1=pod 2 3=head1 NAME 4 5RSA_blinding_on, RSA_blinding_off - protect the RSA operation from timing attacks 6 7=head1 SYNOPSIS 8 9 #include <openssl/rsa.h> 10 11The following functions have been deprecated since OpenSSL 3.0, and can be 12hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value, 13see L<openssl_user_macros(7)>: 14 15 int RSA_blinding_on(RSA *rsa, BN_CTX *ctx); 16 17 void RSA_blinding_off(RSA *rsa); 18 19=head1 DESCRIPTION 20 21All of the functions described on this page are deprecated. 22 23RSA is vulnerable to timing attacks. In a setup where attackers can 24measure the time of RSA decryption or signature operations, blinding 25must be used to protect the RSA operation from that attack. 26 27RSA_blinding_on() turns blinding on for key B<rsa> and generates a 28random blinding factor. B<ctx> is B<NULL> or a preallocated and 29initialized B<BN_CTX>. 30 31RSA_blinding_off() turns blinding off and frees the memory used for 32the blinding factor. 33 34=head1 RETURN VALUES 35 36RSA_blinding_on() returns 1 on success, and 0 if an error occurred. 37 38RSA_blinding_off() returns no value. 39 40=head1 HISTORY 41 42All of these functions were deprecated in OpenSSL 3.0. 43 44=head1 COPYRIGHT 45 46Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved. 47 48Licensed under the Apache License 2.0 (the "License"). You may not use 49this file except in compliance with the License. You can obtain a copy 50in the file LICENSE in the source distribution or at 51L<https://www.openssl.org/source/license.html>. 52 53=cut 54