RSA decrypting data in C# (.NET 3.5) which was encrypted with openssl in php 5.3.2
- by panny
Maybe someone can clear me up. I have been surfing on this a while now.
Step #1: Create a root certificate
Key generation on unix
1) openssl req -x509 -nodes -days 3650 -newkey rsa:1024 -keyout privatekey.pem -out mycert.pem
2) openssl rsa -in privatekey.pem -pubout -out publickey.pem
3) openssl pkcs12 -export -out mycertprivatekey.pfx -in mycert.pem -inkey privatekey.pem -name "my certificate"
Step #2: Does root certificate work on php: YES
PHP side
I used the publickey.pem to read it into php:
$publicKey = "file://C:/publickey.pem";
$privateKey = "file://C:/privatekey.pem";
$plaintext = "123";
openssl_public_encrypt($plaintext, $encrypted, $publicKey);
$transfer = base64_encode($encrypted);
openssl_private_decrypt($encrypted, $decrypted, $privateKey);
echo $decrypted; // "123"
OR
$server_public_key = openssl_pkey_get_public(file_get_contents("C:\publickey.pem"));
// rsa encrypt
openssl_public_encrypt("123", $encrypted, $server_public_key);
and the privatekey.pem to check if it works:
openssl_private_decrypt($encrypted, $decrypted, openssl_get_privatekey(file_get_contents("C:\privatekey.pem")));
echo $decrypted; // "123"
Coming to the conclusion, that encryption/decryption works fine on the php side with these openssl root certificate files.
Step #3: Does root certificate work on .NET: YES
C# side
In same manner I read the keys into a .net C# console program:
X509Certificate2 myCert2 = new X509Certificate2();
RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
try
{
myCert2 = new X509Certificate2(@"C:\mycertprivatekey.pfx");
rsa = (RSACryptoServiceProvider)myCert2.PrivateKey;
}
catch (Exception e)
{
}
byte[] test = {Convert.ToByte("123")};
string t = Convert.ToString(rsa.Decrypt(rsa.Encrypt(test, false), false));
Coming to the point, that encryption/decryption works fine on the c# side with these openssl root certificate files.
Step #4: Enrypt in php and Decrypt in .NET: !!NO!!
PHP side
$onett = "123"
....
openssl_public_encrypt($onett, $encrypted, $server_public_key);
$onettbase64 = base64_encode($encrypted);
copy - paste $onettbase64 ("LkU2GOCy4lqwY4vtPI1JcsxgDgS2t05E6kYghuXjrQe7hSsYXETGdlhzEBlp+qhxzTXV3pw+AS5bEg9CPxqHus8fXHOnXYqsd2HL20QSaz+FjZee6Kvva0cGhWkFdWL+ANDSOWRWo/OMhm7JVqU3P/44c3dLA1eu2UsoDI26OMw=") into c# program:
C# side
byte[] transfered_onettbase64 = Convert.FromBase64String("LkU2GOCy4lqwY4vtPI1JcsxgDgS2t05E6kYghuXjrQe7hSsYXETGdlhzEBlp+qhxzTXV3pw+AS5bEg9CPxqHus8fXHOnXYqsd2HL20QSaz+FjZee6Kvva0cGhWkFdWL+ANDSOWRWo/OMhm7JVqU3P/44c3dLA1eu2UsoDI26OMw=");
string k = Convert.ToString(rsa.Decrypt(transfered_onettbase64, false)); // Bad Data exception
== Exception while decrypting!!! Any ideas?
