AES在.NET中加密并使用Node.js加密解密？

Question

I'm trying to encrypt some data in Mono C#, send it to a NodeJS server and decrypt it there. I'm trying to figure out what algorithms to use to match the two.

I send the encrypted string encoded with base64. So I do something like this in Javascript, where I know the key which was used to encrypt the data in my C# application:

var decipher = crypto.createDecipher('aes192',binkey, biniv);
var dec = decipher.update(crypted,'base64','utf8');
dec += decipher.final('utf8');
console.log("dec", dec);

In Mono I create my Cypher with:

using System.Security.Cryptography;
using (Aes aesAlg = Aes.Create("aes192"))

I need to pass the correct string to Aes.Create() in order to have it use the same algorithm, but I can't find what it should be. "aes192" is not correct it seems.

I don't need aes192 this was just a tryout. Suggest a different encryption flavor if it makes sense. Security is not much of an issue.

Here are links to .NET and Nodejs docs: http://msdn.microsoft.com/en-us/library/system.security.cryptography.aes.aspx http://nodejs.org/api/crypto.html

Answer 1

This code works for my Node.js side, but please replace the static iv, otherwhise aes encryption would be useless.

var crypto = require('crypto');

function encrypt(data, key) {
    key = key || new Buffer(Core.config.crypto.cryptokey, 'binary'),
        cipher = crypto.createCipheriv('aes-256-cbc', key.toString('binary'), str_repeat('\0', 16));
    cipher.update(data.toString(), 'utf8', 'base64');
    return cipher.final('base64');
}

function decipher(data, key) {
    key = key || new Buffer(Core.config.crypto.cryptokey, 'binary'),
        decipher = crypto.createDecipheriv('aes-256-cbc', key.toString('binary'), str_repeat('\0', 16));
    decipher.update(data, 'base64', 'utf8');
    return decipher.final('utf8');
}

function str_repeat(input, multiplier) {
    var y = '';
    while (true) {
        if (multiplier & 1) {
            y += input;
        }
        multiplier >>= 1;
        if (multiplier) {
            input += input;
        } else {
            break;
        }
    }
    return y;
}

I hope this helps You.

NOTE: You need to deliver an 265bit aka 32 character key for this algorithm to work.

POSSIBLE .NET SOLUTION: This may help you Example

Answer 2

You should simply write new AesManaged() .
You don't need to call Create() .

You then need to set Key and IV , then call CreateDecryptor() and put it in a CryptoStream .

Answer 3

It turned out to be a stupid mistake. I thought the create function in Node.js could take a variable argument count. Turns out you need to call the createDecipheriv() instead.

Just for the record, you can easily check the padding and mode by looking at those properties in the Aes object. The defaults are CBC and PKCS7. That padding is also used in nodejs crypto. So a for a 128 key size my code to decrypt a base64 encoded string would be:

var crypto = require('crypto');
var binkey = new Buffer(key, 'base64');
var biniv = new Buffer(iv, 'base64');
var decipher = crypto.createDecipheriv('aes-128-cbc', binkey, biniv);
var decrypted = decipher.update(crypted,'base64','utf8');
decrypted += decipher.final('utf8');
console.log("decrypted", decrypted);