Sync crypto documentation with master branch.

doc/crypto/BN_generate_prime.pod

@@ -2,12 +2,31 @@
 
 =head1 NAME
 
-BN_generate_prime, BN_is_prime, BN_is_prime_fasttest - generate primes and test for primality
+BN_generate_prime_ex, BN_is_prime_ex, BN_is_prime_fasttest_ex, BN_GENCB_call,
+BN_GENCB_set_old, BN_GENCB_set, BN_generate_prime, BN_is_prime,
+BN_is_prime_fasttest - generate primes and test for primality
 
 =head1 SYNOPSIS
 
  #include <openssl/bn.h>
 
+ int BN_generate_prime_ex(BIGNUM *ret,int bits,int safe, const BIGNUM *add,
+     const BIGNUM *rem, BN_GENCB *cb);
+
+ int BN_is_prime_ex(const BIGNUM *p,int nchecks, BN_CTX *ctx, BN_GENCB *cb);
+
+ int BN_is_prime_fasttest_ex(const BIGNUM *p,int nchecks, BN_CTX *ctx,
+     int do_trial_division, BN_GENCB *cb);
+
+ int BN_GENCB_call(BN_GENCB *cb, int a, int b);
+
+ #define BN_GENCB_set_old(gencb, callback, cb_arg) ...
+
+ #define BN_GENCB_set(gencb, callback, cb_arg) ...
+
+
+Deprecated:
+
  BIGNUM *BN_generate_prime(BIGNUM *ret, int num, int safe, BIGNUM *add,
      BIGNUM *rem, void (*callback)(int, int, void *), void *cb_arg);
 
@@ -20,27 +39,27 @@ BN_generate_prime, BN_is_prime, BN_is_prime_fasttest - generate primes and test
 
 =head1 DESCRIPTION
 
-BN_generate_prime() generates a pseudo-random prime number of B<num>
-bits.
+BN_generate_prime_ex() generates a pseudo-random prime number of
+bit length B<bits>.
 If B<ret> is not B<NULL>, it will be used to store the number.
 
-If B<callback> is not B<NULL>, it is called as follows:
+If B<cb> is not B<NULL>, it is used as follows:
 
 =over 4
 
 =item *
 
-B<callback(0, i, cb_arg)> is called after generating the i-th
+B<BN_GENCB_call(cb, 0, i)> is called after generating the i-th
 potential prime number.
 
 =item *
 
-While the number is being tested for primality, B<callback(1, j,
-cb_arg)> is called as described below.
+While the number is being tested for primality,
+B<BN_GENCB_call(cb, 1, j)> is called as described below.
 
 =item *
 
-When a prime has been found, B<callback(2, i, cb_arg)> is called.
+When a prime has been found, B<BN_GENCB_call(cb, 2, i)> is called.
 
 =back
 
@@ -54,37 +73,66 @@ generator.
 If B<safe> is true, it will be a safe prime (i.e. a prime p so
 that (p-1)/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() and BN_is_prime_fasttest() test if the number B<a> is
+BN_is_prime_ex() and BN_is_prime_fasttest_ex() test if the number B<p> is
 prime.  The following tests are performed until one of them shows that
-B<a> is composite; if B<a> passes all these tests, it is considered
+B<p> is composite; if B<p> passes all these tests, it is considered
 prime.
 
-BN_is_prime_fasttest(), when called with B<do_trial_division == 1>,
+BN_is_prime_fasttest_ex(), 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 no divisors are found by this test and B<cb> is not B<NULL>,
+B<BN_GENCB_call(cb, 1, -1)> is called.
 If B<do_trial_division == 0>, this test is skipped.
 
-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_checks>, a number of iterations is used that
+Both BN_is_prime_ex() and BN_is_prime_fasttest_ex() perform a Miller-Rabin
+probabilistic primality test with B<nchecks> iterations. If
+B<nchecks == BN_prime_checks>, a number of iterations is used that
 yields a false positive rate of at most 2^-80 for random input.
 
-If B<callback> is not B<NULL>, B<callback(1, j, cb_arg)> is called
+If B<cb> is not B<NULL>, B<BN_GENCB_call(cb, 1, j)> is called
 after the j-th iteration (j = 0, 1, ...). B<ctx> is a
 pre-allocated B<BN_CTX> (to save the overhead of allocating and
 freeing the structure in a loop), or B<NULL>.
 
+BN_GENCB_call calls the callback function held in the B<BN_GENCB> structure
+and passes the ints B<a> and B<b> as arguments. There are two types of
+B<BN_GENCB> 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<gencb> is a B<BN_GENCB *>, B<callback> is of
+type B<int (*callback)(int, int, BN_GENCB *)> and B<cb_arg> is a B<void *>.
+"Old" style callbacks are the same except they are initialised with a call
+to BN_GENCB_set_old and B<callback> is of type
+B<void (*callback)(int, int, void *)>.
+
+A callback is invoked through a call to B<BN_GENCB_call>. This will check
+the type of the callback and will invoke B<callback(a, b, gencb)> for new
+style callbacks or B<callback(a, b, cb_arg)> 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<callback> parameter, and an argument to pass to it in
+the B<cb_arg>. 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_ex() return 1 on success or 0 on error.
+
+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<nchecks>, and
+-1 on error.
+
 BN_generate_prime() returns the prime number on success, B<NULL> otherwise.
 
-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<checks>, and
--1 on error.
+Callback functions should return 1 on success or 0 on error.
 
 The error codes can be obtained by L<ERR_get_error(3)|ERR_get_error(3)>.