Remove an =over that never ends

B<a> is composite; if B<a> passes all these tests, it is considered

prime.

=over 4

=item *

BN_is_prime_fasttest(), when called with B<do_trial_division == 1>,

first attempts trial division by a number of small primes;

if no divisors are found by this test and B<callback> is not B<NULL>,

B<callback(1, -1, cb_arg)> is called.

If B<do_trial_division == 0>, this test is skipped.

=item *

Both BN_is_prime() and BN_is_prime_fasttest() perform a Miller-Rabin

probabilistic primality test with B<checks> iterations. If

B<checks == BN_prime_check>, a number of iterations is used that

B<NULL> (lacking this parameter, BN_is_prime() always has to allocate

an additional B<CN_CTX>).

=head1 RETURN VALUES

BN_generate_prime() returns the prime number on success, B<NULL> otherwise.