Accessing phpseclib class multiple times - php

Question

Thank you for looking in. I have recently been updating an old symmetric-based encryption system I had set up on a server into an asymmetric-based RSA system for better security. I would consider myself a moderately proficient PHP programmer. With that being said I am completely stumped on this problem using phpseclib.
It seems I am unable to create two instances of the class anywhere in my script. See my code below:
<?php include_once('Crypt/RSA.php');
function signRSA($string_to_sign){
$rsa = new Crypt_RSA();
$rsa->loadKey(file_get_contents('pvk.txt')); // private key
$rsa->setSignatureMode(CRYPT_RSA_SIGNATURE_PKCS1);
$signature = $rsa->sign($string_to_sign);
return base64_encode($signature);
}
function decryptRSA($string_to_decrypt){
$rsa = new Crypt_RSA();
$rsa->loadKey(file_get_contents('pvk.txt')); // private key
return $rsa->decrypt(base64_decode($string_to_decrypt));
}
//Which ever function is on top is the only one that appears to work. The first line below will work, however the second will fail returning me a null value.
$sig = signRSA($_POST['data']);
$plain = decryptRSA($_POST['otherdata']);
?>
I have also tried creating an individual 'global' variable. The same thing happened..
I look forward to getting this issue resolved.
UPDATE:
I was able to successfully combat my issue albeit having nothing to do with what I thought it was. It seems my client app (C#) and the PHP end as seen above were using two different padding algorithms. This was causing the client app to consider the data corrupt. In the PHP script's logic, this was causing only one of the functions above to work.

Answer 1

It works fine for me:
include_once('Crypt/RSA.php');
function signRSA($string_to_sign){
$rsa = new Crypt_RSA();
$rsa->loadKey('-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----'); // private key
$rsa->setSignatureMode(CRYPT_RSA_SIGNATURE_PKCS1);
$signature = $rsa->sign($code);
return base64_encode($signature);
}
function decryptRSA($string_to_decrypt){
$rsa = new Crypt_RSA();
$rsa->loadKey('-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----'); // private key
return $rsa->decrypt(base64_decode($string_to_decrypt));
}
//Which ever function is on top is the only one that appears to work. The first line below will work, however the second will fail returning me a null value.
$sig = signRSA('zzzzzzzzz');
$plain = decryptRSA('G0KqVsNP6qsjVkKbnfCkSsiUdDnxBzIjA1tNHCeeKgkzqdkJF/zFuzVdtc8PrEfeR+SfrvdLiR5DqlAA
LReLD5lPrj19+3Ci+igCQebItT8xmOHmKNHM+nQK2l6uL9AW03Vy/15sCTHqZ/dfmQMarzIb05DQUX57
ftrBGu0XLwM=');
echo base64_encode($sig) . "\r\n";
echo $plain;
Maybe your key isn't in a supported format? Maybe the ciphertext you're trying to decrypt doesn't go with the private key? Does the code snippet I've posted work for you? If so you're gonna need to post more info. Like fill in the keys and plaintext's and what not.