Function compile_to_mpc

ciphercore-base/src/mpc/mpc_compiler.rs:1053–1096

Compiles all the graphs of an already inlined context into graphs for secure computation. Namely, every plaintext operation is replaced by a related MPC protocol from the ABY3 framework. The given input-party map describes what statuses of inputs (public, shared or owned by a party). The `output_parties` argument contains ids of the parties (from 0..PARTIES) that obtain the revealed result of MPC

(
    context: Context,
    input_party_map: Vec<Vec<IOStatus>>,
    output_parties: Vec<Vec<IOStatus>>,
)

/// If private, the output of the main graph is always a tuple of 3 elements where the first element is known to the first party,
/// the second to the second one etc. Thus, the first tuple element can be either a share or a revealed value known to the first party.
fn compile_to_mpc(
    context: Context,
    input_party_map: Vec<Vec<IOStatus>>,
    output_parties: Vec<Vec<IOStatus>>,
) -> Result<MappedContext> {
    for sub_map in &input_party_map {
        for status in sub_map {
            if let IOStatus::Party(id) = *status {
                if id >= PARTIES as u64 {
                    return Err(runtime_error!("Input party should have a valid party ID"));
                }
            }
        }
    }
    for sub_parties in &output_parties {
        for status in sub_parties {
            if let IOStatus::Party(id) = *status {
                if id >= PARTIES as u64 {
                    return Err(runtime_error!("Output party should have a valid party ID"));
                }
            } else {
                return Err(runtime_error!(
                    "Output status should be a party id or shared"
                ));
            }
        }
    }
    let new_context = create_context()?;
    let mut context_map = ContextMappings::default();
    compile_to_mpc_context(
        context.clone(),
        input_party_map,
        output_parties,
        new_context.clone(),
        &mut context_map,
    )?;
    let old_main_graph = context.get_main_graph()?;
    let main_graph = context_map.get_graph(old_main_graph);
    new_context.set_main_graph(main_graph)?;
    new_context.finalize()?;
    let mut mapped_context = MappedContext::new(new_context);
    mapped_context.mappings = context_map;
    Ok(mapped_context)
}

/// Creates a new copy of an input context with PRF nodes containing globally unique inputs (iv's).
/// These global inputs are taken from the set {1,2,...,n} where n is the total number of PRF nodes.