Trait ldap_parser::FromBer

source · [−]
pub trait FromBer<'a, E = Error> {
    fn from_ber(bytes: &'a [u8]) -> Result<(&'a [u8], Self), Err<E>>;
}
Expand description

Base trait for BER object parsers

Library authors should usually not directly implement this trait, but should prefer implementing the TryFrom<Any> trait, which offers greater flexibility and provides an equivalent FromBer implementation for free.

Examples

use asn1_rs::{Any, Result, Tag};
use std::convert::TryFrom;

// The type to be decoded
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct MyType(pub u32);

impl<'a> TryFrom<Any<'a>> for MyType {
    type Error = asn1_rs::Error;

    fn try_from(any: Any<'a>) -> Result<MyType> {
        any.tag().assert_eq(Tag::Integer)?;
        // for this fictive example, the type contains the number of characters
        let n = any.data.len() as u32;
        Ok(MyType(n))
    }
}

// The above code provides a `FromBer` implementation for free.

// Example of parsing code:
use asn1_rs::FromBer;

let input = &[2, 1, 2];
// Objects can be parsed using `from_ber`, which returns the remaining bytes
// and the parsed object:
let (rem, my_type) = MyType::from_ber(input).expect("parsing failed");

Required Methods

Attempt to parse input bytes into a BER object

Implementations on Foreign Types

Implementors

Parse a single LDAP message and return a structure borrowing fields from the input buffer

use ldap_parser::FromBer;
use ldap_parser::ldap::{LdapMessage, MessageID, ProtocolOp, ProtocolOpTag};

static DATA: &[u8] = include_bytes!("../assets/message-search-request-01.bin");

let res = LdapMessage::from_ber(DATA);
match res {
    Ok((rem, msg)) => {
        assert!(rem.is_empty());
        //
        assert_eq!(msg.message_id, MessageID(4));
        assert_eq!(msg.protocol_op.tag(), ProtocolOpTag::SearchRequest);
        match msg.protocol_op {
            ProtocolOp::SearchRequest(req) => {
                assert_eq!(req.base_object.0, "dc=rccad,dc=net");
            },
            _ => panic!("Unexpected message type"),
        }
    },
    _ => panic!("LDAP parsing failed: {:?}", res),
}