use crate::{
asn1::{
Asn1DecodeWrapper, Asn1EncodeWrapper, BOOLEAN_TAG, Boolean, Len, Octetstring, Oid,
SEQUENCE_TAG, asn1_writer, decode_asn1_tlv,
},
codec::{Decode, DecodeWrapper, Encode, EncodeWrapper, GenericCodec},
x509::X509Error,
};
#[derive(Debug, PartialEq)]
pub struct Extension<'bytes> {
pub extn_id: Oid,
pub critical: bool,
pub extn_value: Octetstring<&'bytes [u8]>,
}
impl<'de> Decode<'de, GenericCodec<Asn1DecodeWrapper, ()>> for Extension<'de> {
#[inline]
fn decode(dw: &mut DecodeWrapper<'de, Asn1DecodeWrapper>) -> crate::Result<Self> {
let (SEQUENCE_TAG, _, value, rest) = decode_asn1_tlv(dw.bytes)? else {
return Err(X509Error::InvalidExtension.into());
};
dw.bytes = value;
let extn_id = Oid::decode(dw)?;
let critical =
if dw.bytes.first() == Some(&BOOLEAN_TAG) { Boolean::decode(dw)?.0 } else { false };
let extn_value = Octetstring::decode(dw)?;
dw.bytes = rest;
Ok(Self { extn_id, critical, extn_value })
}
}
impl<'bytes> Encode<GenericCodec<(), Asn1EncodeWrapper>> for Extension<'bytes> {
#[inline]
fn encode(&self, ew: &mut EncodeWrapper<'_, Asn1EncodeWrapper>) -> crate::Result<()> {
asn1_writer(ew, Len::MAX_THREE_BYTES, SEQUENCE_TAG, |local_ew| {
self.extn_id.encode(local_ew)?;
if self.critical {
Boolean(self.critical).encode(local_ew)?;
}
self.extn_value.encode(local_ew)?;
Ok(())
})
}
}