web3.js: Error: The method shh_newSymKey does not exist/is not available on Web3.js

Question

My main goal is to call web3.shh functions using RPC API , Web3.py or Web3.js. I can call web3.shh functions when I use geth attach; which is my last option to do.

I am following this answer.

• geth version: 1.8.0-unstable

• I am running geth with --shh flag and --rpcapi "admin,eth,net,web3,debug,shh"

• console.log(web3.version); returns: api: '0.20.5'.

When I run following script:

Web3 = require("web3");
web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));

if(!web3.isConnected()){ //web3@0.20.5
//if(!web3.eth.net.isListening().then(console.log)){ //web3@1.0.0-beta.34
    console.log("notconnected");
    process.exit();
}

var kId = web3.shh.newSymKey(); //Error occurs. 

---

var kId = web3.shh.newSymKey(); gives following error with web3@'0.20.5':

Error: The method shh_newSymKey does not exist/is not available
    at Object.InvalidResponse (/home/alper/eBlocBroker/node_modules/web3/lib/web3/errors.js:38:16)
    at RequestManager.send (/home/alper/eBlocBroker/node_modules/web3/lib/web3/requestmanager.js:61:22)
    at Shh.send [as newSymKey] (/home/alper/eBlocBroker/node_modules/web3/lib/web3/method.js:145:58)
    at Object.<anonymous> (/home/alper/eBlocBroker/dd.js:9:20)
    at Module._compile (module.js:649:30)
    at Object.Module._extensions..js (module.js:660:10)
    at Module.load (module.js:561:32)
    at tryModuleLoad (module.js:501:12)
    at Function.Module._load (module.js:493:3)
    at Function.Module.runMain (module.js:690:10)

---

Please note that I have tried it with web3@1.0.0-beta.34 that also gives this error that seems like the same error:

Promise { <pending> }
true
(node:16162) UnhandledPromiseRejectionWarning: Error: Returned error: The method shh_newSymKey does not exist/is not available
    at Object.ErrorResponse (/home/alper/eBlocBroker/node_modules/web3-shh/node_modules/web3-core-helpers/src/errors.js:29:16)
    at /home/alper/eBlocBroker/node_modules/web3-shh/node_modules/web3-core-requestmanager/src/index.js:140:36
    at XMLHttpRequest.request.onreadystatechange (/home/alper/eBlocBroker/node_modules/web3/node_modules/web3-providers-http/src/index.js:77:13)
    at XMLHttpRequestEventTarget.dispatchEvent (/home/alper/eBlocBroker/node_modules/xhr2/lib/xhr2.js:64:18)
    at XMLHttpRequest._setReadyState (/home/alper/eBlocBroker/node_modules/xhr2/lib/xhr2.js:354:12)
    at XMLHttpRequest._onHttpResponseEnd (/home/alper/eBlocBroker/node_modules/xhr2/lib/xhr2.js:509:12)
    at IncomingMessage.<anonymous> (/home/alper/eBlocBroker/node_modules/xhr2/lib/xhr2.js:469:24)
    at IncomingMessage.emit (events.js:185:15)
    at endReadableNT (_stream_readable.js:1101:12)
    at process._tickCallback (internal/process/next_tick.js:114:19)
(node:16162) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:16162) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

[Q] How could I fix this error? What do I do wrong?

Please note that available shh functions could be seen here; output of console.log(web3.shh).

Answer 1

The newSymKey(); function returns a promise, which needs to be resolved, to get the returned value.

This is why the error in version web3@1.0.0-beta.34 gives you a promise pending message with UnhandledPromiseRejectionWarning, and in the web3@0.20.5 version, the error states shh_newSymKey does not exist/is not available. [yet]

So try var kId = web3.shh.newSymKey().then(console.log);

or var kId = web3.shh.newSymKey().then(function(result) { console.log(result) //will log results. })

I prefer using the newer async / await function instead of promises (reads easier):

Web3 = require("web3");
web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));     

async function connect() { //note async function declaration
    if(!await web3.isConnected()){ //await web3@0.20.5
    //if(!await web3.eth.net.isListening()){ //await web3@1.0.0-beta.34
        console.log("notconnected");
        process.exit();
    }

    var kId = await web3.shh.newSymKey(); //note await
    console.log(kId);

}

connect();