logo
pub struct OptTaggedParser {
    pub class: Class,
    pub tag: Tag,
}
Available on crate feature mtls only.
Expand description

Helper object to parse TAGGED OPTIONAL types (explicit or implicit)

This object can be used similarly to a builder pattern, to specify the expected class and tag of the object to parse, and the content parsing function.

The content parsing function takes two arguments: the outer header, and the data.

It can be used for both EXPLICIT or IMPLICIT tagged objects by using parsing functions that expect a header (or not) in the contents.

The OptTaggedParser::from method is a shortcut to build an object with ContextSpecific class and the given tag. The OptTaggedParser::new method is more generic.

See also OptTaggedExplicit and OptTaggedImplicit for alternatives that implement FromBer/ FromDer.

Examples

To parse a [APPLICATION 0] EXPLICIT INTEGER OPTIONAL object:

use asn1_rs::{Class, FromDer, Integer, Tag, OptTaggedParser};

let bytes = &[0x60, 0x03, 0x2, 0x1, 0x2];

let (_, tagged) = OptTaggedParser::new(Class::Application, Tag(0))
                    .parse_der(bytes, |_, data| Integer::from_der(data))
                    .unwrap();

assert_eq!(tagged, Some(Integer::from(2)));

To parse a [0] IMPLICIT INTEGER OPTIONAL object:

use asn1_rs::{Integer, OptTaggedParser};

let bytes = &[0xa0, 0x1, 0x2];

let (_, tagged) = OptTaggedParser::from(0)
                    .parse_der(bytes, |_, data| Ok((&[], Integer::new(data))))
                    .unwrap();

assert_eq!(tagged, Some(Integer::from(2)));

Fields

class: Class

The expected class for the object to parse

tag: Tag

The expected tag for the object to parse

Implementations

Build a new OptTaggedParser object.

If using Class::ContextSpecific, using OptTaggedParser::from with either a Tag or u32 is a shorter way to build this object.

Parse input as BER, and apply the provided function to parse object.

Returns the remaining bytes, and Some(T) if expected tag was found, else None.

This function returns an error if tag was found but has a different class, or if parsing fails.

Examples

To parse a [0] EXPLICIT INTEGER OPTIONAL object:

use asn1_rs::{FromBer, Integer, OptTaggedParser};

let bytes = &[0xa0, 0x03, 0x2, 0x1, 0x2];

let (_, tagged) = OptTaggedParser::from(0)
                    .parse_ber(bytes, |_, data| Integer::from_ber(data))
                    .unwrap();

assert_eq!(tagged, Some(Integer::from(2)));

Parse input as DER, and apply the provided function to parse object.

Returns the remaining bytes, and Some(T) if expected tag was found, else None.

This function returns an error if tag was found but has a different class, or if parsing fails.

Examples

To parse a [0] EXPLICIT INTEGER OPTIONAL object:

use asn1_rs::{FromDer, Integer, OptTaggedParser};

let bytes = &[0xa0, 0x03, 0x2, 0x1, 0x2];

let (_, tagged) = OptTaggedParser::from(0)
                    .parse_der(bytes, |_, data| Integer::from_der(data))
                    .unwrap();

assert_eq!(tagged, Some(Integer::from(2)));

Trait Implementations

Formats the value using the given formatter. Read more

Build a TaggedOptional object with class ContextSpecific and given tag

Build a TaggedOptional object with class ContextSpecific and given tag

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more

Instruments this type with the current Span, returning an Instrumented wrapper. Read more

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Converts self into a collection.

Should always be Self

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more