- NAME
- SYNOPSIS
- DESCRIPTION
- RETURN VALUE
- SEE ALSO
- HISTORY
- COPYRIGHT

# 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

BN_num_bits(3)

# HISTORY

RSA_bits() was added in OpenSSL 1.1.0.

# COPYRIGHT

Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the OpenSSL license (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at https://www.openssl.org/source/license.html.