A library for reading and writing ASN.1 data.

Examples

Encoding/decoding simple data

A type implementing DEREncodable can be easily encoded:

extern crate yasna;

fn main() {
let der = yasna::encode_der(&(10, true));
println!("(10, true) = {:?}", der);
}

Similarly, a type implementing BERDecodable can be easily decoded:

extern crate yasna;

fn main() {
let asn: (i64, bool) = yasna::decode_der(
&[48, 6, 2, 1, 10, 1, 1, 255]).unwrap();
println!("{:?} = [48, 6, 2, 1, 10, 1, 1, 255]", asn);
}

Encoding/decoding by hand

Default DEREncodable/BERDecodable implementations can't handle all ASN.1 type. In many cases you have to write your reader/writer by hand.

To serialize ASN.1 data, you can use construct_der.

extern crate yasna;

fn main() {
let der = yasna::construct_der(|writer| {
writer.write_sequence(|writer| {
writer.next().write_i64(10);
writer.next().write_bool(true);
})
});
println!("(10, true) = {:?}", der);
}

To deserialize ASN.1 data, you can use parse_ber or parse_der.

extern crate yasna;

fn main() {
let asn = yasna::parse_der(&[48, 6, 2, 1, 10, 1, 1, 255], |reader| {
reader.read_sequence(|reader| {
let i = try!(reader.next().read_i64());
let b = try!(reader.next().read_bool());
return Ok((i, b));
})
}).unwrap();
println!("{:?} = [48, 6, 2, 1, 10, 1, 1, 255]", asn);
}