Support for Fireblocks

[anxolin]

Some team has implemented EIP-712 signatures in CowProtocol using Fireblocks and managed to trade using the SDK.

Right now the SDK is not web3 library agnostic. This issue would be to allow to use Fireblocks library in the SDK.

They provided the snippet of conde on how they created the order. We already have the signing schema, so this issue would be just to abstract the instantiation of the SDK to accept fireblocks, so the SDK can sign orders using the library.

Snippet the team shared:

        const orderForSigning: UnsignedOrder = {
            sellTokenBalance: OrderBalance.ERC20,
            buyTokenBalance: OrderBalance.ERC20,
            appData:
                "0x0000000000000000000000000000000000000000000000000000000000000000",
            ...order,
        };

        // Sign the order.
        const fbOrderRequest = {
            type: "EIP712",
            index: 0,
            content: {
                types: {
                    Order: [
                        { name: "sellToken", type: "address" },
                        { name: "buyToken", type: "address" },
                        { name: "receiver", type: "address" },
                        { name: "sellAmount", type: "uint256" },
                        { name: "buyAmount", type: "uint256" },
                        { name: "validTo", type: "uint32" },
                        { name: "appData", type: "bytes32" },
                        { name: "feeAmount", type: "uint256" },
                        { name: "kind", type: "string" },
                        { name: "partiallyFillable", type: "bool" },
                        { name: "sellTokenBalance", type: "string" },
                        { name: "buyTokenBalance", type: "string" },
                    ],
                    EIP712Domain: [
                        { name: "name", type: "string" },
                        { name: "version", type: "string" },
                        { name: "chainId", type: "uint256" },
                        { name: "verifyingContract", type: "address" },
                    ],
                },
                domain: {
                    name: "Gnosis Protocol",
                    chainId: "1",
                    version: "v2",
                    verifyingContract:
                        "0x9008d19f58aabd9ed0d60971565aa8510560ab41",
                },
                message: order,
            },
        };

        const { signedMessages, id } = await this.fireblocks.signData(
            fbOrderRequest,
            "defi gateway cowswap"
        );

        const v = signedMessages[0].signature.v;
        invariant(v !== undefined, "no v");
        const cowOrderId = await this.cowswapApi.createOrder(
            orderForSigning,
            signedMessages[0].signature.fullSig,
            v,
            this.walletAddress
        );

And here is the createOrder implementation:


    async createOrder(
        order: UnsignedOrder,
        signature: string,
        v: number,
        walletAddress: string
    ) {
        let vStr = "";
        if (v == 0) {
            // 27 hex
            vStr = "1b";
        } else if (v == 1) {
            // 28 hex
            vStr = "1c";
        } else {
            invariant(false, "invalid v");
        }

        const data = {
            // Add 0x and v field.
            signature: "0x" + signature + vStr,
            from: walletAddress,
            signingScheme: "eip712",
            ...order,
        };
        console.log(data);
        const response = await axios.post(
            COWSWAP_BASE_URL + "/api/v1/orders",
            data
        );
        return response.data;

the fireblocks payload above requires a primaryType: “Order” field