openssl/doc/man3/DSA_generate_parameters.pod
Richard Levitte be80b21d2a Docs: better deprecation text
Expand the text on deprecation to be more descriptive and to refer
back to openssl_user_macros(7).

Incidently, this required a small change in util/find-doc-nits, to
have it skip over any line that isn't part of a block (i.e. that
hasn't been indented with at least one space.  That makes it skip over
deprecation text.

Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/7745)
2018-12-03 12:32:31 +01:00

126 lines
3.8 KiB
Text

=pod
=head1 NAME
DSA_generate_parameters_ex, DSA_generate_parameters - generate DSA parameters
=head1 SYNOPSIS
#include <openssl/dsa.h>
int DSA_generate_parameters_ex(DSA *dsa, int bits,
const unsigned char *seed, int seed_len,
int *counter_ret, unsigned long *h_ret,
BN_GENCB *cb);
Deprecated since OpenSSL 0.9.8, can be hidden entirely by defining
B<OPENSSL_API_COMPAT> with a suitable version value, see
L<openssl_user_macros(7)>:
DSA *DSA_generate_parameters(int bits, unsigned char *seed, int seed_len,
int *counter_ret, unsigned long *h_ret,
void (*callback)(int, int, void *), void *cb_arg);
=head1 DESCRIPTION
DSA_generate_parameters_ex() generates primes p and q and a generator g
for use in the DSA and stores the result in B<dsa>.
B<bits> is the length of the prime p to be generated.
For lengths under 2048 bits, the length of q is 160 bits; for lengths
greater than or equal to 2048 bits, the length of q is set to 256 bits.
If B<seed> is NULL, the primes will be generated at random.
If B<seed_len> is less than the length of q, an error is returned.
DSA_generate_parameters_ex() places the iteration count in
*B<counter_ret> and a counter used for finding a generator in
*B<h_ret>, unless these are B<NULL>.
A callback function may be used to provide feedback about the progress
of the key generation. If B<cb> is not B<NULL>, it will be
called as shown below. For information on the BN_GENCB structure and the
BN_GENCB_call function discussed below, refer to
L<BN_generate_prime(3)>.
DSA_generate_prime() is similar to DSA_generate_prime_ex() but
expects an old-style callback function; see
L<BN_generate_prime(3)> for information on the old-style callback.
=over 2
=item *
When a candidate for q is generated, B<BN_GENCB_call(cb, 0, m++)> is called
(m is 0 for the first candidate).
=item *
When a candidate for q has passed a test by trial division,
B<BN_GENCB_call(cb, 1, -1)> is called.
While a candidate for q is tested by Miller-Rabin primality tests,
B<BN_GENCB_call(cb, 1, i)> is called in the outer loop
(once for each witness that confirms that the candidate may be prime);
i is the loop counter (starting at 0).
=item *
When a prime q has been found, B<BN_GENCB_call(cb, 2, 0)> and
B<BN_GENCB_call(cb, 3, 0)> are called.
=item *
Before a candidate for p (other than the first) is generated and tested,
B<BN_GENCB_call(cb, 0, counter)> is called.
=item *
When a candidate for p has passed the test by trial division,
B<BN_GENCB_call(cb, 1, -1)> is called.
While it is tested by the Miller-Rabin primality test,
B<BN_GENCB_call(cb, 1, i)> is called in the outer loop
(once for each witness that confirms that the candidate may be prime).
i is the loop counter (starting at 0).
=item *
When p has been found, B<BN_GENCB_call(cb, 2, 1)> is called.
=item *
When the generator has been found, B<BN_GENCB_call(cb, 3, 1)> is called.
=back
=head1 RETURN VALUES
DSA_generate_parameters_ex() returns a 1 on success, or 0 otherwise.
The error codes can be obtained by L<ERR_get_error(3)>.
DSA_generate_parameters() returns a pointer to the DSA structure or
B<NULL> if the parameter generation fails.
=head1 BUGS
Seed lengths greater than 20 are not supported.
=head1 SEE ALSO
L<DSA_new(3)>, L<ERR_get_error(3)>, L<RAND_bytes(3)>,
L<DSA_free(3)>, L<BN_generate_prime(3)>
=head1 HISTORY
DSA_generate_parameters() was deprecated in OpenSSL 0.9.8; use
DSA_generate_parameters_ex() instead.
=head1 COPYRIGHT
Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the OpenSSL license (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
in the file LICENSE in the source distribution or at
L<https://www.openssl.org/source/license.html>.
=cut