ethers.Wallet.createRandom() seems taking forever to finish

[emclab]

In my react native 0.64 app, Modal is used to handle an user input on Android emulator. An useEffect hook is executed and check the availability of a few parameters. If a key is missing, then a modal will be activated and take input from user, or generate the key for the user. The routing is done with React Navigation 5.x. The problem is that after user click to generate a new key, the code stuck and never end or complete. I find out that the ethers.Wallet.createRansom() seems taking forever to finish. Just updated to 5.3.0 from 5.2.0 and the issue is the same. Here is the code:

import Modal from "react-native-modal";
import 'react-native-get-random-values';
import "@ethersproject/shims";  //for ethers.js
// Import the ethers library
import { ContractFactory, ethers } from "ethers";  //<<==update to ethers 5.3.0
const [modalVisible, setModalVisible] = useState(false);
const [privateKey, setPrivateKey] = useState("");

const clickModalButton = async () => {  //handle the user click on Modal 
    var navOn = false;
    var _wallet;
    if (privateKey && helper.isHex(privateKey) && privateKey.length == 66) {  //64 hex/32 bytes, + 0x
//do something
    } else if (!privateKey) {  //when no user input, then key is generated
      console.log("generate new private key");  //<<==this console output show. But nothing after that. Suspected that the component is unmounted
      //generate new private key
      _wallet = ethers.Wallet.createRandom();  //<<==this line is taking forever to finish. After removing this line, the code can execute quickly
      console.log("_wallet key ", _wallet.privateKey);
      setPrivateKey(_wallet.privateKey); //<<==Suspect after component unmounted, change state causes hanging of the app
      console.log("likely never be there");  //<<==never show on console output
      _wallet = new ethers.Wallet(_wallet.privateKey, provider);
     //do something simple
   ...}

useEffect(() => {
  //do something
  const fn = async () => {
    if (certain_condition_not_met) {
       setModalVisible(true); //<<==turn on the Modal to take user input
       return;
    }
  }
  fn();
})

return (
    <View style={styles.viewStyles}>
      <Text h1 style={styles.textHeader}>App</Text>
      <Image 
        source={imageFile}
        style={{ width:200,height:250 }}
      />
      <Spinner
          visible={spinner}
          textContent={message}
          textStyle={styles.spinnerTextStyle}
      />
      <View>
        <Modal  //<<==Modal
            style={{alignItems:"center", alignContent:"center"}}
            animationType="slide"
            transparent={false}
            visible={modalVisible}
            onBackdropPress={() => setModalVisible(false)}
            onRequestClose={() => {
              setModalVisible(!modalVisible);
            }}
          > 
            <View style={styles.centeredView}>
              <View style={styles.modalView}>
                <Text style={{padding:20}}>Input Key</Text>
                <TextInput autoFocus={true} value={privateKey} onChangeText={keyChange} placeholder={keyPlaceholder} style={styles.textTitle} />
                <View style={{padding:20}}>
                  <Button style={styles.button} 
                            onPress={() => clickModalButton()} 
                            title="Save/Generate Key"/>
                </View>              
              </View>
            </View>
          </Modal>
      </View>  
    </View>
  );
}

[zemse]

Can you temporarily try to see if new ethers.Wallet('0x1234...') (use a hardcoded bytes32 privatekey) execute in no time?

If it does execute immediately, it means the random number generation logic inside the createRandom (that probably uses react-native-get-random-values under the hood) is time consuming. Can you try and update here?

[emclab]

rimco pointed to await ethers.utils.randomBytes(32) which is fast without hick. The purpose of this call is to generate a private key which is secure enough for crypto app. I still don't know why Wallet.createRandom() takes forever to finish.