Support circom proof convert for both BN254 and BLS12-381

[vivianjeng]

Problem

Now we implemented toEthereumProof and fromEthereumProof

mopro/mopro-ffi/src/circom/ethereum.rs

Lines 27 to 28 in da02fc4

	// Only supports bn254 for now
	pub fn to_ethereum_proof(proof: Vec<u8>) -> ProofCalldata {

But it only supports Bn254 for now
We can add support for BLS12-381

Discussion: #367 (comment)
Discussion: #361 (comment)

Details

Solution 1 (best)

Convert the proofs in circom-prover with the types: https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/snarkjs/index.d.cts
so that the struct becomes

pub struct CircomProof {
    pub a: G1, // each element is BigUint type
    pub b: G2,
    pub c: G1,
    pub protocol: String,
    pub curve: String,
}

// circom-prover
pub struct GenerateProofResult {
    pub proof: CircomProof,
    pub inputs: Vec<BigUint>,
}

// mopro-ffi
pub struct GenerateProofResult {
    pub proof: CircomProof, // convert all BigUint to String
    pub inputs: Vec<String>, // convert all BigUint to String
}

the API becomes

// circom-prover
pub fn prove(
        proof_lib: ProofLib,
        wit_fn: WitnessFn,
        json_input_str: String,
        zkey_path: String,
    ) -> Result<CircomProof> {

pub fn verify(
        proof_lib: ProofLib,
        proof: CircomProof // merge proof and public_signals
        zkey_path: String,
    ) -> Result<bool> {

We have handled all BN254 and BLS12-381 convert in https://github.com/zkmopro/mopro/blob/main/circom-prover/src/prover/ethereum.rs
Then it should support these 2 curves to convert to CircomProof
Just need to update the mopro-ffi and test-e2e types

Solution 2 (short term, not recommended)

add support for toEthereumProof with

mopro/mopro-ffi/src/circom/ethereum.rs

Lines 28 to 29 in da02fc4

	pub fn to_ethereum_proof(proof: Vec<u8>) -> ProofCalldata {
	let deserialized_proof = deserialize_proof::<Bn254>(proof);

deserialize/serialize BLS12-381

Acceptance criteria

Support for both BN254 and BLS12-381 that the proof needs to be

1. readable (like toEthereumProof)
2. verifiable (in verify_circom_proof)
3. exportable (with uniffi)

Next steps (optional)

If choose Solution 1, and we can remove all toEthereumProof, fromEthereumProof, toEthereumInputs, fromEthereumInputs