RSA_blinding_on, RSA_blinding_off - protect the RSA operation from timing
int RSA_blinding_on(RSA *rsa, BN_CTX *ctx);
void RSA_blinding_off(RSA *rsa);
RSA is vulnerable to timing attacks. In a setup where attackers can measure
the time of RSA decryption or signature operations, blinding must be used
to protect the RSA operation from that attack.
RSA_blinding_on() turns blinding on for key rsa and generates a random blinding factor. ctx is NULL or a pre-allocated and initialized BN_CTX. The random number generator must be seeded prior to calling
RSA_blinding_off() turns blinding off and frees the memory
used for the blinding factor.
RSA_blinding_on() returns 1 on success, and 0 if an error
RSA_blinding_off() returns no value.
in SSLeay 0.9.0.