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Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH "NAME" RSA_blinding_on, RSA_blinding_off \- protect the RSA operation from timing attacks .SH "SYNOPSIS" .IX Header "SYNOPSIS" .Vb 1 \& #include <openssl/rsa.h> \& \& int RSA_blinding_on(RSA *rsa, BN_CTX *ctx); \& \& void RSA_blinding_off(RSA *rsa); .Ve .SH "DESCRIPTION" .IX Header "DESCRIPTION" \&\s-1RSA\s0 is vulnerable to timing attacks. In a setup where attackers can measure the time of \s-1RSA\s0 decryption or signature operations, blinding must be used to protect the \s-1RSA\s0 operation from that attack. .PP \&\fBRSA_blinding_on()\fR turns blinding on for key \fBrsa\fR and generates a random blinding factor. \fBctx\fR is \fB\s-1NULL\s0\fR or a preallocated and initialized \fB\s-1BN_CTX\s0\fR. .PP \&\fBRSA_blinding_off()\fR turns blinding off and frees the memory used for the blinding factor. .SH "RETURN VALUES" .IX Header "RETURN VALUES" \&\fBRSA_blinding_on()\fR returns 1 on success, and 0 if an error occurred. .PP \&\fBRSA_blinding_off()\fR returns no value. .SH "COPYRIGHT" .IX Header "COPYRIGHT" Copyright 2000\-2020 The OpenSSL Project Authors. All Rights Reserved. .PP Licensed under the OpenSSL license (the \*(L"License\*(R"). You may not use this file except in compliance with the License. You can obtain a copy in the file \s-1LICENSE\s0 in the source distribution or at <https://www.openssl.org/source/license.html>.