grpc.proto

// File copied from golang tofnd with minor tweaks
syntax = "proto3";

option go_package = "tofnd;tofnd";

package tofnd;

import "common.proto"; // import key presence request/response

// GG20 is the protocol https://eprint.iacr.org/2020/540
// rpc definitions intended to wrap the API for this library: https://github.com/axelarnetwork/tofn
service GG20 {
    rpc Recover(RecoverRequest) returns (RecoverResponse);
    rpc Keygen(stream MessageIn) returns (stream MessageOut);
    rpc Sign(stream MessageIn) returns (stream MessageOut);
    rpc KeyPresence(KeyPresenceRequest) returns (KeyPresenceResponse);
}

message RecoverRequest {
    KeygenInit keygen_init = 1;
    KeygenOutput keygen_output = 2;
}

message RecoverResponse { 
    enum Response {
        RESPONSE_UNSPECIFIED = 0;
        RESPONSE_SUCCESS = 1;
        RESPONSE_FAIL = 2;
    }
    Response response = 1; 
}

// Keygen's success response
message KeygenOutput {
    bytes pub_key = 1;               // pub_key; common for all parties
    bytes group_recover_info = 2;    // recovery info common for all parties
    bytes private_recover_info = 3;  // recovery info unique for each party
}

// generic message types shared by Keygen, Sign

// TODO use nested message types
// eg. KeygenInit, SignInit should be defined inside MessageIn, etc.

message MessageIn {
    oneof data {                    // TODO don't reuse `data`
        KeygenInit keygen_init = 1; // first message only, Keygen
        SignInit sign_init = 2;     // first message only, Sign
        TrafficIn traffic = 3;      // all subsequent messages
        bool abort = 4;             // abort the protocol, ignore the bool value
    }
}

message MessageOut {

    oneof data {                        // TODO don't reuse `data`
        TrafficOut traffic = 1;         // all but final message
        KeygenResult keygen_result = 2; // final message only, Keygen
        SignResult sign_result = 3;     // final message only, Sign
        bool need_recover = 4;   // issue recover from client
    }

    // Keygen's response types
    message KeygenResult {
        oneof keygen_result_data {
            KeygenOutput data = 1;       // Success response
            CriminalList criminals = 2;  // Failure response
        }
    }

    // Sign's response types
    message SignResult {
        oneof sign_result_data {
            bytes signature = 1;        // Success response
            CriminalList criminals = 2; // Failure response
        }
    }

    // Keygen/Sign failure response message
    message CriminalList {
        repeated Criminal criminals = 1;

        message Criminal {
            string party_uid = 1;
        
            enum CrimeType {
                CRIME_TYPE_UNSPECIFIED = 0;
                CRIME_TYPE_NON_MALICIOUS = 1;
                CRIME_TYPE_MALICIOUS = 2;
            }
            CrimeType crime_type = 2;
        }
    }
}

message TrafficIn {
    string from_party_uid = 1;
    bytes payload = 2;
    bool is_broadcast = 3;
}

message TrafficOut {
    string to_party_uid = 1;
    bytes payload = 2;
    bool is_broadcast = 3;
}

// Keygen-specific message types

message KeygenInit {
    string new_key_uid = 1;
    repeated string party_uids = 2;
    repeated uint32 party_share_counts = 5;
    uint32 my_party_index = 3; // parties[my_party_index] belongs to the server
    uint32 threshold = 4;
}

// Sign-specific message types

message SignInit {
    string new_sig_uid = 1;
    string key_uid = 2;
    repeated string party_uids = 3; // TODO replace this with a subset of indices?
    bytes message_to_sign = 4;
}