Node -rsa errors when trying to decrypt a message using a private key

Question

So, I tried to use node with node-rsa and javascript with jsencrypt to create a website (for the job), when the javascript client receives the public key generated by the server (node ​​-rsa), encrypts the message (jsencrypt) that the user entered, sent it to the server and the server received it to decrypt it (node ​​-rsa). Key generation works, encryption works, but decryption does not work. When I run the node script, I do the following for encryption ...

var NodeRSA = require('node-rsa'); var myDecrypter = new NodeRSA({b: 512}); 

When a client requests a key (I use express), the following is done.

 app.get('/getPublicKey', function(req, res){ var publicKeyJson = {"Key": ""}; console.log(myDecrypter.exportKey('public')); publicKeyJson.Key = myDecrypter.exportKey('public'); res.json(JSON.stringify(publicKeyJson)); }); 

The client then saves this key as follows:

 var myEncrypter = new JSEncrypt(); var myJson = ""; $.getJSON( "getPublicKey", function( data ) { myJson = JSON.parse(data).Key; setKey(); }); function setKey() { myEncrypter.setPublicKey(myJson); } 

When I need to encrypt and send a message to the client, I do this ...

 function messageEncrypt() { message = document.getElementById("message").value; var encrypted = myEncrypter.encrypt(message); myMessage = {"username": "", "userId": 0.0, "message": ""}; myMessage.username = me.username; myMessage.userId = me.userId; myMessage.message = encrypted; console.log(encrypted); $.post("sendMessage", myMessage); } 

When the server receives the message, this is what happens, this is where I get the errors.

 app.post('/sendMessage', function(req, res){ var message = req.body; var user = message.username; var id = message.userId; console.log("What a mess, " + user + " said " + message.message + " what on earth does that mean"); //This line below errors var clearMessage = myDecrypter.decrypt(message.message, 'utf8'); console.log(user + " said " + clearMessage); }); 

The error I get is ...

 Error: Error during decryption (probably incorrect key). Original error: Error: error:040A1079:rsa routines:RSA_padding_check_PKCS1_OAEP_mgf1:oaep decoding error at Error (native) at NodeRSA.module.exports.NodeRSA.$$decryptKey (/home/node_modules/node-rsa/src/NodeRSA.js:295:19) at NodeRSA.module.exports.NodeRSA.decrypt (/home/node_modules/node-rsa/src/NodeRSA.js:243:21) at /home/securechat/securechat.js:36:36 at Layer.handle [as handle_request] (/home/node_modules/express/lib/router/layer.js:95:5) at next (/home/node_modules/express/lib/router/route.js:131:13) at Route.dispatch (/home/node_modules/express/lib/router/route.js:112:3) at Layer.handle [as handle_request] (/home/node_modules/express/lib/router/layer.js:95:5) at /home/node_modules/express/lib/router/index.js:277:22 at Function.process_params (/home/node_modules/express/lib/router/index.js:330:12) 

Here, however, it is interesting to get this error message above, I had a private key ...

 -----BEGIN RSA PRIVATE KEY----- MIIBOgIBAAJBAIhdx31QICGN1LKRW4WngeL3RtzPh7cEHmhFJB8m4bQUSTcSi4eg sUvMeZkWyaF9gOxtZKzk5TI6q+8hg8TY6S8CAwEAAQJASds423cVH/c4NsqhXh8e KvYwjBFeeNIjQegIq1KctbHmKNM5MMb4jnDqdY/S5XHHS22EGvLNheLgV8tlRjwG UQIhANpNmbl215eOsGPJ0jqz1XPMBrO35V6I3P04kvr66R1JAiEAn+oL0jtAFETR 4PRfenye5MAu9US3V5MoDN8xUoEvKrcCIQDQT2ZWNNIrHAyzXB2QyJPxqInoqp1j 5QPDWl3ewtj5iQIgY3E1nKw/stsA8LTGUvMAFBv2l4r9wDXAaBC7KSUwYY0CIAj4 0gA9etDbPm3H/XDwK4WXs9mXkKroyxewkWoOoAw/ -----END RSA PRIVATE KEY----- 

and the public key sent to the client was ...

 -----BEGIN PUBLIC KEY----- MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBAIhdx31QICGN1LKRW4WngeL3RtzPh7cE HmhFJB8m4bQUSTcSi4egsUvMeZkWyaF9gOxtZKzk5TI6q+8hg8TY6S8CAwEAAQ== -----END PUBLIC KEY----- 

Encrypted messages (stackoverflow) were ...

 XDViV0InCSnpyBxbNu5Herut0JYSsp87buvhzM4g2f9z3khIx2zA8Ou0Uq0TtmqtvBBVtZi5wZbcS6em/vB78g== 

Interestingly, when I used demo on the jsencrypt website and entered my private key as well as an encrypted message that I get the correct decrypted message.

So my question is ...

What am I doing wrong with my decryption node -rsa ???

If you need more information / code, please post it in the comments below.

Answer 1

To answer your question @Curious_Programmer, by default, node -rsa uses pkcs1_oaep for encryption and decryption, while jsencrypt uses pkcs1. Fortunately, node allows you to change the encryptionScheme, you need to add ...

 myDecrypter.setOptions({encryptionScheme: 'pkcs1'}); 

under

 var myDecrypter = new NodeRSA({b: 512}); 

and everything will work like a charm, I was hoping I helped you;)

Answer 2

It seems that the ciphertext is a buffer, i.e. binary data. Then it is wrapped using JSON, which consists of text. You need to use text encoding on binary data to transfer it through a text interface.

---

Check the following encrypt method encrypt :

 key.encrypt(buffer, [encoding], [source_encoding]); 

with a reminder that the default is 'buffer' for [encoding] .

So you should use:

 var encrypted = myEncrypter.encrypt(message, 'base64', 'utf-8'); 

where 'base64' is for encoding with encrypted text, and 'utf-8' is for encoding plaintext.

---

The decryption procedure should automatically use base64 decoding of the ciphertext:

 var clearMessage = myDecrypter.decrypt(message.message, 'utf8'); 

should be just fine.

Answer 3

I have the same problem.

 encrypt.setOptions({encryptingScheme:'pkcs1'});//Can be 'pkcs1_oaep' or 'pkcs1'. Default 'pkcs1_oaep'. 

but it still failed.

I changed lib from node -rsa to ursa. eg:

 privateKey.decrypt(thirdEncrypted, 'base64', 'utf8',ursa.RSA_PKCS1_PADDING); 

Problem solved in ursa.