Used to provide options for the optimal asymmetric encryption padding oaep scheme. One block includes the oaep padding and the other block same recipient includes the default padding. When printing out all the fields of the message with the openssl command. I was told to encrypt a password using an rsa public key with oaep padding. Oaep padding is only available on microsoft windows xp or later. I can decrypt it by softhsm but in mscrypto i just fail. For oaep with all default parameters label hash sha1 and data. How to decrypt data that is encrypted by openssl with rsa. Specifying rsa oaep label via openssl command line.