osx man page for rsa_size

RSA_size(3)							      OpenSSL							       RSA_size(3)

NAME
       RSA_size - get RSA modulus size

SYNOPSIS
	#include <openssl/rsa.h>

	int RSA_size(const RSA *rsa);

DESCRIPTION
       This function 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->n must not be NULL.

RETURN VALUE
       The size in bytes.

SEE ALSO
       rsa(3)

HISTORY
       RSA_size() is available in all versions of SSLeay and OpenSSL.

50								    2013-03-05							       RSA_size(3)