der_parser/ber/
visit.rs

1use super::{BerObject, BerObjectContent, BitStringObject};
2use asn1_rs::{ASN1DateTime, Any, Class, Oid, Tag};
3
4/// BER object tree traversal to walk a shared borrow of a BER object
5///
6/// When implementing your own visitor, define your own `visit_ber_xxx` methods.
7///
8/// Note that `visit_ber` is called for every object, so if you implement multiple visitor methods they
9/// will be called multiple times for the same object. Generally, if `visit_ber` is implemented, then other
10/// methods are not needed.
11///
12/// For example, on a `Sequence` item, `visit_ber` is called first, then `visit_ber_sequence`, and then
13/// `visit_ber` for every sequence object (recursively).
14///
15/// Entry point: use the [`Visit::run`] or [`Visit::run_at`] methods.
16///
17/// Visitor functions
18#[allow(unused_variables)]
19pub trait Visit<'a> {
20    /// Called for every BER object
21    fn visit_ber(&mut self, ber: &'_ BerObject<'a>, depth: usize) {}
22
23    /// Called for BER bitstring objects
24    fn visit_ber_bitstring(&mut self, ignored: u8, data: &'a BitStringObject, depth: usize) {}
25
26    /// Called for BER bmpstring objects
27    fn visit_ber_bmpstring(&mut self, s: &'a str, depth: usize) {}
28
29    /// Called for BER boolean objects
30    fn visit_ber_boolean(&mut self, b: bool, depth: usize) {}
31
32    /// Called for BER end-of-content objects
33    fn visit_ber_endofcontent(&mut self, depth: usize) {}
34
35    /// Called for BER enum objects
36    fn visit_ber_enum(&mut self, e: u64, depth: usize) {}
37
38    /// Called for BER generalstring objects
39    fn visit_ber_generalstring(&mut self, s: &'a str, depth: usize) {}
40
41    /// Called for BER generalizedtime objects
42    fn visit_ber_generalizedtime(&mut self, t: &'a ASN1DateTime, depth: usize) {}
43
44    /// Called for BER graphicstring objects
45    fn visit_ber_graphicstring(&mut self, s: &'a str, depth: usize) {}
46
47    /// Called for BER ia5string objects
48    fn visit_ber_ia5string(&mut self, s: &'a str, depth: usize) {}
49
50    /// Called for BER integer objects
51    fn visit_ber_integer(&mut self, raw_bytes: &'a [u8], depth: usize) {}
52
53    /// Called for BER null objects
54    fn visit_ber_null(&mut self, depth: usize) {}
55
56    /// Called for BER numericstring objects
57    fn visit_ber_numericstring(&mut self, s: &'a str, depth: usize) {}
58
59    /// Called for BER OID objects
60    fn visit_ber_oid(&mut self, oid: &'a Oid, depth: usize) {}
61
62    /// Called for BER object descriptor objects
63    fn visit_ber_objectdescriptor(&mut self, s: &'a str, depth: usize) {}
64
65    /// Called for BER octetstring objects
66    fn visit_ber_octetstring(&mut self, b: &'a [u8], depth: usize) {}
67
68    /// Called for BER optional objects
69    fn visit_ber_optional(&mut self, obj: Option<&'a BerObject<'a>>, depth: usize) {}
70
71    /// Called for BER printablestring objects
72    fn visit_ber_printablestring(&mut self, s: &'a str, depth: usize) {}
73
74    /// Called for BER relative OID objects
75    fn visit_ber_relative_oid(&mut self, oid: &'a Oid, depth: usize) {}
76
77    /// Called for BER sequence objects
78    fn visit_ber_sequence(&mut self, ber: &'_ [BerObject<'a>], depth: usize) {}
79
80    /// Called for BER set objects
81    fn visit_ber_set(&mut self, ber: &'_ [BerObject<'a>], depth: usize) {}
82
83    /// Called for BER teletexstring objects
84    fn visit_ber_teletexstring(&mut self, s: &'a str, depth: usize) {}
85
86    /// Called for BER tagged objects
87    fn visit_ber_tagged(&mut self, class: Class, tag: Tag, obj: &'_ BerObject<'a>, depth: usize) {}
88
89    /// Called for BER generalizedtime objects
90    fn visit_ber_utctime(&mut self, t: &'a ASN1DateTime, depth: usize) {}
91
92    /// Called for BER utf8string objects
93    fn visit_ber_utf8string(&mut self, s: &'a str, depth: usize) {}
94
95    /// Called for BER universalstring objects
96    fn visit_ber_universalstring(&mut self, raw_bytes: &'a [u8], depth: usize) {}
97
98    /// Called for BER videotexstring objects
99    fn visit_ber_videotextstring(&mut self, raw_bytes: &'a str, depth: usize) {}
100
101    /// Called for BER visiblestring objects
102    fn visit_ber_visiblestring(&mut self, raw_bytes: &'a str, depth: usize) {}
103
104    /// Called for BER unknown objects
105    fn visit_ber_unknown(&mut self, ber: &'_ Any<'a>, depth: usize) {}
106
107    /// Perform a BFS traversal of the BER object, calling the visitor functions during he traversal
108    ///
109    /// Usually, this method should not be redefined (unless implementing a custom traversal)
110    fn run(&mut self, ber: &'a BerObject<'a>) {
111        visit_ber_bfs(self, ber, 0)
112    }
113
114    /// Perform a BFS traversal of the BER object, calling the visitor functions during he traversal
115    ///
116    /// Start at specified depth.
117    ///
118    /// Usually, this method should not be redefined (unless implementing a custom traversal)
119    fn run_at(&mut self, ber: &'a BerObject<'a>, depth: usize) {
120        visit_ber_bfs(self, ber, depth)
121    }
122}
123
124fn visit_ber_bfs<'a, V>(v: &mut V, ber: &'a BerObject<'a>, depth: usize)
125where
126    V: Visit<'a> + ?Sized,
127{
128    v.visit_ber(ber, depth);
129
130    match ber.content {
131        BerObjectContent::BitString(ignored, ref data) => {
132            v.visit_ber_bitstring(ignored, data, depth);
133        }
134        BerObjectContent::BmpString(s) => v.visit_ber_bmpstring(s, depth),
135        BerObjectContent::Boolean(b) => v.visit_ber_boolean(b, depth),
136        BerObjectContent::EndOfContent => v.visit_ber_endofcontent(depth),
137        BerObjectContent::Enum(val) => v.visit_ber_enum(val, depth),
138        BerObjectContent::GeneralString(s) => v.visit_ber_generalstring(s, depth),
139        BerObjectContent::GeneralizedTime(ref t) => v.visit_ber_generalizedtime(t, depth),
140        BerObjectContent::GraphicString(s) => v.visit_ber_graphicstring(s, depth),
141        BerObjectContent::IA5String(s) => v.visit_ber_ia5string(s, depth),
142        BerObjectContent::Integer(s) => v.visit_ber_integer(s, depth),
143        BerObjectContent::Null => v.visit_ber_null(depth),
144        BerObjectContent::NumericString(s) => v.visit_ber_numericstring(s, depth),
145        BerObjectContent::OID(ref oid) => v.visit_ber_oid(oid, depth),
146        BerObjectContent::ObjectDescriptor(s) => v.visit_ber_objectdescriptor(s, depth),
147        BerObjectContent::OctetString(b) => v.visit_ber_octetstring(b, depth),
148        BerObjectContent::Optional(ref obj) => {
149            let opt = obj.as_ref().map(|b| b.as_ref());
150            v.visit_ber_optional(opt, depth)
151        }
152        BerObjectContent::PrintableString(s) => v.visit_ber_printablestring(s, depth),
153        BerObjectContent::RelativeOID(ref oid) => v.visit_ber_relative_oid(oid, depth),
154        BerObjectContent::Sequence(ref l) => {
155            v.visit_ber_sequence(l, depth);
156            for item in l.iter() {
157                visit_ber_bfs(v, item, depth + 1);
158            }
159        }
160        BerObjectContent::Set(ref l) => {
161            v.visit_ber_set(l, depth);
162            for item in l.iter() {
163                visit_ber_bfs(v, item, depth + 1);
164            }
165        }
166        BerObjectContent::T61String(s) => v.visit_ber_teletexstring(s, depth),
167        BerObjectContent::Tagged(class, tag, ref obj) => {
168            v.visit_ber_tagged(class, tag, obj.as_ref(), depth)
169        }
170        BerObjectContent::UTCTime(ref t) => v.visit_ber_utctime(t, depth),
171        BerObjectContent::UTF8String(s) => v.visit_ber_utf8string(s, depth),
172        BerObjectContent::UniversalString(b) => v.visit_ber_universalstring(b, depth),
173        BerObjectContent::Unknown(ref inner) => v.visit_ber_unknown(inner, depth),
174        BerObjectContent::VideotexString(s) => v.visit_ber_videotextstring(s, depth),
175        BerObjectContent::VisibleString(s) => v.visit_ber_visiblestring(s, depth),
176    }
177}
178
179#[cfg(test)]
180mod tests {
181    use super::Visit;
182    use crate::ber::BerObject;
183
184    #[derive(Debug)]
185    struct BerObjectVisitor {}
186
187    impl<'a> Visit<'a> for BerObjectVisitor {
188        fn visit_ber(&mut self, ber: &'_ BerObject<'a>, depth: usize) {
189            eprintln!("Depth {}: Object with tag {}", depth, ber.tag());
190        }
191    }
192}
der_parser/ber/visit.rs

der_parser/ber/
visit.rs
