=pod =head1 NAME RSA_blinding_on, RSA_blinding_off - protect the RSA operation from timing attacks =head1 SYNOPSIS #include <openssl/rsa.h> int RSA_blinding_on(RSA *rsa, BN_CTX *ctx); void RSA_blinding_off(RSA *rsa); =head1 DESCRIPTION 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 B<rsa> and generates a random blinding factor. B<ctx> is B<NULL> or a pre-allocated and initialized B<BN_CTX>. The random number generator must be seeded prior to calling RSA_blinding_on(). RSA_blinding_off() turns blinding off and frees the memory used for the blinding factor. =head1 RETURN VALUES RSA_blinding_on() returns 1 on success, and 0 if an error occurred. RSA_blinding_off() returns no value. =head1 SEE ALSO L<rsa(3)|rsa(3)>, L<rand(3)|rand(3)> =head1 HISTORY RSA_blinding_on() and RSA_blinding_off() appeared in SSLeay 0.9.0. =cut