b3c1d18d03
manual when the specific function is refered to in the current manual text. This correction was originally introduced in OpenBSD's tracking of OpenSSL.
105 lines
3 KiB
Text
105 lines
3 KiB
Text
=pod
|
|
|
|
=head1 NAME
|
|
|
|
DSA_generate_parameters - generate DSA parameters
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
#include <openssl/dsa.h>
|
|
|
|
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() generates primes p and q and a generator g
|
|
for use in the DSA.
|
|
|
|
B<bits> is the length of the prime to be generated; the DSS allows a
|
|
maximum of 1024 bits.
|
|
|
|
If B<seed> is B<NULL> or B<seed_len> E<lt> 20, the primes will be
|
|
generated at random. Otherwise, the seed is used to generate
|
|
them. If the given seed does not yield a prime q, a new random
|
|
seed is chosen and placed at B<seed>.
|
|
|
|
DSA_generate_parameters() 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<callback> is not B<NULL>, it will be
|
|
called as follows:
|
|
|
|
=over 4
|
|
|
|
=item *
|
|
|
|
When a candidate for q is generated, B<callback(0, m++, cb_arg)> is called
|
|
(m is 0 for the first candidate).
|
|
|
|
=item *
|
|
|
|
When a candidate for q has passed a test by trial division,
|
|
B<callback(1, -1, cb_arg)> is called.
|
|
While a candidate for q is tested by Miller-Rabin primality tests,
|
|
B<callback(1, i, cb_arg)> 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<callback(2, 0, cb_arg)> and
|
|
B<callback(3, 0, cb_arg)> are called.
|
|
|
|
=item *
|
|
|
|
Before a candidate for p (other than the first) is generated and tested,
|
|
B<callback(0, counter, cb_arg)> is called.
|
|
|
|
=item *
|
|
|
|
When a candidate for p has passed the test by trial division,
|
|
B<callback(1, -1, cb_arg)> is called.
|
|
While it is tested by the Miller-Rabin primality test,
|
|
B<callback(1, i, cb_arg)> 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<callback(2, 1, cb_arg)> is called.
|
|
|
|
=item *
|
|
|
|
When the generator has been found, B<callback(3, 1, cb_arg)> is called.
|
|
|
|
=back
|
|
|
|
=head1 RETURN VALUE
|
|
|
|
DSA_generate_parameters() returns a pointer to the DSA structure, or
|
|
B<NULL> if the parameter generation fails. The error codes can be
|
|
obtained by L<ERR_get_error(3)|ERR_get_error(3)>.
|
|
|
|
=head1 BUGS
|
|
|
|
Seed lengths E<gt> 20 are not supported.
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<dsa(3)|dsa(3)>, L<ERR_get_error(3)|ERR_get_error(3)>, L<rand(3)|rand(3)>,
|
|
L<DSA_free(3)|DSA_free(3)>
|
|
|
|
=head1 HISTORY
|
|
|
|
DSA_generate_parameters() appeared in SSLeay 0.8. The B<cb_arg>
|
|
argument was added in SSLeay 0.9.0.
|
|
In versions up to OpenSSL 0.9.4, B<callback(1, ...)> was called
|
|
in the inner loop of the Miller-Rabin test whenever it reached the
|
|
squaring step (the parameters to B<callback> did not reveal how many
|
|
witnesses had been tested); since OpenSSL 0.9.5, B<callback(1, ...)>
|
|
is called as in BN_is_prime(3), i.e. once for each witness.
|
|
=cut
|