ciphertext length longer than mod len

[ambika cp]

Hi,

I have an application encryting the data using RSA algorithm. I am using the 
encrypted data and want to decrypt the data to get plaintext. For this I am 
calling a RSA_private_decrypt() open ssl call in my C file. The publickey size 
is 2048bytes. The ciphertext passed from application is 246bytes around and the 
mod len of the key iam getting as 128. because of this i am getting the error 
as :

error:0406506C:rsa routines:RSA_EAY_PRIVATE_DECRYPT:data greater than mod len

I dont have control on the ciphertext. I have to provide the user-name on the 
application UI and it has the intelligency to encrypt it using RSA algorithm. 

How can I get this work.An further information required I can post. Please any 
suggestions are welcome.

Regards
Ambika