DSA_size.3ssl man page

 #include <openssl/dsa.h>

 int DSA_size(const DSA *dsa);

This function returns the size of an ASN.1 encoded DSA signature in bytes. It can be used to determine how much memory must be allocated for a DSA signature.

dsa->q must not be NULL.

The size in bytes.

dsa(3), DSA_sign(3)

DSA_size() is available in all versions of SSLeay and OpenSSL.

BN_num_bytes.3ssl(3), dsa.3ssl(3), DSA_get0_pqg.3ssl(3), DSA_meth_new.3ssl(3).