1*ebfedea0SLionel Sambuc=pod 2*ebfedea0SLionel Sambuc 3*ebfedea0SLionel Sambuc=head1 NAME 4*ebfedea0SLionel Sambuc 5*ebfedea0SLionel SambucRSA_blinding_on, RSA_blinding_off - protect the RSA operation from timing attacks 6*ebfedea0SLionel Sambuc 7*ebfedea0SLionel Sambuc=head1 SYNOPSIS 8*ebfedea0SLionel Sambuc 9*ebfedea0SLionel Sambuc #include <openssl/rsa.h> 10*ebfedea0SLionel Sambuc 11*ebfedea0SLionel Sambuc int RSA_blinding_on(RSA *rsa, BN_CTX *ctx); 12*ebfedea0SLionel Sambuc 13*ebfedea0SLionel Sambuc void RSA_blinding_off(RSA *rsa); 14*ebfedea0SLionel Sambuc 15*ebfedea0SLionel Sambuc=head1 DESCRIPTION 16*ebfedea0SLionel Sambuc 17*ebfedea0SLionel SambucRSA is vulnerable to timing attacks. In a setup where attackers can 18*ebfedea0SLionel Sambucmeasure the time of RSA decryption or signature operations, blinding 19*ebfedea0SLionel Sambucmust be used to protect the RSA operation from that attack. 20*ebfedea0SLionel Sambuc 21*ebfedea0SLionel SambucRSA_blinding_on() turns blinding on for key B<rsa> and generates a 22*ebfedea0SLionel Sambucrandom blinding factor. B<ctx> is B<NULL> or a pre-allocated and 23*ebfedea0SLionel Sambucinitialized B<BN_CTX>. The random number generator must be seeded 24*ebfedea0SLionel Sambucprior to calling RSA_blinding_on(). 25*ebfedea0SLionel Sambuc 26*ebfedea0SLionel SambucRSA_blinding_off() turns blinding off and frees the memory used for 27*ebfedea0SLionel Sambucthe blinding factor. 28*ebfedea0SLionel Sambuc 29*ebfedea0SLionel Sambuc=head1 RETURN VALUES 30*ebfedea0SLionel Sambuc 31*ebfedea0SLionel SambucRSA_blinding_on() returns 1 on success, and 0 if an error occurred. 32*ebfedea0SLionel Sambuc 33*ebfedea0SLionel SambucRSA_blinding_off() returns no value. 34*ebfedea0SLionel Sambuc 35*ebfedea0SLionel Sambuc=head1 SEE ALSO 36*ebfedea0SLionel Sambuc 37*ebfedea0SLionel SambucL<rsa(3)|rsa(3)>, L<rand(3)|rand(3)> 38*ebfedea0SLionel Sambuc 39*ebfedea0SLionel Sambuc=head1 HISTORY 40*ebfedea0SLionel Sambuc 41*ebfedea0SLionel SambucRSA_blinding_on() and RSA_blinding_off() appeared in SSLeay 0.9.0. 42*ebfedea0SLionel Sambuc 43*ebfedea0SLionel Sambuc=cut 44