exchange.IO("signMessage", ...)

Signs messages according to the EIP-191 standard (personal_sign). The signature result is consistent with signMessage of ethers and personal_sign of wallets, and is commonly used in scenarios such as DApp login and off-chain authentication.

    
    
    
exchange.IO(k, message)

    
    
    
exchange.IO(k, message, key)

Examples

Sign a message and recover the signer address through the ecrecover precompiled contract.

    javascript
    
    
function main() {
    // Sign text using UTF-8 encoding (the result is consistent with ethers signMessage and wallet
    // personal_sign)
    var sig = exchange.IO("signMessage", "hello fmz")
    Log("digest:", sig.digest, "signature:", sig.signature)

    // Raw bytes are passed in via {hex: ...}
    var sig2 = exchange.IO("signMessage", { hex: "0x68656c6c6f20666d7a" })
    Log("Consistent with text signature:", sig.signature === sig2.signature)

    // Use the ecrecover precompiled contract to recover the signer address; the result should match
    // the current wallet address
    var ret = exchange.IO("call", "0x0000000000000000000000000000000000000001",
        "0x" + sig.digest.slice(2) + exchange.IO("encode", "uint8,bytes32,bytes32", sig.v, sig.r,
            sig.s))
    Log("Recovered address:", "0x" + String(ret).slice(-40), "Wallet address:",
        exchange.IO("address").toLowerCase())
}

Returns

Arguments

See Also