OpenSSL

Cryptography and SSL/TLS Toolkit

RSA_size

NAME

RSA_size, RSA_bits - get 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 VALUE

The size.

SEE ALSO

rsa, BN_num_bits

HISTORY

RSA_size() is available in all versions of SSLeay and OpenSSL. RSA_bits() was added in OpenSSL 1.1.0.