is true, it will be a safe prime (i.e. a prime p so
that (p1)/2 is also prime).
The PRNG must be seeded prior to calling BN_generate_prime().
+The PRNG must be seeded prior to calling BN_generate_prime_ex().
The prime number generation has a negligible error probability.
BN_is_prime() tests if the number B is prime. This is done by
performing a MillerRabin probabilistic primality test with B
iterations. If B, it uses a number
of iterations that yields a false positive rate of at most 2^80 for
random input.

If B is not B, B is called
after the jth iteration. B is a preallocated B (to save
the overhead of allocating and freeing the structure in a loop), or
NULL.
+BN_is_prime_ex() and BN_is_prime_fasttest_ex() test if the number B is
+prime. The following tests are performed until one of them shows that
+B
is composite; if B
passes all these tests, it is considered
+prime.
+
+BN_is_prime_fasttest_ex(), when called with B,
+first attempts trial division by a number of small primes;
+if no divisors are found by this test and B is not B,
+B is called.
+If B, this test is skipped.
+
+Both BN_is_prime_ex() and BN_is_prime_fasttest_ex() perform a MillerRabin
+probabilistic primality test with B iterations. If
+B, a number of iterations is used that
+yields a false positive rate of at most 2^80 for random input.
+
+If B is not B, B is called
+after the jth iteration (j = 0, 1, ...). B is a
+preallocated B (to save the overhead of allocating and
+freeing the structure in a loop), or B.
+
+BN_GENCB_call calls the callback function held in the B structure
+and passes the ints B and B as arguments. There are two types of
+B structure that are supported: "new" style and "old" style. New
+programs should prefer the "new" style, whilst the "old" style is provided
+for backwards compatibility purposes.
+
+For "new" style callbacks a BN_GENCB structure should be initialised with a
+call to BN_GENCB_set(), where B is a B, B is of
+type B and B is a B.
+"Old" style callbacks are the same except they are initialised with a call
+to BN_GENCB_set_old() and B is of type
+B.
+
+A callback is invoked through a call to B. This will check
+the type of the callback and will invoke B for new
+style callbacks or B for old style.
+
+BN_generate_prime (deprecated) works in the same way as
+BN_generate_prime_ex but expects an old style callback function
+directly in the B parameter, and an argument to pass to it in
+the B. Similarly BN_is_prime and BN_is_prime_fasttest are
+deprecated and can be compared to BN_is_prime_ex and
+BN_is_prime_fasttest_ex respectively.
=head1 RETURN VALUES
BN_generate_prime() returns the prime number on success, NULL otherwise.
+BN_generate_prime_ex() return 1 on success or 0 on error.
BN_is_prime() returns 0 if the number is composite, 1 if it is
prime with an error probability of less than 0.25^B, and
+BN_is_prime_ex(), BN_is_prime_fasttest_ex(), BN_is_prime() and
+BN_is_prime_fasttest() return 0 if the number is composite, 1 if it is
+prime with an error probability of less than 0.25^B, and
1 on error.
+BN_generate_prime() returns the prime number on success, B otherwise.
+
+Callback functions should return 1 on success or 0 on error.
+
The error codes can be obtained by L.
=head1 SEE ALSO
L, L, L
+L, L, L
=head1 HISTORY
The B arguments to BN_generate_prime() and to BN_is_prime()
were added in SSLeay 0.9.0. The B argument to BN_generate_prime()
was added in SSLeay 0.9.1.
+BN_is_prime_fasttest() was added in OpenSSL 0.9.5.
=cut