.\"	$OpenBSD: RSA_size.3,v 1.2 2016/11/06 15:52:50 jmc Exp $
.\"
.Dd $Mdocdate: November 6 2016 $
.Dt RSA_SIZE 3
.Os
.Sh NAME
.Nm RSA_size
.Nd get RSA modulus size
.Sh SYNOPSIS
.In openssl/rsa.h
.Ft int
.Fo RSA_size
.Fa "const RSA *rsa"
.Fc
.Sh 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.
.Pp
.Fa rsa->n
must not be
.Dv NULL .
.Sh RETURN VALUES
The size in bytes.
.Sh SEE ALSO
.Xr rsa 3
.Sh HISTORY
.Fn RSA_size
is available in all versions of SSLeay and OpenSSL.