use crate::{
asn1::{
Any, Asn1DecodeWrapper, Asn1EncodeWrapper, Len, Oid, SEQUENCE_TAG, asn1_writer, decode_asn1_tlv,
},
codec::{Decode, DecodeWrapper, Encode, EncodeWrapper, GenericCodec},
x509::X509Error,
};
#[derive(Clone, Debug, PartialEq)]
pub struct AlgorithmIdentifier<'bytes> {
pub algorithm: Oid,
pub parameters: Option<Any<&'bytes [u8]>>,
}
impl<'bytes> AlgorithmIdentifier<'bytes> {
pub const fn from_algorithm(algorithm: Oid) -> Self {
Self { algorithm, parameters: None }
}
pub const fn new(algorithm: Oid, parameters: Option<Any<&'bytes [u8]>>) -> Self {
Self { algorithm, parameters }
}
}
impl<'de> Decode<'de, GenericCodec<Asn1DecodeWrapper, ()>> for AlgorithmIdentifier<'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::InvalidAlgorithmIdentifier.into());
};
dw.bytes = value;
let algorithm = Oid::decode(dw)?;
let parameters = if dw.bytes.is_empty() { None } else { Some(Any::decode(dw)?) };
dw.bytes = rest;
Ok(Self { algorithm, parameters })
}
}
impl<'bytes> Encode<GenericCodec<(), Asn1EncodeWrapper>> for AlgorithmIdentifier<'bytes> {
#[inline]
fn encode(&self, ew: &mut EncodeWrapper<'_, Asn1EncodeWrapper>) -> crate::Result<()> {
asn1_writer(ew, Len::MAX_ONE_BYTE, SEQUENCE_TAG, |local_ew| {
self.algorithm.encode(local_ew)?;
if let Some(params) = &self.parameters {
params.encode(local_ew)?;
}
Ok(())
})
}
}