false),
    ] {
        let current = memory(capacity, aggregate);
        let query_parser = Parser::new(
            Encoding::Der,
            Limits {
                max_work: u64::try_from(local).unwrap(),
                ..Limits::default()
            },
            current.clone(),
        );
        let query = query_parser.read(&[], 900).unwrap();
        let answer = attribute.folds_in(&query);
        if succeeds {
            assert!(answer.unwrap());
        } else {
            let error = answer.unwrap_err();
            assert!(error.is_resource());
            assert_eq!(error.offset(), 411);
            assert_eq!(error.field(), "name.attribute");
        }
        assert_eq!(current.used(), 0);
        assert_eq!((origin.used(), origin.work_used()), before);
    }
}

#[test]
fn constructed_attribute_preparation_preserves_depth_and_element_limits() {
    // Deferred BER preparation uses the retained attribute's original depth.
    // A fresh query cannot flatten it under depth zero or reset element limits.
    let bytes = named(&[0x55, 4, 3], &tlv(0x2c, &[4, 1, b'a']));
    let origin = memory(65536, 65536);
    let parser = Parser::ber(origin.clone());
    let mut parent = parser.read(&bytes, 400).unwrap();
    let element = parent.next_element().unwrap().unwrap();
    let name = structured_pkix::name::read(&parent, &element, "subject").unwrap();
    let attribute = name.parts()[0].attributes()[0];
    assert!(attribute.folds_in(&parent).unwrap());
    let before = (origin.used(), origin.work_used());
    for limits in [
        Limits {
            max_depth: 2,
            ..Limits::default()
        },
        Limits {
            max_elements: 0,
            ..Limits::default()
        },
    ] {
        let current = memory(65536, 65536);
        let query_parser = Parser::new(Encoding::Ber, limits, current.clone());
        let query = query_parser.read(&[], 900).unwrap();
        let error = attribute.folds_in(&query).unwrap_err();
        assert!(error.is_resource());
        assert_eq!(error.offset(), 411);
        assert_eq!(current.used(), 0);
        assert_eq!((origin.used(), origin.work_used()), before);
    }
}