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.