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.