new

static VALUE
ossl_dsa_initialize(int argc, VALUE *argv, VALUE self)
{
    EVP_PKEY *pkey;
    DSA *dsa;
    BIO *in;
    char *passwd = NULL;
    VALUE arg, pass;

    GetPKey(self, pkey);
    if(rb_scan_args(argc, argv, "02", &arg, &pass) == 0) {
        dsa = DSA_new();
    }
    else if (FIXNUM_P(arg)) {
        if (!(dsa = dsa_generate(FIX2INT(arg)))) {
            ossl_raise(eDSAError, NULL);
        }
    }
    else {
        if (!NIL_P(pass)) passwd = StringValuePtr(pass);
        arg = ossl_to_der_if_possible(arg);
        in = ossl_obj2bio(arg);
        dsa = PEM_read_bio_DSAPrivateKey(in, NULL, ossl_pem_passwd_cb, passwd);
        if (!dsa) {
            OSSL_BIO_reset(in);
            dsa = PEM_read_bio_DSA_PUBKEY(in, NULL, NULL, NULL);
        }
        if (!dsa) {
            OSSL_BIO_reset(in);
            dsa = d2i_DSAPrivateKey_bio(in, NULL);
        }
        if (!dsa) {
            OSSL_BIO_reset(in);
            dsa = d2i_DSA_PUBKEY_bio(in, NULL);
        }
        if (!dsa) {
            OSSL_BIO_reset(in);
            dsa = PEM_read_bio_DSAPublicKey(in, NULL, NULL, NULL);
        }
        BIO_free(in);
        if (!dsa) {
            ERR_clear_error();
            ossl_raise(eDSAError, "Neither PUB key nor PRIV key");
        }
    }
    if (!EVP_PKEY_assign_DSA(pkey, dsa)) {
        DSA_free(dsa);
        ossl_raise(eDSAError, NULL);
    }

    return self;
}