Skip to content

der: add test for derive Sequence with IMPLICIT SequenceRef #2010

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 3 commits into
base: master
Choose a base branch
from
Open

der: add test for derive Sequence with IMPLICIT SequenceRef #2010

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
c33291b
der: add `new` and derives to SequenceRef
kamulos Aug 2, 2025
3ac2a6b
der: add test for derive Sequence with IMPLICIT SequenceRef
dishmaker Aug 22, 2025
88ebffb
der: docs: SequenceRef::new
dishmaker Aug 24, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
12 changes: 10 additions & 2 deletions der/src/asn1/sequence.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2,8 +2,8 @@
//! `SEQUENCE`s to Rust structs.

use crate::{
BytesRef, DecodeValue, EncodeValue, Error, FixedTag, Header, Length, Reader, Result, Tag,
Writer,
BytesRef, DecodeValue, EncodeValue, Error, ErrorKind, FixedTag, Header, Length, Reader, Result,
Tag, Writer,
};

#[cfg(feature = "alloc")]
Expand All @@ -28,12 +28,20 @@ impl<'a, T> Sequence<'a> for Box<T> where T: Sequence<'a> {}
/// DER-encoded `SEQUENCE`.
///
/// This is a zero-copy reference type which borrows from the input data.
#[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
pub struct SequenceRef<'a> {
/// Body of the `SEQUENCE`.
body: &'a BytesRef,
}

impl<'a> SequenceRef<'a> {
/// Create a new [`SequenceRef`] from the DER bytes of the inner value.
pub fn new(slice: &'a [u8]) -> Result<Self> {
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This is one I don't understand.
How does that not break invariants?

SequenceRef::from_der should already work? I'm missing something.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

from_der would parse tag and length first, then the contents.

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Yeah, they do two different things: from_der would need the tag/length header, where this is just the "value" portion sans header

Copy link
Member

@baloo baloo Aug 23, 2025 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

That makes more sense.
But then I would say the comment could probably use an update (as is, it would definitely have tripped me up).

Something like /// Create a new [SequenceRef] from the DER bytes of the inner value or something along those lines.

BytesRef::new(slice)
.map(|body| Self { body })
.map_err(|_| ErrorKind::Length { tag: Self::TAG }.into())
}

/// Borrow the inner byte slice.
pub fn as_bytes(&self) -> &'a [u8] {
self.body.as_slice()
Expand Down
24 changes: 23 additions & 1 deletion der/tests/derive.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -278,7 +278,7 @@ mod sequence {
use core::marker::PhantomData;
use der::{
Decode, Encode, Sequence, ValueOrd,
asn1::{AnyRef, ObjectIdentifier, SetOf},
asn1::{AnyRef, ObjectIdentifier, SequenceRef, SetOf},
};
use hex_literal::hex;

Expand Down Expand Up @@ -723,6 +723,28 @@ mod sequence {
algorithm_identifier.to_der().unwrap()
);
}

#[derive(Debug, Sequence)]
pub struct OidAndImplicitSequence<'a> {
pub oid: ObjectIdentifier,
#[asn1(context_specific = "0", tag_mode = "IMPLICIT")]
pub data: SequenceRef<'a>,
}

#[test]
fn roundtrip_oid_and_implicit_sequence() {
let obj_data: &[u8] = &hex!(
"30 09" // SEQUENCE
"06 03" // OBJECT IDENTIFIER
"29 01 01" // oid "1.1.1.1"
"A0 02" // CONTEXT-SPECIFIC [0] (constructed)
"AA BB"
);
let obj = OidAndImplicitSequence::from_der(obj_data).unwrap();

assert_eq!(obj.data.as_bytes(), &hex!("AA BB"));
assert_eq!(obj_data, &obj.to_der().unwrap());
}
}

/// Custom derive test cases for the `EncodeValue` macro.
Expand Down