.\"	$OpenBSD: RSA_size.3,v 1.4 2016/12/11 12:21:48 schwarze Exp $
.\"	OpenSSL 5bf73873 Aug 5 16:27:01 2002 +0000
.\"
.\" This file was written by Ulf Moeller <ulf@openssl.org>.
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.Dd $Mdocdate: December 11 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
and
.Fa rsa->n
must not be
.Dv NULL .
.Sh RETURN VALUES
The size in bytes.
.Sh SEE ALSO
.Xr RSA_new 3
.Sh HISTORY
.Fn RSA_size
is available in all versions of SSLeay and OpenSSL.