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Sortix nightly manual

This manual documents Sortix nightly, a development build that has not been officially released. You can instead view this document in the latest official manual.

NAME

RSA_blinding_on, RSA_blinding_off — protect the RSA operation from timing attacks

SYNOPSIS

#include <openssl/rsa.h>
int
RSA_blinding_on(RSA *rsa, BN_CTX *ctx);
void
RSA_blinding_off(RSA *rsa);

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 rsa and generates a random blinding factor. ctx is NULL or a pre-allocated and initialized BN_CTX.
RSA_blinding_off() turns blinding off and frees the memory used for the blinding factor.

RETURN VALUES

RSA_blinding_on() returns 1 on success, and 0 if an error occurred.

SEE ALSO

RSA_new(3)

HISTORY

RSA_blinding_on() and RSA_blinding_off() first appeared in SSLeay 0.9.0 and have been available since OpenBSD 2.4.
Copyright 2011-2025 Jonas 'Sortie' Termansen and contributors.
Sortix's source code is free software under the ISC license.
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