rust-asn1

This is a Rust library for parsing and generating ASN.1 data (DER only).

Installation

Add asn1 to your Cargo.toml:

$ cargo add asn1

Builds on Rust 1.83.0 and newer.

rust-asn1 is compatible with #![no_std] environments:

$ cargo add asn1 --no-default-features

Changelog

Unreleased

Added

• Added Set, SetWriter, and SetElementWriter types for parsing and
  writing ASN.1 SET values with DER ordering validation.

[0.23.1]

Added

• Tag now exposes a write_to method that writes the tag's encoded
  representation to a WriteBuf.

[0.23.0]

Added

• Writer now exposes write_explicit_element and write_implicit_element
  methods that allow encoding EXPLICIT/IMPLICIT elements when the tag number
  is not known at compile time.

• NonZero numbers now implement Asn1Writable.

Changes

• Updated MSRV to 1.83.0.

[0.22.0]

Added

• Added Asn1Writable::encoded_length, SimpleAsn1Writable::data_length, and
  Asn1DefinedByWritable::encoded_length. Implementing these functions reduces
  the number of re-allocations required when writing. None can be returned if
  it is not possible to provide an efficient implementation.

Changes

• Updated MSRV to 1.74.0.

[0.21.3]

Added

• BitString::new is now const fn.

[0.21.2]

Added

• BigInt::new, BigUint::new, and DateTime::new are now const fn.

[0.21.1]

Added

• Parser now exposes a peek_tag method that returns the tag of the next
  element in the parse, without consuming that element.
  (#532)
• Parser now exposes read_explicit_element and read_implicit_element
  methods that allow parsing EXPLICIT/IMPLICIT elements when the tag number
  is not known at compile time.
• PrintableString, Utf8String, BMPString, and UniversalString now
  #[derive(Hash)]. (#536)

[0.21.0]

Changes

• Updated MSRV to 1.65.0.

Fixes

• Fixed "perfect derives"
  in conjunction with #[derive(Asn1DefinedByRead)] and
  #[derive(Asn1DefinedByWrite)].
  (#506)

[0.20.0]

:rotating_light: Breaking changes

• Removed Writer::{write_explicit_element, write_optional_explicit_element, write_implicit_element, write_optional_implicit_element}.
  These can all be better accomplished with the asn1::Explicit and
  asn1::Implicit types.

Fixes

• Fixed "perfect derives"
  in conjunction with #[implicit] and #[explicit].
  (#502)

[0.19.0]

:rotating_light: Breaking changes

• GeneralizedTime has been renamed to X509GeneralizedTime. The type does
  not allow fractional seconds, however this restriction is not actually a DER
  rule, it is specific to X.509.
  (#494)

• GeneralizedTime is a new type that accepts fractional seconds
  replacing the old GeneralizedTime.
  (#492)

• #[derive(asn1::Asn1Read)] and #[derive(asn1::Asn1Write)] now implement
  "perfect derives".
  (#496)