encoding decoding Json using RSA Angular and Express.js - json

Question

I have a frontend Angular.ts and a backend Express.js. I am decrypting user credentials in the frontend using RSA and sending all the data as an encrypted string to the backend.
When I try to catch the data in the backend to decrypt it, it reads the received object as [object Object] which makes it impossible to decrypt. This is the code =>:
FRONTEND httpService.ts:
sendmail(user: { name: any; email: any; host: any }) {
console.log(user);
const encJsonUser = this.rsaHelper.encryptWithPublicKey(
JSON.stringify(user)
);
console.log(encJsonUser);
return this.http.post(environment.apiUrl + '/sendemail', encJsonUser);
}
BACKENDemail.js:
router.post('/', async (req, res) => {
let path = null;
const encryptedData = req.body;
console.log("RECEIVED ENCRYPTED BODY: " + encryptedData);
const privateKey = fs.readFileSync("privateKey.key.pem", "utf8");
console.log("toDecryptData::: " + encryptedData);
const decryptedData = decryptedDataFromAngular(encryptedData, privateKey);
console.log("DECRYPTED-DATA: " + decryptedData);
axios.post("http://localhost:8080/pdf", {host: encryptedData.host}).then(async function (response) {
path = response.data.scan_id;
}).then(() => {
emailPdfGenerator(encryptedData);
});
})
function decryptedDataFromAngular(encryptedData, privateKey) {
// encryptedData = Buffer.from(encryptedData, "base64");
const body = JSON.parse(encryptedData);
// console.log("ENCRYPTED DATA 2222:::: " + encryptedData);
console.log("ENCRYPTED DATA 2222:::: " + body);
const decryptedData = crypto.privateDecrypt(
{
key: privateKey,
// In order to decrypt the data, we need to specify the
// same hashing function and padding scheme that we used to
// encrypt the data in the previous step
padding: crypto.constants.RSA_PKCS1_OAEP_PADDING,
oaepHash: "sha256",
},
body
);
console.log("decrypted data: ", decryptedData.toString());
console.log("DE RAW DATA" + decryptedData);
return decryptedData;
}
error message:
RECEIVED ENCRYPTED BODY: [object Object] toDecryptData::: [object Object] undefined:1 [object Object] ^
SyntaxError: Unexpected token o in JSON at position 1
at JSON.parse ()
at decryptedDataFromAngular (C:\Users\hayan\Desktop\HSLeiden\Year2-IN2B\IPSEN5\Security-Check-Express-User\routes\email.js:60:23)
at C:\Users\hayan\Desktop\HSLeiden\Year2-IN2B\IPSEN5\Security-Check-Express-User\routes\email.js:31:27
at Layer.handle [as handle_request] (C:\Users\hayan\Desktop\HSLeiden\Year2-IN2B\IPSEN5\Security-Check-Express-User\node_modules\express\lib\router\layer.js:95:5)
at next (C:\Users\hayan\Desktop\HSLeiden\Year2-IN2B\IPSEN5\Security-Check-Express-User\node_modules\express\lib\router\route.js:144:13)
at Route.dispatch (C:\Users\hayan\Desktop\HSLeiden\Year2-IN2B\IPSEN5\Security-Check-Express-User\node_modules\express\lib\router\route.js:114:3)
at Layer.handle [as handle_request] (C:\Users\hayan\Desktop\HSLeiden\Year2-IN2B\IPSEN5\Security-Check-Express-User\node_modules\express\lib\router\layer.js:95:5)
at C:\Users\hayan\Desktop\HSLeiden\Year2-IN2B\IPSEN5\Security-Check-Express-User\node_modules\express\lib\router\index.js:284:15
at Function.process_params (C:\Users\hayan\Desktop\HSLeiden\Year2-IN2B\IPSEN5\Security-Check-Express-User\node_modules\express\lib\router\index.js:346:12)
at next (C:\Users\hayan\Desktop\HSLeiden\Year2-IN2B\IPSEN5\Security-Check-Express-User\node_modules\express\lib\router\index.js:280:10)
[nodemon] app crashed - waiting for file changes before starting...

Answer 1

I stopped using crypto, and I am using forge to solve the problem because crypto just didn't help me.
This is my code:
async function decryptUser(encryptedUserData) {
const name = await decryptString(encryptedUserData.name);
const email = await decryptString(encryptedUserData.email);
const host = await decryptString(encryptedUserData.host);
const decryptedUser = {
name: name,
email: email,
host: host,
}
return decryptedUser
}
async function decryptString(encryptedString) {
const rsa = forge.pki.privateKeyFromPem(PRIVATE_KEY);
return await rsa.decrypt(encryptedString);
}