79 lines
2.5 KiB
Rust

use crate::data_model::rc::AccessDescription;
pub(super) fn encode_access_description_der_for_vcir_ccr_projection(
access_description: &AccessDescription,
) -> Result<Vec<u8>, String> {
let oid = encode_oid_der_for_vcir_ccr_projection(&access_description.access_method_oid)?;
let uri = encode_tlv_for_vcir_ccr_projection(
0x86,
access_description.access_location.as_bytes().to_vec(),
);
Ok(encode_sequence_for_vcir_ccr_projection(&[oid, uri]))
}
fn encode_oid_der_for_vcir_ccr_projection(oid: &str) -> Result<Vec<u8>, String> {
let arcs = oid
.split('.')
.map(|part| {
part.parse::<u64>()
.map_err(|_| format!("unsupported accessMethod OID: {oid}"))
})
.collect::<Result<Vec<_>, _>>()?;
if arcs.len() < 2 {
return Err(format!("unsupported accessMethod OID: {oid}"));
}
if arcs[0] > 2 || (arcs[0] < 2 && arcs[1] >= 40) {
return Err(format!("unsupported accessMethod OID: {oid}"));
}
let mut body = Vec::new();
body.push((arcs[0] * 40 + arcs[1]) as u8);
for arc in &arcs[2..] {
encode_base128_for_vcir_ccr_projection(*arc, &mut body);
}
Ok(encode_tlv_for_vcir_ccr_projection(0x06, body))
}
fn encode_base128_for_vcir_ccr_projection(mut value: u64, out: &mut Vec<u8>) {
let mut tmp = vec![(value & 0x7F) as u8];
value >>= 7;
while value > 0 {
tmp.push(((value & 0x7F) as u8) | 0x80);
value >>= 7;
}
tmp.reverse();
out.extend_from_slice(&tmp);
}
fn encode_sequence_for_vcir_ccr_projection(elements: &[Vec<u8>]) -> Vec<u8> {
let total_len: usize = elements.iter().map(Vec::len).sum();
let mut buf = Vec::with_capacity(total_len);
for element in elements {
buf.extend_from_slice(element);
}
encode_tlv_for_vcir_ccr_projection(0x30, buf)
}
fn encode_tlv_for_vcir_ccr_projection(tag: u8, value: Vec<u8>) -> Vec<u8> {
let mut out = Vec::with_capacity(1 + 9 + value.len());
out.push(tag);
encode_length_for_vcir_ccr_projection(value.len(), &mut out);
out.extend_from_slice(&value);
out
}
fn encode_length_for_vcir_ccr_projection(len: usize, out: &mut Vec<u8>) {
if len < 0x80 {
out.push(len as u8);
return;
}
let mut bytes = Vec::new();
let mut value = len;
while value > 0 {
bytes.push((value & 0xFF) as u8);
value >>= 8;
}
bytes.reverse();
out.push(0x80 | (bytes.len() as u8));
out.extend_from_slice(&bytes);
}