Skip to main content

Configuration

co-circom uses a configuration for general settings and network configuration. The configuration can be done via a config file, environment variables, and cli arguments. Values are loaded in hierarchical order file < environment variables < cli args.

A path to the configuration file can be passed to all commands using --config <CONFIG>. Different commands have different required values that must be passed by file, env, or cli. The network section is only required for the commands generate-witness, translate-witness and generate-proof.

TOML File​

The configuration file is a TOML file with the following (non-exhaustive) structure:

protocol = "REP3"
curve = "BN254"

[compiler]
version = "2.0.0"
link_library = ["circomlibs", "utils"]
allow_leaky_loops = false

[vm]
allow_leaky_logs = false

[network]
my_id = 0
bind_addr = "0.0.0.0:10000"
key_path = "data/key0.der"
[[network.parties]]
id = 0
# normally we would use DNS name here such as localhost, but localhost under windows is resolved to ::1, which causes problems since we bind to ipv4 above
dns_name = "127.0.0.1:10000"
cert_path = "data/cert0.der"
[[network.parties]]
id = 1
dns_name = "127.0.0.1:10001"
cert_path = "data/cert1.der"
[[network.parties]]
id = 2
dns_name = "127.0.0.1:10002"
cert_path = "data/cert2.der"

See the example configuration in the collaborative-circom/examples/configs folder, with pre-generated certificates and keys in the collaborative-circom/examples/data folder.

Env Variables​

Environment variables use the prefix COCIRCOM_. The different types can be set as follows:

  • Boolean: true, false (e.g. COCIRCOM_VAR=true)
  • Strings/Enums: delimited by " (e.g. COCIRCOM_VAR=\"foo\") or else (e.g. COCIRCOM_VAR=foo)
  • Arrays: delimited by [] (e.g. COCIRCOM_VAR=[1, 2, 3])
  • Structs: as dictionary with {key=value} (e.g. COCIRCOM_VAR={foo=1, bar=true})

E.g. the protocol can be set with COCIRCOM_PROTOCOL=BN254. Structs such as the CompilerConfig can be set with COCIRCOM_COMPILER={allow_leaky_loops=true}.

Cli Arguments​

See co-circom CLI

Compiler Configuration​

This section configures the co-circom MPC compiler.

Keys​

  • version: Allows leaking of secret values in loops (default: "2.0.0")
  • link_library: A list of strings that represent paths for circom to look for library files (-l flag in circom) (default: [])
  • allow_leaky_loops: Allows leaking of secret values in loops (default: false) (currently not implemented).
  • simplification: Controls the simplification level applied during constraint generation (default: O2(usize::MAX))
    • O0: No simplification
    • O1: Only applies signal to signal and signal to constant simplification
    • O2(n): Full constraint simplification (applied for n rounds)
  • verbose: Shows logs during compilation
  • inspect: Does an additional check over the constraints produced

VM Configuration​

This section configures the co-circom VM.

Keys​

  • allow_leaky_logs: Allows leaking of secret values in logs (default: false).

Network Configuration​

co-circom requires a network configuration for establishing connections to other MPC parties for the generate-witness and generate-proof commands.

Keys​

  • my_id is the party id of the party executing the co-circom binary using the configuration file.
  • bind_addr is the local socket address this party is binding to and listening for incoming connections from other parties.
  • key_path is a path to a DER encoded PKCS8 private key file corresponding to the public key used in the certificate for our party.
  • parties is an array of tables containing the public information of each MPC party.
    • id: the party id of the MPC party
    • dns_name: the hostname/port combination where the party is publicly reachable. The hostname must be the a valid CN or SNI in the used certificate.
    • cert_path: a path to the DER encoded certificate (chain) file that is used to authenticate the connection with the party and is used to establish the secure communication channel.