How do I hash and un-hash the image in react native - react-native

Question

I have created an app which captures images and upload to AWS s3. Currently, those are storing in the gallery. I want to hash/encrypt those images once I captured those and before uploading, I want to un-hash /decrypt those. How can I implement those in react native? I googled it but I did not find any way.
My code is,
import React, {Component} from 'react';
import {Platform, StyleSheet,Alert, Text,TouchableOpacity, View,Picker,Animated,Easing,Image, NetInfo,
Dimensions,Button,ScrollView } from 'react-native';
import ImagePicker from 'react-native-image-picker';
import DeviceInfo from 'react-native-device-info';
import { RNS3 } from 'react-native-aws3';
import Form from './Form';
const SIZE = 40;
const { width } = Dimensions.get('window');
class SecondScreen extends React.Component {
constructor(props) {
super(props);
this.state = {
SelectedClass : '',
SelectedSection : '',
SelectedSubject : '',
serverTime : null,
saveImages : [],
testImage : [],
isConnected :false,
schoolId : 10,
userId :9,
connection_Status : "",
logout:false
}
}
getServerTime() {
fetch('http://worldclockapi.com/api/json/utc/now')
.then((response) => response.json())
.then((responseJson) => {
if (responseJson) {
this.setState({
serverTime: responseJson
})
}
console.log(responseJson);
console.log(responseJson);
})
.catch((error) => {
console.error(error);
});
}
componentDidMount = () => {
NetInfo.isConnected.addEventListener(
'connectionChange',
this._handleConnectivityChange
);
NetInfo.isConnected.fetch().done((isConnected) => {
if(isConnected == true)
{
this.setState({connection_Status : "Online"})
}
else
{
this.setState({connection_Status : "Offline"})
}
});
}
componentWillUnmount = () => {
NetInfo.isConnected.removeEventListener(
'connectionChange',
this._handleConnectivityChange
);
}
_handleConnectivityChange = (isConnected) => {
if(isConnected == true)
{
this.setState({connection_Status : 1})
}
else
{
this.setState({connection_Status : 0})
}
};
//change state of class, sesssion and subject
updateClass = (SelectedClass) => {
this.setState({ SelectedClass: SelectedClass })
}
updateSession = (SelectedSection) => {
this.setState({ SelectedSection: SelectedSection })
}
updateSubject = (SelectedSubject) => {
this.setState({ SelectedSubject: SelectedSubject })
}
takePic = () => {
if(this.state.connection_Status==="Online"){
this.getServerTime();
try{
this.setState({capturedTime:this.state.serverTime.currentFileTime+'_'+time},
() => console.log(this.state.serverTime.currentFileTime)
);
} catch (err) {
var date = new Date();
var time = date.getTime();
this.setState({capturedTime:time});
console.log("localtime")
}
}
const options = {
quality: 1.0,
maxWidth: 75,
maxHeight: 75,
base64: true,
skipProcessing: true
}
ImagePicker.launchCamera(options,(responce)=>{
this.state.testImage.push({ uri: responce.uri });
const file ={
uri : responce.uri,
name :responce.fileName,
method: 'POST',
width : 50,
height : 50,
path : responce.path,
type : responce.type,
notification: {
enabled: true
}
}
this.setState(prevState => {
// get the previous state values for the arrays
let saveImages = prevState.saveImages;
// add the values to the arrays like before
saveImages.push(file);
// return the new state
return {
saveImages
}
});
})
}
_upload=()=>{
if(this.state.connection_Status==="Online"){
const config ={
keyPrefix :'uploads/',
bucket : '***********',
region :'********',
accessKey:'************',
secretKey :'*************',
successActionStatus :201
}
this.state.saveImages.map((image) => {
RNS3.put(image,config)
.then((responce) => {
console.log(image);
});
});
if (this.state.saveImages && this.state.saveImages.length) {
Alert.alert('Successfully, saved');
this.setState({saveImages:''});
this.setState({testImage:''});
} else {
Alert.alert('No images captured');
}
} else {
Alert.alert('Upload failed. User is in offline');
}
}
signout = () => {
this.setState({
logout: true
})
}
render() {
return (
<View>
{this.state.error ? <Text>Error: {this.state.error}</Text> : null}
<View style={styles.Camera}>
<TouchableOpacity onPress={this.takePic.bind(this)}>
<Text>Take Picture</Text>
</TouchableOpacity>
</View>
<View style={styles.Send}>
<TouchableOpacity onPress={() => this._upload()}>
<Text>Send</Text>
</TouchableOpacity>
</View>
</View >
}</View>
);
}
}
const styles = StyleSheet.create({
});
export default SecondScreen;