dvb-ci

DVB Common Interface (EN 50221) — the host ↔ CICAM wire protocol, as typed Rust. Parses and builds the EN 50221 protocol objects across all three layers (transport, session, application), the DVB CI extensions (ETSI TS 101 699) and the CI Plus extension APDUs (ETSI TS 103 205), plus a CA_PMT builder that turns a dvb-si PMT into the object handed to a Conditional Access Module.

dvb-si PmtSection --> dvb_ci::builder::build_ca_pmt --> ca_pmt object (9F 80 32) --> CICAM

What it does / what it does not

Does. Turns bytes into typed objects and back, losslessly: every TPDU, SPDU and APDU (including the CI-extension and CI Plus resource objects) parses into a struct with every spec field, and serializes back to identical bytes. It builds ca_pmt objects from a parsed PMT and filters them to the CAM's advertised CA_system_ids. It is sans-IO: it never touches a device.

Does not.

• It does not talk to hardware. The PC-Card / CA-device transport, the TPDU poll loop and the resource state machines live in dvb-ci-runtime.
• It does not implement CI Plus cryptography (the Content Control resource's authentication, key derivation and SAC encryption). The CI Plus APDU framing is typed; the cryptography is not, and the Content Control SAC payloads are carried as typed datatypes, never decrypted.
• It does not implement CI+ over USB (ETSI TS 103 605) or the PCMCIA electrical layer.
• It is not a descrambler: it never sees a control word being applied (see dvb-csa).

Standards supported

Features

Quick start

use broadcast_common::Serialize;
use dvb_ci::AnyApdu;
use dvb_ci::length::LengthForm;
use dvb_ci::objects::ca_info::CaInfo;

// A ca_info() APDU advertising two CA_system_ids.
let info = CaInfo {
    length_form: LengthForm::Minimal,
    ca_system_ids: vec![0x0500, 0x0B00],
};
let wire = info.try_to_bytes().unwrap(); // 9F 80 31 04 05 00 0B 00
assert_eq!(wire, [0x9F, 0x80, 0x31, 0x04, 0x05, 0x00, 0x0B, 0x00]);

// Route any APDU by its 3-byte tag without knowing the type up front.
let any = AnyApdu::parse(&wire).unwrap();
assert_eq!(any.name(), "CA_INFO");
assert_eq!(any.try_to_bytes().unwrap(), wire); // round-trips byte-for-byte

Two runnable examples ship with the crate (cargo run -p dvb-ci --example <name>): build_ca_pmt (PMT to ca_pmt, stripping non-CA descriptors) and parse_apdu (dispatch and round-trip, including an unknown tag).

What is implemented

Design notes

• Symmetric Parse/Serialize. Every wire type implements broadcast_common::Parse / Serialize; parse to serialize is byte-identical or the parse is an error (a longer length_field than a fixed layout allows is rejected). A property test drives every dispatch enum with pseudo-random bodies.
• Preserved framing. A CAM may code a length in a longer form than necessary (82 00 09 for 9, captured on real hardware); LengthForm is kept on every object and re-emitted. Reserved bits a peer sent are kept in typed reserved fields (reserved::Reserved), defaulting to the spec fill.
• Typed PIDs. Every 13-bit PID field is mpeg_ts::pid::Pid.
• Resource-scoped dispatch. The extension resources reuse 0x9F80xx tags, so they cannot join the global AnyApdu; dispatch is by resource id first.
• #![no_std] + alloc, structured thiserror errors, #[non_exhaustive] on dispatch enums.
• Not verified against real CAM hardware beyond the captured length-coding case; hardware work is in dvb-ci-runtime.

Related crates

dvb-ci depends on broadcast-common (traits), dvb-si (PMT / CA descriptors) and mpeg-ts (Pid). dvb-ci-runtime builds the driver runtime on top of it.

MSRV and licence

MSRV 1.95.0. Licensed under MIT OR Apache-2.0.