RSA_SIZE(3) Library Functions Manual RSA_SIZE(3)
NAME
RSA_size, RSA_bits — get the RSA modulus size
SYNOPSIS
#include <openssl/rsa.h>
int
RSA_size(const RSA *rsa);
int
RSA_bits(const RSA *rsa);
DESCRIPTION
RSA_size() returns the RSA modulus size in bytes. It can be used to determine how much memory must be allocated for an RSA encrypted value.
RSA_bits() returns the number of significant bits.
rsa and rsa->n must not be NULL.
RETURN VALUES
The size.
SEE ALSO
BN_num_bits(3), RSA_get0_key(3), RSA_new(3), RSA_security_bits(3)
HISTORY
RSA_size() first appeared in SSLeay 0.4.4 and has been available since OpenBSD 2.4.
RSA_bits() first appeared in OpenSSL 1.1.0 and has been available since OpenBSD 6.3. GNU July 13, 2022 RSA_SIZE(3)