asn1_der 0.6.3

This crate provides a simple ASN.1-DER en-/decoder

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Welcome to my asn1_der-crate 🎉

What this crate is:

This crate helps you to DER-(de-)serialize various types. It provides some traits to convert between encoded data, DER-objects and native types as well and implements them for some common types. If you build it with the derive-feature (enabled by default), you can use #[derive(Asn1Der)] to derive the traits for your named structs.

The following types have built-in support:

  • DerObject: A generic DER-object-wrapper that can hold any object (DerObject{ tag: u8, payload: Vec<u8> })
  • (): The ASN.1-NULL-type
  • bool: The ASN.1-BOOLEAN-type
  • Vec<u8>: The ASN.1-OctetString-type
  • String: The ASN.1-UTF8String-type
  • u128: The ASN.1-INTEGER-type (within [0, 2^128))
  • Vec<T>: The ASN.1-SEQUENCE-type for any type T that implements FromDerObject and IntoDerObject

With the derive-feature you can automatically derive FromDerObject and IntoDerObject:

#[derive(Asn1Der)] // Now our struct supports all DER-conversion-traits
struct Address {
	street: String,
	house_number: u128,
	postal_code: u128,
	state: String,
	country: String

struct Customer {
	name: String,
	e_mail_address: String,
	postal_address: Address

// Serialization:
let mut serialized = vec![0u8; my_customer.serialized_len()];

// Deserialization (this returns our customer if the data is valid):
let my_customer = Customer::deserialize(serialized.iter()).unwrap();

Changes from 0.5.10 to 0.6.0

From 0.5.10 to 0.6.0 the library was nearly completely rewritten with a much more modular approach.

  • The library is now separated into two modules:

    • The der module which contains the generic DER implementation which is more stringent than the previous version and uses iterators instead of slices to avoid unexpected panics
    • The types module which defines the FromDerObject and IntoDerObject traits and already implements them for some native types
  • The tests are also separated into multiple files that map to the modules

  • The asn1_der_impl!-macro was replaced with a procedural derive macro in the asn1_der_derive-subcrate

If you are looking for the old version, you can find it here – however please note that the old version is deprecated and may contain some serious issues.


This depends on your selected features. If you use the derive-feature (enabled by default), the crate depends on the quote and syn crates which are used in the procedural macro implementation.

If you don't use the derive-feature, this crate is dependency-less.

Long-Term Goals:

  • Create a C-interface to make this library usable from C-FFI-compatible languages