RSA_SIZE

Section: OpenSSL (3)
Updated: 2021-03-26
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NAME

RSA_size, RSA_bits, RSA_security_bits - get RSA modulus size or security bits

SYNOPSIS

 #include <openssl/rsa.h>

 int RSA_size(const RSA *rsa);

 int RSA_bits(const RSA *rsa);

 int RSA_security_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.

RSA_security_bits() returns the number of security bits of the given rsa key. See BN_security_bits(3).

RETURN VALUES

RSA_size() returns the size of modulus in bytes.

DSA_bits() returns the number of bits in the key.

RSA_security_bits() returns the number of security bits.

HISTORY

The RSA_bits() function was added in OpenSSL 1.1.0.

COPYRIGHT

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>.