RSA_blinding_on.3ossl - Man Page

protect the RSA operation from timing attacks


 #include <openssl/rsa.h>

The following functions have been deprecated since OpenSSL 3.0, and can be hidden entirely by defining OPENSSL_API_COMPAT with a suitable version value, see openssl_user_macros(7):

 int RSA_blinding_on(RSA *rsa, BN_CTX *ctx);

 void RSA_blinding_off(RSA *rsa);


All of the functions described on this page are deprecated.

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 preallocated 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.

RSA_blinding_off() returns no value.


All of these functions were deprecated in OpenSSL 3.0.

Referenced By

The man page RSA_blinding_off.3ossl(3) is an alias of RSA_blinding_on.3ossl(3).

2023-03-21 3.0.8 OpenSSL