json_encode does not work on encrypted string - php

Question

I'm having a little trouble, as i want to encrypt some post data i get from a form and then send them to my nodejs server in json format to put them into a database.
My Problem: i seem to be unable to post the data once it is encrypted. I can post the json string just fine, but not anything more:
My code:
$rsa->loadKey($keydata);
$rsa->setEncryptionMode(CRYPT_RSA_ENCRYPTION_PKCS1);
$encrypted = $rsa->encrypt("test");
$jsonArray = array(
'crypt' => $encrypted
);
$jsonArrayEncoded = json_encode($jsonArray);
echo $jsonArrayEncoded;
$ch = curl_init('https://..........');
curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: application/json'));
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $jsonArrayEncoded);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
$response = json_decode(curl_exec($ch), true);
curl_close($ch);
I don't even get the echo output. But the string seems to get encrypted, as i can echo that (a lot of charset errors + some random letters and numbers) and if i decode it in the php skript i get the correct result as well. I don't get any console warnings or errors, neither in chrome, nor firefox.
Anything i do wrong? (quite sure there is)
e: I'm using this as crypto library: http://phpseclib.sourceforge.net/rsa/examples.html#encrypt,enc1
edit2: well, as adviced in the comments i converted the string to utf8, but now it seems to be too long to be decrypted with my key... Tough o only encrypted the word "test"...
I think i have to dig deeper...
If anyone knows: for decryption I'm using the Ursa module for node.js with following code:
var buffer = new Buffer(req.body.crypt);
var data = private.decrypt(buffer, 'utf8', 'utf8', ursa.RSA_PKCS1_PADDING);

Answer 1

well, as adviced in the comments i converted the string to utf8, but
now it seems to be too long to be decrypted with my key... Tough o
only encrypted the word "test"...
It'd help to see your updated code that does that. In lieu of doing that...
json_encode doesn't natively handle binary data. My recommendation would be to do something like this:
$jsonArray = array(
'crypt' => bin2hex($encrypted)
);
$jsonArrayEncoded = json_encode($jsonArray);
echo $jsonArrayEncoded;
You'd need to compress it back down to binary, though, after you json decode'd it in Java.
Alternatively, you could do base64_encode and base64 decode it later.
The concern I'd have with utf8 encoding is that PHP's internal string type isn't utf8. If Java's is then that could cause problems it seems.

Answer 2

The json_encoding function has numerous flags that you can pass to it, which enable the function to parse particular character sets. The following call might solve the problems you are having
json_encode($jsonArray, JSON_UNESCAPED_SLASHES | JSON_HEX_APOS | JSON_HEX_QUOT | JSON_HEX_AMP );